Add m-esr52 at 52.6.0

114 files changed, 14496 insertions, 0 deletions

diff --git a/devtools/client/shared/components/.eslintrc.js b/devtools/client/shared/components/.eslintrc.js
new file mode 100644
index 000000000..3112895e9
--- /dev/null
+++ b/devtools/client/shared/components/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  "globals": {
+    "define": true,
+  }
+};
diff --git a/devtools/client/shared/components/frame.js b/devtools/client/shared/components/frame.js
new file mode 100644
index 000000000..5abe5f057
--- /dev/null
+++ b/devtools/client/shared/components/frame.js
@@ -0,0 +1,239 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { DOM: dom, createClass, PropTypes } = require("devtools/client/shared/vendor/react");
+const { getSourceNames, parseURL,
+        isScratchpadScheme, getSourceMappedFile } = require("devtools/client/shared/source-utils");
+const { LocalizationHelper } = require("devtools/shared/l10n");
+
+const l10n = new LocalizationHelper("devtools/client/locales/components.properties");
+const webl10n = new LocalizationHelper("devtools/client/locales/webconsole.properties");
+
+module.exports = createClass({
+  displayName: "Frame",
+
+  propTypes: {
+    // SavedFrame, or an object containing all the required properties.
+    frame: PropTypes.shape({
+      functionDisplayName: PropTypes.string,
+      source: PropTypes.string.isRequired,
+      line: PropTypes.oneOfType([ PropTypes.string, PropTypes.number ]),
+      column: PropTypes.oneOfType([ PropTypes.string, PropTypes.number ]),
+    }).isRequired,
+    // Clicking on the frame link -- probably should link to the debugger.
+    onClick: PropTypes.func.isRequired,
+    // Option to display a function name before the source link.
+    showFunctionName: PropTypes.bool,
+    // Option to display a function name even if it's anonymous.
+    showAnonymousFunctionName: PropTypes.bool,
+    // Option to display a host name after the source link.
+    showHost: PropTypes.bool,
+    // Option to display a host name if the filename is empty or just '/'
+    showEmptyPathAsHost: PropTypes.bool,
+    // Option to display a full source instead of just the filename.
+    showFullSourceUrl: PropTypes.bool,
+    // Service to enable the source map feature for console.
+    sourceMapService: PropTypes.object,
+  },
+
+  getDefaultProps() {
+    return {
+      showFunctionName: false,
+      showAnonymousFunctionName: false,
+      showHost: false,
+      showEmptyPathAsHost: false,
+      showFullSourceUrl: false,
+    };
+  },
+
+  componentWillMount() {
+    const sourceMapService = this.props.sourceMapService;
+    if (sourceMapService) {
+      const source = this.getSource();
+      sourceMapService.subscribe(source, this.onSourceUpdated);
+    }
+  },
+
+  componentWillUnmount() {
+    const sourceMapService = this.props.sourceMapService;
+    if (sourceMapService) {
+      const source = this.getSource();
+      sourceMapService.unsubscribe(source, this.onSourceUpdated);
+    }
+  },
+
+  /**
+   * Component method to update the FrameView when a resolved location is available
+   * @param event
+   * @param location
+   */
+  onSourceUpdated(event, location, resolvedLocation) {
+    const frame = this.getFrame(resolvedLocation);
+    this.setState({
+      frame,
+      isSourceMapped: true,
+    });
+  },
+
+  /**
+   * Utility method to convert the Frame object to the
+   * Source Object model required by SourceMapService
+   * @param frame
+   * @returns {{url: *, line: *, column: *}}
+   */
+  getSource(frame) {
+    frame = frame || this.props.frame;
+    const { source, line, column } = frame;
+    return {
+      url: source,
+      line,
+      column,
+    };
+  },
+
+  /**
+   * Utility method to convert the Source object model to the
+   * Frame object model required by FrameView class.
+   * @param source
+   * @returns {{source: *, line: *, column: *, functionDisplayName: *}}
+   */
+  getFrame(source) {
+    const { url, line, column } = source;
+    return {
+      source: url,
+      line,
+      column,
+      functionDisplayName: this.props.frame.functionDisplayName,
+    };
+  },
+
+  render() {
+    let frame, isSourceMapped;
+    let {
+      onClick,
+      showFunctionName,
+      showAnonymousFunctionName,
+      showHost,
+      showEmptyPathAsHost,
+      showFullSourceUrl
+    } = this.props;
+
+    if (this.state && this.state.isSourceMapped) {
+      frame = this.state.frame;
+      isSourceMapped = this.state.isSourceMapped;
+    } else {
+      frame = this.props.frame;
+    }
+
+    let source = frame.source ? String(frame.source) : "";
+    let line = frame.line != void 0 ? Number(frame.line) : null;
+    let column = frame.column != void 0 ? Number(frame.column) : null;
+
+    const { short, long, host } = getSourceNames(source);
+    // Reparse the URL to determine if we should link this; `getSourceNames`
+    // has already cached this indirectly. We don't want to attempt to
+    // link to "self-hosted" and "(unknown)". However, we do want to link
+    // to Scratchpad URIs.
+    // Source mapped sources might not necessary linkable, but they
+    // are still valid in the debugger.
+    const isLinkable = !!(isScratchpadScheme(source) || parseURL(source))
+      || isSourceMapped;
+    const elements = [];
+    const sourceElements = [];
+    let sourceEl;
+
+    let tooltip = long;
+
+    // Exclude all falsy values, including `0`, as line numbers start with 1.
+    if (line) {
+      tooltip += `:${line}`;
+      // Intentionally exclude 0
+      if (column) {
+        tooltip += `:${column}`;
+      }
+    }
+
+    let attributes = {
+      "data-url": long,
+      className: "frame-link",
+    };
+
+    if (showFunctionName) {
+      let functionDisplayName = frame.functionDisplayName;
+      if (!functionDisplayName && showAnonymousFunctionName) {
+        functionDisplayName = webl10n.getStr("stacktrace.anonymousFunction");
+      }
+
+      if (functionDisplayName) {
+        elements.push(
+          dom.span({ className: "frame-link-function-display-name" },
+            functionDisplayName),
+          " "
+        );
+      }
+    }
+
+    let displaySource = showFullSourceUrl ? long : short;
+    if (isSourceMapped) {
+      displaySource = getSourceMappedFile(displaySource);
+    } else if (showEmptyPathAsHost && (displaySource === "" || displaySource === "/")) {
+      displaySource = host;
+    }
+
+    sourceElements.push(dom.span({
+      className: "frame-link-filename",
+    }, displaySource));
+
+    // If we have a line number > 0.
+    if (line) {
+      let lineInfo = `:${line}`;
+      // Add `data-line` attribute for testing
+      attributes["data-line"] = line;
+
+      // Intentionally exclude 0
+      if (column) {
+        lineInfo += `:${column}`;
+        // Add `data-column` attribute for testing
+        attributes["data-column"] = column;
+      }
+
+      sourceElements.push(dom.span({ className: "frame-link-line" }, lineInfo));
+    }
+
+    // Inner el is useful for achieving ellipsis on the left and correct LTR/RTL
+    // ordering. See CSS styles for frame-link-source-[inner] and bug 1290056.
+    let sourceInnerEl = dom.span({
+      className: "frame-link-source-inner",
+      title: isLinkable ?
+        l10n.getFormatStr("frame.viewsourceindebugger", tooltip) : tooltip,
+    }, sourceElements);
+
+    // If source is not a URL (self-hosted, eval, etc.), don't make
+    // it an anchor link, as we can't link to it.
+    if (isLinkable) {
+      sourceEl = dom.a({
+        onClick: e => {
+          e.preventDefault();
+          onClick(this.getSource(frame));
+        },
+        href: source,
+        className: "frame-link-source",
+        draggable: false,
+      }, sourceInnerEl);
+    } else {
+      sourceEl = dom.span({
+        className: "frame-link-source",
+      }, sourceInnerEl);
+    }
+    elements.push(sourceEl);
+
+    if (showHost && host) {
+      elements.push(" ", dom.span({ className: "frame-link-host" }, host));
+    }
+
+    return dom.span(attributes, ...elements);
+  }
+});
diff --git a/devtools/client/shared/components/h-split-box.js b/devtools/client/shared/components/h-split-box.js
new file mode 100644
index 000000000..d804a6ba1
--- /dev/null
+++ b/devtools/client/shared/components/h-split-box.js
@@ -0,0 +1,154 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* eslint-env browser */
+"use strict";
+
+// A box with a start and a end pane, separated by a dragable splitter that
+// allows the user to resize the relative widths of the panes.
+//
+//     +-----------------------+---------------------+
+//     |                       |                     |
+//     |                       |                     |
+//     |                       S                     |
+//     |      Start Pane       p     End Pane        |
+//     |                       l                     |
+//     |                       i                     |
+//     |                       t                     |
+//     |                       t                     |
+//     |                       e                     |
+//     |                       r                     |
+//     |                       |                     |
+//     |                       |                     |
+//     +-----------------------+---------------------+
+
+const {
+  DOM: dom,
+  createClass,
+  PropTypes,
+} = require("devtools/client/shared/vendor/react");
+const { assert } = require("devtools/shared/DevToolsUtils");
+
+module.exports = createClass({
+  displayName: "HSplitBox",
+
+  propTypes: {
+    // The contents of the start pane.
+    start: PropTypes.any.isRequired,
+
+    // The contents of the end pane.
+    end: PropTypes.any.isRequired,
+
+    // The relative width of the start pane, expressed as a number between 0 and
+    // 1. The relative width of the end pane is 1 - startWidth. For example,
+    // with startWidth = .5, both panes are of equal width; with startWidth =
+    // .25, the start panel will take up 1/4 width and the end panel will take
+    // up 3/4 width.
+    startWidth: PropTypes.number,
+
+    // A minimum css width value for the start and end panes.
+    minStartWidth: PropTypes.any,
+    minEndWidth: PropTypes.any,
+
+    // A callback fired when the user drags the splitter to resize the relative
+    // pane widths. The function is passed the startWidth value that would put
+    // the splitter underneath the users mouse.
+    onResize: PropTypes.func.isRequired,
+  },
+
+  getDefaultProps() {
+    return {
+      startWidth: 0.5,
+      minStartWidth: "20px",
+      minEndWidth: "20px",
+    };
+  },
+
+  getInitialState() {
+    return {
+      mouseDown: false
+    };
+  },
+
+  componentDidMount() {
+    document.defaultView.top.addEventListener("mouseup", this._onMouseUp,
+                                              false);
+    document.defaultView.top.addEventListener("mousemove", this._onMouseMove,
+                                              false);
+  },
+
+  componentWillUnmount() {
+    document.defaultView.top.removeEventListener("mouseup", this._onMouseUp,
+                                                 false);
+    document.defaultView.top.removeEventListener("mousemove", this._onMouseMove,
+                                                 false);
+  },
+
+  _onMouseDown(event) {
+    if (event.button !== 0) {
+      return;
+    }
+
+    this.setState({ mouseDown: true });
+    event.preventDefault();
+  },
+
+  _onMouseUp(event) {
+    if (event.button !== 0 || !this.state.mouseDown) {
+      return;
+    }
+
+    this.setState({ mouseDown: false });
+    event.preventDefault();
+  },
+
+  _onMouseMove(event) {
+    if (!this.state.mouseDown) {
+      return;
+    }
+
+    const rect = this.refs.box.getBoundingClientRect();
+    const { left, right } = rect;
+    const width = right - left;
+    const relative = event.clientX - left;
+    this.props.onResize(relative / width);
+
+    event.preventDefault();
+  },
+
+  render() {
+    /* eslint-disable no-shadow */
+    const { start, end, startWidth, minStartWidth, minEndWidth } = this.props;
+    assert(startWidth => 0 && startWidth <= 1,
+           "0 <= this.props.startWidth <= 1");
+    /* eslint-enable */
+    return dom.div(
+      {
+        className: "h-split-box",
+        ref: "box",
+      },
+
+      dom.div(
+        {
+          className: "h-split-box-pane",
+          style: { flex: startWidth, minWidth: minStartWidth },
+        },
+        start
+      ),
+
+      dom.div({
+        className: "devtools-side-splitter",
+        onMouseDown: this._onMouseDown,
+      }),
+
+      dom.div(
+        {
+          className: "h-split-box-pane",
+          style: { flex: 1 - startWidth, minWidth: minEndWidth },
+        },
+        end
+      )
+    );
+  }
+});
diff --git a/devtools/client/shared/components/moz.build b/devtools/client/shared/components/moz.build
new file mode 100644
index 000000000..0d67e90b5
--- /dev/null
+++ b/devtools/client/shared/components/moz.build
@@ -0,0 +1,27 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += [
+    'reps',
+    'splitter',
+    'tabs',
+    'tree'
+]
+
+DevToolsModules(
+    'frame.js',
+    'h-split-box.js',
+    'notification-box.css',
+    'notification-box.js',
+    'search-box.js',
+    'sidebar-toggle.css',
+    'sidebar-toggle.js',
+    'stack-trace.js',
+    'tree.js',
+)
+
+MOCHITEST_CHROME_MANIFESTS += ['test/mochitest/chrome.ini']
+BROWSER_CHROME_MANIFESTS += ['test/browser/browser.ini']
diff --git a/devtools/client/shared/components/notification-box.css b/devtools/client/shared/components/notification-box.css
new file mode 100644
index 000000000..83c29b616
--- /dev/null
+++ b/devtools/client/shared/components/notification-box.css
@@ -0,0 +1,95 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Layout */
+
+.notificationbox .notificationInner {
+  display: flex;
+  flex-direction: row;
+}
+
+.notificationbox .details {
+  flex-grow: 1;
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+}
+
+.notificationbox .notification-button {
+  text-align: right;
+}
+
+.notificationbox .messageText {
+  flex-grow: 1;
+}
+
+.notificationbox .details:-moz-dir(rtl)
+.notificationbox .notificationInner:-moz-dir(rtl) {
+  flex-direction: row-reverse;
+}
+
+/* Style */
+
+.notificationbox .notification {
+  background-color: InfoBackground;
+  text-shadow: none;
+  border-top: 1px solid ThreeDShadow;
+  border-bottom: 1px solid ThreeDShadow;
+}
+
+.notificationbox .notification[data-type="info"] {
+  color: -moz-DialogText;
+  background-color: -moz-Dialog;
+}
+
+.notificationbox .notification[data-type="critical"] {
+  color: white;
+  background-image: linear-gradient(rgb(212,0,0), rgb(152,0,0));
+}
+
+.notificationbox .messageImage {
+  display: inline-block;
+  width: 16px;
+  height: 16px;
+  margin: 6px;
+}
+
+/* Default icons for notifications */
+
+.notificationbox .messageImage[data-type="info"] {
+  background-image: url("chrome://global/skin/icons/information-16.png");
+}
+
+.notificationbox .messageImage[data-type="warning"] {
+  background-image: url("chrome://global/skin/icons/warning-16.png");
+}
+
+.notificationbox .messageImage[data-type="critical"] {
+  background-image: url("chrome://global/skin/icons/error-16.png");
+}
+
+/* Close button */
+
+.notificationbox .messageCloseButton {
+  width: 20px;
+  height: 20px;
+  margin: 4px;
+  margin-inline-end: 8px;
+  background-image: url("chrome://devtools/skin/images/close.svg");
+  background-position: center;
+  background-color: transparent;
+  background-repeat: no-repeat;
+  border-radius: 11px;
+  filter: invert(0);
+}
+
+.notificationbox .messageCloseButton:hover {
+  background-color: gray;
+  filter: invert(1);
+}
+
+.notificationbox .messageCloseButton:active {
+  background-color: rgba(170, 170, 170, .4); /* --toolbar-tab-hover-active */
+}
diff --git a/devtools/client/shared/components/notification-box.js b/devtools/client/shared/components/notification-box.js
new file mode 100644
index 000000000..87fc76cd6
--- /dev/null
+++ b/devtools/client/shared/components/notification-box.js
@@ -0,0 +1,263 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const React = require("devtools/client/shared/vendor/react");
+const Immutable = require("devtools/client/shared/vendor/immutable");
+const { LocalizationHelper } = require("devtools/shared/l10n");
+const l10n = new LocalizationHelper("devtools/client/locales/components.properties");
+
+// Shortcuts
+const { PropTypes, createClass, DOM } = React;
+const { div, span, button } = DOM;
+
+// Priority Levels
+const PriorityLevels = {
+  PRIORITY_INFO_LOW: 1,
+  PRIORITY_INFO_MEDIUM: 2,
+  PRIORITY_INFO_HIGH: 3,
+  PRIORITY_WARNING_LOW: 4,
+  PRIORITY_WARNING_MEDIUM: 5,
+  PRIORITY_WARNING_HIGH: 6,
+  PRIORITY_CRITICAL_LOW: 7,
+  PRIORITY_CRITICAL_MEDIUM: 8,
+  PRIORITY_CRITICAL_HIGH: 9,
+  PRIORITY_CRITICAL_BLOCK: 10,
+};
+
+/**
+ * This component represents Notification Box - HTML alternative for
+ * <xul:notifictionbox> binding.
+ *
+ * See also MDN for more info about <xul:notificationbox>:
+ * https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/notificationbox
+ */
+var NotificationBox = createClass({
+  displayName: "NotificationBox",
+
+  propTypes: {
+    // List of notifications appended into the box.
+    notifications: PropTypes.arrayOf(PropTypes.shape({
+      // label to appear on the notification.
+      label: PropTypes.string.isRequired,
+
+      // Value used to identify the notification
+      value: PropTypes.string.isRequired,
+
+      // URL of image to appear on the notification. If "" then an icon
+      // appropriate for the priority level is used.
+      image: PropTypes.string.isRequired,
+
+      // Notification priority; see Priority Levels.
+      priority: PropTypes.number.isRequired,
+
+      // Array of button descriptions to appear on the notification.
+      buttons: PropTypes.arrayOf(PropTypes.shape({
+        // Function to be called when the button is activated.
+        // This function is passed three arguments:
+        // 1) the NotificationBox component the button is associated with
+        // 2) the button description as passed to appendNotification.
+        // 3) the element which was the target of the button press event.
+        // If the return value from this function is not True, then the
+        // notification is closed. The notification is also not closed
+        // if an error is thrown.
+        callback: PropTypes.func.isRequired,
+
+        // The label to appear on the button.
+        label: PropTypes.string.isRequired,
+
+        // The accesskey attribute set on the <button> element.
+        accesskey: PropTypes.string,
+      })),
+
+      // A function to call to notify you of interesting things that happen
+      // with the notification box.
+      eventCallback: PropTypes.func,
+    })),
+
+    // Message that should be shown when hovering over the close button
+    closeButtonTooltip: PropTypes.string
+  },
+
+  getDefaultProps() {
+    return {
+      closeButtonTooltip: l10n.getStr("notificationBox.closeTooltip")
+    };
+  },
+
+  getInitialState() {
+    return {
+      notifications: new Immutable.OrderedMap()
+    };
+  },
+
+  /**
+   * Create a new notification and display it. If another notification is
+   * already present with a higher priority, the new notification will be
+   * added behind it. See `propTypes` for arguments description.
+   */
+  appendNotification(label, value, image, priority, buttons = [],
+    eventCallback) {
+    // Priority level must be within expected interval
+    // (see priority levels at the top of this file).
+    if (priority < PriorityLevels.PRIORITY_INFO_LOW ||
+      priority > PriorityLevels.PRIORITY_CRITICAL_BLOCK) {
+      throw new Error("Invalid notification priority " + priority);
+    }
+
+    // Custom image URL is not supported yet.
+    if (image) {
+      throw new Error("Custom image URL is not supported yet");
+    }
+
+    let type = "warning";
+    if (priority >= PriorityLevels.PRIORITY_CRITICAL_LOW) {
+      type = "critical";
+    } else if (priority <= PriorityLevels.PRIORITY_INFO_HIGH) {
+      type = "info";
+    }
+
+    let notifications = this.state.notifications.set(value, {
+      label: label,
+      value: value,
+      image: image,
+      priority: priority,
+      type: type,
+      buttons: buttons,
+      eventCallback: eventCallback,
+    });
+
+    // High priorities must be on top.
+    notifications = notifications.sortBy((val, key) => {
+      return -val.priority;
+    });
+
+    this.setState({
+      notifications: notifications
+    });
+  },
+
+  /**
+   * Remove specific notification from the list.
+   */
+  removeNotification(notification) {
+    this.close(this.state.notifications.get(notification.value));
+  },
+
+  /**
+   * Returns an object that represents a notification. It can be
+   * used to close it.
+   */
+  getNotificationWithValue(value) {
+    let notification = this.state.notifications.get(value);
+    if (!notification) {
+      return null;
+    }
+
+    // Return an object that can be used to remove the notification
+    // later (using `removeNotification` method) or directly close it.
+    return Object.assign({}, notification, {
+      close: () => {
+        this.close(notification);
+      }
+    });
+  },
+
+  getCurrentNotification() {
+    return this.state.notifications.first();
+  },
+
+  /**
+   * Close specified notification.
+   */
+  close(notification) {
+    if (!notification) {
+      return;
+    }
+
+    if (notification.eventCallback) {
+      notification.eventCallback("removed");
+    }
+
+    this.setState({
+      notifications: this.state.notifications.remove(notification.value)
+    });
+  },
+
+  /**
+   * Render a button. A notification can have a set of custom buttons.
+   * These are used to execute custom callback.
+   */
+  renderButton(props, notification) {
+    let onClick = event => {
+      if (props.callback) {
+        let result = props.callback(this, props, event.target);
+        if (!result) {
+          this.close(notification);
+        }
+        event.stopPropagation();
+      }
+    };
+
+    return (
+      button({
+        key: props.label,
+        className: "notification-button",
+        accesskey: props.accesskey,
+        onClick: onClick},
+        props.label
+      )
+    );
+  },
+
+  /**
+   * Render a notification.
+   */
+  renderNotification(notification) {
+    return (
+      div({
+        key: notification.value,
+        className: "notification",
+        "data-type": notification.type},
+        div({className: "notificationInner"},
+          div({className: "details"},
+            div({
+              className: "messageImage",
+              "data-type": notification.type}),
+            span({className: "messageText"},
+              notification.label
+            ),
+            notification.buttons.map(props =>
+              this.renderButton(props, notification)
+            )
+          ),
+          div({
+            className: "messageCloseButton",
+            title: this.props.closeButtonTooltip,
+            onClick: this.close.bind(this, notification)}
+          )
+        )
+      )
+    );
+  },
+
+  /**
+   * Render the top (highest priority) notification. Only one
+   * notification is rendered at a time.
+   */
+  render() {
+    let notification = this.state.notifications.first();
+    let content = notification ?
+      this.renderNotification(notification) :
+      null;
+
+    return div({className: "notificationbox"},
+      content
+    );
+  },
+});
+
+module.exports.NotificationBox = NotificationBox;
+module.exports.PriorityLevels = PriorityLevels;
diff --git a/devtools/client/shared/components/reps/array.js b/devtools/client/shared/components/reps/array.js
new file mode 100644
index 000000000..8ec1443e1
--- /dev/null
+++ b/devtools/client/shared/components/reps/array.js
@@ -0,0 +1,186 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { createFactories } = require("./rep-utils");
+  const { Caption } = createFactories(require("./caption"));
+
+  // Shortcuts
+  const DOM = React.DOM;
+
+  /**
+   * Renders an array. The array is enclosed by left and right bracket
+   * and the max number of rendered items depends on the current mode.
+   */
+  let ArrayRep = React.createClass({
+    displayName: "ArrayRep",
+
+    getTitle: function (object, context) {
+      return "[" + object.length + "]";
+    },
+
+    arrayIterator: function (array, max) {
+      let items = [];
+      let delim;
+
+      for (let i = 0; i < array.length && i < max; i++) {
+        try {
+          let value = array[i];
+
+          delim = (i == array.length - 1 ? "" : ", ");
+
+          items.push(ItemRep({
+            object: value,
+            // Hardcode tiny mode to avoid recursive handling.
+            mode: "tiny",
+            delim: delim
+          }));
+        } catch (exc) {
+          items.push(ItemRep({
+            object: exc,
+            mode: "tiny",
+            delim: delim
+          }));
+        }
+      }
+
+      if (array.length > max) {
+        let objectLink = this.props.objectLink || DOM.span;
+        items.push(Caption({
+          object: objectLink({
+            object: this.props.object
+          }, (array.length - max) + " more…")
+        }));
+      }
+
+      return items;
+    },
+
+    /**
+     * Returns true if the passed object is an array with additional (custom)
+     * properties, otherwise returns false. Custom properties should be
+     * displayed in extra expandable section.
+     *
+     * Example array with a custom property.
+     * let arr = [0, 1];
+     * arr.myProp = "Hello";
+     *
+     * @param {Array} array The array object.
+     */
+    hasSpecialProperties: function (array) {
+      function isInteger(x) {
+        let y = parseInt(x, 10);
+        if (isNaN(y)) {
+          return false;
+        }
+        return x === y.toString();
+      }
+
+      let props = Object.getOwnPropertyNames(array);
+      for (let i = 0; i < props.length; i++) {
+        let p = props[i];
+
+        // Valid indexes are skipped
+        if (isInteger(p)) {
+          continue;
+        }
+
+        // Ignore standard 'length' property, anything else is custom.
+        if (p != "length") {
+          return true;
+        }
+      }
+
+      return false;
+    },
+
+    // Event Handlers
+
+    onToggleProperties: function (event) {
+    },
+
+    onClickBracket: function (event) {
+    },
+
+    render: function () {
+      let mode = this.props.mode || "short";
+      let object = this.props.object;
+      let items;
+      let brackets;
+      let needSpace = function (space) {
+        return space ? { left: "[ ", right: " ]"} : { left: "[", right: "]"};
+      };
+
+      if (mode == "tiny") {
+        let isEmpty = object.length === 0;
+        items = [DOM.span({className: "length"}, isEmpty ? "" : object.length)];
+        brackets = needSpace(false);
+      } else {
+        let max = (mode == "short") ? 3 : 300;
+        items = this.arrayIterator(object, max);
+        brackets = needSpace(items.length > 0);
+      }
+
+      let objectLink = this.props.objectLink || DOM.span;
+
+      return (
+        DOM.span({
+          className: "objectBox objectBox-array"},
+          objectLink({
+            className: "arrayLeftBracket",
+            object: object
+          }, brackets.left),
+          ...items,
+          objectLink({
+            className: "arrayRightBracket",
+            object: object
+          }, brackets.right),
+          DOM.span({
+            className: "arrayProperties",
+            role: "group"}
+          )
+        )
+      );
+    },
+  });
+
+  /**
+   * Renders array item. Individual values are separated by a comma.
+   */
+  let ItemRep = React.createFactory(React.createClass({
+    displayName: "ItemRep",
+
+    render: function () {
+      const { Rep } = createFactories(require("./rep"));
+
+      let object = this.props.object;
+      let delim = this.props.delim;
+      let mode = this.props.mode;
+      return (
+        DOM.span({},
+          Rep({object: object, mode: mode}),
+          delim
+        )
+      );
+    }
+  }));
+
+  function supportsObject(object, type) {
+    return Array.isArray(object) ||
+      Object.prototype.toString.call(object) === "[object Arguments]";
+  }
+
+  // Exports from this module
+  exports.ArrayRep = {
+    rep: ArrayRep,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/attribute.js b/devtools/client/shared/components/reps/attribute.js
new file mode 100644
index 000000000..f57ed0380
--- /dev/null
+++ b/devtools/client/shared/components/reps/attribute.js
@@ -0,0 +1,70 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { StringRep } = require("./string");
+
+  // Shortcuts
+  const { span } = React.DOM;
+  const { rep: StringRepFactory } = createFactories(StringRep);
+
+  /**
+   * Renders DOM attribute
+   */
+  let Attribute = React.createClass({
+    displayName: "Attr",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    getTitle: function (grip) {
+      return grip.preview.nodeName;
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      let value = grip.preview.value;
+      let objectLink = this.props.objectLink || span;
+
+      return (
+        objectLink({className: "objectLink-Attr"},
+          span({},
+            span({className: "attrTitle"},
+              this.getTitle(grip)
+            ),
+            span({className: "attrEqual"},
+              "="
+            ),
+            StringRepFactory({object: value})
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (type == "Attr" && grip.preview);
+  }
+
+  exports.Attribute = {
+    rep: Attribute,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/caption.js b/devtools/client/shared/components/reps/caption.js
new file mode 100644
index 000000000..7f00b01e8
--- /dev/null
+++ b/devtools/client/shared/components/reps/caption.js
@@ -0,0 +1,31 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const DOM = React.DOM;
+
+  /**
+   * Renders a caption. This template is used by other components
+   * that needs to distinguish between a simple text/value and a label.
+   */
+  const Caption = React.createClass({
+    displayName: "Caption",
+
+    render: function () {
+      return (
+        DOM.span({"className": "caption"}, this.props.object)
+      );
+    },
+  });
+
+  // Exports from this module
+  exports.Caption = Caption;
+});
diff --git a/devtools/client/shared/components/reps/comment-node.js b/devtools/client/shared/components/reps/comment-node.js
new file mode 100644
index 000000000..2c69c1414
--- /dev/null
+++ b/devtools/client/shared/components/reps/comment-node.js
@@ -0,0 +1,60 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+  const { isGrip, cropString, cropMultipleLines } = require("./rep-utils");
+
+  // Utils
+  const nodeConstants = require("devtools/shared/dom-node-constants");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders DOM comment node.
+   */
+  const CommentNode = React.createClass({
+    displayName: "CommentNode",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+    },
+
+    render: function () {
+      let {object} = this.props;
+
+      let mode = this.props.mode || "short";
+
+      let {textContent} = object.preview;
+      if (mode === "tiny") {
+        textContent = cropMultipleLines(textContent, 30);
+      } else if (mode === "short") {
+        textContent = cropString(textContent, 50);
+      }
+
+      return span({className: "objectBox theme-comment"}, `<!-- ${textContent} -->`);
+    },
+  });
+
+  // Registration
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+    return object.preview && object.preview.nodeType === nodeConstants.COMMENT_NODE;
+  }
+
+  // Exports from this module
+  exports.CommentNode = {
+    rep: CommentNode,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/date-time.js b/devtools/client/shared/components/reps/date-time.js
new file mode 100644
index 000000000..55dfb7d2d
--- /dev/null
+++ b/devtools/client/shared/components/reps/date-time.js
@@ -0,0 +1,70 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Used to render JS built-in Date() object.
+   */
+  let DateTime = React.createClass({
+    displayName: "Date",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: grip
+        }, grip.class + " ");
+      }
+      return "";
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      let date;
+      try {
+        date = span({className: "objectBox"},
+          this.getTitle(grip),
+          span({className: "Date"},
+            new Date(grip.preview.timestamp).toISOString()
+          )
+        );
+      } catch (e) {
+        date = span({className: "objectBox"}, "Invalid Date");
+      }
+      return date;
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (type == "Date" && grip.preview);
+  }
+
+  // Exports from this module
+  exports.DateTime = {
+    rep: DateTime,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/document.js b/devtools/client/shared/components/reps/document.js
new file mode 100644
index 000000000..25e42609f
--- /dev/null
+++ b/devtools/client/shared/components/reps/document.js
@@ -0,0 +1,78 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, getURLDisplayString } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders DOM document object.
+   */
+  let Document = React.createClass({
+    displayName: "Document",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    getLocation: function (grip) {
+      let location = grip.preview.location;
+      return location ? getURLDisplayString(location) : "";
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return span({className: "objectBox"},
+          this.props.objectLink({
+            object: grip
+          }, grip.class + " ")
+        );
+      }
+      return "";
+    },
+
+    getTooltip: function (doc) {
+      return doc.location.href;
+    },
+
+    render: function () {
+      let grip = this.props.object;
+
+      return (
+        span({className: "objectBox objectBox-object"},
+          this.getTitle(grip),
+          span({className: "objectPropValue"},
+            this.getLocation(grip)
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+
+    return (object.preview && type == "HTMLDocument");
+  }
+
+  // Exports from this module
+  exports.Document = {
+    rep: Document,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/element-node.js b/devtools/client/shared/components/reps/element-node.js
new file mode 100644
index 000000000..6315fb5b1
--- /dev/null
+++ b/devtools/client/shared/components/reps/element-node.js
@@ -0,0 +1,114 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+  const { isGrip } = require("./rep-utils");
+
+  // Utils
+  const nodeConstants = require("devtools/shared/dom-node-constants");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders DOM element node.
+   */
+  const ElementNode = React.createClass({
+    displayName: "ElementNode",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+    },
+
+    getElements: function (grip, mode) {
+      let {attributes, nodeName} = grip.preview;
+      const nodeNameElement = span({
+        className: "tag-name theme-fg-color3"
+      }, nodeName);
+
+      if (mode === "tiny") {
+        let elements = [nodeNameElement];
+        if (attributes.id) {
+          elements.push(
+            span({className: "attr-name theme-fg-color2"}, `#${attributes.id}`));
+        }
+        if (attributes.class) {
+          elements.push(
+            span({className: "attr-name theme-fg-color2"},
+              attributes.class
+                .replace(/(^\s+)|(\s+$)/g, "")
+                .split(" ")
+                .map(cls => `.${cls}`)
+                .join("")
+            )
+          );
+        }
+        return elements;
+      }
+      let attributeElements = Object.keys(attributes)
+        .sort(function getIdAndClassFirst(a1, a2) {
+          if ([a1, a2].includes("id")) {
+            return 3 * (a1 === "id" ? -1 : 1);
+          }
+          if ([a1, a2].includes("class")) {
+            return 2 * (a1 === "class" ? -1 : 1);
+          }
+
+          // `id` and `class` excepted,
+          // we want to keep the same order that in `attributes`.
+          return 0;
+        })
+        .reduce((arr, name, i, keys) => {
+          let value = attributes[name];
+          let attribute = span({},
+            span({className: "attr-name theme-fg-color2"}, `${name}`),
+            `="`,
+            span({className: "attr-value theme-fg-color6"}, `${value}`),
+            `"`
+          );
+
+          return arr.concat([" ", attribute]);
+        }, []);
+
+      return [
+        "<",
+        nodeNameElement,
+        ...attributeElements,
+        ">",
+      ];
+    },
+
+    render: function () {
+      let {object, mode} = this.props;
+      let elements = this.getElements(object, mode);
+      const baseElement = span({className: "objectBox"}, ...elements);
+
+      if (this.props.objectLink) {
+        return this.props.objectLink({object}, baseElement);
+      }
+      return baseElement;
+    },
+  });
+
+  // Registration
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+    return object.preview && object.preview.nodeType === nodeConstants.ELEMENT_NODE;
+  }
+
+  // Exports from this module
+  exports.ElementNode = {
+    rep: ElementNode,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/event.js b/devtools/client/shared/components/reps/event.js
new file mode 100644
index 000000000..1d37e0150
--- /dev/null
+++ b/devtools/client/shared/components/reps/event.js
@@ -0,0 +1,81 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { rep } = createFactories(require("./grip").Grip);
+
+  /**
+   * Renders DOM event objects.
+   */
+  let Event = React.createClass({
+    displayName: "event",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    render: function () {
+      // Use `Object.assign` to keep `this.props` without changes because:
+      // 1. JSON.stringify/JSON.parse is slow.
+      // 2. Immutable.js is planned for the future.
+      let props = Object.assign({}, this.props);
+      props.object = Object.assign({}, this.props.object);
+      props.object.preview = Object.assign({}, this.props.object.preview);
+      props.object.preview.ownProperties = props.object.preview.properties;
+      delete props.object.preview.properties;
+      props.object.ownPropertyLength =
+        Object.keys(props.object.preview.ownProperties).length;
+
+      switch (props.object.class) {
+        case "MouseEvent":
+          props.isInterestingProp = (type, value, name) => {
+            return (name == "clientX" ||
+                    name == "clientY" ||
+                    name == "layerX" ||
+                    name == "layerY");
+          };
+          break;
+        case "KeyboardEvent":
+          props.isInterestingProp = (type, value, name) => {
+            return (name == "key" ||
+                    name == "charCode" ||
+                    name == "keyCode");
+          };
+          break;
+        case "MessageEvent":
+          props.isInterestingProp = (type, value, name) => {
+            return (name == "isTrusted" ||
+                    name == "data");
+          };
+          break;
+      }
+      return rep(props);
+    }
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (grip.preview && grip.preview.kind == "DOMEvent");
+  }
+
+  // Exports from this module
+  exports.Event = {
+    rep: Event,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/function.js b/devtools/client/shared/components/reps/function.js
new file mode 100644
index 000000000..fd20dc318
--- /dev/null
+++ b/devtools/client/shared/components/reps/function.js
@@ -0,0 +1,73 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, cropString } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * This component represents a template for Function objects.
+   */
+  let Func = React.createClass({
+    displayName: "Func",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: grip
+        }, "function ");
+      }
+      return "";
+    },
+
+    summarizeFunction: function (grip) {
+      let name = grip.userDisplayName || grip.displayName || grip.name || "function";
+      return cropString(name + "()", 100);
+    },
+
+    render: function () {
+      let grip = this.props.object;
+
+      return (
+        // Set dir="ltr" to prevent function parentheses from
+        // appearing in the wrong direction
+        span({dir: "ltr", className: "objectBox objectBox-function"},
+          this.getTitle(grip),
+          this.summarizeFunction(grip)
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return (type == "function");
+    }
+
+    return (type == "Function");
+  }
+
+  // Exports from this module
+
+  exports.Func = {
+    rep: Func,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/grip-array.js b/devtools/client/shared/components/reps/grip-array.js
new file mode 100644
index 000000000..04a5603bb
--- /dev/null
+++ b/devtools/client/shared/components/reps/grip-array.js
@@ -0,0 +1,198 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { Caption } = createFactories(require("./caption"));
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders an array. The array is enclosed by left and right bracket
+   * and the max number of rendered items depends on the current mode.
+   */
+  let GripArray = React.createClass({
+    displayName: "GripArray",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+      provider: React.PropTypes.object,
+    },
+
+    getLength: function (grip) {
+      if (!grip.preview) {
+        return 0;
+      }
+
+      return grip.preview.length || grip.preview.childNodesLength || 0;
+    },
+
+    getTitle: function (object, context) {
+      let objectLink = this.props.objectLink || span;
+      if (this.props.mode != "tiny") {
+        return objectLink({
+          object: object
+        }, object.class + " ");
+      }
+      return "";
+    },
+
+    getPreviewItems: function (grip) {
+      if (!grip.preview) {
+        return null;
+      }
+
+      return grip.preview.items || grip.preview.childNodes || null;
+    },
+
+    arrayIterator: function (grip, max) {
+      let items = [];
+      const gripLength = this.getLength(grip);
+
+      if (!gripLength) {
+        return items;
+      }
+
+      const previewItems = this.getPreviewItems(grip);
+      if (!previewItems) {
+        return items;
+      }
+
+      let delim;
+      // number of grip preview items is limited to 10, but we may have more
+      // items in grip-array.
+      let delimMax = gripLength > previewItems.length ?
+        previewItems.length : previewItems.length - 1;
+      let provider = this.props.provider;
+
+      for (let i = 0; i < previewItems.length && i < max; i++) {
+        try {
+          let itemGrip = previewItems[i];
+          let value = provider ? provider.getValue(itemGrip) : itemGrip;
+
+          delim = (i == delimMax ? "" : ", ");
+
+          items.push(GripArrayItem(Object.assign({}, this.props, {
+            object: value,
+            delim: delim
+          })));
+        } catch (exc) {
+          items.push(GripArrayItem(Object.assign({}, this.props, {
+            object: exc,
+            delim: delim
+          })));
+        }
+      }
+      if (previewItems.length > max || gripLength > previewItems.length) {
+        let objectLink = this.props.objectLink || span;
+        let leftItemNum = gripLength - max > 0 ?
+          gripLength - max : gripLength - previewItems.length;
+        items.push(Caption({
+          object: objectLink({
+            object: this.props.object
+          }, leftItemNum + " more…")
+        }));
+      }
+
+      return items;
+    },
+
+    render: function () {
+      let mode = this.props.mode || "short";
+      let object = this.props.object;
+
+      let items;
+      let brackets;
+      let needSpace = function (space) {
+        return space ? { left: "[ ", right: " ]"} : { left: "[", right: "]"};
+      };
+
+      if (mode == "tiny") {
+        let objectLength = this.getLength(object);
+        let isEmpty = objectLength === 0;
+        items = [span({className: "length"}, isEmpty ? "" : objectLength)];
+        brackets = needSpace(false);
+      } else {
+        let max = (mode == "short") ? 3 : 300;
+        items = this.arrayIterator(object, max);
+        brackets = needSpace(items.length > 0);
+      }
+
+      let objectLink = this.props.objectLink || span;
+      let title = this.getTitle(object);
+
+      return (
+        span({
+          className: "objectBox objectBox-array"},
+          title,
+          objectLink({
+            className: "arrayLeftBracket",
+            object: object
+          }, brackets.left),
+          ...items,
+          objectLink({
+            className: "arrayRightBracket",
+            object: object
+          }, brackets.right),
+          span({
+            className: "arrayProperties",
+            role: "group"}
+          )
+        )
+      );
+    },
+  });
+
+  /**
+   * Renders array item. Individual values are separated by
+   * a delimiter (a comma by default).
+   */
+  let GripArrayItem = React.createFactory(React.createClass({
+    displayName: "GripArrayItem",
+
+    propTypes: {
+      delim: React.PropTypes.string,
+    },
+
+    render: function () {
+      let { Rep } = createFactories(require("./rep"));
+
+      return (
+        span({},
+          Rep(Object.assign({}, this.props, {
+            mode: "tiny"
+          })),
+          this.props.delim
+        )
+      );
+    }
+  }));
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (grip.preview && (
+        grip.preview.kind == "ArrayLike" ||
+        type === "DocumentFragment"
+      )
+    );
+  }
+
+  // Exports from this module
+  exports.GripArray = {
+    rep: GripArray,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/grip-map.js b/devtools/client/shared/components/reps/grip-map.js
new file mode 100644
index 000000000..df673d005
--- /dev/null
+++ b/devtools/client/shared/components/reps/grip-map.js
@@ -0,0 +1,193 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { Caption } = createFactories(require("./caption"));
+  const { PropRep } = createFactories(require("./prop-rep"));
+
+  // Shortcuts
+  const { span } = React.DOM;
+  /**
+   * Renders an map. A map is represented by a list of its
+   * entries enclosed in curly brackets.
+   */
+  const GripMap = React.createClass({
+    displayName: "GripMap",
+
+    propTypes: {
+      object: React.PropTypes.object,
+      mode: React.PropTypes.string,
+    },
+
+    getTitle: function (object) {
+      let title = object && object.class ? object.class : "Map";
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: object
+        }, title);
+      }
+      return title;
+    },
+
+    safeEntriesIterator: function (object, max) {
+      max = (typeof max === "undefined") ? 3 : max;
+      try {
+        return this.entriesIterator(object, max);
+      } catch (err) {
+        console.error(err);
+      }
+      return [];
+    },
+
+    entriesIterator: function (object, max) {
+      // Entry filter. Show only interesting entries to the user.
+      let isInterestingEntry = this.props.isInterestingEntry || ((type, value) => {
+        return (
+          type == "boolean" ||
+          type == "number" ||
+          (type == "string" && value.length != 0)
+        );
+      });
+
+      let mapEntries = object.preview && object.preview.entries
+        ? object.preview.entries : [];
+
+      let indexes = this.getEntriesIndexes(mapEntries, max, isInterestingEntry);
+      if (indexes.length < max && indexes.length < mapEntries.length) {
+        // There are not enough entries yet, so we add uninteresting entries.
+        indexes = indexes.concat(
+          this.getEntriesIndexes(mapEntries, max - indexes.length, (t, value, name) => {
+            return !isInterestingEntry(t, value, name);
+          })
+        );
+      }
+
+      let entries = this.getEntries(mapEntries, indexes);
+      if (entries.length < mapEntries.length) {
+        // There are some undisplayed entries. Then display "more…".
+        let objectLink = this.props.objectLink || span;
+
+        entries.push(Caption({
+          key: "more",
+          object: objectLink({
+            object: object
+          }, `${mapEntries.length - max} more…`)
+        }));
+      }
+
+      return entries;
+    },
+
+    /**
+     * Get entries ordered by index.
+     *
+     * @param {Array} entries Entries array.
+     * @param {Array} indexes Indexes of entries.
+     * @return {Array} Array of PropRep.
+     */
+    getEntries: function (entries, indexes) {
+      // Make indexes ordered by ascending.
+      indexes.sort(function (a, b) {
+        return a - b;
+      });
+
+      return indexes.map((index, i) => {
+        let [key, entryValue] = entries[index];
+        let value = entryValue.value !== undefined ? entryValue.value : entryValue;
+
+        return PropRep({
+          // key,
+          name: key,
+          equal: ": ",
+          object: value,
+          // Do not add a trailing comma on the last entry
+          // if there won't be a "more..." item.
+          delim: (i < indexes.length - 1 || indexes.length < entries.length) ? ", " : "",
+          mode: "tiny",
+          objectLink: this.props.objectLink,
+        });
+      });
+    },
+
+    /**
+     * Get the indexes of entries in the map.
+     *
+     * @param {Array} entries Entries array.
+     * @param {Number} max The maximum length of indexes array.
+     * @param {Function} filter Filter the entry you want.
+     * @return {Array} Indexes of filtered entries in the map.
+     */
+    getEntriesIndexes: function (entries, max, filter) {
+      return entries
+        .reduce((indexes, [key, entry], i) => {
+          if (indexes.length < max) {
+            let value = (entry && entry.value !== undefined) ? entry.value : entry;
+            // Type is specified in grip's "class" field and for primitive
+            // values use typeof.
+            let type = (value && value.class ? value.class : typeof value).toLowerCase();
+
+            if (filter(type, value, key)) {
+              indexes.push(i);
+            }
+          }
+
+          return indexes;
+        }, []);
+    },
+
+    render: function () {
+      let object = this.props.object;
+      let props = this.safeEntriesIterator(object,
+        (this.props.mode == "long") ? 100 : 3);
+
+      let objectLink = this.props.objectLink || span;
+      if (this.props.mode == "tiny") {
+        return (
+          span({className: "objectBox objectBox-object"},
+            this.getTitle(object),
+            objectLink({
+              className: "objectLeftBrace",
+              object: object
+            }, "")
+          )
+        );
+      }
+
+      return (
+        span({className: "objectBox objectBox-object"},
+          this.getTitle(object),
+          objectLink({
+            className: "objectLeftBrace",
+            object: object
+          }, " { "),
+          props,
+          objectLink({
+            className: "objectRightBrace",
+            object: object
+          }, " }")
+        )
+      );
+    },
+  });
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+    return (grip.preview && grip.preview.kind == "MapLike");
+  }
+
+  // Exports from this module
+  exports.GripMap = {
+    rep: GripMap,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/grip.js b/devtools/client/shared/components/reps/grip.js
new file mode 100644
index 000000000..c63ee19f3
--- /dev/null
+++ b/devtools/client/shared/components/reps/grip.js
@@ -0,0 +1,247 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+  // Dependencies
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { Caption } = createFactories(require("./caption"));
+  const { PropRep } = createFactories(require("./prop-rep"));
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders generic grip. Grip is client representation
+   * of remote JS object and is used as an input object
+   * for this rep component.
+   */
+  const GripRep = React.createClass({
+    displayName: "Grip",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+      isInterestingProp: React.PropTypes.func
+    },
+
+    getTitle: function (object) {
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: object
+        }, object.class);
+      }
+      return object.class || "Object";
+    },
+
+    safePropIterator: function (object, max) {
+      max = (typeof max === "undefined") ? 3 : max;
+      try {
+        return this.propIterator(object, max);
+      } catch (err) {
+        console.error(err);
+      }
+      return [];
+    },
+
+    propIterator: function (object, max) {
+      if (object.preview && Object.keys(object.preview).includes("wrappedValue")) {
+        const { Rep } = createFactories(require("./rep"));
+
+        return [Rep({
+          object: object.preview.wrappedValue,
+          mode: this.props.mode || "tiny",
+          defaultRep: Grip,
+        })];
+      }
+
+      // Property filter. Show only interesting properties to the user.
+      let isInterestingProp = this.props.isInterestingProp || ((type, value) => {
+        return (
+          type == "boolean" ||
+          type == "number" ||
+          (type == "string" && value.length != 0)
+        );
+      });
+
+      let properties = object.preview
+        ? object.preview.ownProperties
+        : {};
+      let propertiesLength = object.preview && object.preview.ownPropertiesLength
+        ? object.preview.ownPropertiesLength
+        : object.ownPropertyLength;
+
+      if (object.preview && object.preview.safeGetterValues) {
+        properties = Object.assign({}, properties, object.preview.safeGetterValues);
+        propertiesLength += Object.keys(object.preview.safeGetterValues).length;
+      }
+
+      let indexes = this.getPropIndexes(properties, max, isInterestingProp);
+      if (indexes.length < max && indexes.length < propertiesLength) {
+        // There are not enough props yet. Then add uninteresting props to display them.
+        indexes = indexes.concat(
+          this.getPropIndexes(properties, max - indexes.length, (t, value, name) => {
+            return !isInterestingProp(t, value, name);
+          })
+        );
+      }
+
+      const truncate = Object.keys(properties).length > max;
+      let props = this.getProps(properties, indexes, truncate);
+      if (truncate) {
+        // There are some undisplayed props. Then display "more...".
+        let objectLink = this.props.objectLink || span;
+
+        props.push(Caption({
+          object: objectLink({
+            object: object
+          }, `${object.ownPropertyLength - max} more…`)
+        }));
+      }
+
+      return props;
+    },
+
+    /**
+     * Get props ordered by index.
+     *
+     * @param {Object} properties Props object.
+     * @param {Array} indexes Indexes of props.
+     * @param {Boolean} truncate true if the grip will be truncated.
+     * @return {Array} Props.
+     */
+    getProps: function (properties, indexes, truncate) {
+      let props = [];
+
+      // Make indexes ordered by ascending.
+      indexes.sort(function (a, b) {
+        return a - b;
+      });
+
+      indexes.forEach((i) => {
+        let name = Object.keys(properties)[i];
+        let value = this.getPropValue(properties[name]);
+
+        props.push(PropRep(Object.assign({}, this.props, {
+          mode: "tiny",
+          name: name,
+          object: value,
+          equal: ": ",
+          delim: i !== indexes.length - 1 || truncate ? ", " : "",
+          defaultRep: Grip
+        })));
+      });
+
+      return props;
+    },
+
+    /**
+     * Get the indexes of props in the object.
+     *
+     * @param {Object} properties Props object.
+     * @param {Number} max The maximum length of indexes array.
+     * @param {Function} filter Filter the props you want.
+     * @return {Array} Indexes of interesting props in the object.
+     */
+    getPropIndexes: function (properties, max, filter) {
+      let indexes = [];
+
+      try {
+        let i = 0;
+        for (let name in properties) {
+          if (indexes.length >= max) {
+            return indexes;
+          }
+
+          // Type is specified in grip's "class" field and for primitive
+          // values use typeof.
+          let value = this.getPropValue(properties[name]);
+          let type = (value.class || typeof value);
+          type = type.toLowerCase();
+
+          if (filter(type, value, name)) {
+            indexes.push(i);
+          }
+          i++;
+        }
+      } catch (err) {
+        console.error(err);
+      }
+      return indexes;
+    },
+
+    /**
+     * Get the actual value of a property.
+     *
+     * @param {Object} property
+     * @return {Object} Value of the property.
+     */
+    getPropValue: function (property) {
+      let value = property;
+      if (typeof property === "object") {
+        let keys = Object.keys(property);
+        if (keys.includes("value")) {
+          value = property.value;
+        } else if (keys.includes("getterValue")) {
+          value = property.getterValue;
+        }
+      }
+      return value;
+    },
+
+    render: function () {
+      let object = this.props.object;
+      let props = this.safePropIterator(object,
+        (this.props.mode == "long") ? 100 : 3);
+
+      let objectLink = this.props.objectLink || span;
+      if (this.props.mode == "tiny") {
+        return (
+          span({className: "objectBox objectBox-object"},
+            this.getTitle(object),
+            objectLink({
+              className: "objectLeftBrace",
+              object: object
+            }, "")
+          )
+        );
+      }
+
+      return (
+        span({className: "objectBox objectBox-object"},
+          this.getTitle(object),
+          objectLink({
+            className: "objectLeftBrace",
+            object: object
+          }, " { "),
+          ...props,
+          objectLink({
+            className: "objectRightBrace",
+            object: object
+          }, " }")
+        )
+      );
+    },
+  });
+
+  // Registration
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+    return (object.preview && object.preview.ownProperties);
+  }
+
+  let Grip = {
+    rep: GripRep,
+    supportsObject: supportsObject
+  };
+
+  // Exports from this module
+  exports.Grip = Grip;
+});
diff --git a/devtools/client/shared/components/reps/infinity.js b/devtools/client/shared/components/reps/infinity.js
new file mode 100644
index 000000000..604e31f06
--- /dev/null
+++ b/devtools/client/shared/components/reps/infinity.js
@@ -0,0 +1,41 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a Infinity object
+   */
+  const InfinityRep = React.createClass({
+    displayName: "Infinity",
+
+    render: function () {
+      return (
+        span({className: "objectBox objectBox-number"},
+          this.props.object.type
+        )
+      );
+    }
+  });
+
+  function supportsObject(object, type) {
+    return type == "Infinity" || type == "-Infinity";
+  }
+
+  // Exports from this module
+  exports.InfinityRep = {
+    rep: InfinityRep,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/long-string.js b/devtools/client/shared/components/reps/long-string.js
new file mode 100644
index 000000000..f19f020dc
--- /dev/null
+++ b/devtools/client/shared/components/reps/long-string.js
@@ -0,0 +1,71 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { sanitizeString, isGrip } = require("./rep-utils");
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a long string grip.
+   */
+  const LongStringRep = React.createClass({
+    displayName: "LongStringRep",
+
+    propTypes: {
+      useQuotes: React.PropTypes.bool,
+      style: React.PropTypes.object,
+    },
+
+    getDefaultProps: function () {
+      return {
+        useQuotes: true,
+      };
+    },
+
+    render: function () {
+      let {
+        cropLimit,
+        member,
+        object,
+        style,
+        useQuotes
+      } = this.props;
+      let {fullText, initial, length} = object;
+
+      let config = {className: "objectBox objectBox-string"};
+      if (style) {
+        config.style = style;
+      }
+
+      let string = member && member.open
+        ? fullText || initial
+        : initial.substring(0, cropLimit);
+
+      if (string.length < length) {
+        string += "\u2026";
+      }
+      let formattedString = useQuotes ? `"${string}"` : string;
+      return span(config, sanitizeString(formattedString));
+    },
+  });
+
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+    return object.type === "longString";
+  }
+
+  // Exports from this module
+  exports.LongStringRep = {
+    rep: LongStringRep,
+    supportsObject: supportsObject,
+  };
+});
diff --git a/devtools/client/shared/components/reps/moz.build b/devtools/client/shared/components/reps/moz.build
new file mode 100644
index 000000000..f5df589f7
--- /dev/null
+++ b/devtools/client/shared/components/reps/moz.build
@@ -0,0 +1,40 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'array.js',
+    'attribute.js',
+    'caption.js',
+    'comment-node.js',
+    'date-time.js',
+    'document.js',
+    'element-node.js',
+    'event.js',
+    'function.js',
+    'grip-array.js',
+    'grip-map.js',
+    'grip.js',
+    'infinity.js',
+    'long-string.js',
+    'nan.js',
+    'null.js',
+    'number.js',
+    'object-with-text.js',
+    'object-with-url.js',
+    'object.js',
+    'promise.js',
+    'prop-rep.js',
+    'regexp.js',
+    'rep-utils.js',
+    'rep.js',
+    'reps.css',
+    'string.js',
+    'stylesheet.js',
+    'symbol.js',
+    'text-node.js',
+    'undefined.js',
+    'window.js',
+)
diff --git a/devtools/client/shared/components/reps/nan.js b/devtools/client/shared/components/reps/nan.js
new file mode 100644
index 000000000..b76a5cfd3
--- /dev/null
+++ b/devtools/client/shared/components/reps/nan.js
@@ -0,0 +1,41 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a NaN object
+   */
+  const NaNRep = React.createClass({
+    displayName: "NaN",
+
+    render: function () {
+      return (
+        span({className: "objectBox objectBox-nan"},
+          "NaN"
+        )
+      );
+    }
+  });
+
+  function supportsObject(object, type) {
+    return type == "NaN";
+  }
+
+  // Exports from this module
+  exports.NaNRep = {
+    rep: NaNRep,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/null.js b/devtools/client/shared/components/reps/null.js
new file mode 100644
index 000000000..5de00f026
--- /dev/null
+++ b/devtools/client/shared/components/reps/null.js
@@ -0,0 +1,46 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders null value
+   */
+  const Null = React.createClass({
+    displayName: "NullRep",
+
+    render: function () {
+      return (
+        span({className: "objectBox objectBox-null"},
+          "null"
+        )
+      );
+    },
+  });
+
+  function supportsObject(object, type) {
+    if (object && object.type && object.type == "null") {
+      return true;
+    }
+
+    return (object == null);
+  }
+
+  // Exports from this module
+
+  exports.Null = {
+    rep: Null,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/number.js b/devtools/client/shared/components/reps/number.js
new file mode 100644
index 000000000..31be3009b
--- /dev/null
+++ b/devtools/client/shared/components/reps/number.js
@@ -0,0 +1,51 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a number
+   */
+  const Number = React.createClass({
+    displayName: "Number",
+
+    stringify: function (object) {
+      let isNegativeZero = Object.is(object, -0) ||
+        (object.type && object.type == "-0");
+
+      return (isNegativeZero ? "-0" : String(object));
+    },
+
+    render: function () {
+      let value = this.props.object;
+
+      return (
+        span({className: "objectBox objectBox-number"},
+          this.stringify(value)
+        )
+      );
+    }
+  });
+
+  function supportsObject(object, type) {
+    return ["boolean", "number", "-0"].includes(type);
+  }
+
+  // Exports from this module
+
+  exports.Number = {
+    rep: Number,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/object-with-text.js b/devtools/client/shared/components/reps/object-with-text.js
new file mode 100644
index 000000000..85168ce78
--- /dev/null
+++ b/devtools/client/shared/components/reps/object-with-text.js
@@ -0,0 +1,76 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a grip object with textual data.
+   */
+  let ObjectWithText = React.createClass({
+    displayName: "ObjectWithText",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return span({className: "objectBox"},
+          this.props.objectLink({
+            object: grip
+          }, this.getType(grip) + " ")
+        );
+      }
+      return "";
+    },
+
+    getType: function (grip) {
+      return grip.class;
+    },
+
+    getDescription: function (grip) {
+      return "\"" + grip.preview.text + "\"";
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      return (
+        span({className: "objectBox objectBox-" + this.getType(grip)},
+          this.getTitle(grip),
+          span({className: "objectPropValue"},
+            this.getDescription(grip)
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (grip.preview && grip.preview.kind == "ObjectWithText");
+  }
+
+  // Exports from this module
+  exports.ObjectWithText = {
+    rep: ObjectWithText,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/object-with-url.js b/devtools/client/shared/components/reps/object-with-url.js
new file mode 100644
index 000000000..9c4b9a229
--- /dev/null
+++ b/devtools/client/shared/components/reps/object-with-url.js
@@ -0,0 +1,76 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, getURLDisplayString } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a grip object with URL data.
+   */
+  let ObjectWithURL = React.createClass({
+    displayName: "ObjectWithURL",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return span({className: "objectBox"},
+          this.props.objectLink({
+            object: grip
+          }, this.getType(grip) + " ")
+        );
+      }
+      return "";
+    },
+
+    getType: function (grip) {
+      return grip.class;
+    },
+
+    getDescription: function (grip) {
+      return getURLDisplayString(grip.preview.url);
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      return (
+        span({className: "objectBox objectBox-" + this.getType(grip)},
+          this.getTitle(grip),
+          span({className: "objectPropValue"},
+            this.getDescription(grip)
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (grip.preview && grip.preview.kind == "ObjectWithURL");
+  }
+
+  // Exports from this module
+  exports.ObjectWithURL = {
+    rep: ObjectWithURL,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/object.js b/devtools/client/shared/components/reps/object.js
new file mode 100644
index 000000000..ffb1d1525
--- /dev/null
+++ b/devtools/client/shared/components/reps/object.js
@@ -0,0 +1,171 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { createFactories } = require("./rep-utils");
+  const { Caption } = createFactories(require("./caption"));
+  const { PropRep } = createFactories(require("./prop-rep"));
+  // Shortcuts
+  const { span } = React.DOM;
+  /**
+   * Renders an object. An object is represented by a list of its
+   * properties enclosed in curly brackets.
+   */
+  const Obj = React.createClass({
+    displayName: "Obj",
+
+    propTypes: {
+      object: React.PropTypes.object,
+      mode: React.PropTypes.string,
+    },
+
+    getTitle: function (object) {
+      let className = object && object.class ? object.class : "Object";
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: object
+        }, className);
+      }
+      return className;
+    },
+
+    safePropIterator: function (object, max) {
+      max = (typeof max === "undefined") ? 3 : max;
+      try {
+        return this.propIterator(object, max);
+      } catch (err) {
+        console.error(err);
+      }
+      return [];
+    },
+
+    propIterator: function (object, max) {
+      let isInterestingProp = (t, value) => {
+        // Do not pick objects, it could cause recursion.
+        return (t == "boolean" || t == "number" || (t == "string" && value));
+      };
+
+      // Work around https://bugzilla.mozilla.org/show_bug.cgi?id=945377
+      if (Object.prototype.toString.call(object) === "[object Generator]") {
+        object = Object.getPrototypeOf(object);
+      }
+
+      // Object members with non-empty values are preferred since it gives the
+      // user a better overview of the object.
+      let props = this.getProps(object, max, isInterestingProp);
+
+      if (props.length <= max) {
+        // There are not enough props yet (or at least, not enough props to
+        // be able to know whether we should print "more…" or not).
+        // Let's display also empty members and functions.
+        props = props.concat(this.getProps(object, max, (t, value) => {
+          return !isInterestingProp(t, value);
+        }));
+      }
+
+      if (props.length > max) {
+        props.pop();
+        let objectLink = this.props.objectLink || span;
+
+        props.push(Caption({
+          object: objectLink({
+            object: object
+          }, (Object.keys(object).length - max) + " more…")
+        }));
+      } else if (props.length > 0) {
+        // Remove the last comma.
+        props[props.length - 1] = React.cloneElement(
+          props[props.length - 1], { delim: "" });
+      }
+
+      return props;
+    },
+
+    getProps: function (object, max, filter) {
+      let props = [];
+
+      max = max || 3;
+      if (!object) {
+        return props;
+      }
+
+      // Hardcode tiny mode to avoid recursive handling.
+      let mode = "tiny";
+
+      try {
+        for (let name in object) {
+          if (props.length > max) {
+            return props;
+          }
+
+          let value;
+          try {
+            value = object[name];
+          } catch (exc) {
+            continue;
+          }
+
+          let t = typeof value;
+          if (filter(t, value)) {
+            props.push(PropRep({
+              mode: mode,
+              name: name,
+              object: value,
+              equal: ": ",
+              delim: ", ",
+            }));
+          }
+        }
+      } catch (err) {
+        console.error(err);
+      }
+
+      return props;
+    },
+
+    render: function () {
+      let object = this.props.object;
+      let props = this.safePropIterator(object);
+      let objectLink = this.props.objectLink || span;
+
+      if (this.props.mode == "tiny" || !props.length) {
+        return (
+          span({className: "objectBox objectBox-object"},
+            objectLink({className: "objectTitle"}, this.getTitle(object))
+          )
+        );
+      }
+
+      return (
+        span({className: "objectBox objectBox-object"},
+          this.getTitle(object),
+          objectLink({
+            className: "objectLeftBrace",
+            object: object
+          }, " { "),
+          ...props,
+          objectLink({
+            className: "objectRightBrace",
+            object: object
+          }, " }")
+        )
+      );
+    },
+  });
+  function supportsObject(object, type) {
+    return true;
+  }
+
+  // Exports from this module
+  exports.Obj = {
+    rep: Obj,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/promise.js b/devtools/client/shared/components/reps/promise.js
new file mode 100644
index 000000000..0a903d366
--- /dev/null
+++ b/devtools/client/shared/components/reps/promise.js
@@ -0,0 +1,111 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+  // Dependencies
+  const { createFactories, isGrip } = require("./rep-utils");
+  const { PropRep } = createFactories(require("./prop-rep"));
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a DOM Promise object.
+   */
+  const PromiseRep = React.createClass({
+    displayName: "Promise",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+    },
+
+    getTitle: function (object) {
+      const title = object.class;
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: object
+        }, title);
+      }
+      return title;
+    },
+
+    getProps: function (promiseState) {
+      const keys = ["state"];
+      if (Object.keys(promiseState).includes("value")) {
+        keys.push("value");
+      }
+
+      return keys.map((key, i) => {
+        return PropRep(Object.assign({}, this.props, {
+          mode: "tiny",
+          name: `<${key}>`,
+          object: promiseState[key],
+          equal: ": ",
+          delim: i < keys.length - 1 ? ", " : ""
+        }));
+      });
+    },
+
+    render: function () {
+      const object = this.props.object;
+      const {promiseState} = object;
+      let objectLink = this.props.objectLink || span;
+
+      if (this.props.mode == "tiny") {
+        let { Rep } = createFactories(require("./rep"));
+
+        return (
+          span({className: "objectBox objectBox-object"},
+            this.getTitle(object),
+            objectLink({
+              className: "objectLeftBrace",
+              object: object
+            }, " { "),
+            Rep({object: promiseState.state}),
+            objectLink({
+              className: "objectRightBrace",
+              object: object
+            }, " }")
+          )
+        );
+      }
+
+      const props = this.getProps(promiseState);
+      return (
+        span({className: "objectBox objectBox-object"},
+          this.getTitle(object),
+          objectLink({
+            className: "objectLeftBrace",
+            object: object
+          }, " { "),
+          ...props,
+          objectLink({
+            className: "objectRightBrace",
+            object: object
+          }, " }")
+        )
+      );
+    },
+  });
+
+  // Registration
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+    return type === "Promise";
+  }
+
+  // Exports from this module
+  exports.PromiseRep = {
+    rep: PromiseRep,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/prop-rep.js b/devtools/client/shared/components/reps/prop-rep.js
new file mode 100644
index 000000000..775dfea2b
--- /dev/null
+++ b/devtools/client/shared/components/reps/prop-rep.js
@@ -0,0 +1,70 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  const React = require("devtools/client/shared/vendor/react");
+  const { createFactories } = require("./rep-utils");
+  const { span } = React.DOM;
+
+  /**
+   * Property for Obj (local JS objects), Grip (remote JS objects)
+   * and GripMap (remote JS maps and weakmaps) reps.
+   * It's used to render object properties.
+   */
+  let PropRep = React.createFactory(React.createClass({
+    displayName: "PropRep",
+
+    propTypes: {
+      // Property name.
+      name: React.PropTypes.oneOfType([
+        React.PropTypes.string,
+        React.PropTypes.object,
+      ]).isRequired,
+      // Equal character rendered between property name and value.
+      equal: React.PropTypes.string,
+      // Delimiter character used to separate individual properties.
+      delim: React.PropTypes.string,
+      mode: React.PropTypes.string,
+    },
+
+    render: function () {
+      const { Grip } = require("./grip");
+      let { Rep } = createFactories(require("./rep"));
+
+      let key;
+      // The key can be a simple string, for plain objects,
+      // or another object for maps and weakmaps.
+      if (typeof this.props.name === "string") {
+        key = span({"className": "nodeName"}, this.props.name);
+      } else {
+        key = Rep({
+          object: this.props.name,
+          mode: this.props.mode || "tiny",
+          defaultRep: Grip,
+          objectLink: this.props.objectLink,
+        });
+      }
+
+      return (
+        span({},
+          key,
+          span({
+            "className": "objectEqual"
+          }, this.props.equal),
+          Rep(this.props),
+          span({
+            "className": "objectComma"
+          }, this.props.delim)
+        )
+      );
+    }
+  }));
+
+  // Exports from this module
+  exports.PropRep = PropRep;
+});
diff --git a/devtools/client/shared/components/reps/regexp.js b/devtools/client/shared/components/reps/regexp.js
new file mode 100644
index 000000000..2f9212658
--- /dev/null
+++ b/devtools/client/shared/components/reps/regexp.js
@@ -0,0 +1,63 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a grip object with regular expression.
+   */
+  let RegExp = React.createClass({
+    displayName: "regexp",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+    },
+
+    getSource: function (grip) {
+      return grip.displayString;
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      let objectLink = this.props.objectLink || span;
+
+      return (
+        span({className: "objectBox objectBox-regexp"},
+          objectLink({
+            object: grip,
+            className: "regexpSource"
+          }, this.getSource(grip))
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+
+    return (type == "RegExp");
+  }
+
+  // Exports from this module
+  exports.RegExp = {
+    rep: RegExp,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/rep-utils.js b/devtools/client/shared/components/reps/rep-utils.js
new file mode 100644
index 000000000..d9580ac8d
--- /dev/null
+++ b/devtools/client/shared/components/reps/rep-utils.js
@@ -0,0 +1,160 @@
+/* globals URLSearchParams */
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  /**
+   * Create React factories for given arguments.
+   * Example:
+   *   const { Rep } = createFactories(require("./rep"));
+   */
+  function createFactories(args) {
+    let result = {};
+    for (let p in args) {
+      result[p] = React.createFactory(args[p]);
+    }
+    return result;
+  }
+
+  /**
+   * Returns true if the given object is a grip (see RDP protocol)
+   */
+  function isGrip(object) {
+    return object && object.actor;
+  }
+
+  function escapeNewLines(value) {
+    return value.replace(/\r/gm, "\\r").replace(/\n/gm, "\\n");
+  }
+
+  function cropMultipleLines(text, limit) {
+    return escapeNewLines(cropString(text, limit));
+  }
+
+  function cropString(text, limit, alternativeText) {
+    if (!alternativeText) {
+      alternativeText = "\u2026";
+    }
+
+    // Make sure it's a string and sanitize it.
+    text = sanitizeString(text + "");
+
+    // Crop the string only if a limit is actually specified.
+    if (!limit || limit <= 0) {
+      return text;
+    }
+
+    // Set the limit at least to the length of the alternative text
+    // plus one character of the original text.
+    if (limit <= alternativeText.length) {
+      limit = alternativeText.length + 1;
+    }
+
+    let halfLimit = (limit - alternativeText.length) / 2;
+
+    if (text.length > limit) {
+      return text.substr(0, Math.ceil(halfLimit)) + alternativeText +
+        text.substr(text.length - Math.floor(halfLimit));
+    }
+
+    return text;
+  }
+
+  function sanitizeString(text) {
+    // Replace all non-printable characters, except of
+    // (horizontal) tab (HT: \x09) and newline (LF: \x0A, CR: \x0D),
+    // with unicode replacement character (u+fffd).
+    // eslint-disable-next-line no-control-regex
+    let re = new RegExp("[\x00-\x08\x0B\x0C\x0E-\x1F\x80-\x9F]", "g");
+    return text.replace(re, "\ufffd");
+  }
+
+  function parseURLParams(url) {
+    url = new URL(url);
+    return parseURLEncodedText(url.searchParams);
+  }
+
+  function parseURLEncodedText(text) {
+    let params = [];
+
+    // In case the text is empty just return the empty parameters
+    if (text == "") {
+      return params;
+    }
+
+    let searchParams = new URLSearchParams(text);
+    let entries = [...searchParams.entries()];
+    return entries.map(entry => {
+      return {
+        name: entry[0],
+        value: entry[1]
+      };
+    });
+  }
+
+  function getFileName(url) {
+    let split = splitURLBase(url);
+    return split.name;
+  }
+
+  function splitURLBase(url) {
+    if (!isDataURL(url)) {
+      return splitURLTrue(url);
+    }
+    return {};
+  }
+
+  function getURLDisplayString(url) {
+    return cropString(url);
+  }
+
+  function isDataURL(url) {
+    return (url && url.substr(0, 5) == "data:");
+  }
+
+  function splitURLTrue(url) {
+    const reSplitFile = /(.*?):\/{2,3}([^\/]*)(.*?)([^\/]*?)($|\?.*)/;
+    let m = reSplitFile.exec(url);
+
+    if (!m) {
+      return {
+        name: url,
+        path: url
+      };
+    } else if (m[4] == "" && m[5] == "") {
+      return {
+        protocol: m[1],
+        domain: m[2],
+        path: m[3],
+        name: m[3] != "/" ? m[3] : m[2]
+      };
+    }
+
+    return {
+      protocol: m[1],
+      domain: m[2],
+      path: m[2] + m[3],
+      name: m[4] + m[5]
+    };
+  }
+
+  // Exports from this module
+  exports.createFactories = createFactories;
+  exports.isGrip = isGrip;
+  exports.cropString = cropString;
+  exports.cropMultipleLines = cropMultipleLines;
+  exports.parseURLParams = parseURLParams;
+  exports.parseURLEncodedText = parseURLEncodedText;
+  exports.getFileName = getFileName;
+  exports.getURLDisplayString = getURLDisplayString;
+  exports.sanitizeString = sanitizeString;
+});
diff --git a/devtools/client/shared/components/reps/rep.js b/devtools/client/shared/components/reps/rep.js
new file mode 100644
index 000000000..0891fe0ce
--- /dev/null
+++ b/devtools/client/shared/components/reps/rep.js
@@ -0,0 +1,144 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  const { isGrip } = require("./rep-utils");
+
+  // Load all existing rep templates
+  const { Undefined } = require("./undefined");
+  const { Null } = require("./null");
+  const { StringRep } = require("./string");
+  const { LongStringRep } = require("./long-string");
+  const { Number } = require("./number");
+  const { ArrayRep } = require("./array");
+  const { Obj } = require("./object");
+  const { SymbolRep } = require("./symbol");
+  const { InfinityRep } = require("./infinity");
+  const { NaNRep } = require("./nan");
+
+  // DOM types (grips)
+  const { Attribute } = require("./attribute");
+  const { DateTime } = require("./date-time");
+  const { Document } = require("./document");
+  const { Event } = require("./event");
+  const { Func } = require("./function");
+  const { PromiseRep } = require("./promise");
+  const { RegExp } = require("./regexp");
+  const { StyleSheet } = require("./stylesheet");
+  const { CommentNode } = require("./comment-node");
+  const { ElementNode } = require("./element-node");
+  const { TextNode } = require("./text-node");
+  const { Window } = require("./window");
+  const { ObjectWithText } = require("./object-with-text");
+  const { ObjectWithURL } = require("./object-with-url");
+  const { GripArray } = require("./grip-array");
+  const { GripMap } = require("./grip-map");
+  const { Grip } = require("./grip");
+
+  // List of all registered template.
+  // XXX there should be a way for extensions to register a new
+  // or modify an existing rep.
+  let reps = [
+    RegExp,
+    StyleSheet,
+    Event,
+    DateTime,
+    CommentNode,
+    ElementNode,
+    TextNode,
+    Attribute,
+    LongStringRep,
+    Func,
+    PromiseRep,
+    ArrayRep,
+    Document,
+    Window,
+    ObjectWithText,
+    ObjectWithURL,
+    GripArray,
+    GripMap,
+    Grip,
+    Undefined,
+    Null,
+    StringRep,
+    Number,
+    SymbolRep,
+    InfinityRep,
+    NaNRep,
+  ];
+
+  /**
+   * Generic rep that is using for rendering native JS types or an object.
+   * The right template used for rendering is picked automatically according
+   * to the current value type. The value must be passed is as 'object'
+   * property.
+   */
+  const Rep = React.createClass({
+    displayName: "Rep",
+
+    propTypes: {
+      object: React.PropTypes.any,
+      defaultRep: React.PropTypes.object,
+      mode: React.PropTypes.string
+    },
+
+    render: function () {
+      let rep = getRep(this.props.object, this.props.defaultRep);
+      return rep(this.props);
+    },
+  });
+
+  // Helpers
+
+  /**
+   * Return a rep object that is responsible for rendering given
+   * object.
+   *
+   * @param object {Object} Object to be rendered in the UI. This
+   * can be generic JS object as well as a grip (handle to a remote
+   * debuggee object).
+   *
+   * @param defaultObject {React.Component} The default template
+   * that should be used to render given object if none is found.
+   */
+  function getRep(object, defaultRep = Obj) {
+    let type = typeof object;
+    if (type == "object" && object instanceof String) {
+      type = "string";
+    } else if (object && type == "object" && object.type) {
+      type = object.type;
+    }
+
+    if (isGrip(object)) {
+      type = object.class;
+    }
+
+    for (let i = 0; i < reps.length; i++) {
+      let rep = reps[i];
+      try {
+        // supportsObject could return weight (not only true/false
+        // but a number), which would allow to priorities templates and
+        // support better extensibility.
+        if (rep.supportsObject(object, type)) {
+          return React.createFactory(rep.rep);
+        }
+      } catch (err) {
+        console.error(err);
+      }
+    }
+
+    return React.createFactory(defaultRep.rep);
+  }
+
+  // Exports from this module
+  exports.Rep = Rep;
+});
diff --git a/devtools/client/shared/components/reps/reps.css b/devtools/client/shared/components/reps/reps.css
new file mode 100644
index 000000000..61e5e3dac
--- /dev/null
+++ b/devtools/client/shared/components/reps/reps.css
@@ -0,0 +1,174 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+.theme-dark,
+.theme-light {
+  --number-color: var(--theme-highlight-green);
+  --string-color: var(--theme-highlight-orange);
+  --null-color: var(--theme-comment);
+  --object-color: var(--theme-body-color);
+  --caption-color: var(--theme-highlight-blue);
+  --location-color: var(--theme-content-color1);
+  --source-link-color: var(--theme-highlight-blue);
+  --node-color: var(--theme-highlight-bluegrey);
+  --reference-color: var(--theme-highlight-purple);
+}
+
+.theme-firebug {
+  --number-color: #000088;
+  --string-color: #FF0000;
+  --null-color: #787878;
+  --object-color: DarkGreen;
+  --caption-color: #444444;
+  --location-color: #555555;
+  --source-link-color: blue;
+  --node-color: rgb(0, 0, 136);
+  --reference-color: rgb(102, 102, 255);
+}
+
+/******************************************************************************/
+
+.objectLink:hover {
+  cursor: pointer;
+  text-decoration: underline;
+}
+
+.inline {
+  display: inline;
+  white-space: normal;
+}
+
+.objectBox-object {
+  font-weight: bold;
+  color: var(--object-color);
+  white-space: pre-wrap;
+}
+
+.objectBox-string,
+.objectBox-symbol,
+.objectBox-text,
+.objectLink-textNode,
+.objectBox-table {
+  white-space: pre-wrap;
+}
+
+.objectBox-number,
+.objectLink-styleRule,
+.objectLink-element,
+.objectLink-textNode,
+.objectBox-array > .length {
+  color: var(--number-color);
+}
+
+.objectBox-textNode,
+.objectBox-string,
+.objectBox-symbol {
+  color: var(--string-color);
+}
+
+.objectLink-function,
+.objectBox-stackTrace,
+.objectLink-profile {
+  color: var(--object-color);
+}
+
+.objectLink-Location {
+  font-style: italic;
+  color: var(--location-color);
+}
+
+.objectBox-null,
+.objectBox-undefined,
+.objectBox-hint,
+.logRowHint {
+  font-style: italic;
+  color: var(--null-color);
+}
+
+.objectLink-sourceLink {
+  position: absolute;
+  right: 4px;
+  top: 2px;
+  padding-left: 8px;
+  font-weight: bold;
+  color: var(--source-link-color);
+}
+
+/******************************************************************************/
+
+.objectLink-event,
+.objectLink-eventLog,
+.objectLink-regexp,
+.objectLink-object,
+.objectLink-Date {
+  font-weight: bold;
+  color: var(--object-color);
+  white-space: pre-wrap;
+}
+
+/******************************************************************************/
+
+.objectLink-object .nodeName,
+.objectLink-NamedNodeMap .nodeName,
+.objectLink-NamedNodeMap .objectEqual,
+.objectLink-NamedNodeMap .arrayLeftBracket,
+.objectLink-NamedNodeMap .arrayRightBracket,
+.objectLink-Attr .attrEqual,
+.objectLink-Attr .attrTitle {
+  color: var(--node-color);
+}
+
+.objectLink-object .nodeName {
+  font-weight: normal;
+}
+
+/******************************************************************************/
+
+.objectLeftBrace,
+.objectRightBrace,
+.arrayLeftBracket,
+.arrayRightBracket {
+  cursor: pointer;
+  font-weight: bold;
+}
+
+/******************************************************************************/
+/* Cycle reference*/
+
+.objectLink-Reference {
+  font-weight: bold;
+  color: var(--reference-color);
+}
+
+.objectBox-array > .objectTitle {
+  font-weight: bold;
+  color: var(--object-color);
+}
+
+.caption {
+  font-weight: bold;
+  color:  var(--caption-color);
+}
+
+/******************************************************************************/
+/* Themes */
+
+.theme-dark .objectBox-null,
+.theme-dark .objectBox-undefined,
+.theme-light .objectBox-null,
+.theme-light .objectBox-undefined {
+  font-style: normal;
+}
+
+.theme-dark .objectBox-object,
+.theme-light .objectBox-object {
+  font-weight: normal;
+  white-space: pre-wrap;
+}
+
+.theme-dark .caption,
+.theme-light .caption {
+  font-weight: normal;
+}
diff --git a/devtools/client/shared/components/reps/string.js b/devtools/client/shared/components/reps/string.js
new file mode 100644
index 000000000..f8b4b1986
--- /dev/null
+++ b/devtools/client/shared/components/reps/string.js
@@ -0,0 +1,69 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+  const { cropString } = require("./rep-utils");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a string. String value is enclosed within quotes.
+   */
+  const StringRep = React.createClass({
+    displayName: "StringRep",
+
+    propTypes: {
+      useQuotes: React.PropTypes.bool,
+      style: React.PropTypes.object,
+    },
+
+    getDefaultProps: function () {
+      return {
+        useQuotes: true,
+      };
+    },
+
+    render: function () {
+      let text = this.props.object;
+      let member = this.props.member;
+      let style = this.props.style;
+
+      let config = {className: "objectBox objectBox-string"};
+      if (style) {
+        config.style = style;
+      }
+
+      if (member && member.open) {
+        return span(config, "\"" + text + "\"");
+      }
+
+      let croppedString = this.props.cropLimit ?
+        cropString(text, this.props.cropLimit) : cropString(text);
+
+      let formattedString = this.props.useQuotes ?
+        "\"" + croppedString + "\"" : croppedString;
+
+      return span(config, formattedString);
+    },
+  });
+
+  function supportsObject(object, type) {
+    return (type == "string");
+  }
+
+  // Exports from this module
+
+  exports.StringRep = {
+    rep: StringRep,
+    supportsObject: supportsObject,
+  };
+});
diff --git a/devtools/client/shared/components/reps/stylesheet.js b/devtools/client/shared/components/reps/stylesheet.js
new file mode 100644
index 000000000..c1fc7f1be
--- /dev/null
+++ b/devtools/client/shared/components/reps/stylesheet.js
@@ -0,0 +1,77 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, getURLDisplayString } = require("./rep-utils");
+
+  // Shortcuts
+  const DOM = React.DOM;
+
+  /**
+   * Renders a grip representing CSSStyleSheet
+   */
+  let StyleSheet = React.createClass({
+    displayName: "object",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+    },
+
+    getTitle: function (grip) {
+      let title = "StyleSheet ";
+      if (this.props.objectLink) {
+        return DOM.span({className: "objectBox"},
+          this.props.objectLink({
+            object: grip
+          }, title)
+        );
+      }
+      return title;
+    },
+
+    getLocation: function (grip) {
+      // Embedded stylesheets don't have URL and so, no preview.
+      let url = grip.preview ? grip.preview.url : "";
+      return url ? getURLDisplayString(url) : "";
+    },
+
+    render: function () {
+      let grip = this.props.object;
+
+      return (
+        DOM.span({className: "objectBox objectBox-object"},
+          this.getTitle(grip),
+          DOM.span({className: "objectPropValue"},
+            this.getLocation(grip)
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+
+    return (type == "CSSStyleSheet");
+  }
+
+  // Exports from this module
+
+  exports.StyleSheet = {
+    rep: StyleSheet,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/symbol.js b/devtools/client/shared/components/reps/symbol.js
new file mode 100644
index 000000000..111794008
--- /dev/null
+++ b/devtools/client/shared/components/reps/symbol.js
@@ -0,0 +1,48 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders a symbol.
+   */
+  const SymbolRep = React.createClass({
+    displayName: "SymbolRep",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired
+    },
+
+    render: function () {
+      let {object} = this.props;
+      let {name} = object;
+
+      return (
+        span({className: "objectBox objectBox-symbol"},
+          `Symbol(${name || ""})`
+        )
+      );
+    },
+  });
+
+  function supportsObject(object, type) {
+    return (type == "symbol");
+  }
+
+  // Exports from this module
+  exports.SymbolRep = {
+    rep: SymbolRep,
+    supportsObject: supportsObject,
+  };
+});
diff --git a/devtools/client/shared/components/reps/text-node.js b/devtools/client/shared/components/reps/text-node.js
new file mode 100644
index 000000000..d80545cea
--- /dev/null
+++ b/devtools/client/shared/components/reps/text-node.js
@@ -0,0 +1,94 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, cropString } = require("./rep-utils");
+
+  // Shortcuts
+  const DOM = React.DOM;
+
+  /**
+   * Renders DOM #text node.
+   */
+  let TextNode = React.createClass({
+    displayName: "TextNode",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+      mode: React.PropTypes.string,
+    },
+
+    getTextContent: function (grip) {
+      return cropString(grip.preview.textContent);
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return this.props.objectLink({
+          object: grip
+        }, "#text ");
+      }
+      return "";
+    },
+
+    render: function () {
+      let grip = this.props.object;
+      let mode = this.props.mode || "short";
+
+      if (mode == "short" || mode == "tiny") {
+        return (
+          DOM.span({className: "objectBox objectBox-textNode"},
+            this.getTitle(grip),
+            DOM.span({className: "nodeValue"},
+              "\"" + this.getTextContent(grip) + "\""
+            )
+          )
+        );
+      }
+
+      let objectLink = this.props.objectLink || DOM.span;
+      return (
+        DOM.span({className: "objectBox objectBox-textNode"},
+          this.getTitle(grip),
+          objectLink({
+            object: grip
+          }, "<"),
+          DOM.span({className: "nodeTag"}, "TextNode"),
+          " textContent=\"",
+          DOM.span({className: "nodeValue"},
+            this.getTextContent(grip)
+          ),
+          "\"",
+          objectLink({
+            object: grip
+          }, ">;")
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(grip, type) {
+    if (!isGrip(grip)) {
+      return false;
+    }
+
+    return (grip.preview && grip.class == "Text");
+  }
+
+  // Exports from this module
+  exports.TextNode = {
+    rep: TextNode,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/undefined.js b/devtools/client/shared/components/reps/undefined.js
new file mode 100644
index 000000000..c4e64a12c
--- /dev/null
+++ b/devtools/client/shared/components/reps/undefined.js
@@ -0,0 +1,46 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // Dependencies
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { span } = React.DOM;
+
+  /**
+   * Renders undefined value
+   */
+  const Undefined = React.createClass({
+    displayName: "UndefinedRep",
+
+    render: function () {
+      return (
+        span({className: "objectBox objectBox-undefined"},
+          "undefined"
+        )
+      );
+    },
+  });
+
+  function supportsObject(object, type) {
+    if (object && object.type && object.type == "undefined") {
+      return true;
+    }
+
+    return (type == "undefined");
+  }
+
+  // Exports from this module
+
+  exports.Undefined = {
+    rep: Undefined,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/reps/window.js b/devtools/client/shared/components/reps/window.js
new file mode 100644
index 000000000..628d69562
--- /dev/null
+++ b/devtools/client/shared/components/reps/window.js
@@ -0,0 +1,73 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { isGrip, getURLDisplayString } = require("./rep-utils");
+
+  // Shortcuts
+  const DOM = React.DOM;
+
+  /**
+   * Renders a grip representing a window.
+   */
+  let Window = React.createClass({
+    displayName: "Window",
+
+    propTypes: {
+      object: React.PropTypes.object.isRequired,
+    },
+
+    getTitle: function (grip) {
+      if (this.props.objectLink) {
+        return DOM.span({className: "objectBox"},
+          this.props.objectLink({
+            object: grip
+          }, grip.class + " ")
+        );
+      }
+      return "";
+    },
+
+    getLocation: function (grip) {
+      return getURLDisplayString(grip.preview.url);
+    },
+
+    render: function () {
+      let grip = this.props.object;
+
+      return (
+        DOM.span({className: "objectBox objectBox-Window"},
+          this.getTitle(grip),
+          DOM.span({className: "objectPropValue"},
+            this.getLocation(grip)
+          )
+        )
+      );
+    },
+  });
+
+  // Registration
+
+  function supportsObject(object, type) {
+    if (!isGrip(object)) {
+      return false;
+    }
+
+    return (object.preview && type == "Window");
+  }
+
+  // Exports from this module
+  exports.Window = {
+    rep: Window,
+    supportsObject: supportsObject
+  };
+});
diff --git a/devtools/client/shared/components/search-box.js b/devtools/client/shared/components/search-box.js
new file mode 100644
index 000000000..bd572f8b2
--- /dev/null
+++ b/devtools/client/shared/components/search-box.js
@@ -0,0 +1,110 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* global window */
+
+"use strict";
+
+const { DOM: dom, createClass, PropTypes } = require("devtools/client/shared/vendor/react");
+const {KeyShortcuts} = require("devtools/client/shared/key-shortcuts");
+
+/**
+ * A generic search box component for use across devtools
+ */
+module.exports = createClass({
+  displayName: "SearchBox",
+
+  propTypes: {
+    delay: PropTypes.number,
+    keyShortcut: PropTypes.string,
+    onChange: PropTypes.func,
+    placeholder: PropTypes.string,
+    type: PropTypes.string
+  },
+
+  getInitialState() {
+    return {
+      value: ""
+    };
+  },
+
+  componentDidMount() {
+    if (!this.props.keyShortcut) {
+      return;
+    }
+
+    this.shortcuts = new KeyShortcuts({
+      window
+    });
+    this.shortcuts.on(this.props.keyShortcut, (name, event) => {
+      event.preventDefault();
+      this.refs.input.focus();
+    });
+  },
+
+  componentWillUnmount() {
+    if (this.shortcuts) {
+      this.shortcuts.destroy();
+    }
+
+    // Clean up an existing timeout.
+    if (this.searchTimeout) {
+      clearTimeout(this.searchTimeout);
+    }
+  },
+
+  onChange() {
+    if (this.state.value !== this.refs.input.value) {
+      this.setState({ value: this.refs.input.value });
+    }
+
+    if (!this.props.delay) {
+      this.props.onChange(this.state.value);
+      return;
+    }
+
+    // Clean up an existing timeout before creating a new one.
+    if (this.searchTimeout) {
+      clearTimeout(this.searchTimeout);
+    }
+
+    // Execute the search after a timeout. It makes the UX
+    // smoother if the user is typing quickly.
+    this.searchTimeout = setTimeout(() => {
+      this.searchTimeout = null;
+      this.props.onChange(this.state.value);
+    }, this.props.delay);
+  },
+
+  onClearButtonClick() {
+    this.refs.input.value = "";
+    this.onChange();
+  },
+
+  render() {
+    let { type = "search", placeholder } = this.props;
+    let { value } = this.state;
+    let divClassList = ["devtools-searchbox", "has-clear-btn"];
+    let inputClassList = [`devtools-${type}input`];
+
+    if (value !== "") {
+      inputClassList.push("filled");
+    }
+    return dom.div(
+      { className: divClassList.join(" ") },
+      dom.input({
+        className: inputClassList.join(" "),
+        onChange: this.onChange,
+        placeholder,
+        ref: "input",
+        value
+      }),
+      dom.button({
+        className: "devtools-searchinput-clear",
+        hidden: value == "",
+        onClick: this.onClearButtonClick
+      })
+    );
+  }
+});
diff --git a/devtools/client/shared/components/sidebar-toggle.css b/devtools/client/shared/components/sidebar-toggle.css
new file mode 100644
index 000000000..659a3d23f
--- /dev/null
+++ b/devtools/client/shared/components/sidebar-toggle.css
@@ -0,0 +1,32 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+.sidebar-toggle {
+  display: block;
+}
+
+.sidebar-toggle::before,
+.sidebar-toggle.pane-collapsed:dir(rtl)::before {
+  background-image: var(--theme-pane-collapse-image);
+}
+
+.sidebar-toggle.pane-collapsed::before,
+.sidebar-toggle:dir(rtl)::before {
+  background-image: var(--theme-pane-expand-image);
+}
+
+/* Rotate button icon 90deg if the toolbox container is
+  in vertical mode (sidebar displayed under the main panel) */
+@media (max-width: 700px) {
+  .sidebar-toggle::before {
+    transform: rotate(90deg);
+  }
+
+  /* Since RTL swaps the used images, we need to flip them
+     the other way round */
+  .sidebar-toggle:dir(rtl)::before {
+    transform: rotate(-90deg);
+  }
+}
diff --git a/devtools/client/shared/components/sidebar-toggle.js b/devtools/client/shared/components/sidebar-toggle.js
new file mode 100644
index 000000000..013e95f3d
--- /dev/null
+++ b/devtools/client/shared/components/sidebar-toggle.js
@@ -0,0 +1,66 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { DOM, createClass, PropTypes } = require("devtools/client/shared/vendor/react");
+
+// Shortcuts
+const { button } = DOM;
+
+/**
+ * Sidebar toggle button. This button is used to exapand
+ * and collapse Sidebar.
+ */
+var SidebarToggle = createClass({
+  displayName: "SidebarToggle",
+
+  propTypes: {
+    // Set to true if collapsed.
+    collapsed: PropTypes.bool.isRequired,
+    // Tooltip text used when the button indicates expanded state.
+    collapsePaneTitle: PropTypes.string.isRequired,
+    // Tooltip text used when the button indicates collapsed state.
+    expandPaneTitle: PropTypes.string.isRequired,
+    // Click callback
+    onClick: PropTypes.func.isRequired,
+  },
+
+  getInitialState: function () {
+    return {
+      collapsed: this.props.collapsed,
+    };
+  },
+
+  // Events
+
+  onClick: function (event) {
+    this.props.onClick(event);
+  },
+
+  // Rendering
+
+  render: function () {
+    let title = this.state.collapsed ?
+      this.props.expandPaneTitle :
+      this.props.collapsePaneTitle;
+
+    let classNames = ["devtools-button", "sidebar-toggle"];
+    if (this.state.collapsed) {
+      classNames.push("pane-collapsed");
+    }
+
+    return (
+      button({
+        className: classNames.join(" "),
+        title: title,
+        onClick: this.onClick
+      })
+    );
+  }
+});
+
+module.exports = SidebarToggle;
diff --git a/devtools/client/shared/components/splitter/draggable.js b/devtools/client/shared/components/splitter/draggable.js
new file mode 100644
index 000000000..9caf93089
--- /dev/null
+++ b/devtools/client/shared/components/splitter/draggable.js
@@ -0,0 +1,54 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const React = require("devtools/client/shared/vendor/react");
+const ReactDOM = require("devtools/client/shared/vendor/react-dom");
+const { DOM: dom, PropTypes } = React;
+
+const Draggable = React.createClass({
+  displayName: "Draggable",
+
+  propTypes: {
+    onMove: PropTypes.func.isRequired,
+    onStart: PropTypes.func,
+    onStop: PropTypes.func,
+    style: PropTypes.object,
+    className: PropTypes.string
+  },
+
+  startDragging(ev) {
+    ev.preventDefault();
+    const doc = ReactDOM.findDOMNode(this).ownerDocument;
+    doc.addEventListener("mousemove", this.onMove);
+    doc.addEventListener("mouseup", this.onUp);
+    this.props.onStart && this.props.onStart();
+  },
+
+  onMove(ev) {
+    ev.preventDefault();
+    // Use viewport coordinates so, moving mouse over iframes
+    // doesn't mangle (relative) coordinates.
+    this.props.onMove(ev.clientX, ev.clientY);
+  },
+
+  onUp(ev) {
+    ev.preventDefault();
+    const doc = ReactDOM.findDOMNode(this).ownerDocument;
+    doc.removeEventListener("mousemove", this.onMove);
+    doc.removeEventListener("mouseup", this.onUp);
+    this.props.onStop && this.props.onStop();
+  },
+
+  render() {
+    return dom.div({
+      style: this.props.style,
+      className: this.props.className,
+      onMouseDown: this.startDragging
+    });
+  }
+});
+
+module.exports = Draggable;
diff --git a/devtools/client/shared/components/splitter/moz.build b/devtools/client/shared/components/splitter/moz.build
new file mode 100644
index 000000000..924732aea
--- /dev/null
+++ b/devtools/client/shared/components/splitter/moz.build
@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'draggable.js',
+    'split-box.css',
+    'split-box.js',
+)
diff --git a/devtools/client/shared/components/splitter/split-box.css b/devtools/client/shared/components/splitter/split-box.css
new file mode 100644
index 000000000..ea8fdaa6f
--- /dev/null
+++ b/devtools/client/shared/components/splitter/split-box.css
@@ -0,0 +1,88 @@
+/* vim:set ts=2 sw=2 sts=2 et: */

+/* This Source Code Form is subject to the terms of the Mozilla Public

+ * License, v. 2.0. If a copy of the MPL was not distributed with this

+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

+

+.split-box {

+  display: flex;

+  flex: 1;

+  min-width: 0;

+  height: 100%;

+  width: 100%;

+}

+

+.split-box.vert {

+  flex-direction: row;

+}

+

+.split-box.horz {

+  flex-direction: column;

+}

+

+.split-box > .uncontrolled {

+  display: flex;

+  flex: 1;

+  min-width: 0;

+  overflow: auto;

+}

+

+.split-box > .controlled {

+  display: flex;

+  overflow: auto;

+}

+

+.split-box > .splitter {

+  background-image: none;

+  border: 0;

+  border-style: solid;

+  border-color: transparent;

+  background-color: var(--theme-splitter-color);

+  background-clip: content-box;

+  position: relative;

+

+  box-sizing: border-box;

+

+  /* Positive z-index positions the splitter on top of its siblings and makes

+     it clickable on both sides. */

+  z-index: 1;

+}

+

+.split-box.vert > .splitter {

+  min-width: calc(var(--devtools-splitter-inline-start-width) +

+    var(--devtools-splitter-inline-end-width) + 1px);

+

+  border-inline-start-width: var(--devtools-splitter-inline-start-width);

+  border-inline-end-width: var(--devtools-splitter-inline-end-width);

+

+  margin-inline-start: calc(-1 * var(--devtools-splitter-inline-start-width) - 1px);

+  margin-inline-end: calc(-1 * var(--devtools-splitter-inline-end-width));

+

+  cursor: ew-resize;

+}

+

+.split-box.horz > .splitter {

+  min-height: calc(var(--devtools-splitter-top-width) +

+    var(--devtools-splitter-bottom-width) + 1px);

+

+  border-top-width: var(--devtools-splitter-top-width);

+  border-bottom-width: var(--devtools-splitter-bottom-width);

+

+  margin-top: calc(-1 * var(--devtools-splitter-top-width) - 1px);

+  margin-bottom: calc(-1 * var(--devtools-splitter-bottom-width));

+

+  cursor: ns-resize;

+}

+

+.split-box.disabled {

+  pointer-events: none;

+}

+

+/**

+ * Make sure splitter panels are not processing any mouse

+ * events. This is good for performance during splitter

+ * bar dragging.

+ */

+.split-box.dragging > .controlled,

+.split-box.dragging > .uncontrolled {

+  pointer-events: none;

+}

diff --git a/devtools/client/shared/components/splitter/split-box.js b/devtools/client/shared/components/splitter/split-box.js
new file mode 100644
index 000000000..85835f3e1
--- /dev/null
+++ b/devtools/client/shared/components/splitter/split-box.js
@@ -0,0 +1,205 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const React = require("devtools/client/shared/vendor/react");
+const ReactDOM = require("devtools/client/shared/vendor/react-dom");
+const Draggable = React.createFactory(require("devtools/client/shared/components/splitter/draggable"));
+const { DOM: dom, PropTypes } = React;
+
+/**
+ * This component represents a Splitter. The splitter supports vertical
+ * as well as horizontal mode.
+ */
+const SplitBox = React.createClass({
+  displayName: "SplitBox",
+
+  propTypes: {
+    // Custom class name. You can use more names separated by a space.
+    className: PropTypes.string,
+    // Initial size of controlled panel.
+    initialSize: PropTypes.number,
+    // Left/top panel
+    startPanel: PropTypes.any,
+    // Min panel size.
+    minSize: PropTypes.number,
+    // Max panel size.
+    maxSize: PropTypes.number,
+    // Right/bottom panel
+    endPanel: PropTypes.any,
+    // True if the right/bottom panel should be controlled.
+    endPanelControl: PropTypes.bool,
+    // Size of the splitter handle bar.
+    splitterSize: PropTypes.number,
+    // True if the splitter bar is vertical (default is vertical).
+    vert: PropTypes.bool
+  },
+
+  getDefaultProps() {
+    return {
+      splitterSize: 5,
+      vert: true,
+      endPanelControl: false
+    };
+  },
+
+  /**
+   * The state stores the current orientation (vertical or horizontal)
+   * and the current size (width/height). All these values can change
+   * during the component's life time.
+   */
+  getInitialState() {
+    return {
+      vert: this.props.vert,
+      width: this.props.initialWidth || this.props.initialSize,
+      height: this.props.initialHeight || this.props.initialSize
+    };
+  },
+
+  // Dragging Events
+
+  /**
+   * Set 'resizing' cursor on entire document during splitter dragging.
+   * This avoids cursor-flickering that happens when the mouse leaves
+   * the splitter bar area (happens frequently).
+   */
+  onStartMove() {
+    const splitBox = ReactDOM.findDOMNode(this);
+    const doc = splitBox.ownerDocument;
+    let defaultCursor = doc.documentElement.style.cursor;
+    doc.documentElement.style.cursor = (this.state.vert ? "ew-resize" : "ns-resize");
+
+    splitBox.classList.add("dragging");
+
+    this.setState({
+      defaultCursor: defaultCursor
+    });
+  },
+
+  onStopMove() {
+    const splitBox = ReactDOM.findDOMNode(this);
+    const doc = splitBox.ownerDocument;
+    doc.documentElement.style.cursor = this.state.defaultCursor;
+
+    splitBox.classList.remove("dragging");
+  },
+
+  /**
+   * Adjust size of the controlled panel. Depending on the current
+   * orientation we either remember the width or height of
+   * the splitter box.
+   */
+  onMove(x, y) {
+    const node = ReactDOM.findDOMNode(this);
+    const doc = node.ownerDocument;
+    const win = doc.defaultView;
+
+    let size;
+    let { endPanelControl } = this.props;
+
+    if (this.state.vert) {
+      // Switch the control flag in case of RTL. Note that RTL
+      // has impact on vertical splitter only.
+      let dir = win.getComputedStyle(doc.documentElement).direction;
+      if (dir == "rtl") {
+        endPanelControl = !endPanelControl;
+      }
+
+      size = endPanelControl ?
+        (node.offsetLeft + node.offsetWidth) - x :
+        x - node.offsetLeft;
+
+      this.setState({
+        width: size
+      });
+    } else {
+      size = endPanelControl ?
+        (node.offsetTop + node.offsetHeight) - y :
+        y - node.offsetTop;
+
+      this.setState({
+        height: size
+      });
+    }
+  },
+
+  // Rendering
+
+  render() {
+    const vert = this.state.vert;
+    const { startPanel, endPanel, endPanelControl, minSize,
+      maxSize, splitterSize } = this.props;
+
+    let style = Object.assign({}, this.props.style);
+
+    // Calculate class names list.
+    let classNames = ["split-box"];
+    classNames.push(vert ? "vert" : "horz");
+    if (this.props.className) {
+      classNames = classNames.concat(this.props.className.split(" "));
+    }
+
+    let leftPanelStyle;
+    let rightPanelStyle;
+
+    // Set proper size for panels depending on the current state.
+    if (vert) {
+      leftPanelStyle = {
+        maxWidth: endPanelControl ? null : maxSize,
+        minWidth: endPanelControl ? null : minSize,
+        width: endPanelControl ? null : this.state.width
+      };
+      rightPanelStyle = {
+        maxWidth: endPanelControl ? maxSize : null,
+        minWidth: endPanelControl ? minSize : null,
+        width: endPanelControl ? this.state.width : null
+      };
+    } else {
+      leftPanelStyle = {
+        maxHeight: endPanelControl ? null : maxSize,
+        minHeight: endPanelControl ? null : minSize,
+        height: endPanelControl ? null : this.state.height
+      };
+      rightPanelStyle = {
+        maxHeight: endPanelControl ? maxSize : null,
+        minHeight: endPanelControl ? minSize : null,
+        height: endPanelControl ? this.state.height : null
+      };
+    }
+
+    // Calculate splitter size
+    let splitterStyle = {
+      flex: "0 0 " + splitterSize + "px"
+    };
+
+    return (
+      dom.div({
+        className: classNames.join(" "),
+        style: style },
+        startPanel ?
+          dom.div({
+            className: endPanelControl ? "uncontrolled" : "controlled",
+            style: leftPanelStyle},
+            startPanel
+          ) : null,
+        Draggable({
+          className: "splitter",
+          style: splitterStyle,
+          onStart: this.onStartMove,
+          onStop: this.onStopMove,
+          onMove: this.onMove
+        }),
+        endPanel ?
+          dom.div({
+            className: endPanelControl ? "controlled" : "uncontrolled",
+            style: rightPanelStyle},
+            endPanel
+          ) : null
+      )
+    );
+  }
+});
+
+module.exports = SplitBox;
diff --git a/devtools/client/shared/components/stack-trace.js b/devtools/client/shared/components/stack-trace.js
new file mode 100644
index 000000000..43d0b8716
--- /dev/null
+++ b/devtools/client/shared/components/stack-trace.js
@@ -0,0 +1,68 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const React = require("devtools/client/shared/vendor/react");
+const { DOM: dom, createClass, createFactory, PropTypes } = React;
+const { LocalizationHelper } = require("devtools/shared/l10n");
+const Frame = createFactory(require("./frame"));
+
+const l10n = new LocalizationHelper("devtools/client/locales/webconsole.properties");
+
+const AsyncFrame = createFactory(createClass({
+  displayName: "AsyncFrame",
+
+  PropTypes: {
+    asyncCause: PropTypes.string.isRequired
+  },
+
+  render() {
+    let { asyncCause } = this.props;
+
+    return dom.span(
+      { className: "frame-link-async-cause" },
+      l10n.getFormatStr("stacktrace.asyncStack", asyncCause)
+    );
+  }
+}));
+
+const StackTrace = createClass({
+  displayName: "StackTrace",
+
+  PropTypes: {
+    stacktrace: PropTypes.array.isRequired,
+    onViewSourceInDebugger: PropTypes.func.isRequired
+  },
+
+  render() {
+    let { stacktrace, onViewSourceInDebugger } = this.props;
+
+    let frames = [];
+    stacktrace.forEach(s => {
+      if (s.asyncCause) {
+        frames.push("\t", AsyncFrame({
+          asyncCause: s.asyncCause
+        }), "\n");
+      }
+
+      frames.push("\t", Frame({
+        frame: {
+          functionDisplayName: s.functionName,
+          source: s.filename.split(" -> ").pop(),
+          line: s.lineNumber,
+          column: s.columnNumber,
+        },
+        showFunctionName: true,
+        showAnonymousFunctionName: true,
+        showFullSourceUrl: true,
+        onClick: onViewSourceInDebugger
+      }), "\n");
+    });
+
+    return dom.div({ className: "stack-trace" }, frames);
+  }
+});
+
+module.exports = StackTrace;
diff --git a/devtools/client/shared/components/tabs/moz.build b/devtools/client/shared/components/tabs/moz.build
new file mode 100644
index 000000000..d4d5dc35d
--- /dev/null
+++ b/devtools/client/shared/components/tabs/moz.build
@@ -0,0 +1,12 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'tabbar.css',
+    'tabbar.js',
+    'tabs.css',
+    'tabs.js',
+)
diff --git a/devtools/client/shared/components/tabs/tabbar.css b/devtools/client/shared/components/tabs/tabbar.css
new file mode 100644
index 000000000..72445e43e
--- /dev/null
+++ b/devtools/client/shared/components/tabs/tabbar.css
@@ -0,0 +1,53 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+.tabs .tabs-navigation {
+  line-height: 15px;
+}
+
+.tabs .tabs-navigation {
+  height: 24px;
+}
+
+.tabs .tabs-menu-item:first-child {
+  border-inline-start-width: 0;
+}
+
+.tabs .tabs-navigation .tabs-menu-item:focus {
+  outline: var(--theme-focus-outline);
+  outline-offset: -2px;
+}
+
+.tabs .tabs-menu-item.is-active {
+  height: 23px;
+}
+
+/* Firebug theme is using slightly different height. */
+.theme-firebug .tabs .tabs-navigation {
+  height: 24px;
+}
+
+/* The tab takes entire horizontal space and individual tabs
+  should stretch accordingly. Use flexbox for the behavior.
+  Use also `overflow: hidden` so, 'overflow' and 'underflow'
+  events are fired (it's utilized by the all-tabs-menu). */
+.tabs .tabs-navigation .tabs-menu {
+  overflow: hidden;
+  display: flex;
+}
+
+.tabs .tabs-navigation .tabs-menu-item {
+  flex-grow: 1;
+}
+
+.tabs .tabs-navigation .tabs-menu-item a {
+  text-align: center;
+}
+
+/* Firebug theme doesn't stretch the tabs. */
+.theme-firebug .tabs .tabs-navigation .tabs-menu-item {
+  flex-grow: 0;
+}
+
diff --git a/devtools/client/shared/components/tabs/tabbar.js b/devtools/client/shared/components/tabs/tabbar.js
new file mode 100644
index 000000000..1e3aa4617
--- /dev/null
+++ b/devtools/client/shared/components/tabs/tabbar.js
@@ -0,0 +1,204 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { DOM, createClass, PropTypes, createFactory } = require("devtools/client/shared/vendor/react");
+const Tabs = createFactory(require("devtools/client/shared/components/tabs/tabs").Tabs);
+
+const Menu = require("devtools/client/framework/menu");
+const MenuItem = require("devtools/client/framework/menu-item");
+
+// Shortcuts
+const { div } = DOM;
+
+/**
+ * Renders Tabbar component.
+ */
+let Tabbar = createClass({
+  displayName: "Tabbar",
+
+  propTypes: {
+    onSelect: PropTypes.func,
+    showAllTabsMenu: PropTypes.bool,
+    toolbox: PropTypes.object,
+  },
+
+  getDefaultProps: function () {
+    return {
+      showAllTabsMenu: false,
+    };
+  },
+
+  getInitialState: function () {
+    return {
+      tabs: [],
+      activeTab: 0
+    };
+  },
+
+  // Public API
+
+  addTab: function (id, title, selected = false, panel, url) {
+    let tabs = this.state.tabs.slice();
+    tabs.push({id, title, panel, url});
+
+    let newState = Object.assign({}, this.state, {
+      tabs: tabs,
+    });
+
+    if (selected) {
+      newState.activeTab = tabs.length - 1;
+    }
+
+    this.setState(newState, () => {
+      if (this.props.onSelect && selected) {
+        this.props.onSelect(id);
+      }
+    });
+  },
+
+  toggleTab: function (tabId, isVisible) {
+    let index = this.getTabIndex(tabId);
+    if (index < 0) {
+      return;
+    }
+
+    let tabs = this.state.tabs.slice();
+    tabs[index] = Object.assign({}, tabs[index], {
+      isVisible: isVisible
+    });
+
+    this.setState(Object.assign({}, this.state, {
+      tabs: tabs,
+    }));
+  },
+
+  removeTab: function (tabId) {
+    let index = this.getTabIndex(tabId);
+    if (index < 0) {
+      return;
+    }
+
+    let tabs = this.state.tabs.slice();
+    tabs.splice(index, 1);
+
+    this.setState(Object.assign({}, this.state, {
+      tabs: tabs,
+    }));
+  },
+
+  select: function (tabId) {
+    let index = this.getTabIndex(tabId);
+    if (index < 0) {
+      return;
+    }
+
+    let newState = Object.assign({}, this.state, {
+      activeTab: index,
+    });
+
+    this.setState(newState, () => {
+      if (this.props.onSelect) {
+        this.props.onSelect(tabId);
+      }
+    });
+  },
+
+  // Helpers
+
+  getTabIndex: function (tabId) {
+    let tabIndex = -1;
+    this.state.tabs.forEach((tab, index) => {
+      if (tab.id == tabId) {
+        tabIndex = index;
+      }
+    });
+    return tabIndex;
+  },
+
+  getTabId: function (index) {
+    return this.state.tabs[index].id;
+  },
+
+  getCurrentTabId: function () {
+    return this.state.tabs[this.state.activeTab].id;
+  },
+
+  // Event Handlers
+
+  onTabChanged: function (index) {
+    this.setState({
+      activeTab: index
+    });
+
+    if (this.props.onSelect) {
+      this.props.onSelect(this.state.tabs[index].id);
+    }
+  },
+
+  onAllTabsMenuClick: function (event) {
+    let menu = new Menu();
+    let target = event.target;
+
+    // Generate list of menu items from the list of tabs.
+    this.state.tabs.forEach(tab => {
+      menu.append(new MenuItem({
+        label: tab.title,
+        type: "checkbox",
+        checked: this.getCurrentTabId() == tab.id,
+        click: () => this.select(tab.id),
+      }));
+    });
+
+    // Show a drop down menu with frames.
+    // XXX Missing menu API for specifying target (anchor)
+    // and relative position to it. See also:
+    // https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/Method/openPopup
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1274551
+    let rect = target.getBoundingClientRect();
+    let screenX = target.ownerDocument.defaultView.mozInnerScreenX;
+    let screenY = target.ownerDocument.defaultView.mozInnerScreenY;
+    menu.popup(rect.left + screenX, rect.bottom + screenY, this.props.toolbox);
+
+    return menu;
+  },
+
+  // Rendering
+
+  renderTab: function (tab) {
+    if (typeof tab.panel === "function") {
+      return tab.panel({
+        key: tab.id,
+        title: tab.title,
+        id: tab.id,
+        url: tab.url,
+      });
+    }
+
+    return tab.panel;
+  },
+
+  render: function () {
+    let tabs = this.state.tabs.map(tab => {
+      return this.renderTab(tab);
+    });
+
+    return (
+      div({className: "devtools-sidebar-tabs"},
+        Tabs({
+          onAllTabsMenuClick: this.onAllTabsMenuClick,
+          showAllTabsMenu: this.props.showAllTabsMenu,
+          tabActive: this.state.activeTab,
+          onAfterChange: this.onTabChanged},
+          tabs
+        )
+      )
+    );
+  },
+});
+
+module.exports = Tabbar;
diff --git a/devtools/client/shared/components/tabs/tabs.css b/devtools/client/shared/components/tabs/tabs.css
new file mode 100644
index 000000000..0e70549c5
--- /dev/null
+++ b/devtools/client/shared/components/tabs/tabs.css
@@ -0,0 +1,183 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Tabs General Styles */
+
+.tabs {
+  height: 100%;
+}
+
+.tabs .tabs-menu {
+  display: table;
+  list-style: none;
+  padding: 0;
+  margin: 0;
+}
+
+.tabs .tabs-menu-item {
+  display: inline-block;
+}
+
+.tabs .tabs-menu-item a {
+  display: block;
+  color: #A9A9A9;
+  padding: 4px 8px;
+  border: 1px solid transparent;
+  text-decoration: none;
+  white-space: nowrap;
+}
+
+.tabs .tabs-menu-item a {
+  cursor: default;
+}
+
+/* Make sure panel content takes entire vertical space.
+  (minus the height of the tab bar) */
+.tabs .panels {
+  height: calc(100% - 24px);
+}
+
+.tabs .tab-panel {
+  height: 100%;
+}
+
+.tabs .all-tabs-menu  {
+  position: absolute;
+  top: 0;
+  offset-inline-end: 0;
+  width: 15px;
+  height: 100%;
+  border-inline-start: 1px solid var(--theme-splitter-color);
+  background: url("chrome://devtools/skin/images/dropmarker.svg");
+  background-repeat: no-repeat;
+  background-position: center;
+  background-color: var(--theme-tab-toolbar-background);
+}
+
+/* Light Theme */
+
+.theme-dark .tabs,
+.theme-light .tabs {
+  background: var(--theme-body-background);
+}
+
+.theme-dark .tabs .tabs-navigation,
+.theme-light .tabs .tabs-navigation {
+  position: relative;
+  border-bottom: 1px solid var(--theme-splitter-color);
+  background: var(--theme-tab-toolbar-background);
+}
+
+.theme-dark .tabs .tabs-menu-item,
+.theme-light .tabs .tabs-menu-item {
+  margin: 0;
+  padding: 0;
+  border-style: solid;
+  border-width: 0;
+  border-inline-start-width: 1px;
+  border-color: var(--theme-splitter-color);
+}
+
+.theme-dark .tabs .tabs-menu-item:last-child,
+.theme-light:not(.theme-firebug) .tabs .tabs-menu-item:last-child {
+  border-inline-end-width: 1px;
+}
+
+.theme-dark .tabs .tabs-menu-item a,
+.theme-light .tabs .tabs-menu-item a {
+  color: var(--theme-content-color1);
+  padding: 3px 15px;
+}
+
+.theme-dark .tabs .tabs-menu-item:hover:not(.is-active),
+.theme-light .tabs .tabs-menu-item:hover:not(.is-active) {
+  background-color: var(--toolbar-tab-hover);
+}
+
+.theme-dark .tabs .tabs-menu-item:hover:active:not(.is-active),
+.theme-light .tabs .tabs-menu-item:hover:active:not(.is-active) {
+  background-color: var(--toolbar-tab-hover-active);
+}
+
+.theme-dark .tabs .tabs-menu-item.is-active,
+.theme-light .tabs .tabs-menu-item.is-active {
+  background-color: var(--theme-selection-background);
+}
+
+.theme-dark .tabs .tabs-menu-item.is-active a,
+.theme-light .tabs .tabs-menu-item.is-active a {
+  color: var(--theme-selection-color);
+}
+
+/* Dark Theme */
+
+.theme-dark .tabs .tabs-menu-item a {
+  color: var(--theme-body-color-alt);
+}
+
+.theme-dark .tabs .tabs-menu-item:hover:not(.is-active) a {
+  color: #CED3D9;
+}
+
+.theme-dark .tabs .tabs-menu-item:hover:active a {
+  color: var(--theme-selection-color);
+}
+
+/* Firebug Theme */
+
+.theme-firebug .tabs .tabs-navigation {
+  background-image: linear-gradient(rgba(253, 253, 253, 0.2), rgba(253, 253, 253, 0));
+  padding-top: 3px;
+  padding-left: 3px;
+  border-bottom: 1px solid rgb(170, 188, 207);
+}
+
+.theme-firebug .tabs .tabs-menu {
+  margin-bottom: -1px;
+}
+
+.theme-firebug .tabs .tabs-menu-item.is-active,
+.theme-firebug .tabs .tabs-menu-item.is-active:hover {
+  background-color: transparent;
+}
+
+.theme-firebug .tabs .tabs-menu-item {
+  position: relative;
+  border-inline-start-width: 0;
+}
+
+.theme-firebug .tabs .tabs-menu-item a {
+  font-family: var(--proportional-font-family);
+  font-weight: bold;
+  color: var(--theme-body-color);
+  border-radius: 4px 4px 0 0;
+}
+
+.theme-firebug .tabs .tabs-menu-item:hover:not(.is-active) a {
+  border: 1px solid #C8C8C8;
+  border-bottom: 1px solid transparent;
+  background-color: transparent;
+}
+
+.theme-firebug .tabs .tabs-menu-item.is-active a {
+  background-color: rgb(247, 251, 254);
+  border: 1px solid rgb(170, 188, 207);
+  border-bottom-color: transparent;
+  color: var(--theme-body-color);
+}
+
+.theme-firebug .tabs .tabs-menu-item:hover:active a {
+  background-color: var(--toolbar-tab-hover-active);
+}
+
+.theme-firebug .tabs .tabs-menu-item.is-active:hover:active a {
+  background-color: var(--theme-selection-background);
+  color: var(--theme-selection-color);
+}
+
+.theme-firebug .tabs .tabs-menu-item a {
+  border: 1px solid transparent;
+  padding: 4px 8px;
+}
diff --git a/devtools/client/shared/components/tabs/tabs.js b/devtools/client/shared/components/tabs/tabs.js
new file mode 100644
index 000000000..eaa0738b3
--- /dev/null
+++ b/devtools/client/shared/components/tabs/tabs.js
@@ -0,0 +1,369 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+define(function (require, exports, module) {
+  const React = require("devtools/client/shared/vendor/react");
+  const { DOM } = React;
+  const { findDOMNode } = require("devtools/client/shared/vendor/react-dom");
+
+  /**
+   * Renders simple 'tab' widget.
+   *
+   * Based on ReactSimpleTabs component
+   * https://github.com/pedronauck/react-simpletabs
+   *
+   * Component markup (+CSS) example:
+   *
+   * <div class='tabs'>
+   *  <nav class='tabs-navigation'>
+   *    <ul class='tabs-menu'>
+   *      <li class='tabs-menu-item is-active'>Tab #1</li>
+   *      <li class='tabs-menu-item'>Tab #2</li>
+   *    </ul>
+   *  </nav>
+   *  <div class='panels'>
+   *    The content of active panel here
+   *  </div>
+   * <div>
+   */
+  let Tabs = React.createClass({
+    displayName: "Tabs",
+
+    propTypes: {
+      className: React.PropTypes.oneOfType([
+        React.PropTypes.array,
+        React.PropTypes.string,
+        React.PropTypes.object
+      ]),
+      tabActive: React.PropTypes.number,
+      onMount: React.PropTypes.func,
+      onBeforeChange: React.PropTypes.func,
+      onAfterChange: React.PropTypes.func,
+      children: React.PropTypes.oneOfType([
+        React.PropTypes.array,
+        React.PropTypes.element
+      ]).isRequired,
+      showAllTabsMenu: React.PropTypes.bool,
+      onAllTabsMenuClick: React.PropTypes.func,
+    },
+
+    getDefaultProps: function () {
+      return {
+        tabActive: 0,
+        showAllTabsMenu: false,
+      };
+    },
+
+    getInitialState: function () {
+      return {
+        tabActive: this.props.tabActive,
+
+        // This array is used to store an information whether a tab
+        // at specific index has already been created (e.g. selected
+        // at least once).
+        // If yes, it's rendered even if not currently selected.
+        // This is because in some cases we don't want to re-create
+        // tab content when it's being unselected/selected.
+        // E.g. in case of an iframe being used as a tab-content
+        // we want the iframe to stay in the DOM.
+        created: [],
+
+        // True if tabs can't fit into available horizontal space.
+        overflow: false,
+      };
+    },
+
+    componentDidMount: function () {
+      let node = findDOMNode(this);
+      node.addEventListener("keydown", this.onKeyDown, false);
+
+      // Register overflow listeners to manage visibility
+      // of all-tabs-menu. This menu is displayed when there
+      // is not enough h-space to render all tabs.
+      // It allows the user to select a tab even if it's hidden.
+      if (this.props.showAllTabsMenu) {
+        node.addEventListener("overflow", this.onOverflow, false);
+        node.addEventListener("underflow", this.onUnderflow, false);
+      }
+
+      let index = this.state.tabActive;
+      if (this.props.onMount) {
+        this.props.onMount(index);
+      }
+    },
+
+    componentWillReceiveProps: function (newProps) {
+      // Check type of 'tabActive' props to see if it's valid
+      // (it's 0-based index).
+      if (typeof newProps.tabActive == "number") {
+        let created = [...this.state.created];
+        created[newProps.tabActive] = true;
+
+        this.setState(Object.assign({}, this.state, {
+          tabActive: newProps.tabActive,
+          created: created,
+        }));
+      }
+    },
+
+    componentWillUnmount: function () {
+      let node = findDOMNode(this);
+      node.removeEventListener("keydown", this.onKeyDown, false);
+
+      if (this.props.showAllTabsMenu) {
+        node.removeEventListener("overflow", this.onOverflow, false);
+        node.removeEventListener("underflow", this.onUnderflow, false);
+      }
+    },
+
+    // DOM Events
+
+    onOverflow: function (event) {
+      if (event.target.classList.contains("tabs-menu")) {
+        this.setState({
+          overflow: true
+        });
+      }
+    },
+
+    onUnderflow: function (event) {
+      if (event.target.classList.contains("tabs-menu")) {
+        this.setState({
+          overflow: false
+        });
+      }
+    },
+
+    onKeyDown: function (event) {
+      // Bail out if the focus isn't on a tab.
+      if (!event.target.closest(".tabs-menu-item")) {
+        return;
+      }
+
+      let tabActive = this.state.tabActive;
+      let tabCount = this.props.children.length;
+
+      switch (event.code) {
+        case "ArrowRight":
+          tabActive = Math.min(tabCount - 1, tabActive + 1);
+          break;
+        case "ArrowLeft":
+          tabActive = Math.max(0, tabActive - 1);
+          break;
+      }
+
+      if (this.state.tabActive != tabActive) {
+        this.setActive(tabActive);
+      }
+    },
+
+    onClickTab: function (index, event) {
+      this.setActive(index);
+      event.preventDefault();
+    },
+
+    onAllTabsMenuClick: function (event) {
+      if (this.props.onAllTabsMenuClick) {
+        this.props.onAllTabsMenuClick(event);
+      }
+    },
+
+    // API
+
+    setActive: function (index) {
+      let onAfterChange = this.props.onAfterChange;
+      let onBeforeChange = this.props.onBeforeChange;
+
+      if (onBeforeChange) {
+        let cancel = onBeforeChange(index);
+        if (cancel) {
+          return;
+        }
+      }
+
+      let created = [...this.state.created];
+      created[index] = true;
+
+      let newState = Object.assign({}, this.state, {
+        tabActive: index,
+        created: created
+      });
+
+      this.setState(newState, () => {
+        // Properly set focus on selected tab.
+        let node = findDOMNode(this);
+        let selectedTab = node.querySelector(".is-active > a");
+        if (selectedTab) {
+          selectedTab.focus();
+        }
+
+        if (onAfterChange) {
+          onAfterChange(index);
+        }
+      });
+    },
+
+    // Rendering
+
+    renderMenuItems: function () {
+      if (!this.props.children) {
+        throw new Error("There must be at least one Tab");
+      }
+
+      if (!Array.isArray(this.props.children)) {
+        this.props.children = [this.props.children];
+      }
+
+      let tabs = this.props.children
+        .map(tab => {
+          return typeof tab === "function" ? tab() : tab;
+        }).filter(tab => {
+          return tab;
+        }).map((tab, index) => {
+          let ref = ("tab-menu-" + index);
+          let title = tab.props.title;
+          let tabClassName = tab.props.className;
+          let isTabSelected = this.state.tabActive === index;
+
+          let classes = [
+            "tabs-menu-item",
+            tabClassName,
+            isTabSelected ? "is-active" : ""
+          ].join(" ");
+
+          // Set tabindex to -1 (except the selected tab) so, it's focusable,
+          // but not reachable via sequential tab-key navigation.
+          // Changing selected tab (and so, moving focus) is done through
+          // left and right arrow keys.
+          // See also `onKeyDown()` event handler.
+          return (
+            DOM.li({
+              ref: ref,
+              key: index,
+              id: "tab-" + index,
+              className: classes,
+              role: "presentation",
+            },
+              DOM.a({
+                tabIndex: this.state.tabActive === index ? 0 : -1,
+                "aria-controls": "panel-" + index,
+                "aria-selected": isTabSelected,
+                role: "tab",
+                onClick: this.onClickTab.bind(this, index),
+              },
+                title
+              )
+            )
+          );
+        });
+
+      // Display the menu only if there is not enough horizontal
+      // space for all tabs (and overflow happened).
+      let allTabsMenu = this.state.overflow ? (
+        DOM.div({
+          className: "all-tabs-menu",
+          onClick: this.props.onAllTabsMenuClick
+        })
+      ) : null;
+
+      return (
+        DOM.nav({className: "tabs-navigation"},
+          DOM.ul({className: "tabs-menu", role: "tablist"},
+            tabs
+          ),
+          allTabsMenu
+        )
+      );
+    },
+
+    renderPanels: function () {
+      if (!this.props.children) {
+        throw new Error("There must be at least one Tab");
+      }
+
+      if (!Array.isArray(this.props.children)) {
+        this.props.children = [this.props.children];
+      }
+
+      let selectedIndex = this.state.tabActive;
+
+      let panels = this.props.children
+        .map(tab => {
+          return typeof tab === "function" ? tab() : tab;
+        }).filter(tab => {
+          return tab;
+        }).map((tab, index) => {
+          let selected = selectedIndex == index;
+
+          // Use 'visibility:hidden' + 'width/height:0' for hiding
+          // content of non-selected tab. It's faster (not sure why)
+          // than display:none and visibility:collapse.
+          let style = {
+            visibility: selected ? "visible" : "hidden",
+            height: selected ? "100%" : "0",
+            width: selected ? "100%" : "0",
+          };
+
+          return (
+            DOM.div({
+              key: index,
+              id: "panel-" + index,
+              style: style,
+              className: "tab-panel-box",
+              role: "tabpanel",
+              "aria-labelledby": "tab-" + index,
+            },
+              (selected || this.state.created[index]) ? tab : null
+            )
+          );
+        });
+
+      return (
+        DOM.div({className: "panels"},
+          panels
+        )
+      );
+    },
+
+    render: function () {
+      let classNames = ["tabs", this.props.className].join(" ");
+
+      return (
+        DOM.div({className: classNames},
+          this.renderMenuItems(),
+          this.renderPanels()
+        )
+      );
+    },
+  });
+
+  /**
+   * Renders simple tab 'panel'.
+   */
+  let Panel = React.createClass({
+    displayName: "Panel",
+
+    propTypes: {
+      title: React.PropTypes.string.isRequired,
+      children: React.PropTypes.oneOfType([
+        React.PropTypes.array,
+        React.PropTypes.element
+      ]).isRequired
+    },
+
+    render: function () {
+      return DOM.div({className: "tab-panel"},
+        this.props.children
+      );
+    }
+  });
+
+  // Exports from this module
+  exports.TabPanel = Panel;
+  exports.Tabs = Tabs;
+});
diff --git a/devtools/client/shared/components/test/browser/.eslintrc.js b/devtools/client/shared/components/test/browser/.eslintrc.js
new file mode 100644
index 000000000..76904829d
--- /dev/null
+++ b/devtools/client/shared/components/test/browser/.eslintrc.js
@@ -0,0 +1,6 @@
+"use strict";
+
+module.exports = {
+  // Extend from the shared list of defined globals for mochitests.
+  "extends": "../../../../../.eslintrc.mochitests.js",
+};
diff --git a/devtools/client/shared/components/test/browser/browser.ini b/devtools/client/shared/components/test/browser/browser.ini
new file mode 100644
index 000000000..9db9eca66
--- /dev/null
+++ b/devtools/client/shared/components/test/browser/browser.ini
@@ -0,0 +1,7 @@
+[DEFAULT]
+tags = devtools
+subsuite = devtools
+support-files =
+  !/devtools/client/framework/test/shared-head.js
+
+[browser_notification_box_basic.js]
diff --git a/devtools/client/shared/components/test/browser/browser_notification_box_basic.js b/devtools/client/shared/components/test/browser/browser_notification_box_basic.js
new file mode 100644
index 000000000..b7c6a669b
--- /dev/null
+++ b/devtools/client/shared/components/test/browser/browser_notification_box_basic.js
@@ -0,0 +1,36 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/* import-globals-from ../../../../framework/test/shared-head.js */
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/framework/test/shared-head.js", this);
+
+const TEST_URI = "data:text/html;charset=utf-8,Test page";
+
+/**
+ * Basic test that checks existence of the Notification box.
+ */
+add_task(function* () {
+  info("Test Notification box basic started");
+
+  let toolbox = yield openNewTabAndToolbox(TEST_URI, "webconsole");
+
+  // Append a notification
+  let notificationBox = toolbox.getNotificationBox();
+  notificationBox.appendNotification(
+    "Info message",
+    "id1",
+    null,
+    notificationBox.PRIORITY_INFO_HIGH
+  );
+
+  // Verify existence of one notification.
+  let parentNode = toolbox.doc.getElementById("toolbox-notificationbox");
+  let nodes = parentNode.querySelectorAll(".notification");
+  is(nodes.length, 1, "There must be one notification");
+});
diff --git a/devtools/client/shared/components/test/mochitest/.eslintrc.js b/devtools/client/shared/components/test/mochitest/.eslintrc.js
new file mode 100644
index 000000000..677cbb424
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/.eslintrc.js
@@ -0,0 +1,6 @@
+"use strict";
+
+module.exports = {
+  // Extend from the shared list of defined globals for mochitests.
+  "extends": "../../../../../.eslintrc.mochitests.js"
+};
diff --git a/devtools/client/shared/components/test/mochitest/chrome.ini b/devtools/client/shared/components/test/mochitest/chrome.ini
new file mode 100644
index 000000000..27a4be137
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/chrome.ini
@@ -0,0 +1,51 @@
+[DEFAULT]
+support-files =
+  head.js
+
+[test_frame_01.html]
+[test_HSplitBox_01.html]
+[test_notification_box_01.html]
+[test_notification_box_02.html]
+[test_notification_box_03.html]
+[test_reps_array.html]
+[test_reps_attribute.html]
+[test_reps_comment-node.html]
+[test_reps_date-time.html]
+[test_reps_document.html]
+[test_reps_element-node.html]
+[test_reps_event.html]
+[test_reps_function.html]
+[test_reps_grip.html]
+[test_reps_grip-array.html]
+[test_reps_grip-map.html]
+[test_reps_infinity.html]
+[test_reps_long-string.html]
+[test_reps_nan.html]
+[test_reps_null.html]
+[test_reps_number.html]
+[test_reps_object.html]
+[test_reps_object-with-text.html]
+[test_reps_object-with-url.html]
+[test_reps_promise.html]
+[test_reps_regexp.html]
+[test_reps_string.html]
+[test_reps_stylesheet.html]
+[test_reps_symbol.html]
+[test_reps_text-node.html]
+[test_reps_undefined.html]
+[test_reps_window.html]
+[test_sidebar_toggle.html]
+[test_stack-trace.html]
+[test_tabs_accessibility.html]
+[test_tabs_menu.html]
+[test_tree_01.html]
+[test_tree_02.html]
+[test_tree_03.html]
+[test_tree_04.html]
+[test_tree_05.html]
+[test_tree_06.html]
+[test_tree_07.html]
+[test_tree_08.html]
+[test_tree_09.html]
+[test_tree_10.html]
+[test_tree_11.html]
diff --git a/devtools/client/shared/components/test/mochitest/head.js b/devtools/client/shared/components/test/mochitest/head.js
new file mode 100644
index 000000000..b66b72814
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/head.js
@@ -0,0 +1,217 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* eslint no-unused-vars: [2, {"vars": "local"}] */
+
+"use strict";
+
+var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+var { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
+var { Assert } = require("resource://testing-common/Assert.jsm");
+var { gDevTools } = require("devtools/client/framework/devtools");
+var { BrowserLoader } = Cu.import("resource://devtools/client/shared/browser-loader.js", {});
+var promise = require("promise");
+var defer = require("devtools/shared/defer");
+var Services = require("Services");
+var { DebuggerServer } = require("devtools/server/main");
+var { DebuggerClient } = require("devtools/shared/client/main");
+var DevToolsUtils = require("devtools/shared/DevToolsUtils");
+var flags = require("devtools/shared/flags");
+var { Task } = require("devtools/shared/task");
+var { TargetFactory } = require("devtools/client/framework/target");
+var { Toolbox } = require("devtools/client/framework/toolbox");
+
+flags.testing = true;
+var { require: browserRequire } = BrowserLoader({
+  baseURI: "resource://devtools/client/shared/",
+  window
+});
+
+let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+let React = browserRequire("devtools/client/shared/vendor/react");
+var TestUtils = React.addons.TestUtils;
+
+var EXAMPLE_URL = "http://example.com/browser/browser/devtools/shared/test/";
+
+function forceRender(comp) {
+  return setState(comp, {})
+    .then(() => setState(comp, {}));
+}
+
+// All tests are asynchronous.
+SimpleTest.waitForExplicitFinish();
+
+function onNextAnimationFrame(fn) {
+  return () =>
+    requestAnimationFrame(() =>
+      requestAnimationFrame(fn));
+}
+
+function setState(component, newState) {
+  return new Promise(resolve => {
+    component.setState(newState, onNextAnimationFrame(resolve));
+  });
+}
+
+function setProps(component, newProps) {
+  return new Promise(resolve => {
+    component.setProps(newProps, onNextAnimationFrame(resolve));
+  });
+}
+
+function dumpn(msg) {
+  dump(`SHARED-COMPONENTS-TEST: ${msg}\n`);
+}
+
+/**
+ * Tree
+ */
+
+var TEST_TREE_INTERFACE = {
+  getParent: x => TEST_TREE.parent[x],
+  getChildren: x => TEST_TREE.children[x],
+  renderItem: (x, depth, focused) => "-".repeat(depth) + x + ":" + focused + "\n",
+  getRoots: () => ["A", "M"],
+  getKey: x => "key-" + x,
+  itemHeight: 1,
+  onExpand: x => TEST_TREE.expanded.add(x),
+  onCollapse: x => TEST_TREE.expanded.delete(x),
+  isExpanded: x => TEST_TREE.expanded.has(x),
+};
+
+function isRenderedTree(actual, expectedDescription, msg) {
+  const expected = expectedDescription.map(x => x + "\n").join("");
+  dumpn(`Expected tree:\n${expected}`);
+  dumpn(`Actual tree:\n${actual}`);
+  is(actual, expected, msg);
+}
+
+// Encoding of the following tree/forest:
+//
+// A
+// |-- B
+// |   |-- E
+// |   |   |-- K
+// |   |   `-- L
+// |   |-- F
+// |   `-- G
+// |-- C
+// |   |-- H
+// |   `-- I
+// `-- D
+//     `-- J
+// M
+// `-- N
+//     `-- O
+var TEST_TREE = {
+  children: {
+    A: ["B", "C", "D"],
+    B: ["E", "F", "G"],
+    C: ["H", "I"],
+    D: ["J"],
+    E: ["K", "L"],
+    F: [],
+    G: [],
+    H: [],
+    I: [],
+    J: [],
+    K: [],
+    L: [],
+    M: ["N"],
+    N: ["O"],
+    O: []
+  },
+  parent: {
+    A: null,
+    B: "A",
+    C: "A",
+    D: "A",
+    E: "B",
+    F: "B",
+    G: "B",
+    H: "C",
+    I: "C",
+    J: "D",
+    K: "E",
+    L: "E",
+    M: null,
+    N: "M",
+    O: "N"
+  },
+  expanded: new Set(),
+};
+
+/**
+ * Frame
+ */
+function checkFrameString({
+  el, file, line, column, source, functionName, shouldLink, tooltip
+}) {
+  let $ = selector => el.querySelector(selector);
+
+  let $func = $(".frame-link-function-display-name");
+  let $source = $(".frame-link-source");
+  let $sourceInner = $(".frame-link-source-inner");
+  let $filename = $(".frame-link-filename");
+  let $line = $(".frame-link-line");
+
+  is($filename.textContent, file, "Correct filename");
+  is(el.getAttribute("data-line"), line ? `${line}` : null, "Expected `data-line` found");
+  is(el.getAttribute("data-column"),
+     column ? `${column}` : null, "Expected `data-column` found");
+  is($sourceInner.getAttribute("title"), tooltip, "Correct tooltip");
+  is($source.tagName, shouldLink ? "A" : "SPAN", "Correct linkable status");
+  if (shouldLink) {
+    is($source.getAttribute("href"), source, "Correct source");
+  }
+
+  if (line != null) {
+    let lineText = `:${line}`;
+    if (column != null) {
+      lineText += `:${column}`;
+    }
+
+    is($line.textContent, lineText, "Correct line number");
+  } else {
+    ok(!$line, "Should not have an element for `line`");
+  }
+
+  if (functionName != null) {
+    is($func.textContent, functionName, "Correct function name");
+  } else {
+    ok(!$func, "Should not have an element for `functionName`");
+  }
+}
+
+function renderComponent(component, props) {
+  const el = React.createElement(component, props, {});
+  // By default, renderIntoDocument() won't work for stateless components, but
+  // it will work if the stateless component is wrapped in a stateful one.
+  // See https://github.com/facebook/react/issues/4839
+  const wrappedEl = React.DOM.span({}, [el]);
+  const renderedComponent = TestUtils.renderIntoDocument(wrappedEl);
+  return ReactDOM.findDOMNode(renderedComponent).children[0];
+}
+
+function shallowRenderComponent(component, props) {
+  const el = React.createElement(component, props);
+  const renderer = TestUtils.createRenderer();
+  renderer.render(el, {});
+  return renderer.getRenderOutput();
+}
+
+/**
+ * Test that a rep renders correctly across different modes.
+ */
+function testRepRenderModes(modeTests, testName, componentUnderTest, gripStub) {
+  modeTests.forEach(({mode, expectedOutput, message}) => {
+    const modeString = typeof mode === "undefined" ? "no mode" : mode;
+    if (!message) {
+      message = `${testName}: ${modeString} renders correctly.`;
+    }
+
+    const rendered = renderComponent(componentUnderTest.rep, { object: gripStub, mode });
+    is(rendered.textContent, expectedOutput, message);
+  });
+}
diff --git a/devtools/client/shared/components/test/mochitest/test_HSplitBox_01.html b/devtools/client/shared/components/test/mochitest/test_HSplitBox_01.html
new file mode 100644
index 000000000..7a7187de6
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_HSplitBox_01.html
@@ -0,0 +1,126 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Basic tests for the HSplitBox component.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript "src="chrome://mochikit/content/tests/SimpleTest/EventUtils.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+  <link rel="stylesheet" href="resource://devtools/client/themes/splitters.css" type="text/css"/>
+  <link rel="stylesheet" href="chrome://devtools/skin/components-h-split-box.css" type="text/css"/>
+  <style>
+    html {
+      --theme-splitter-color: black;
+    }
+  </style>
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+const FUDGE_FACTOR = .1;
+function aboutEq(a, b) {
+  dumpn(`Checking ${a} ~= ${b}`);
+  return Math.abs(a - b) < FUDGE_FACTOR;
+}
+
+window.onload = Task.async(function* () {
+  try {
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+
+    let HSplitBox = React.createFactory(browserRequire("devtools/client/shared/components/h-split-box"));
+    ok(HSplitBox, "Should get HSplitBox");
+
+    const newSizes = [];
+    const box = ReactDOM.render(HSplitBox({
+      start: "hello!",
+      end: "world!",
+      startWidth: .5,
+      onResize(newSize) {
+        newSizes.push(newSize);
+      },
+    }), window.document.body);
+
+    // Test that we properly rendered our two panes.
+
+    let panes = document.querySelectorAll(".h-split-box-pane");
+    is(panes.length, 2, "Should get two panes");
+    is(panes[0].style.flexGrow, "0.5", "Each pane should have .5 width");
+    is(panes[1].style.flexGrow, "0.5", "Each pane should have .5 width");
+    is(panes[0].textContent.trim(), "hello!", "First pane should be hello");
+    is(panes[1].textContent.trim(), "world!", "Second pane should be world");
+
+    // Now change the left width and assert that the changes are reflected.
+
+    yield setProps(box, { startWidth: .25 });
+    panes = document.querySelectorAll(".h-split-box-pane");
+    is(panes.length, 2, "Should still have two panes");
+    is(panes[0].style.flexGrow, "0.25", "First pane's width should be .25");
+    is(panes[1].style.flexGrow, "0.75", "Second pane's width should be .75");
+
+    // Mouse moves without having grabbed the splitter should have no effect.
+
+    let container = document.querySelector(".h-split-box");
+    ok(container, "Should get our container .h-split-box");
+
+    const { left, top, width } = container.getBoundingClientRect();
+    const middle = left + width / 2;
+    const oneQuarter = left + width / 4;
+    const threeQuarters = left + 3 * width / 4;
+
+    synthesizeMouse(container, middle, top, { type: "mousemove" }, window);
+    is(newSizes.length, 0, "Mouse moves without dragging the splitter should have no effect");
+
+    // Send a mouse down on the splitter, and then move the mouse a couple
+    // times. Now we should get resizes.
+
+    const splitter = document.querySelector(".devtools-side-splitter");
+    ok(splitter, "Should get our splitter");
+
+    synthesizeMouseAtCenter(splitter, { button: 0, type: "mousedown" }, window);
+
+    function mouseMove(clientX) {
+      const event = new MouseEvent("mousemove", { clientX });
+      document.defaultView.top.dispatchEvent(event);
+    }
+
+    mouseMove(middle);
+    is(newSizes.length, 1, "Should get 1 resize");
+    ok(aboutEq(newSizes[0], .5), "New size should be ~.5");
+
+    mouseMove(left);
+    is(newSizes.length, 2, "Should get 2 resizes");
+    ok(aboutEq(newSizes[1], 0), "New size should be ~0");
+
+    mouseMove(oneQuarter);
+    is(newSizes.length, 3, "Sould get 3 resizes");
+    ok(aboutEq(newSizes[2], .25), "New size should be ~.25");
+
+    mouseMove(threeQuarters);
+    is(newSizes.length, 4, "Should get 4 resizes");
+    ok(aboutEq(newSizes[3], .75), "New size should be ~.75");
+
+    synthesizeMouseAtCenter(splitter, { button: 0, type: "mouseup" }, window);
+
+    // Now that we have let go of the splitter, mouse moves should not result in resizes.
+
+    synthesizeMouse(container, middle, top, { type: "mousemove" }, window);
+    is(newSizes.length, 4, "Should still have 4 resizes");
+
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_frame_01.html b/devtools/client/shared/components/test/mochitest/test_frame_01.html
new file mode 100644
index 000000000..ed3bc90c2
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_frame_01.html
@@ -0,0 +1,309 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test the formatting of the file name, line and columns are correct in frame components,
+with optional columns, unknown and non-URL sources.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Frame component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let Frame = React.createFactory(browserRequire("devtools/client/shared/components/frame"));
+    ok(Frame, "Should get Frame");
+
+    // Check when there's a column
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 55,
+        column: 10,
+      }
+    }, {
+      file: "mahscripts.js",
+      line: 55,
+      column: 10,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js:55:10",
+    });
+
+    // Check when there's no column
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 55,
+      }
+    }, {
+      file: "mahscripts.js",
+      line: 55,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js:55",
+    });
+
+    // Check when column === 0
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 55,
+        column: 0,
+      }
+    }, {
+      file: "mahscripts.js",
+      line: 55,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js:55",
+    });
+
+    // Check when there's no parseable URL source;
+    // should not link but should render line/columns
+    yield checkFrameComponent({
+      frame: {
+        source: "self-hosted",
+        line: 1,
+      }
+    }, {
+      file: "self-hosted",
+      line: "1",
+      shouldLink: false,
+      tooltip: "self-hosted:1",
+    });
+    yield checkFrameComponent({
+      frame: {
+        source: "self-hosted",
+        line: 1,
+        column: 10,
+      }
+    }, {
+      file: "self-hosted",
+      line: "1",
+      column: "10",
+      shouldLink: false,
+      tooltip: "self-hosted:1:10",
+    });
+
+    // Check when there's no source;
+    // should not link but should render line/columns
+    yield checkFrameComponent({
+      frame: {
+        line: 1,
+      }
+    }, {
+      file: "(unknown)",
+      line: "1",
+      shouldLink: false,
+      tooltip: "(unknown):1",
+    });
+    yield checkFrameComponent({
+      frame: {
+        line: 1,
+        column: 10,
+      }
+    }, {
+      file: "(unknown)",
+      line: "1",
+      column: "10",
+      shouldLink: false,
+      tooltip: "(unknown):1:10",
+    });
+
+    // Check when there's a column, but no line;
+    // no line/column info should render
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        column: 55,
+      }
+    }, {
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check when line is 0; this should be an invalid
+    // line option, so don't render line/column
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+        column: 55,
+      }
+    }, {
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check when source is via Scratchpad; we should render out the
+    // lines and columns as this is linkable.
+    yield checkFrameComponent({
+      frame: {
+        source: "Scratchpad/1",
+        line: 10,
+        column: 50,
+      }
+    }, {
+      file: "Scratchpad/1",
+      line: 10,
+      column: 50,
+      shouldLink: true,
+      tooltip: "View source in Debugger → Scratchpad/1:10:50",
+    });
+
+    // Check that line and column can be strings
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: "10",
+        column: "55",
+      }
+    }, {
+      file: "mahscripts.js",
+      line: 10,
+      column: 55,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js:10:55",
+    });
+
+    // Check that line and column can be strings,
+    // and that the `0` rendering rules apply when they are strings as well
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: "0",
+        column: "55",
+      }
+    }, {
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check that the showFullSourceUrl option works correctly
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+      },
+      showFullSourceUrl: true
+    }, {
+      file: "http://myfile.com/mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check that the showFunctionName option works correctly
+    yield checkFrameComponent({
+      frame: {
+        functionDisplayName: "myfun",
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+      }
+    }, {
+      functionName: null,
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    yield checkFrameComponent({
+      frame: {
+        functionDisplayName: "myfun",
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+      },
+      showFunctionName: true
+    }, {
+      functionName: "myfun",
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check that anonymous function name is not displayed unless explicitly enabled
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+      },
+      showFunctionName: true
+    }, {
+      functionName: null,
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    yield checkFrameComponent({
+      frame: {
+        source: "http://myfile.com/mahscripts.js",
+        line: 0,
+      },
+      showFunctionName: true,
+      showAnonymousFunctionName: true
+    }, {
+      functionName: "<anonymous>",
+      file: "mahscripts.js",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js",
+    });
+
+    // Check if file is rendered with "/" for root documents when showEmptyPathAsHost is false
+    yield checkFrameComponent({
+      frame: {
+        source: "http://www.cnn.com/",
+        line: "1",
+      },
+      showEmptyPathAsHost: false,
+    }, {
+      file: "/",
+      line: "1",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://www.cnn.com/:1",
+    });
+
+    // Check if file is rendered with hostname for root documents when showEmptyPathAsHost is true
+    yield checkFrameComponent({
+      frame: {
+        source: "http://www.cnn.com/",
+        line: "1",
+      },
+      showEmptyPathAsHost: true,
+    }, {
+      file: "www.cnn.com",
+      line: "1",
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://www.cnn.com/:1",
+    });
+
+    function* checkFrameComponent(input, expected) {
+      let props = Object.assign({ onClick: () => {} }, input);
+      let frame = ReactDOM.render(Frame(props), window.document.body);
+      yield forceRender(frame);
+
+      let el = frame.getDOMNode();
+      let { source } = input.frame;
+      checkFrameString(Object.assign({ el, source }, expected));
+    }
+
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_notification_box_01.html b/devtools/client/shared/components/test/mochitest/test_notification_box_01.html
new file mode 100644
index 000000000..947fb9803
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_notification_box_01.html
@@ -0,0 +1,108 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test for Notification Box. The test is checking:
+* Basic rendering
+* Appending a notification
+* Notification priority
+* Closing notification
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Notification Box</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { NotificationBox, PriorityLevels } = browserRequire("devtools/client/shared/components/notification-box");
+
+    const renderedBox = shallowRenderComponent(NotificationBox, {});
+    is(renderedBox.type, "div", "NotificationBox is rendered as <div>");
+
+    // Test rendering
+    let boxElement = React.createElement(NotificationBox);
+    let notificationBox = TestUtils.renderIntoDocument(boxElement);
+    let notificationNode = ReactDOM.findDOMNode(notificationBox);
+
+    is(notificationNode.className, "notificationbox",
+      "NotificationBox has expected classname");
+    is(notificationNode.textContent, "",
+      "Empty NotificationBox has no text content");
+
+    checkNumberOfNotifications(notificationBox, 0);
+
+    // Append a notification
+    notificationBox.appendNotification(
+      "Info message",
+      "id1",
+      null,
+      PriorityLevels.PRIORITY_INFO_HIGH
+    );
+
+    is (notificationNode.textContent, "Info message",
+      "The box must display notification message");
+    checkNumberOfNotifications(notificationBox, 1);
+
+    // Append more important notification
+    notificationBox.appendNotification(
+      "Critical message",
+      "id2",
+      null,
+      PriorityLevels.PRIORITY_CRITICAL_BLOCK
+    );
+
+    checkNumberOfNotifications(notificationBox, 1);
+
+    is (notificationNode.textContent, "Critical message",
+      "The box must display more important notification message");
+
+    // Append less important notification
+    notificationBox.appendNotification(
+      "Warning message",
+      "id3",
+      null,
+      PriorityLevels.PRIORITY_WARNING_HIGH
+    );
+
+    checkNumberOfNotifications(notificationBox, 1);
+
+    is (notificationNode.textContent, "Critical message",
+      "The box must still display the more important notification");
+
+    ok(notificationBox.getCurrentNotification(),
+      "There must be current notification");
+
+    notificationBox.getNotificationWithValue("id1").close();
+    checkNumberOfNotifications(notificationBox, 1);
+
+    notificationBox.getNotificationWithValue("id2").close();
+    checkNumberOfNotifications(notificationBox, 1);
+
+    notificationBox.getNotificationWithValue("id3").close();
+    checkNumberOfNotifications(notificationBox, 0);
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+
+function checkNumberOfNotifications(notificationBox, expected) {
+  is(TestUtils.scryRenderedDOMComponentsWithClass(
+    notificationBox, "notification").length, expected,
+    "The notification box must have expected number of notifications");
+}
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_notification_box_02.html b/devtools/client/shared/components/test/mochitest/test_notification_box_02.html
new file mode 100644
index 000000000..ebeb0400d
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_notification_box_02.html
@@ -0,0 +1,70 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test for Notification Box. The test is checking:
+* Using custom callback in a notification
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Notification Box</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { NotificationBox, PriorityLevels } = browserRequire("devtools/client/shared/components/notification-box");
+
+    // Test rendering
+    let boxElement = React.createElement(NotificationBox);
+    let notificationBox = TestUtils.renderIntoDocument(boxElement);
+    let notificationNode = ReactDOM.findDOMNode(notificationBox);
+
+    let callbackExecuted = false;
+
+    // Append a notification.
+    notificationBox.appendNotification(
+      "Info message",
+      "id1",
+      null,
+      PriorityLevels.PRIORITY_INFO_LOW,
+      undefined,
+      (reason) => {
+        callbackExecuted = true;
+        is(reason, "removed", "The reason must be expected string");
+      }
+    );
+
+    is(TestUtils.scryRenderedDOMComponentsWithClass(
+      notificationBox, "notification").length, 1,
+      "There must be one notification");
+
+    let closeButton = notificationNode.querySelector(
+      ".messageCloseButton");
+
+    // Click the close button to close the notification.
+    TestUtils.Simulate.click(closeButton);
+
+    is(TestUtils.scryRenderedDOMComponentsWithClass(
+      notificationBox, "notification").length, 0,
+      "The notification box must be empty now");
+
+    ok(callbackExecuted, "Event callback must be executed.");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_notification_box_03.html b/devtools/client/shared/components/test/mochitest/test_notification_box_03.html
new file mode 100644
index 000000000..d7fc146fe
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_notification_box_03.html
@@ -0,0 +1,84 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test for Notification Box. The test is checking:
+* Using custom buttons in a notification
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Notification Box</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { NotificationBox, PriorityLevels } = browserRequire("devtools/client/shared/components/notification-box");
+
+    // Test rendering
+    let boxElement = React.createElement(NotificationBox);
+    let notificationBox = TestUtils.renderIntoDocument(boxElement);
+    let notificationNode = ReactDOM.findDOMNode(notificationBox);
+
+    let buttonCallbackExecuted = false;
+    var buttons = [{
+      label: "Button1",
+      callback: () => {
+        buttonCallbackExecuted = true;
+
+        // Do not close the notification
+        return true;
+      },
+    }, {
+      label: "Button2",
+      callback: () => {
+        // Close the notification (return value undefined)
+      },
+    }];
+
+    // Append a notification with buttons.
+    notificationBox.appendNotification(
+      "Info message",
+      "id1",
+      null,
+      PriorityLevels.PRIORITY_INFO_LOW,
+      buttons
+    );
+
+    let buttonNodes = notificationNode.querySelectorAll(
+      ".notification-button");
+
+    is(buttonNodes.length, 2, "There must be two buttons");
+
+    // Click the first button
+    TestUtils.Simulate.click(buttonNodes[0]);
+    ok(buttonCallbackExecuted, "Button callback must be executed.");
+
+    is(TestUtils.scryRenderedDOMComponentsWithClass(
+      notificationBox, "notification").length, 1,
+      "There must be one notification");
+
+    // Click the second button (closing the notification)
+    TestUtils.Simulate.click(buttonNodes[1]);
+
+    is(TestUtils.scryRenderedDOMComponentsWithClass(
+      notificationBox, "notification").length, 0,
+      "The notification box must be empty now");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_array.html b/devtools/client/shared/components/test/mochitest/test_reps_array.html
new file mode 100644
index 000000000..6ad7f2c43
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_array.html
@@ -0,0 +1,259 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test ArrayRep rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - ArrayRep</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+/* import-globals-from head.js */
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { ArrayRep } = browserRequire("devtools/client/shared/components/reps/array");
+
+  let componentUnderTest = ArrayRep;
+  const maxLength = {
+    short: 3,
+    long: 300
+  };
+
+  try {
+    yield testBasic();
+
+    // Test property iterator
+    yield testMaxProps();
+    yield testMoreThanShortMaxProps();
+    yield testMoreThanLongMaxProps();
+    yield testRecursiveArray();
+
+    // Test that properties are rendered as expected by ItemRep
+    yield testNested();
+
+    yield testArray();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testBasic() {
+    // Test that correct rep is chosen
+    const stub = [];
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ArrayRep.rep,
+       `Rep correctly selects ${ArrayRep.rep.displayName}`);
+
+
+    // Test rendering
+    const defaultOutput = `[]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testBasic", componentUnderTest, stub);
+  }
+
+  function testMaxProps() {
+    const stub = [1, "foo", {}];
+    const defaultOutput = `[ 1, "foo", Object ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[3]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMaxProps", componentUnderTest, stub);
+  }
+
+  function testMoreThanShortMaxProps() {
+    const stub = Array(maxLength.short + 1).fill("foo");
+    const defaultShortOutput = `[ ${Array(maxLength.short).fill("\"foo\"").join(", ")}, 1 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[${maxLength.short + 1}]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: `[ ${Array(maxLength.short + 1).fill("\"foo\"").join(", ")} ]`,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMoreThanMaxProps", componentUnderTest, stub);
+  }
+
+  function testMoreThanLongMaxProps() {
+    const stub = Array(maxLength.long + 1).fill("foo");
+    const defaultShortOutput = `[ ${Array(maxLength.short).fill("\"foo\"").join(", ")}, ${maxLength.long + 1 - maxLength.short} more… ]`;
+    const defaultLongOutput = `[ ${Array(maxLength.long).fill("\"foo\"").join(", ")}, 1 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[${maxLength.long + 1}]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultLongOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMoreThanMaxProps", componentUnderTest, stub);
+  }
+
+  function testRecursiveArray() {
+    let stub = [1];
+    stub.push(stub);
+    const defaultOutput = `[ 1, [2] ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[2]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testRecursiveArray", componentUnderTest, stub);
+  }
+
+  function testNested() {
+    let stub = [
+      {
+        p1: "s1",
+        p2: ["a1", "a2", "a3"],
+        p3: "s3",
+        p4: "s4"
+      }
+    ];
+    const defaultOutput = `[ Object ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[1]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testNested", componentUnderTest, stub);
+  }
+
+  function testArray() {
+    let stub = [
+      "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
+      "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"
+    ];
+
+    const defaultOutput = `[ "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",` +
+                          ` "k", "l", "m", "n", "o", "p", "q", "r", "s", "t",` +
+                          ` "u", "v", "w", "x", "y", "z" ]`;
+    const shortOutput = `[ "a", "b", "c", 23 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: shortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[26]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: shortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testNested", componentUnderTest, stub);
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_attribute.html b/devtools/client/shared/components/test/mochitest/test_reps_attribute.html
new file mode 100644
index 000000000..aa8a5dfad
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_attribute.html
@@ -0,0 +1,56 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Attribute rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Attribute</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { Attribute } = browserRequire("devtools/client/shared/components/reps/attribute");
+
+    let gripStub = {
+      "type": "object",
+      "class": "Attr",
+      "actor": "server1.conn19.obj65",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "kind": "DOMNode",
+        "nodeType": 2,
+        "nodeName": "class",
+        "value": "autocomplete-suggestions"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Attribute.rep, `Rep correctly selects ${Attribute.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(Attribute.rep, { object: gripStub });
+    is(renderedComponent.textContent, "class=\"autocomplete-suggestions\"", "Attribute rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_comment-node.html b/devtools/client/shared/components/test/mochitest/test_reps_comment-node.html
new file mode 100644
index 000000000..4e03d8b30
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_comment-node.html
@@ -0,0 +1,80 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test comment-node rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - comment-node</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { CommentNode } = browserRequire("devtools/client/shared/components/reps/comment-node");
+
+    let gripStub = {
+      "type": "object",
+      "actor": "server1.conn1.child1/obj47",
+      "class": "Comment",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "kind": "DOMNode",
+        "nodeType": 8,
+        "nodeName": "#comment",
+        "textContent": "test\nand test\nand test\nand test\nand test\nand test\nand test"
+      }
+    };
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, CommentNode.rep,
+      `Rep correctly selects ${CommentNode.rep.displayName}`);
+
+    // Test rendering.
+    const renderedComponent = renderComponent(CommentNode.rep, { object: gripStub });
+    is(renderedComponent.className, "objectBox theme-comment",
+      "CommentNode rep has expected class names");
+    is(renderedComponent.textContent,
+      `<!-- test\nand test\nand test\nan…d test\nand test\nand test -->`,
+      "CommentNode rep has expected text content");
+
+    // Test tiny rendering.
+    const tinyRenderedComponent = renderComponent(CommentNode.rep, {
+      object: gripStub,
+      mode: "tiny"
+    });
+    is(tinyRenderedComponent.textContent,
+      `<!-- test\\nand test\\na… test\\nand test -->`,
+      "CommentNode rep has expected text content in tiny mode");
+
+    // Test long rendering.
+    const longRenderedComponent = renderComponent(CommentNode.rep, {
+      object: gripStub,
+      mode: "long"
+    });
+    is(longRenderedComponent.textContent, `<!-- ${gripStub.preview.textContent} -->`,
+      "CommentNode rep has expected text content in long mode");
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_date-time.html b/devtools/client/shared/components/test/mochitest/test_reps_date-time.html
new file mode 100644
index 000000000..a82783b6b
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_date-time.html
@@ -0,0 +1,79 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test DateTime rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - DateTime</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { DateTime } = browserRequire("devtools/client/shared/components/reps/date-time");
+
+  try {
+    testValid();
+    testInvalid();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testValid() {
+    let gripStub = {
+      "type": "object",
+      "class": "Date",
+      "actor": "server1.conn0.child1/obj32",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "timestamp": 1459372644859
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, DateTime.rep, `Rep correctly selects ${DateTime.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(DateTime.rep, { object: gripStub });
+    is(renderedComponent.textContent, "2016-03-30T21:17:24.859Z", "DateTime rep has expected text content for valid date");
+  }
+
+  function testInvalid() {
+    let gripStub = {
+      "type": "object",
+      "actor": "server1.conn0.child1/obj32",
+      "class": "Date",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "timestamp": {
+          "type": "NaN"
+        }
+      }
+    };
+
+    // Test rendering
+    const renderedComponent = renderComponent(DateTime.rep, { object: gripStub });
+    is(renderedComponent.textContent, "Invalid Date", "DateTime rep has expected text content for invalid date");
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_document.html b/devtools/client/shared/components/test/mochitest/test_reps_document.html
new file mode 100644
index 000000000..2afabca44
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_document.html
@@ -0,0 +1,56 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Document rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Document</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Document } = browserRequire("devtools/client/shared/components/reps/document");
+
+  try {
+    let gripStub = {
+      "type": "object",
+      "class": "HTMLDocument",
+      "actor": "server1.conn17.obj115",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 1,
+      "preview": {
+        "kind": "DOMNode",
+        "nodeType": 9,
+        "nodeName": "#document",
+        "location": "https://www.mozilla.org/en-US/firefox/new/"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Document.rep, `Rep correctly selects ${Document.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(Document.rep, { object: gripStub });
+    is(renderedComponent.textContent, "https://www.mozilla.org/en-US/firefox/new/", "Document rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_element-node.html b/devtools/client/shared/components/test/mochitest/test_reps_element-node.html
new file mode 100644
index 000000000..d4e22c7ab
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_element-node.html
@@ -0,0 +1,341 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Element node rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Element node</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { ElementNode } = browserRequire("devtools/client/shared/components/reps/element-node");
+
+  try {
+    yield testBodyNode();
+    yield testDocumentElement();
+    yield testNode();
+    yield testNodeWithLeadingAndTrailingSpacesClassName();
+    yield testNodeWithoutAttributes();
+    yield testLotsOfAttributes();
+    yield testSvgNode();
+    yield testSvgNodeInXHTML();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testBodyNode() {
+    const stub = getGripStub("testBodyNode");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for body node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent, `<body id="body-id" class="body-class">`,
+      "Element node rep has expected text content for body node");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `body#body-id.body-class`,
+      "Element node rep has expected text content for body node in tiny mode");
+  }
+
+  function testDocumentElement() {
+    const stub = getGripStub("testDocumentElement");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for document element node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent, `<html dir="ltr" lang="en-US">`,
+      "Element node rep has expected text content for document element node");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `html`,
+      "Element node rep has expected text content for document element in tiny mode");
+  }
+
+  function testNode() {
+    const stub = getGripStub("testNode");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for element node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent,
+      `<input id="newtab-customize-button" class="bar baz" dir="ltr" ` +
+      `title="Customize your New Tab page" value="foo" type="button">`,
+      "Element node rep has expected text content for element node");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent,
+      `input#newtab-customize-button.bar.baz`,
+      "Element node rep has expected text content for element node in tiny mode");
+  }
+
+  function testNodeWithLeadingAndTrailingSpacesClassName() {
+    const stub = getGripStub("testNodeWithLeadingAndTrailingSpacesClassName");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for element node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent,
+      `<body id="nightly-whatsnew" class="  html-ltr    ">`,
+      "Element node rep output element node with the class trailing spaces");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent,
+      `body#nightly-whatsnew.html-ltr`,
+      "Element node rep does not show leading nor trailing spaces " +
+      "on class attribute in tiny mode");
+  }
+
+  function testNodeWithoutAttributes() {
+    const stub = getGripStub("testNodeWithoutAttributes");
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent, "<p>",
+      "Element node rep has expected text content for element node without attributes");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `p`,
+      "Element node rep has expected text content for element node without attributes");
+  }
+
+  function testLotsOfAttributes() {
+    const stub = getGripStub("testLotsOfAttributes");
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent,
+      '<p id="lots-of-attributes" a="" b="" c="" d="" e="" f="" g="" ' +
+      'h="" i="" j="" k="" l="" m="" n="">',
+      "Element node rep has expected text content for node with lots of attributes");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `p#lots-of-attributes`,
+      "Element node rep has expected text content for node in tiny mode");
+  }
+
+  function testSvgNode() {
+    const stub = getGripStub("testSvgNode");
+
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for SVG element node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent,
+      '<clipPath id="clip" class="svg-element">',
+      "Element node rep has expected text content for SVG element node");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `clipPath#clip.svg-element`,
+      "Element node rep has expected text content for SVG element node in tiny mode");
+  }
+
+  function testSvgNodeInXHTML() {
+    const stub = getGripStub("testSvgNodeInXHTML");
+
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, ElementNode.rep,
+      `Rep correctly selects ${ElementNode.rep.displayName} for XHTML SVG element node`);
+
+    const renderedComponent = renderComponent(ElementNode.rep, { object: stub });
+    is(renderedComponent.textContent,
+      '<svg:circle class="svg-element" cx="0" cy="0" r="5">',
+      "Element node rep has expected text content for XHTML SVG element node");
+
+    const tinyRenderedComponent = renderComponent(
+      ElementNode.rep, { object: stub, mode: "tiny" });
+    is(tinyRenderedComponent.textContent, `svg:circle.svg-element`,
+      "Element node rep has expected text content for XHTML SVG element in tiny mode");
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testBodyNode":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj30",
+          "class": "HTMLBodyElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "body",
+            "attributes": {
+              "class": "body-class",
+              "id": "body-id"
+            },
+            "attributesLength": 2
+          }
+        };
+      case "testDocumentElement":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj40",
+          "class": "HTMLHtmlElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "html",
+            "attributes": {
+              "dir": "ltr",
+              "lang": "en-US"
+            },
+            "attributesLength": 2
+          }
+        };
+      case "testNode":
+        return {
+          "type": "object",
+          "actor": "server1.conn2.child1/obj116",
+          "class": "HTMLInputElement",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "input",
+            "attributes": {
+              "id": "newtab-customize-button",
+              "dir": "ltr",
+              "title": "Customize your New Tab page",
+              "class": "bar baz",
+              "value": "foo",
+              "type": "button"
+            },
+            "attributesLength": 6
+          }
+        };
+      case "testNodeWithLeadingAndTrailingSpacesClassName":
+        return {
+          "type": "object",
+          "actor": "server1.conn3.child1/obj59",
+          "class": "HTMLBodyElement",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "body",
+            "attributes": {
+              "id": "nightly-whatsnew",
+              "class": "  html-ltr    "
+            },
+            "attributesLength": 2
+          }
+        };
+      case "testNodeWithoutAttributes":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj32",
+          "class": "HTMLParagraphElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "p",
+            "attributes": {},
+            "attributesLength": 1
+          }
+        };
+      case "testLotsOfAttributes":
+        return {
+          "type": "object",
+          "actor": "server1.conn2.child1/obj30",
+          "class": "HTMLParagraphElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "p",
+            "attributes": {
+              "id": "lots-of-attributes",
+              "a": "",
+              "b": "",
+              "c": "",
+              "d": "",
+              "e": "",
+              "f": "",
+              "g": "",
+              "h": "",
+              "i": "",
+              "j": "",
+              "k": "",
+              "l": "",
+              "m": "",
+              "n": ""
+            },
+            "attributesLength": 15
+          }
+        };
+      case "testSvgNode":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj42",
+          "class": "SVGClipPathElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "clipPath",
+            "attributes": {
+              "id": "clip",
+              "class": "svg-element"
+            },
+            "attributesLength": 0
+          }
+        };
+      case "testSvgNodeInXHTML":
+        return {
+          "type": "object",
+          "actor": "server1.conn3.child1/obj34",
+          "class": "SVGCircleElement",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 1,
+            "nodeName": "svg:circle",
+            "attributes": {
+              "class": "svg-element",
+              "cx": "0",
+              "cy": "0",
+              "r": "5"
+            },
+            "attributesLength": 3
+          }
+        };
+    }
+    return null;
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_event.html b/devtools/client/shared/components/test/mochitest/test_reps_event.html
new file mode 100644
index 000000000..7dfe72d6f
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_event.html
@@ -0,0 +1,300 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Event rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Event</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Event } = browserRequire("devtools/client/shared/components/reps/event");
+
+  try {
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testEvent") });
+    is(renderedRep.type, Event.rep, `Rep correctly selects ${Event.rep.displayName}`);
+
+    yield testEvent();
+    yield testMouseEvent();
+    yield testKeyboardEvent();
+    yield testMessageEvent();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testEvent() {
+    const renderedComponent = renderComponent(Event.rep, { object: getGripStub("testEvent") });
+    is(renderedComponent.textContent,
+       "Event { isTrusted: true, eventPhase: 2, bubbles: false, 7 more… }",
+       "Event rep has expected text content for an event");
+  }
+
+  function testMouseEvent() {
+    const renderedComponent = renderComponent(Event.rep, { object: getGripStub("testMouseEvent") });
+    is(renderedComponent.textContent,
+       "MouseEvent { clientX: 62, clientY: 18, layerX: 0, 2 more… }",
+       "Event rep has expected text content for a mouse event");
+  }
+
+  function testKeyboardEvent() {
+    const renderedComponent = renderComponent(Event.rep, { object: getGripStub("testKeyboardEvent") });
+    is(renderedComponent.textContent,
+       "KeyboardEvent { key: \"Control\", charCode: 0, keyCode: 17 }",
+       "Event rep has expected text content for a keyboard event");
+  }
+
+  function testMessageEvent() {
+    const renderedComponent = renderComponent(Event.rep, { object: getGripStub("testMessageEvent") });
+    is(renderedComponent.textContent,
+       "MessageEvent { isTrusted: false, data: \"test data\", origin: \"null\", 7 more… }",
+       "Event rep has expected text content for a message event");
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testEvent":
+        return {
+          "type": "object",
+          "class": "Event",
+          "actor": "server1.conn23.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "DOMEvent",
+            "type": "beforeprint",
+            "properties": {
+              "isTrusted": true,
+              "currentTarget": {
+                "type": "object",
+                "class": "Window",
+                "actor": "server1.conn23.obj37",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 760,
+                "preview": {
+                  "kind": "ObjectWithURL",
+                  "url": "http://example.com"
+                }
+              },
+              "eventPhase": 2,
+              "bubbles": false,
+              "cancelable": false,
+              "defaultPrevented": false,
+              "timeStamp": 1466780008434005,
+              "originalTarget": {
+                "type": "object",
+                "class": "Window",
+                "actor": "server1.conn23.obj38",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 760,
+                "preview": {
+                  "kind": "ObjectWithURL",
+                  "url": "http://example.com"
+                }
+              },
+              "explicitOriginalTarget": {
+                "type": "object",
+                "class": "Window",
+                "actor": "server1.conn23.obj39",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 760,
+                "preview": {
+                  "kind": "ObjectWithURL",
+                  "url": "http://example.com"
+                }
+              },
+              "NONE": 0
+            },
+            "target": {
+              "type": "object",
+              "class": "Window",
+              "actor": "server1.conn23.obj36",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 760,
+              "preview": {
+                "kind": "ObjectWithURL",
+                "url": "http://example.com"
+              }
+            }
+          }
+        };
+
+      case "testMouseEvent":
+        return {
+          "type": "object",
+          "class": "MouseEvent",
+          "actor": "server1.conn20.obj39",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "DOMEvent",
+            "type": "click",
+            "properties": {
+              "buttons": 0,
+              "clientX": 62,
+              "clientY": 18,
+              "layerX": 0,
+              "layerY": 0
+            },
+            "target": {
+              "type": "object",
+              "class": "HTMLDivElement",
+              "actor": "server1.conn20.obj40",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 0,
+              "preview": {
+                "kind": "DOMNode",
+                "nodeType": 1,
+                "nodeName": "div",
+                "attributes": {
+                  "id": "test"
+                },
+                "attributesLength": 1
+              }
+            }
+          }
+        };
+
+      case "testKeyboardEvent":
+        return {
+          "type": "object",
+          "class": "KeyboardEvent",
+          "actor": "server1.conn21.obj49",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "DOMEvent",
+            "type": "keyup",
+            "properties": {
+              "key": "Control",
+              "charCode": 0,
+              "keyCode": 17
+            },
+            "target": {
+              "type": "object",
+              "class": "HTMLBodyElement",
+              "actor": "server1.conn21.obj50",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 0,
+              "preview": {
+                "kind": "DOMNode",
+                "nodeType": 1,
+                "nodeName": "body",
+                "attributes": {},
+                "attributesLength": 0
+              }
+            },
+            "eventKind": "key",
+            "modifiers": []
+          }
+        };
+
+      case "testMessageEvent":
+        return {
+          "type": "object",
+          "class": "MessageEvent",
+          "actor": "server1.conn3.obj34",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "DOMEvent",
+            "type": "message",
+            "properties": {
+              "isTrusted": false,
+              "data": "test data",
+              "origin": "null",
+              "lastEventId": "",
+              "source": {
+                "type": "object",
+                "class": "Window",
+                "actor": "server1.conn3.obj36",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 760,
+                "preview": {
+                  "kind": "ObjectWithURL",
+                  "url": ""
+                }
+              },
+              "ports": {
+                "type": "object",
+                "class": "Array",
+                "actor": "server1.conn3.obj37",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0
+              },
+              "currentTarget": {
+                "type": "object",
+                "class": "Window",
+                "actor": "server1.conn3.obj38",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 760,
+                "preview": {
+                  "kind": "ObjectWithURL",
+                  "url": ""
+                }
+              },
+              "eventPhase": 2,
+              "bubbles": false,
+              "cancelable": false
+            },
+            "target": {
+              "type": "object",
+              "class": "Window",
+              "actor": "server1.conn3.obj35",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 760,
+              "preview": {
+                "kind": "ObjectWithURL",
+                "url": ""
+              }
+            }
+          }
+        };
+
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_function.html b/devtools/client/shared/components/test/mochitest/test_reps_function.html
new file mode 100644
index 000000000..ede694329
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_function.html
@@ -0,0 +1,206 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Func rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Func</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Func } = browserRequire("devtools/client/shared/components/reps/function");
+
+  const componentUnderTest = Func;
+
+  try {
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testNamed");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Func.rep, `Rep correctly selects ${Func.rep.displayName}`);
+
+    yield testNamed();
+    yield testVarNamed();
+    yield testAnon();
+    yield testLongName();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testNamed() {
+    // Test declaration: `function testName{ let innerVar = "foo" }`
+    const testName = "testNamed";
+
+    const defaultOutput = `testName()`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testUserNamed() {
+    // Test declaration: `function testName{ let innerVar = "foo" }`
+    const testName = "testUserNamed";
+
+    const defaultOutput = `testUserName()`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testVarNamed() {
+    // Test declaration: `let testVarName = function() { }`
+    const testName = "testVarNamed";
+
+    const defaultOutput = `testVarName()`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testAnon() {
+    // Test declaration: `() => {}`
+    const testName = "testAnon";
+
+    const defaultOutput = `function()`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testLongName() {
+    // Test declaration: `let f = function loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong() { }`
+    const testName = "testLongName";
+
+    const defaultOutput = `looooooooooooooooooooooooooooooooooooooooooooooooo\u2026ooooooooooooooooooooooooooooooooooooooooooooong()`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function getGripStub(functionName) {
+    switch (functionName) {
+      case "testNamed":
+        return {
+          "type": "object",
+          "class": "Function",
+          "actor": "server1.conn6.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "name": "testName",
+          "displayName": "testName",
+          "location": {
+            "url": "debugger eval code",
+            "line": 1
+          }
+        };
+
+      case "testUserNamed":
+        return {
+          "type": "object",
+          "class": "Function",
+          "actor": "server1.conn6.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "name": "testName",
+          "userDisplayName": "testUserName",
+          "displayName": "testName",
+          "location": {
+            "url": "debugger eval code",
+            "line": 1
+          }
+        };
+
+      case "testVarNamed":
+        return {
+          "type": "object",
+          "class": "Function",
+          "actor": "server1.conn7.obj41",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "displayName": "testVarName",
+          "location": {
+            "url": "debugger eval code",
+            "line": 1
+          }
+        };
+
+      case "testAnon":
+        return {
+          "type": "object",
+          "class": "Function",
+          "actor": "server1.conn7.obj45",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "location": {
+            "url": "debugger eval code",
+            "line": 1
+          }
+        };
+
+      case "testLongName":
+        return {
+          "type": "object",
+          "class": "Function",
+          "actor": "server1.conn7.obj67",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "name": "loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong",
+          "displayName": "loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong",
+          "location": {
+            "url": "debugger eval code",
+            "line": 1
+          }
+        };
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_grip-array.html b/devtools/client/shared/components/test/mochitest/test_reps_grip-array.html
new file mode 100644
index 000000000..db4f0296e
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_grip-array.html
@@ -0,0 +1,707 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test GripArray rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - GripArray</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { GripArray } = browserRequire("devtools/client/shared/components/reps/grip-array");
+
+  let componentUnderTest = GripArray;
+  const maxLength = {
+    short: 3,
+    long: 300
+  };
+
+  try {
+    yield testBasic();
+
+    // Test property iterator
+    yield testMaxProps();
+    yield testMoreThanShortMaxProps();
+    yield testMoreThanLongMaxProps();
+    yield testRecursiveArray();
+    yield testPreviewLimit();
+    yield testNamedNodeMap();
+    yield testNodeList();
+    yield testDocumentFragment();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testBasic() {
+    // Test array: `[]`
+    const testName = "testBasic";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testBasic");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, GripArray.rep, `Rep correctly selects ${GripArray.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Array []`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMaxProps() {
+    // Test array: `[1, "foo", {}]`;
+    const testName = "testMaxProps";
+
+    const defaultOutput = `Array [ 1, "foo", Object ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[3]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMoreThanShortMaxProps() {
+    // Test array = `["test string"…] //4 items`
+    const testName = "testMoreThanShortMaxProps";
+
+    const defaultOutput = `Array [ ${Array(maxLength.short).fill("\"test string\"").join(", ")}, 1 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[${maxLength.short + 1}]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: `Array [ ${Array(maxLength.short + 1).fill("\"test string\"").join(", ")} ]`,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMoreThanLongMaxProps() {
+    // Test array = `["test string"…] //301 items`
+    const testName = "testMoreThanLongMaxProps";
+
+    const defaultShortOutput = `Array [ ${Array(maxLength.short).fill("\"test string\"").join(", ")}, ${maxLength.long + 1 - maxLength.short} more… ]`;
+    const defaultLongOutput = `Array [ ${Array(maxLength.long).fill("\"test string\"").join(", ")}, 1 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[${maxLength.long + 1}]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultLongOutput
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testRecursiveArray() {
+    // Test array = `let a = []; a = [a]`
+    const testName = "testRecursiveArray";
+
+    const defaultOutput = `Array [ [1] ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[1]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testPreviewLimit() {
+    const testName = "testPreviewLimit";
+
+    const shortOutput = `Array [ 0, 1, 2, 8 more… ]`;
+    const defaultOutput = `Array [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1 more… ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: shortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[11]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: shortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testNamedNodeMap() {
+    const testName = "testNamedNodeMap";
+
+    const defaultOutput = `NamedNodeMap [ class="myclass", cellpadding="7", border="3" ]`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[3]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testNodeList() {
+    const testName = "testNodeList";
+    const defaultOutput = "NodeList [ button#btn-1.btn.btn-log, " +
+      "button#btn-2.btn.btn-err, button#btn-3.btn.btn-count ]";
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[3]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testDocumentFragment() {
+    const testName = "testDocumentFragment";
+
+    const defaultOutput = "DocumentFragment [ li#li-0.list-element, " +
+      "li#li-1.list-element, li#li-2.list-element, 2 more… ]";
+
+    const longOutput = "DocumentFragment [ " +
+      "li#li-0.list-element, li#li-1.list-element, li#li-2.list-element, " +
+      "li#li-3.list-element, li#li-4.list-element ]";
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `[5]`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: longOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function getGripStub(functionName) {
+    switch (functionName) {
+      case "testBasic":
+        return {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn0.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 0,
+            "items": []
+          }
+        };
+
+      case "testMaxProps":
+        return {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn1.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 3,
+            "items": [
+              1,
+              "foo",
+              {
+                "type": "object",
+                "class": "Object",
+                "actor": "server1.conn1.obj36",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0
+              }
+            ]
+          }
+        };
+
+      case "testMoreThanShortMaxProps":
+        let shortArrayGrip = {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn1.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": maxLength.short + 1,
+            "items": []
+          }
+        };
+
+        // Generate array grip with length 4, which is more that the maximum
+        // limit in case of the 'short' mode.
+        for (let i = 0; i < maxLength.short + 1; i++) {
+          shortArrayGrip.preview.items.push("test string");
+        }
+
+        return shortArrayGrip;
+
+      case "testMoreThanLongMaxProps":
+        let longArrayGrip = {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn1.obj35",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": maxLength.long + 1,
+            "items": []
+          }
+        };
+
+        // Generate array grip with length 301, which is more that the maximum
+        // limit in case of the 'long' mode.
+        for (let i = 0; i < maxLength.long + 1; i++) {
+          longArrayGrip.preview.items.push("test string");
+        }
+
+        return longArrayGrip;
+
+      case "testPreviewLimit":
+        return {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn1.obj31",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 12,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 11,
+            "items": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+          }
+        };
+
+      case "testRecursiveArray":
+        return {
+          "type": "object",
+          "class": "Array",
+          "actor": "server1.conn3.obj42",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 2,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 1,
+            "items": [
+              {
+                "type": "object",
+                "class": "Array",
+                "actor": "server1.conn3.obj43",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 2,
+                "preview": {
+                  "kind": "ArrayLike",
+                  "length": 1
+                }
+              }
+            ]
+          }
+        };
+
+      case "testNamedNodeMap":
+        return {
+          "type": "object",
+          "class": "NamedNodeMap",
+          "actor": "server1.conn3.obj42",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 6,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 3,
+            "items": [
+              {
+                "type": "object",
+                "class": "Attr",
+                "actor": "server1.conn3.obj43",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 2,
+                  "nodeName": "class",
+                  "value": "myclass"
+                }
+              },
+              {
+                "type": "object",
+                "class": "Attr",
+                "actor": "server1.conn3.obj44",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 2,
+                  "nodeName": "cellpadding",
+                  "value": "7"
+                }
+              },
+              {
+                "type": "object",
+                "class": "Attr",
+                "actor": "server1.conn3.obj44",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 2,
+                  "nodeName": "border",
+                  "value": "3"
+                }
+              }
+            ]
+          }
+        };
+
+      case "testNodeList":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj51",
+          "class": "NodeList",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 3,
+          "preview": {
+            "kind": "ArrayLike",
+            "length": 3,
+            "items": [
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj52",
+                "class": "HTMLButtonElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "button",
+                  "attributes": {
+                    "id": "btn-1",
+                    "class": "btn btn-log",
+                    "type": "button"
+                  },
+                  "attributesLength": 3
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj53",
+                "class": "HTMLButtonElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "button",
+                  "attributes": {
+                    "id": "btn-2",
+                    "class": "btn btn-err",
+                    "type": "button"
+                  },
+                  "attributesLength": 3
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj54",
+                "class": "HTMLButtonElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "button",
+                  "attributes": {
+                    "id": "btn-3",
+                    "class": "btn btn-count",
+                    "type": "button"
+                  },
+                  "attributesLength": 3
+                }
+              }
+            ]
+          }
+        };
+
+      case "testDocumentFragment":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj45",
+          "class": "DocumentFragment",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "DOMNode",
+            "nodeType": 11,
+            "nodeName": "#document-fragment",
+            "childNodesLength": 5,
+            "childNodes": [
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj46",
+                "class": "HTMLLIElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "li",
+                  "attributes": {
+                    "id": "li-0",
+                    "class": "list-element"
+                  },
+                  "attributesLength": 2
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj47",
+                "class": "HTMLLIElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "li",
+                  "attributes": {
+                    "id": "li-1",
+                    "class": "list-element"
+                  },
+                  "attributesLength": 2
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj48",
+                "class": "HTMLLIElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "li",
+                  "attributes": {
+                    "id": "li-2",
+                    "class": "list-element"
+                  },
+                  "attributesLength": 2
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj49",
+                "class": "HTMLLIElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "li",
+                  "attributes": {
+                    "id": "li-3",
+                    "class": "list-element"
+                  },
+                  "attributesLength": 2
+                }
+              },
+              {
+                "type": "object",
+                "actor": "server1.conn1.child1/obj50",
+                "class": "HTMLLIElement",
+                "extensible": true,
+                "frozen": false,
+                "sealed": false,
+                "ownPropertyLength": 0,
+                "preview": {
+                  "kind": "DOMNode",
+                  "nodeType": 1,
+                  "nodeName": "li",
+                  "attributes": {
+                    "id": "li-4",
+                    "class": "list-element"
+                  },
+                  "attributesLength": 2
+                }
+              }
+            ]
+          }
+        };
+    }
+    return null;
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_grip-map.html b/devtools/client/shared/components/test/mochitest/test_reps_grip-map.html
new file mode 100644
index 000000000..18470367c
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_grip-map.html
@@ -0,0 +1,405 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test GripMap rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - GripMap</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { GripMap } = browserRequire("devtools/client/shared/components/reps/grip-map");
+
+  const componentUnderTest = GripMap;
+
+  try {
+    yield testEmptyMap();
+    yield testSymbolKeyedMap();
+    yield testWeakMap();
+
+    // // Test entries iterator
+    yield testMaxEntries();
+    yield testMoreThanMaxEntries();
+    yield testUninterestingEntries();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testEmptyMap() {
+    // Test object: `new Map()`
+    const testName = "testEmptyMap";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testEmptyMap");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, GripMap.rep, `Rep correctly selects ${GripMap.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Map {  }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: "Map",
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testSymbolKeyedMap() {
+    // Test object:
+    // `new Map([[Symbol("a"), "value-a"], [Symbol("b"), "value-b"]])`
+    const testName = "testSymbolKeyedMap";
+
+    const defaultOutput = `Map { Symbol(a): "value-a", Symbol(b): "value-b" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: "Map",
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testWeakMap() {
+    // Test object: `new WeakMap([[{a: "key-a"}, "value-a"]])`
+    const testName = "testWeakMap";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testWeakMap");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, GripMap.rep, `Rep correctly selects ${GripMap.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `WeakMap { Object: "value-a" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: "WeakMap",
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMaxEntries() {
+    // Test object:
+    // `new Map([["key-a","value-a"], ["key-b","value-b"], ["key-c","value-c"]])`
+    const testName = "testMaxEntries";
+
+    const defaultOutput = `Map { key-a: "value-a", key-b: "value-b", key-c: "value-c" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: "Map",
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMoreThanMaxEntries() {
+    // Test object = `new Map(
+    //   [["key-0", "value-0"], ["key-1", "value-1"]], …, ["key-100", "value-100"]]}`
+    const testName = "testMoreThanMaxEntries";
+
+    const defaultOutput =
+      `Map { key-0: "value-0", key-1: "value-1", key-2: "value-2", 98 more… }`;
+
+    // Generate string with 101 entries, which is the max limit for 'long' mode.
+    let longString = Array.from({length: 100}).map((_, i) => `key-${i}: "value-${i}"`);
+    const longOutput = `Map { ${longString.join(", ")}, 1 more… }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Map`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: longOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testUninterestingEntries() {
+    // Test object:
+    // `new Map([["key-a",null], ["key-b",undefined], ["key-c","value-c"], ["key-d",4]])`
+    const testName = "testUninterestingEntries";
+
+    const defaultOutput =
+      `Map { key-a: null, key-c: "value-c", key-d: 4, 1 more… }`;
+    const longOutput =
+      `Map { key-a: null, key-b: undefined, key-c: "value-c", key-d: 4 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Map`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: longOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function getGripStub(functionName) {
+    switch (functionName) {
+      case "testEmptyMap":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj97",
+          "class": "Map",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": 0,
+            "entries": []
+          }
+        };
+
+      case "testSymbolKeyedMap":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj118",
+          "class": "Map",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": 2,
+            "entries": [
+              [
+                {
+                  "type": "symbol",
+                  "name": "a"
+                },
+                "value-a"
+              ],
+              [
+                {
+                  "type": "symbol",
+                  "name": "b"
+                },
+                "value-b"
+              ]
+            ]
+          }
+        };
+
+      case "testWeakMap":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj115",
+          "class": "WeakMap",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": 1,
+            "entries": [
+              [
+                {
+                  "type": "object",
+                  "actor": "server1.conn1.child1/obj116",
+                  "class": "Object",
+                  "extensible": true,
+                  "frozen": false,
+                  "sealed": false,
+                  "ownPropertyLength": 1
+                },
+                "value-a"
+              ]
+            ]
+          }
+        };
+
+      case "testMaxEntries":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj109",
+          "class": "Map",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": 3,
+            "entries": [
+              [
+                "key-a",
+                "value-a"
+              ],
+              [
+                "key-b",
+                "value-b"
+              ],
+              [
+                "key-c",
+                "value-c"
+              ]
+            ]
+          }
+        };
+
+      case "testMoreThanMaxEntries": {
+        let entryNb = 101;
+        return {
+          "type": "object",
+          "class": "Map",
+          "actor": "server1.conn0.obj332",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": entryNb,
+            // Generate 101 entries, which is more that the maximum
+            // limit in case of the 'long' mode.
+            "entries": Array.from({length: entryNb}).map((_, i) => {
+              return [`key-${i}`, `value-${i}`];
+            })
+          }
+        };
+      }
+
+      case "testUninterestingEntries":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj111",
+          "class": "Map",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "MapLike",
+            "size": 4,
+            "entries": [
+              [
+                "key-a",
+                {
+                  "type": "null"
+                }
+              ],
+              [
+                "key-b",
+                {
+                  "type": "undefined"
+                }
+              ],
+              [
+                "key-c",
+                "value-c"
+              ],
+              [
+                "key-d",
+                4
+              ]
+            ]
+          }
+        };
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_grip.html b/devtools/client/shared/components/test/mochitest/test_reps_grip.html
new file mode 100644
index 000000000..15d4e1d25
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_grip.html
@@ -0,0 +1,887 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test grip rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - grip</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Grip } = browserRequire("devtools/client/shared/components/reps/grip");
+
+  const componentUnderTest = Grip;
+
+  try {
+    yield testBasic();
+    yield testBooleanObject();
+    yield testNumberObject();
+    yield testStringObject();
+    yield testProxy();
+    yield testArrayBuffer();
+    yield testSharedArrayBuffer();
+
+    // Test property iterator
+    yield testMaxProps();
+    yield testMoreThanMaxProps();
+    yield testUninterestingProps();
+    yield testNonEnumerableProps();
+
+    // Test that properties are rendered as expected by PropRep
+    yield testNestedObject();
+    yield testNestedArray();
+
+    // Test that 'more' property doesn't clobber the caption.
+    yield testMoreProp();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testBasic() {
+    // Test object: `{}`
+    const testName = "testBasic";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testBasic");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Object {  }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testBooleanObject() {
+    // Test object: `new Boolean(true)`
+    const testName = "testBooleanObject";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Boolean { true }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Boolean`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testNumberObject() {
+    // Test object: `new Number(42)`
+    const testName = "testNumberObject";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Number { 42 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Number`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testStringObject() {
+    // Test object: `new String("foo")`
+    const testName = "testStringObject";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `String { "foo" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `String`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testProxy() {
+    // Test object: `new Proxy({a:1},[1,2,3])`
+    const testName = "testProxy";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Proxy { <target>: Object, <handler>: [3] }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Proxy`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testArrayBuffer() {
+    // Test object: `new ArrayBuffer(10)`
+    const testName = "testArrayBuffer";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `ArrayBuffer { byteLength: 10 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `ArrayBuffer`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testSharedArrayBuffer() {
+    // Test object: `new SharedArrayBuffer(5)`
+    const testName = "testSharedArrayBuffer";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `SharedArrayBuffer { byteLength: 5 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `SharedArrayBuffer`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMaxProps() {
+    // Test object: `{a: "a", b: "b", c: "c"}`;
+    const testName = "testMaxProps";
+
+    const defaultOutput = `Object { a: "a", b: "b", c: "c" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMoreThanMaxProps() {
+    // Test object = `{p0: "0", p1: "1", p2: "2", …, p100: "100"}`
+    const testName = "testMoreThanMaxProps";
+
+    const defaultOutput = `Object { p0: "0", p1: "1", p2: "2", 98 more… }`;
+
+    // Generate string with 100 properties, which is the max limit
+    // for 'long' mode.
+    let props = "";
+    for (let i = 0; i < 100; i++) {
+      props += "p" + i + ": \"" + i + "\", ";
+    }
+
+    const longOutput = `Object { ${props}1 more… }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: longOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testUninterestingProps() {
+    // Test object: `{a: undefined, b: undefined, c: "c", d: 1}`
+    // @TODO This is not how we actually want the preview to be output.
+    // See https://bugzilla.mozilla.org/show_bug.cgi?id=1276376
+    const expectedOutput = `Object { a: undefined, b: undefined, c: "c", 1 more… }`;
+  }
+
+  function testNonEnumerableProps() {
+    // Test object: `Object.defineProperty({}, "foo", {enumerable : false});`
+    const testName = "testNonEnumerableProps";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub("testNonEnumerableProps");
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Object {  }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testNestedObject() {
+    // Test object: `{objProp: {id: 1}, strProp: "test string"}`
+    const testName = "testNestedObject";
+
+    const defaultOutput = `Object { objProp: Object, strProp: "test string" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testNestedArray() {
+    // Test object: `{arrProp: ["foo", "bar", "baz"]}`
+    const testName = "testNestedArray";
+
+    const defaultOutput = `Object { arrProp: [3] }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function testMoreProp() {
+    // Test object: `{a: undefined, b: 1, more: 2, d: 3}`;
+    const testName = "testMoreProp";
+
+    const defaultOutput = `Object { b: 1, more: 2, d: 3, 1 more… }`;
+    const longOutput = `Object { a: undefined, b: 1, more: 2, d: 3 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: longOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
+  function getGripStub(functionName) {
+    switch (functionName) {
+      case "testBasic":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj304",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+
+      case "testMaxProps":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj337",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 3,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "a": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": "a"
+              },
+              "b": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": "b"
+              },
+              "c": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": "c"
+              }
+            },
+            "ownPropertiesLength": 3,
+            "safeGetterValues": {}
+          }
+        };
+
+      case "testMoreThanMaxProps": {
+        let grip = {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj332",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 101,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 101,
+            "safeGetterValues": {}
+          }
+        };
+
+        // Generate 101 properties, which is more that the maximum
+        // limit in case of the 'long' mode.
+        for (let i = 0; i < 101; i++) {
+          grip.preview.ownProperties["p" + i] = {
+            "configurable": true,
+            "enumerable": true,
+            "writable": true,
+            "value": i + ""
+          };
+        }
+
+        return grip;
+      }
+
+      case "testUninterestingProps":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj342",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "a": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": {
+                  "type": "undefined"
+                }
+              },
+              "b": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": {
+                  "type": "undefined"
+                }
+              },
+              "c": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": "c"
+              },
+              "d": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": 1
+              }
+            },
+            "ownPropertiesLength": 4,
+            "safeGetterValues": {}
+          }
+        };
+      case "testNonEnumerableProps":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj30",
+          "class": "Object",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 1,
+            "safeGetterValues": {}
+          }
+        };
+      case "testNestedObject":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj145",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 2,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "objProp": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": {
+                  "type": "object",
+                  "class": "Object",
+                  "actor": "server1.conn0.obj146",
+                  "extensible": true,
+                  "frozen": false,
+                  "sealed": false,
+                  "ownPropertyLength": 1
+                }
+              },
+              "strProp": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": "test string"
+              }
+            },
+            "ownPropertiesLength": 2,
+            "safeGetterValues": {}
+          }
+        };
+
+      case "testNestedArray":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj326",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 1,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "arrProp": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": {
+                  "type": "object",
+                  "class": "Array",
+                  "actor": "server1.conn0.obj327",
+                  "extensible": true,
+                  "frozen": false,
+                  "sealed": false,
+                  "ownPropertyLength": 4,
+                  "preview": {
+                    "kind": "ArrayLike",
+                    "length": 3
+                  }
+                }
+              }
+            },
+            "ownPropertiesLength": 1,
+            "safeGetterValues": {}
+          },
+        };
+
+      case "testMoreProp":
+        return {
+          "type": "object",
+          "class": "Object",
+          "actor": "server1.conn0.obj342",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "a": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": {
+                  "type": "undefined"
+                }
+              },
+              "b": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": 1
+              },
+              "more": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": 2
+              },
+              "d": {
+                "configurable": true,
+                "enumerable": true,
+                "writable": true,
+                "value": 3
+              }
+            },
+            "ownPropertiesLength": 4,
+            "safeGetterValues": {}
+          }
+        };
+      case "testBooleanObject":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj57",
+          "class": "Boolean",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {},
+            "wrappedValue": true
+          }
+        };
+      case "testNumberObject":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj59",
+          "class": "Number",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {},
+            "wrappedValue": 42
+          }
+        };
+      case "testStringObject":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj61",
+          "class": "String",
+          "ownPropertyLength": 4,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 4,
+            "safeGetterValues": {},
+            "wrappedValue": "foo"
+          }
+        };
+      case "testProxy":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj47",
+          "class": "Proxy",
+          "proxyTarget": {
+            "type": "object",
+            "actor": "server1.conn1.child1/obj48",
+            "class": "Object",
+            "ownPropertyLength": 1
+          },
+          "proxyHandler": {
+            "type": "object",
+            "actor": "server1.conn1.child1/obj49",
+            "class": "Array",
+            "ownPropertyLength": 4,
+            "preview": {
+              "kind": "ArrayLike",
+              "length": 3
+            }
+          },
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {
+              "<target>": {
+                "value": {
+                  "type": "object",
+                  "actor": "server1.conn1.child1/obj48",
+                  "class": "Object",
+                  "ownPropertyLength": 1
+                }
+              },
+              "<handler>": {
+                "value": {
+                  "type": "object",
+                  "actor": "server1.conn1.child1/obj49",
+                  "class": "Array",
+                  "ownPropertyLength": 4,
+                  "preview": {
+                    "kind": "ArrayLike",
+                    "length": 3
+                  }
+                }
+              }
+            },
+            "ownPropertiesLength": 2
+          }
+        };
+      case "testArrayBuffer":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj170",
+          "class": "ArrayBuffer",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {
+              "byteLength": {
+                "getterValue": 10,
+                "getterPrototypeLevel": 1,
+                "enumerable": false,
+                "writable": true
+              }
+            }
+          }
+        };
+      case "testSharedArrayBuffer":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj171",
+          "class": "SharedArrayBuffer",
+          "extensible": true,
+          "frozen": false,
+          "sealed": false,
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {
+              "byteLength": {
+                "getterValue": 5,
+                "getterPrototypeLevel": 1,
+                "enumerable": false,
+                "writable": true
+              }
+            }
+          }
+        };
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_infinity.html b/devtools/client/shared/components/test/mochitest/test_reps_infinity.html
new file mode 100644
index 000000000..e3a7e871f
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_infinity.html
@@ -0,0 +1,73 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Infinity rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Infinity</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { InfinityRep } = browserRequire("devtools/client/shared/components/reps/infinity");
+
+  try {
+    yield testInfinity();
+    yield testNegativeInfinity();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testInfinity() {
+    const stub = getGripStub("testInfinity");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, InfinityRep.rep,
+      `Rep correctly selects ${InfinityRep.rep.displayName} for Infinity value`);
+
+    const renderedComponent = renderComponent(InfinityRep.rep, { object: stub });
+    is(renderedComponent.textContent, "Infinity",
+      "Infinity rep has expected text content for Infinity");
+  }
+
+  function testNegativeInfinity() {
+    const stub = getGripStub("testNegativeInfinity");
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, InfinityRep.rep,
+      `Rep correctly selects ${InfinityRep.rep.displayName} for negative Infinity value`);
+
+    const renderedComponent = renderComponent(InfinityRep.rep, { object: stub });
+    is(renderedComponent.textContent, "-Infinity",
+      "Infinity rep has expected text content for negative Infinity");
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testInfinity":
+        return {
+          type: "Infinity"
+        };
+      case "testNegativeInfinity":
+        return {
+          type: "-Infinity"
+        };
+    }
+    return null;
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_long-string.html b/devtools/client/shared/components/test/mochitest/test_reps_long-string.html
new file mode 100644
index 000000000..3caaac913
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_long-string.html
@@ -0,0 +1,125 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test LongString rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - LongString</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { LongStringRep } = browserRequire("devtools/client/shared/components/reps/long-string");
+
+  try {
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testMultiline") });
+    is(renderedRep.type, LongStringRep.rep,
+      `Rep correctly selects ${LongStringRep.rep.displayName}`);
+
+    // Test rendering
+    yield testMultiline();
+    yield testMultilineOpen();
+    yield testFullText();
+    yield testMultilineLimit();
+    yield testUseQuotes();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testMultiline() {
+    const stub = getGripStub("testMultiline");
+    const renderedComponent = renderComponent(
+      LongStringRep.rep, { object: stub });
+
+    is(renderedComponent.textContent, `"${stub.initial}…"`,
+      "LongString rep has expected text content for multiline string");
+  }
+
+  function testMultilineLimit() {
+    const renderedComponent = renderComponent(
+      LongStringRep.rep, { object: getGripStub("testMultiline"), cropLimit: 20 });
+
+    is(
+      renderedComponent.textContent,
+      `"a\naaaaaaaaaaaaaaaaaa…"`,
+      "LongString rep has expected text content for multiline string " +
+      "with specified number of characters");
+  }
+
+  function testMultilineOpen() {
+    const stub = getGripStub("testMultiline");
+    const renderedComponent = renderComponent(
+      LongStringRep.rep, { object: stub, member: {open: true}, cropLimit: 20 });
+
+    is(renderedComponent.textContent, `"${stub.initial}…"`,
+      "LongString rep has expected text content for multiline string when open");
+  }
+
+  function testFullText() {
+    const stub = getGripStub("testFullText");
+    const renderedComponentOpen = renderComponent(
+      LongStringRep.rep, { object: stub, member: {open: true}, cropLimit: 20 });
+
+    is(renderedComponentOpen.textContent, `"${stub.fullText}"`,
+      "LongString rep has expected text content when grip has a fullText " +
+      "property and is open");
+
+    const renderedComponentNotOpen = renderComponent(
+      LongStringRep.rep, { object: stub, cropLimit: 20 });
+
+    is(renderedComponentNotOpen.textContent,
+      `"a\naaaaaaaaaaaaaaaaaa…"`,
+      "LongString rep has expected text content when grip has a fullText " +
+      "property and is not open");
+  }
+
+  function testUseQuotes() {
+    const renderedComponent = renderComponent(LongStringRep.rep,
+      { object: getGripStub("testMultiline"), cropLimit: 20, useQuotes: false });
+
+    is(renderedComponent.textContent,
+      "a\naaaaaaaaaaaaaaaaaa…",
+      "LongString rep was expected to omit quotes");
+  }
+
+  function getGripStub(name) {
+    const multilineFullText = "a\n" + Array(20000).fill("a").join("");
+    const fullTextLength = multilineFullText.length;
+    const initialText = multilineFullText.substring(0, 10000);
+
+    switch (name) {
+      case "testMultiline":
+        return {
+          "type": "longString",
+          "initial": initialText,
+          "length": fullTextLength,
+          "actor": "server1.conn1.child1/longString58"
+        };
+      case "testFullText":
+        return {
+          "type": "longString",
+          "fullText": multilineFullText,
+          "initial": initialText,
+          "length": fullTextLength,
+          "actor": "server1.conn1.child1/longString58"
+        };
+    }
+    return null;
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_nan.html b/devtools/client/shared/components/test/mochitest/test_reps_nan.html
new file mode 100644
index 000000000..35dc5a08f
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_nan.html
@@ -0,0 +1,48 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test NaN rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - NaN</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { NaNRep } = browserRequire("devtools/client/shared/components/reps/nan");
+
+  try {
+    yield testNaN();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testNaN() {
+    const stub = {
+      type: "NaN"
+    };
+    const renderedRep = shallowRenderComponent(Rep, {object: stub});
+    is(renderedRep.type, NaNRep.rep,
+      `Rep correctly selects ${NaNRep.rep.displayName} for NaN value`);
+
+    const renderedComponent = renderComponent(NaNRep.rep, {object: stub});
+    is(renderedComponent.textContent, "NaN", "NaN rep has expected text content");
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_null.html b/devtools/client/shared/components/test/mochitest/test_reps_null.html
new file mode 100644
index 000000000..99a06fed1
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_null.html
@@ -0,0 +1,44 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Null rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Null</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { Null } = browserRequire("devtools/client/shared/components/reps/null");
+
+    let gripStub = {
+      "type": "null"
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Null.rep, `Rep correctly selects ${Null.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(Null.rep, { object: gripStub });
+    is(renderedComponent.textContent, "null", "Null rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_number.html b/devtools/client/shared/components/test/mochitest/test_reps_number.html
new file mode 100644
index 000000000..50f91d8b0
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_number.html
@@ -0,0 +1,97 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Number rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Number</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Number } = browserRequire("devtools/client/shared/components/reps/number");
+
+  try {
+    yield testInt();
+    yield testBoolean();
+    yield testNegativeZero();
+    yield testUnsafeInt();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+
+  function testInt() {
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testInt") });
+    is(renderedRep.type, Number.rep, `Rep correctly selects ${Number.rep.displayName} for integer value`);
+
+    const renderedComponent = renderComponent(Number.rep, { object: getGripStub("testInt") });
+    is(renderedComponent.textContent, "5", "Number rep has expected text content for integer");
+  }
+
+  function testBoolean() {
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testTrue") });
+    is(renderedRep.type, Number.rep, `Rep correctly selects ${Number.rep.displayName} for boolean value`);
+
+    let renderedComponent = renderComponent(Number.rep, { object: getGripStub("testTrue") });
+    is(renderedComponent.textContent, "true", "Number rep has expected text content for boolean true");
+
+    renderedComponent = renderComponent(Number.rep, { object: getGripStub("testFalse") });
+    is(renderedComponent.textContent, "false", "Number rep has expected text content for boolean false");
+  }
+
+  function testNegativeZero() {
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testNegZeroGrip") });
+    is(renderedRep.type, Number.rep, `Rep correctly selects ${Number.rep.displayName} for negative zero value`);
+
+    let renderedComponent = renderComponent(Number.rep, { object: getGripStub("testNegZeroGrip") });
+    is(renderedComponent.textContent, "-0", "Number rep has expected text content for negative zero grip");
+
+    renderedComponent = renderComponent(Number.rep, { object: getGripStub("testNegZeroValue") });
+    is(renderedComponent.textContent, "-0", "Number rep has expected text content for negative zero value");
+  }
+
+  function testUnsafeInt() {
+    const renderedComponent = renderComponent(Number.rep, { object: getGripStub("testUnsafeInt") });
+    is(renderedComponent.textContent, "900719925474099100", "Number rep has expected text content for a long number");
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testInt":
+        return 5;
+
+      case "testTrue":
+        return true;
+
+      case "testFalse":
+        return false;
+
+      case "testNegZeroValue":
+        return -0;
+
+      case "testNegZeroGrip":
+        return {
+          "type": "-0"
+        };
+
+      case "testUnsafeInt":
+        return 900719925474099122;
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_object-with-text.html b/devtools/client/shared/components/test/mochitest/test_reps_object-with-text.html
new file mode 100644
index 000000000..eeb4aa325
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_object-with-text.html
@@ -0,0 +1,54 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test ObjectWithText rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - ObjectWithText</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { ObjectWithText } = browserRequire("devtools/client/shared/components/reps/object-with-text");
+
+    let gripStub = {
+      "type": "object",
+      "class": "CSSStyleRule",
+      "actor": "server1.conn3.obj273",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "kind": "ObjectWithText",
+        "text": ".Shadow"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, ObjectWithText.rep, `Rep correctly selects ${ObjectWithText.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(ObjectWithText.rep, { object: gripStub });
+    is(renderedComponent.textContent, "\".Shadow\"", "ObjectWithText rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_object-with-url.html b/devtools/client/shared/components/test/mochitest/test_reps_object-with-url.html
new file mode 100644
index 000000000..488c28dc2
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_object-with-url.html
@@ -0,0 +1,60 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test ObjectWithURL rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - ObjectWithURL</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { ObjectWithURL } = browserRequire("devtools/client/shared/components/reps/object-with-url");
+
+    let gripStub = {
+      "type": "object",
+      "class": "Location",
+      "actor": "server1.conn2.obj272",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 15,
+      "preview": {
+        "kind": "ObjectWithURL",
+        "url": "https://www.mozilla.org/en-US/"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, ObjectWithURL.rep, `Rep correctly selects ${ObjectWithURL.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(ObjectWithURL.rep, { object: gripStub });
+    ok(renderedComponent.className.includes("objectBox-Location"), "ObjectWithURL rep has expected class name");
+    const innerNode = renderedComponent.querySelector(".objectPropValue");
+    is(innerNode.textContent, "https://www.mozilla.org/en-US/", "ObjectWithURL rep has expected inner HTML structure and text content");
+
+    // @TODO test link once Bug 1245303 has been implemented.
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_object.html b/devtools/client/shared/components/test/mochitest/test_reps_object.html
new file mode 100644
index 000000000..c3332361d
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_object.html
@@ -0,0 +1,225 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Obj rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Obj</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { Obj } = browserRequire("devtools/client/shared/components/reps/object");
+
+  const componentUnderTest = Obj;
+
+  try {
+    yield testBasic();
+
+    // Test property iterator
+    yield testMaxProps();
+    yield testMoreThanMaxProps();
+    yield testUninterestingProps();
+
+    // Test that properties are rendered as expected by PropRep
+    yield testNested();
+
+    // Test that 'more' property doesn't clobber the caption.
+    yield testMoreProp();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testBasic() {
+    const stub = {};
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, Obj.rep, `Rep correctly selects ${Obj.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput = `Object`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testBasic", componentUnderTest, stub);
+  }
+
+  function testMaxProps() {
+    const testName = "testMaxProps";
+
+    const stub = {a: "a", b: "b", c: "c"};
+    const defaultOutput = `Object { a: "a", b: "b", c: "c" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMaxProps", componentUnderTest, stub);
+  }
+
+  function testMoreThanMaxProps() {
+    let stub = {};
+    for (let i = 0; i<100; i++) {
+      stub[`p${i}`] = i
+    }
+    const defaultOutput = `Object { p0: 0, p1: 1, p2: 2, 97 more… }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMoreThanMaxProps", componentUnderTest, stub);
+  }
+
+  function testUninterestingProps() {
+    const stub = {a:undefined, b:undefined, c:"c", d:0};
+    const defaultOutput = `Object { c: "c", d: 0, a: undefined, 1 more… }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testUninterestingProps", componentUnderTest, stub);
+  }
+
+  function testNested() {
+    const stub = {
+      objProp: {
+        id: 1,
+        arr: [2]
+      },
+      strProp: "test string",
+      arrProp: [1]
+    };
+    const defaultOutput = `Object { strProp: "test string", objProp: Object, arrProp: [1] }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testNestedObject", componentUnderTest, stub);
+  }
+
+  function testMoreProp() {
+    const stub = {
+      a: undefined,
+      b: 1,
+      'more': 2,
+      d: 3
+    };
+    const defaultOutput = `Object { b: 1, more: 2, d: 3, 1 more… }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Object`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testMoreProp", componentUnderTest, stub);
+  }});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_promise.html b/devtools/client/shared/components/test/mochitest/test_reps_promise.html
new file mode 100644
index 000000000..31de7136d
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_promise.html
@@ -0,0 +1,333 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Promise rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Promise</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { PromiseRep } = browserRequire("devtools/client/shared/components/reps/promise");
+
+  const componentUnderTest = PromiseRep;
+
+  try {
+    yield testPending();
+    yield testFulfilledWithNumber();
+    yield testFulfilledWithString();
+    yield testFulfilledWithObject();
+    yield testFulfilledWithArray();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testPending() {
+    // Test object = `new Promise((resolve, reject) => true)`
+    const stub = getGripStub("testPending");
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    is(renderedRep.type, PromiseRep.rep,
+      `Rep correctly selects ${PromiseRep.rep.displayName} for pending Promise`);
+
+    // Test rendering
+    const defaultOutput = `Promise { <state>: "pending" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Promise { "pending" }`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testPending", componentUnderTest, stub);
+  }
+  function testFulfilledWithNumber() {
+    // Test object = `Promise.resolve(42)`
+    const stub = getGripStub("testFulfilledWithNumber");
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    const {displayName} = PromiseRep.rep;
+    is(renderedRep.type, PromiseRep.rep,
+      `Rep correctly selects ${displayName} for Promise fulfilled with a number`);
+
+    // Test rendering
+    const defaultOutput = `Promise { <state>: "fulfilled", <value>: 42 }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Promise { "fulfilled" }`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testFulfilledWithNumber", componentUnderTest, stub);
+  }
+  function testFulfilledWithString() {
+    // Test object = `Promise.resolve("foo")`
+    const stub = getGripStub("testFulfilledWithString");
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    const {displayName} = PromiseRep.rep;
+    is(renderedRep.type, PromiseRep.rep,
+      `Rep correctly selects ${displayName} for Promise fulfilled with a string`);
+
+    // Test rendering
+    const defaultOutput = `Promise { <state>: "fulfilled", <value>: "foo" }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Promise { "fulfilled" }`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testFulfilledWithString", componentUnderTest, stub);
+  }
+
+  function testFulfilledWithObject() {
+    // Test object = `Promise.resolve({foo: "bar", baz: "boo"})`
+    const stub = getGripStub("testFulfilledWithObject");
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    const {displayName} = PromiseRep.rep;
+    is(renderedRep.type, PromiseRep.rep,
+      `Rep correctly selects ${displayName} for Promise fulfilled with an object`);
+
+    // Test rendering
+    const defaultOutput = `Promise { <state>: "fulfilled", <value>: Object }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Promise { "fulfilled" }`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testFulfilledWithObject", componentUnderTest, stub);
+  }
+
+  function testFulfilledWithArray() {
+    // Test object = `Promise.resolve([1,2,3])`
+    const stub = getGripStub("testFulfilledWithArray");
+
+    // Test that correct rep is chosen.
+    const renderedRep = shallowRenderComponent(Rep, { object: stub });
+    const {displayName} = PromiseRep.rep;
+    is(renderedRep.type, PromiseRep.rep,
+      `Rep correctly selects ${displayName} for Promise fulfilled with an array`);
+
+    // Test rendering
+    const defaultOutput = `Promise { <state>: "fulfilled", <value>: [3] }`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: `Promise { "fulfilled" }`,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testFulfilledWithArray", componentUnderTest, stub);
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testPending":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj54",
+          "class": "Promise",
+          "promiseState": {
+            "state": "pending",
+            "creationTimestamp": 1477327760242.5752
+          },
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+      case "testFulfilledWithNumber":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj55",
+          "class": "Promise",
+          "promiseState": {
+            "state": "fulfilled",
+            "value": 42,
+            "creationTimestamp": 1477327760242.721,
+            "timeToSettle": 0.018497000000479602
+          },
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+      case "testFulfilledWithString":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj56",
+          "class": "Promise",
+          "promiseState": {
+            "state": "fulfilled",
+            "value": "foo",
+            "creationTimestamp": 1477327760243.2483,
+            "timeToSettle": 0.0019969999998465937
+          },
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+      case "testFulfilledWithObject":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj59",
+          "class": "Promise",
+          "promiseState": {
+            "state": "fulfilled",
+            "value": {
+              "type": "object",
+              "actor": "server1.conn1.child1/obj60",
+              "class": "Object",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 2
+            },
+            "creationTimestamp": 1477327760243.2214,
+            "timeToSettle": 0.002035999999861815
+          },
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+      case "testFulfilledWithArray":
+        return {
+          "type": "object",
+          "actor": "server1.conn1.child1/obj57",
+          "class": "Promise",
+          "promiseState": {
+            "state": "fulfilled",
+            "value": {
+              "type": "object",
+              "actor": "server1.conn1.child1/obj58",
+              "class": "Array",
+              "extensible": true,
+              "frozen": false,
+              "sealed": false,
+              "ownPropertyLength": 4,
+              "preview": {
+                "kind": "ArrayLike",
+                "length": 3
+              }
+            },
+            "creationTimestamp": 1477327760242.9597,
+            "timeToSettle": 0.006158000000141328
+          },
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {}
+          }
+        };
+    }
+    return null;
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_regexp.html b/devtools/client/shared/components/test/mochitest/test_reps_regexp.html
new file mode 100644
index 000000000..074948494
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_regexp.html
@@ -0,0 +1,51 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test RegExp rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - RegExp</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { RegExp } = browserRequire("devtools/client/shared/components/reps/regexp");
+
+    let gripStub = {
+      "type": "object",
+      "class": "RegExp",
+      "actor": "server1.conn22.obj39",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 1,
+      "displayString": "/ab+c/i"
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, RegExp.rep, `Rep correctly selects ${RegExp.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(RegExp.rep, { object: gripStub });
+    is(renderedComponent.textContent, "/ab+c/i", "RegExp rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_string.html b/devtools/client/shared/components/test/mochitest/test_reps_string.html
new file mode 100644
index 000000000..f9fc9e5b0
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_string.html
@@ -0,0 +1,79 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test String rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - String</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { StringRep } = browserRequire("devtools/client/shared/components/reps/string");
+
+  try {
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: getGripStub("testMultiline") });
+    is(renderedRep.type, StringRep.rep, `Rep correctly selects ${StringRep.rep.displayName}`);
+
+    // Test rendering
+    yield testMultiline();
+    yield testMultilineOpen();
+    yield testMultilineLimit();
+    yield testUseQuotes();
+    yield testNonPritableCharacters();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testMultiline() {
+    const renderedComponent = renderComponent(StringRep.rep, { object: getGripStub("testMultiline") });
+    is(renderedComponent.textContent, "\"aaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbb\ncccccccccccccccc\n\"", "String rep has expected text content for multiline string");
+  }
+
+  function testMultilineLimit() {
+    const renderedComponent = renderComponent(StringRep.rep, { object: getGripStub("testMultiline"), cropLimit: 20 });
+    is(renderedComponent.textContent, "\"aaaaaaaaaa…cccccccc\n\"", "String rep has expected text content for multiline string with specified number of characters");
+  }
+
+  function testMultilineOpen() {
+    const renderedComponent = renderComponent(StringRep.rep, { object: getGripStub("testMultiline"), member: {open: true} });
+    is(renderedComponent.textContent, "\"aaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbb\ncccccccccccccccc\n\"", "String rep has expected text content for multiline string when open");
+  }
+
+  function testUseQuotes(){
+     const renderedComponent = renderComponent(StringRep.rep, { object: getGripStub("testUseQuotes"), useQuotes: false });
+     is(renderedComponent.textContent, "abc", "String rep was expected to omit quotes");
+  }
+
+  function testNonPritableCharacters(){
+     const renderedComponent = renderComponent(StringRep.rep, { object: getGripStub("testNonPritableCharacters"), useQuotes: false });
+     is(renderedComponent.textContent, "a\ufffdb", "String rep was expected to omit non printable characters");
+  }
+
+  function getGripStub(name) {
+    switch (name) {
+      case "testMultiline":
+        return "aaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbb\ncccccccccccccccc\n";
+      case "testUseQuotes":
+        return "abc";
+      case "testNonPritableCharacters":
+        return "a\x01b";
+    }
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_stylesheet.html b/devtools/client/shared/components/test/mochitest/test_reps_stylesheet.html
new file mode 100644
index 000000000..6f54dee48
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_stylesheet.html
@@ -0,0 +1,54 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Stylesheet rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - Stylesheet</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { StyleSheet } = browserRequire("devtools/client/shared/components/reps/stylesheet");
+
+    let gripStub = {
+      "type": "object",
+      "class": "CSSStyleSheet",
+      "actor": "server1.conn2.obj1067",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "kind": "ObjectWithURL",
+        "url": "https://example.com/styles.css"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, StyleSheet.rep, `Rep correctly selects ${StyleSheet.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(StyleSheet.rep, { object: gripStub });
+    is(renderedComponent.textContent, "StyleSheet https://example.com/styles.css", "StyleSheet rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_symbol.html b/devtools/client/shared/components/test/mochitest/test_reps_symbol.html
new file mode 100644
index 000000000..0112eac0f
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_symbol.html
@@ -0,0 +1,77 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Symbol rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - String</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+/* import-globals-from head.js */
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { SymbolRep } = browserRequire("devtools/client/shared/components/reps/symbol");
+
+  let gripStubs = new Map();
+  gripStubs.set("testSymbolFoo", {
+    type: "symbol",
+    name: "foo"
+  });
+  gripStubs.set("testSymbolWithoutIdentifier", {
+    type: "symbol"
+  });
+
+  try {
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(
+      Rep,
+      { object: gripStubs.get("testSymbolFoo")}
+    );
+
+    is(renderedRep.type, SymbolRep.rep,
+      `Rep correctly selects ${SymbolRep.rep.displayName}`);
+
+    // Test rendering
+    yield testSymbol();
+    yield testSymbolWithoutIdentifier();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testSymbol() {
+    const renderedComponent = renderComponent(
+      SymbolRep.rep,
+      { object: gripStubs.get("testSymbolFoo") }
+    );
+
+    is(renderedComponent.textContent, "Symbol(foo)",
+      "Symbol rep has expected text content");
+  }
+
+  function testSymbolWithoutIdentifier() {
+    const renderedComponent = renderComponent(
+      SymbolRep.rep,
+      { object: gripStubs.get("testSymbolWithoutIdentifier") }
+    );
+
+    is(renderedComponent.textContent, "Symbol()",
+      "Symbol rep without identifier has expected text content");
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_text-node.html b/devtools/client/shared/components/test/mochitest/test_reps_text-node.html
new file mode 100644
index 000000000..f64902a63
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_text-node.html
@@ -0,0 +1,115 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test text-node rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - text-node</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+"use strict";
+
+window.onload = Task.async(function* () {
+  let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+  let { TextNode } = browserRequire("devtools/client/shared/components/reps/text-node");
+
+  let gripStubs = new Map();
+  gripStubs.set("testRendering", {
+    "class": "Text",
+    "actor": "server1.conn1.child1/obj50",
+    "preview": {
+      "textContent": "hello world"
+    }
+  });
+  gripStubs.set("testRenderingWithEOL", {
+    "class": "Text",
+    "actor": "server1.conn1.child1/obj50",
+    "preview": {
+      "textContent": "hello\nworld"
+    }
+  });
+
+  try {
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, {
+      object: gripStubs.get("testRendering")
+    });
+
+    is(renderedRep.type, TextNode.rep,
+      `Rep correctly selects ${TextNode.rep.displayName}`);
+
+    yield testRendering();
+    yield testRenderingWithEOL();
+  } catch (e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function testRendering() {
+    const stub = gripStubs.get("testRendering");
+    const defaultShortOutput = `"hello world"`;
+    const defaultLongOutput = `<TextNode textContent="hello world">;`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultLongOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testRendering", TextNode, stub);
+  }
+
+  function testRenderingWithEOL() {
+    const stub = gripStubs.get("testRenderingWithEOL");
+    const defaultShortOutput = `"hello\nworld"`;
+    const defaultLongOutput = `<TextNode textContent="hello\nworld">;`;
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "tiny",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "short",
+        expectedOutput: defaultShortOutput,
+      },
+      {
+        mode: "long",
+        expectedOutput: defaultLongOutput,
+      }
+    ];
+
+    testRepRenderModes(modeTests, "testRenderingWithEOL", TextNode, stub);
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_undefined.html b/devtools/client/shared/components/test/mochitest/test_reps_undefined.html
new file mode 100644
index 000000000..26b3345ac
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_undefined.html
@@ -0,0 +1,47 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test undefined rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep test - undefined</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { Undefined } = browserRequire("devtools/client/shared/components/reps/undefined");
+
+    let gripStub = {
+      "type": "undefined"
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Undefined.rep, `Rep correctly selects ${Undefined.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(Undefined.rep, {});
+    is(renderedComponent.className, "objectBox objectBox-undefined", "Undefined rep has expected class names");
+    is(renderedComponent.textContent, "undefined", "Undefined rep has expected text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_reps_window.html b/devtools/client/shared/components/test/mochitest/test_reps_window.html
new file mode 100644
index 000000000..55d60e9f5
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_reps_window.html
@@ -0,0 +1,58 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test window rep
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Rep tests - window</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let { Rep } = browserRequire("devtools/client/shared/components/reps/rep");
+    let { Window } = browserRequire("devtools/client/shared/components/reps/window");
+
+    let gripStub = {
+      "type": "object",
+      "class": "Window",
+      "actor": "server1.conn3.obj198",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 887,
+      "preview": {
+        "kind": "ObjectWithURL",
+        "url": "about:newtab"
+      }
+    };
+
+    // Test that correct rep is chosen
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Window.rep, `Rep correctly selects ${Window.rep.displayName}`);
+
+    // Test rendering
+    const renderedComponent = renderComponent(Window.rep, { object: gripStub });
+    ok(renderedComponent.className.includes("objectBox-Window"), "Window rep has expected class name");
+    const innerNode = renderedComponent.querySelector(".objectPropValue");
+    is(innerNode.textContent, "about:newtab", "Window rep has expected inner HTML structure and text content");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_sidebar_toggle.html b/devtools/client/shared/components/test/mochitest/test_sidebar_toggle.html
new file mode 100644
index 000000000..252f2fbb1
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_sidebar_toggle.html
@@ -0,0 +1,56 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test sidebar toggle button
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Sidebar toggle button test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  let SidebarToggle = browserRequire("devtools/client/shared/components/sidebar-toggle.js");
+
+  try {
+    yield test();
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+
+  function test() {
+    const output1 = shallowRenderComponent(SidebarToggle, {
+      collapsed: false,
+      collapsePaneTitle: "Expand",
+      expandPaneTitle: "Collapse"
+    });
+
+    is(output1.type, "button", "Output is a button element");
+    is(output1.props.title, "Expand", "Proper title is set");
+    is(output1.props.className.indexOf("pane-collapsed"), -1,
+      "Proper class name is set");
+
+    const output2 = shallowRenderComponent(SidebarToggle, {
+      collapsed: true,
+      collapsePaneTitle: "Expand",
+      expandPaneTitle: "Collapse"
+    });
+
+    is(output2.props.title, "Collapse", "Proper title is set");
+    ok(output2.props.className.indexOf("pane-collapsed") >= 0,
+      "Proper class name is set");
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_stack-trace.html b/devtools/client/shared/components/test/mochitest/test_stack-trace.html
new file mode 100644
index 000000000..121316cb4
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_stack-trace.html
@@ -0,0 +1,102 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test the rendering of a stack trace
+-->
+<head>
+  <meta charset="utf-8">
+  <title>StackTrace component test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<script src="head.js"></script>
+<script>
+/* import-globals-from head.js */
+"use strict";
+
+window.onload = function () {
+  let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+  let React = browserRequire("devtools/client/shared/vendor/react");
+  let StackTrace = React.createFactory(
+    browserRequire("devtools/client/shared/components/stack-trace")
+  );
+  ok(StackTrace, "Got the StackTrace factory");
+
+  add_task(function* () {
+    let stacktrace = [
+      {
+        filename: "http://myfile.com/mahscripts.js",
+        lineNumber: 55,
+        columnNumber: 10
+      },
+      {
+        asyncCause: "because",
+        functionName: "loadFunc",
+        filename: "http://myfile.com/loader.js -> http://myfile.com/loadee.js",
+        lineNumber: 10
+      }
+    ];
+
+    let props = {
+      stacktrace,
+      onViewSourceInDebugger: () => {}
+    };
+
+    let trace = ReactDOM.render(StackTrace(props), window.document.body);
+    yield forceRender(trace);
+
+    let traceEl = trace.getDOMNode();
+    ok(traceEl, "Rendered StackTrace has an element");
+
+    // Get the child nodes and filter out the text-only whitespace ones
+    let frameEls = Array.from(traceEl.childNodes)
+      .filter(n => n.className.includes("frame"));
+    ok(frameEls, "Rendered StackTrace has frames");
+    is(frameEls.length, 3, "StackTrace has 3 frames");
+
+    // Check the top frame, function name should be anonymous
+    checkFrameString({
+      el: frameEls[0],
+      functionName: "<anonymous>",
+      source: "http://myfile.com/mahscripts.js",
+      file: "http://myfile.com/mahscripts.js",
+      line: 55,
+      column: 10,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/mahscripts.js:55:10",
+    });
+
+    // Check the async cause node
+    is(frameEls[1].className, "frame-link-async-cause",
+       "Async cause has the right class");
+    is(frameEls[1].textContent, "(Async: because)", "Async cause has the right label");
+
+    // Check the third frame, the source should be parsed into a valid source URL
+    checkFrameString({
+      el: frameEls[2],
+      functionName: "loadFunc",
+      source: "http://myfile.com/loadee.js",
+      file: "http://myfile.com/loadee.js",
+      line: 10,
+      column: null,
+      shouldLink: true,
+      tooltip: "View source in Debugger → http://myfile.com/loadee.js:10",
+    });
+
+    // Check the tabs and newlines in the stack trace textContent
+    let traceText = traceEl.textContent;
+    let traceLines = traceText.split("\n");
+    ok(traceLines.length > 0, "There are newlines in the stack trace text");
+    is(traceLines.pop(), "", "There is a newline at the end of the stack trace text");
+    is(traceLines.length, 3, "The stack trace text has 3 lines");
+    ok(traceLines.every(l => l[0] == "\t"), "Every stack trace line starts with tab");
+  });
+};
+</script>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tabs_accessibility.html b/devtools/client/shared/components/test/mochitest/test_tabs_accessibility.html
new file mode 100644
index 000000000..a86082187
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tabs_accessibility.html
@@ -0,0 +1,79 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test tabs accessibility.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tabs component accessibility test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const InspectorTabPanel = React.createFactory(browserRequire("devtools/client/inspector/components/inspector-tab-panel"));
+    const Tabbar = React.createFactory(browserRequire("devtools/client/shared/components/tabs/tabbar"));
+    const tabbar = Tabbar();
+    const tabbarReact = ReactDOM.render(tabbar, window.document.body);
+    const tabbarEl = ReactDOM.findDOMNode(tabbarReact);
+
+    // Setup for InspectorTabPanel
+    const tabpanels = document.createElement("div");
+    tabpanels.id = "tabpanels";
+    document.body.appendChild(tabpanels);
+
+    yield addTabWithPanel(0);
+    yield addTabWithPanel(1);
+
+    const tabAnchors = tabbarEl.querySelectorAll("li.tabs-menu-item a");
+
+    is(tabAnchors[0].parentElement.getAttribute("role"), "presentation", "li role is set correctly");
+    is(tabAnchors[0].getAttribute("role"), "tab", "Anchor role is set correctly");
+    is(tabAnchors[0].getAttribute("aria-selected"), "true", "Anchor aria-selected is set correctly by default");
+    is(tabAnchors[0].getAttribute("aria-controls"), "panel-0", "Anchor aria-controls is set correctly");
+    is(tabAnchors[1].parentElement.getAttribute("role"), "presentation", "li role is set correctly");
+    is(tabAnchors[1].getAttribute("role"), "tab", "Anchor role is set correctly");
+    is(tabAnchors[1].getAttribute("aria-selected"), "false", "Anchor aria-selected is set correctly by default");
+    is(tabAnchors[1].getAttribute("aria-controls"), "panel-1", "Anchor aria-controls is set correctly");
+
+    yield setState(tabbarReact, Object.assign({}, tabbarReact.state, {
+      activeTab: 1
+    }));
+
+    is(tabAnchors[0].getAttribute("aria-selected"), "false", "Anchor aria-selected is reset correctly");
+    is(tabAnchors[1].getAttribute("aria-selected"), "true", "Anchor aria-selected is reset correctly");
+
+    function addTabWithPanel(tabId) {
+      // Setup for InspectorTabPanel
+      let panel = document.createElement("div");
+      panel.id = `sidebar-panel-${tabId}`;
+      document.body.appendChild(panel);
+
+      return setState(tabbarReact, Object.assign({}, tabbarReact.state, {
+        tabs: tabbarReact.state.tabs.concat({
+          id: `sidebar-panel-${tabId}`,
+          title: `tab-${tabId}`,
+          panel: InspectorTabPanel
+        }),
+      }));
+    }
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tabs_menu.html b/devtools/client/shared/components/test/mochitest/test_tabs_menu.html
new file mode 100644
index 000000000..ac8e99289
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tabs_menu.html
@@ -0,0 +1,81 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html class="theme-light">
+<!--
+Test all-tabs menu.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tabs component All-tabs menu test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/themes/variables.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/themes/common.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/themes/light-theme.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/shared/components/tabs/tabs.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/shared/components/tabs/tabbar.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/inspector/components/side-panel.css">
+  <link rel="stylesheet" type="text/css" href="resource://devtools/client/inspector/components/inspector-tab-panel.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const Tabbar = React.createFactory(browserRequire("devtools/client/shared/components/tabs/tabbar"));
+
+    // Create container for the TabBar. Set smaller width
+    // to ensure that tabs won't fit and the all-tabs menu
+    // needs to appear.
+    const tabBarBox = document.createElement("div");
+    tabBarBox.style.width = "200px";
+    tabBarBox.style.height = "200px";
+    tabBarBox.style.border = "1px solid lightgray";
+    document.body.appendChild(tabBarBox);
+
+    // Render the tab-bar.
+    const tabbar = Tabbar({
+      showAllTabsMenu: true,
+    });
+
+    const tabbarReact = ReactDOM.render(tabbar, tabBarBox);
+
+    // Test panel.
+    let TabPanel = React.createFactory(React.createClass({
+      render: function () {
+        return React.DOM.div({}, "content");
+      }
+    }));
+
+    // Create a few panels.
+    yield addTabWithPanel(1);
+    yield addTabWithPanel(2);
+    yield addTabWithPanel(3);
+    yield addTabWithPanel(4);
+    yield addTabWithPanel(5);
+
+    // Make sure the all-tabs menu is there.
+    const allTabsMenu = tabBarBox.querySelector(".all-tabs-menu");
+    ok(allTabsMenu, "All-tabs menu must be rendered");
+
+    function addTabWithPanel(tabId) {
+      return setState(tabbarReact, Object.assign({}, tabbarReact.state, {
+        tabs: tabbarReact.state.tabs.concat({id: `${tabId}`,
+          title: `tab-${tabId}`, panel: TabPanel}),
+      }));
+    }
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_01.html b/devtools/client/shared/components/test/mochitest/test_tree_01.html
new file mode 100644
index 000000000..dfd666348
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_01.html
@@ -0,0 +1,64 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test trees get displayed with the items in correct order and at the correct
+depth.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    ok(React, "Should get React");
+    ok(Tree, "Should get Tree");
+
+    const t = Tree(TEST_TREE_INTERFACE);
+    ok(t, "Should be able to create Tree instances");
+
+    const tree = ReactDOM.render(t, window.document.body);
+    ok(tree, "Should be able to mount Tree instances");
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "Should get the items rendered and indented as expected");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_02.html b/devtools/client/shared/components/test/mochitest/test_tree_02.html
new file mode 100644
index 000000000..a1fc33a38
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_02.html
@@ -0,0 +1,45 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that collapsed subtrees aren't rendered.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    const tree = ReactDOM.render(Tree(TEST_TREE_INTERFACE), window.document.body);
+
+    TEST_TREE.expanded = new Set("MNO".split(""));
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "Collapsed subtrees shouldn't be rendered");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_03.html b/devtools/client/shared/components/test/mochitest/test_tree_03.html
new file mode 100644
index 000000000..feabc7e0a
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_03.html
@@ -0,0 +1,46 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test Tree's autoExpandDepth.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    let ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    let React = browserRequire("devtools/client/shared/vendor/react");
+    let Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    const tree = ReactDOM.render(Tree(Object.assign({}, TEST_TREE_INTERFACE, {
+      autoExpandDepth: 1
+    })), window.document.body);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "-C:false",
+      "-D:false",
+      "M:false",
+      "-N:false",
+    ], "Tree should be auto expanded one level");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_04.html b/devtools/client/shared/components/test/mochitest/test_tree_04.html
new file mode 100644
index 000000000..24948c003
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_04.html
@@ -0,0 +1,128 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we only render visible tree items.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    function getSpacerHeights() {
+      return {
+        top: document.querySelector(".tree > div:first-of-type").clientHeight,
+        bottom: document.querySelector(".tree > div:last-of-type").clientHeight,
+      };
+    }
+
+    const ITEM_HEIGHT = 3;
+
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    const tree = ReactDOM.render(
+      Tree(Object.assign({}, TEST_TREE_INTERFACE, { itemHeight: ITEM_HEIGHT })),
+      window.document.body);
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+
+    yield setState(tree, {
+      height: 3 * ITEM_HEIGHT,
+      scroll: 1 * ITEM_HEIGHT
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+    ], "Tree should show the 2nd, 3rd, and 4th items + buffer of 1 item at each end");
+
+    let spacers = getSpacerHeights();
+    is(spacers.top, 0, "Top spacer has the correct height");
+    is(spacers.bottom, 10 * ITEM_HEIGHT, "Bottom spacer has the correct height");
+
+    yield setState(tree, {
+      height: 2 * ITEM_HEIGHT,
+      scroll: 3 * ITEM_HEIGHT
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+    ], "Tree should show the 4th and 5th item + buffer of 1 item at each end");
+
+    spacers = getSpacerHeights();
+    is(spacers.top, 2 * ITEM_HEIGHT, "Top spacer has the correct height");
+    is(spacers.bottom, 9 * ITEM_HEIGHT, "Bottom spacer has the correct height");
+
+    // Set height to 2 items + 1 pixel at each end, scroll so that 4 items are visible
+    // (2 fully, 2 partially with 1 visible pixel)
+    yield setState(tree, {
+      height: 2 * ITEM_HEIGHT + 2,
+      scroll: 3 * ITEM_HEIGHT - 1
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+    ], "Tree should show the 4 visible items + buffer of 1 item at each end");
+
+    spacers = getSpacerHeights();
+    is(spacers.top, 1 * ITEM_HEIGHT, "Top spacer has the correct height");
+    is(spacers.bottom, 8 * ITEM_HEIGHT, "Bottom spacer has the correct height");
+
+    yield setState(tree, {
+      height: 20 * ITEM_HEIGHT,
+      scroll: 0
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "Tree should show all rows");
+
+    spacers = getSpacerHeights();
+    is(spacers.top, 0, "Top spacer has zero height");
+    is(spacers.bottom, 0, "Bottom spacer has zero height");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_05.html b/devtools/client/shared/components/test/mochitest/test_tree_05.html
new file mode 100644
index 000000000..76116ab51
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_05.html
@@ -0,0 +1,83 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test focusing with the Tree component.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+    const tree = ReactDOM.render(Tree(Object.assign({}, TEST_TREE_INTERFACE, {
+      onFocus: x => setProps(tree, { focused: x }),
+    })), window.document.body);
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+    yield setProps(tree, {
+      focused: "G",
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:true",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "G should be focused");
+
+    // Click the first tree node
+    Simulate.click(document.querySelector(".tree-node"));
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:true",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "A should be focused");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_06.html b/devtools/client/shared/components/test/mochitest/test_tree_06.html
new file mode 100644
index 000000000..1d8f28ec9
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_06.html
@@ -0,0 +1,320 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test keyboard navigation with the Tree component.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+    const tree = ReactDOM.render(Tree(Object.assign({}, TEST_TREE_INTERFACE, {
+      onFocus: x => setProps(tree, { focused: x }),
+    })), window.document.body);
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+
+    // UP ----------------------------------------------------------------------
+
+    info("Up to the previous sibling.");
+
+    yield setProps(tree, {
+      focused: "L"
+    });
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowUp" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:true",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the UP, K should be focused.");
+
+    info("Up to the parent.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowUp" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:true",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the UP, E should be focused.");
+
+    info("Try and navigate up, past the first item.");
+
+    yield setProps(tree, {
+      focused: "A"
+    });
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowUp" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:true",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the UP, A should be focused and we shouldn't have overflowed past it.");
+
+    // DOWN --------------------------------------------------------------------
+
+    yield setProps(tree, {
+      focused: "K"
+    });
+
+    info("Down to next sibling.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowDown" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:true",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the DOWN, L should be focused.");
+
+    info("Down to parent's next sibling.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowDown" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:true",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the DOWN, F should be focused.");
+
+    info("Try and go down past the last item.");
+
+    yield setProps(tree, {
+      focused: "O"
+    });
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowDown" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:true",
+    ], "After the DOWN, O should still be focused and we shouldn't have overflowed past it.");
+
+    // LEFT --------------------------------------------------------------------
+
+    info("Left to go to parent.");
+
+    yield setProps(tree, {
+      focused: "L"
+    })
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowLeft" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:true",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the LEFT, E should be focused.");
+
+    info("Left to collapse children.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowLeft" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:true",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the LEFT, E's children should be collapsed.");
+
+    // RIGHT -------------------------------------------------------------------
+
+    info("Right to expand children.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowRight" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:true",
+      "---K:false",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the RIGHT, E's children should be expanded again.");
+
+    info("Right to go to next item.");
+
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowRight" });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:true",
+      "---L:false",
+      "--F:false",
+      "--G:false",
+      "-C:false",
+      "--H:false",
+      "--I:false",
+      "-D:false",
+      "--J:false",
+      "M:false",
+      "-N:false",
+      "--O:false",
+    ], "After the RIGHT, K should be focused.");
+
+    // Check that keys are ignored if any modifier is present.
+    let keysWithModifier = [
+      { key: "ArrowDown", altKey: true },
+      { key: "ArrowDown", ctrlKey: true },
+      { key: "ArrowDown", metaKey: true },
+      { key: "ArrowDown", shiftKey: true },
+    ];
+    for (let key of keysWithModifier) {
+      Simulate.keyDown(document.querySelector(".tree"), key);
+      yield forceRender(tree);
+      isRenderedTree(document.body.textContent, [
+        "A:false",
+        "-B:false",
+        "--E:false",
+        "---K:true",
+        "---L:false",
+        "--F:false",
+        "--G:false",
+        "-C:false",
+        "--H:false",
+        "--I:false",
+        "-D:false",
+        "--J:false",
+        "M:false",
+        "-N:false",
+        "--O:false",
+      ], "After DOWN + (alt|ctrl|meta|shift), K should remain focused.");
+    }
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_07.html b/devtools/client/shared/components/test/mochitest/test_tree_07.html
new file mode 100644
index 000000000..178ac77e3
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_07.html
@@ -0,0 +1,64 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that arrows get the open attribute when their item's children are expanded.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" href="chrome://devtools/skin/light-theme.css" type="text/css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+    const tree = ReactDOM.render(Tree(TEST_TREE_INTERFACE), window.document.body);
+
+    yield setProps(tree, {
+      renderItem: (item, depth, focused, arrow) => {
+        return React.DOM.div(
+          {
+            id: item,
+            style: { marginLeft: depth * 16 + "px" }
+          },
+          arrow,
+          item
+        );
+      }
+    });
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+    yield forceRender(tree);
+
+    let arrows = document.querySelectorAll(".arrow");
+    for (let a of arrows) {
+      ok(a.classList.contains("open"), "Every arrow should be open.");
+    }
+
+    TEST_TREE.expanded = new Set();
+    yield forceRender(tree);
+
+    arrows = document.querySelectorAll(".arrow");
+    for (let a of arrows) {
+      ok(!a.classList.contains("open"), "Every arrow should be closed.");
+    }
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_08.html b/devtools/client/shared/components/test/mochitest/test_tree_08.html
new file mode 100644
index 000000000..d024f37f8
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_08.html
@@ -0,0 +1,51 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when an item in the Tree component is clicked, it steals focus from
+other inputs.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" href="chrome://devtools/skin/light-theme.css" type="text/css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+    const tree = ReactDOM.render(Tree(Object.assign({}, TEST_TREE_INTERFACE, {
+      onFocus: x => setProps(tree, { focused: x }),
+    })), window.document.body);
+
+    const input = document.createElement("input");
+    document.body.appendChild(input);
+
+    input.focus();
+    is(document.activeElement, input, "The text input should be focused.");
+
+    Simulate.click(document.querySelector(".tree-node"));
+    yield forceRender(tree);
+
+    isnot(document.activeElement, input,
+          "The input should have had it's focus stolen by clicking on a tree item.");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_09.html b/devtools/client/shared/components/test/mochitest/test_tree_09.html
new file mode 100644
index 000000000..96650134b
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_09.html
@@ -0,0 +1,77 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when an item in the Tree component is expanded or collapsed the appropriate event handler fires.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" href="chrome://devtools/skin/light-theme.css" type="text/css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    let numberOfExpands = 0;
+    let lastExpandedItem = null;
+
+    let numberOfCollapses = 0;
+    let lastCollapsedItem = null;
+
+    const tree = ReactDOM.render(Tree(Object.assign({}, TEST_TREE_INTERFACE, {
+      autoExpandDepth: 0,
+      onExpand: item => {
+        lastExpandedItem = item;
+        numberOfExpands++;
+        TEST_TREE.expanded.add(item);
+      },
+      onCollapse: item => {
+        lastCollapsedItem = item;
+        numberOfCollapses++;
+        TEST_TREE.expanded.delete(item);
+      },
+      onFocus: item => setProps(tree, { focused: item }),
+    })), window.document.body);
+
+    yield setProps(tree, {
+      focused: "A"
+    });
+
+    is(lastExpandedItem, null);
+    is(lastCollapsedItem, null);
+
+    // Expand "A" via the keyboard and then let the component re-render.
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowRight" });
+    yield forceRender(tree);
+
+    is(lastExpandedItem, "A", "Our onExpand callback should have been fired.");
+    is(numberOfExpands, 1);
+
+    // Now collapse "A" via the keyboard and then let the component re-render.
+    Simulate.keyDown(document.querySelector(".tree"), { key: "ArrowLeft" });
+    yield forceRender(tree);
+
+    is(lastCollapsedItem, "A", "Our onCollapsed callback should have been fired.");
+    is(numberOfCollapses, 1);
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_10.html b/devtools/client/shared/components/test/mochitest/test_tree_10.html
new file mode 100644
index 000000000..34f8a2633
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_10.html
@@ -0,0 +1,52 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when an item in the Tree component is expanded or collapsed the appropriate event handler fires.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" href="chrome://devtools/skin/light-theme.css" type="text/css">
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    const tree = ReactDOM.render(Tree(Object.assign({
+      autoExpandDepth: 1
+    }, TEST_TREE_INTERFACE)), window.document.body);
+
+    yield setProps(tree, {
+      focused: "A"
+    });
+
+    isRenderedTree(document.body.textContent, [
+      "A:true",
+      "-B:false",
+      "-C:false",
+      "-D:false",
+      "M:false",
+      "-N:false",
+    ], "Should have auto-expanded one level.");
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/test/mochitest/test_tree_11.html b/devtools/client/shared/components/test/mochitest/test_tree_11.html
new file mode 100644
index 000000000..1611f7d26
--- /dev/null
+++ b/devtools/client/shared/components/test/mochitest/test_tree_11.html
@@ -0,0 +1,92 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when an item in the Tree component is focused by arrow key, the view is scrolled.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Tree component test</title>
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+  <link rel="stylesheet" href="chrome://devtools/skin/light-theme.css" type="text/css">
+  <style>
+   * {
+       margin: 0;
+       padding: 0;
+       height: 30px;
+       max-height: 30px;
+       min-height: 30px;
+       font-size: 10px;
+       overflow: auto;
+   }
+  </style>
+</head>
+<body>
+<pre id="test">
+<script src="head.js" type="application/javascript;version=1.8"></script>
+<script type="application/javascript;version=1.8">
+window.onload = Task.async(function* () {
+  try {
+    const ReactDOM = browserRequire("devtools/client/shared/vendor/react-dom");
+    const React = browserRequire("devtools/client/shared/vendor/react");
+    const { Simulate } = React.addons.TestUtils;
+    const Tree = React.createFactory(browserRequire("devtools/client/shared/components/tree"));
+
+    TEST_TREE.expanded = new Set("ABCDEFGHIJKLMNO".split(""));
+
+    const tree = ReactDOM.render(Tree(TEST_TREE_INTERFACE), window.document.body);
+
+    yield setProps(tree, {
+      itemHeight: 10,
+      onFocus: item => setProps(tree, { focused: item }),
+      focused: "K",
+    });
+    yield setState(tree, {
+      scroll: 10,
+    });
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "A:false",
+      "-B:false",
+      "--E:false",
+      "---K:true",
+      "---L:false",
+    ], "Should render initial correctly");
+
+    yield new Promise(resolve => {
+      const treeElem = document.querySelector(".tree");
+      treeElem.addEventListener("scroll", function onScroll() {
+        dumpn("Got scroll event");
+        treeElem.removeEventListener("scroll", onScroll);
+        resolve();
+      });
+
+      dumpn("Sending ArrowDown key");
+      Simulate.keyDown(treeElem, { key: "ArrowDown" });
+    });
+
+    dumpn("Forcing re-render");
+    yield forceRender(tree);
+
+    isRenderedTree(document.body.textContent, [
+      "-B:false",
+      "--E:false",
+      "---K:false",
+      "---L:true",
+      "--F:false",
+    ], "Should have scrolled down one");
+
+  } catch(e) {
+    ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+  } finally {
+    SimpleTest.finish();
+  }
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/devtools/client/shared/components/tree.js b/devtools/client/shared/components/tree.js
new file mode 100644
index 000000000..49b5d1497
--- /dev/null
+++ b/devtools/client/shared/components/tree.js
@@ -0,0 +1,773 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* eslint-env browser */
+"use strict";
+
+const { DOM: dom, createClass, createFactory, PropTypes } = require("devtools/client/shared/vendor/react");
+
+const AUTO_EXPAND_DEPTH = 0;
+const NUMBER_OF_OFFSCREEN_ITEMS = 1;
+
+/**
+ * A fast, generic, expandable and collapsible tree component.
+ *
+ * This tree component is fast: it can handle trees with *many* items. It only
+ * renders the subset of those items which are visible in the viewport. It's
+ * been battle tested on huge trees in the memory panel. We've optimized tree
+ * traversal and rendering, even in the presence of cross-compartment wrappers.
+ *
+ * This tree component doesn't make any assumptions about the structure of your
+ * tree data. Whether children are computed on demand, or stored in an array in
+ * the parent's `_children` property, it doesn't matter. We only require the
+ * implementation of `getChildren`, `getRoots`, `getParent`, and `isExpanded`
+ * functions.
+ *
+ * This tree component is well tested and reliable. See
+ * devtools/client/shared/components/test/mochitest/test_tree_* and its usage in
+ * the performance and memory panels.
+ *
+ * This tree component doesn't make any assumptions about how to render items in
+ * the tree. You provide a `renderItem` function, and this component will ensure
+ * that only those items whose parents are expanded and which are visible in the
+ * viewport are rendered. The `renderItem` function could render the items as a
+ * "traditional" tree or as rows in a table or anything else. It doesn't
+ * restrict you to only one certain kind of tree.
+ *
+ * The only requirement is that every item in the tree render as the same
+ * height. This is required in order to compute which items are visible in the
+ * viewport in constant time.
+ *
+ * ### Example Usage
+ *
+ * Suppose we have some tree data where each item has this form:
+ *
+ *     {
+ *       id: Number,
+ *       label: String,
+ *       parent: Item or null,
+ *       children: Array of child items,
+ *       expanded: bool,
+ *     }
+ *
+ * Here is how we could render that data with this component:
+ *
+ *     const MyTree = createClass({
+ *       displayName: "MyTree",
+ *
+ *       propTypes: {
+ *         // The root item of the tree, with the form described above.
+ *         root: PropTypes.object.isRequired
+ *       },
+ *
+ *       render() {
+ *         return Tree({
+ *           itemHeight: 20, // px
+ *
+ *           getRoots: () => [this.props.root],
+ *
+ *           getParent: item => item.parent,
+ *           getChildren: item => item.children,
+ *           getKey: item => item.id,
+ *           isExpanded: item => item.expanded,
+ *
+ *           renderItem: (item, depth, isFocused, arrow, isExpanded) => {
+ *             let className = "my-tree-item";
+ *             if (isFocused) {
+ *               className += " focused";
+ *             }
+ *             return dom.div(
+ *               {
+ *                 className,
+ *                 // Apply 10px nesting per expansion depth.
+ *                 style: { marginLeft: depth * 10 + "px" }
+ *               },
+ *               // Here is the expando arrow so users can toggle expansion and
+ *               // collapse state.
+ *               arrow,
+ *               // And here is the label for this item.
+ *               dom.span({ className: "my-tree-item-label" }, item.label)
+ *             );
+ *           },
+ *
+ *           onExpand: item => dispatchExpandActionToRedux(item),
+ *           onCollapse: item => dispatchCollapseActionToRedux(item),
+ *         });
+ *       }
+ *     });
+ */
+module.exports = createClass({
+  displayName: "Tree",
+
+  propTypes: {
+    // Required props
+
+    // A function to get an item's parent, or null if it is a root.
+    //
+    // Type: getParent(item: Item) -> Maybe<Item>
+    //
+    // Example:
+    //
+    //     // The parent of this item is stored in its `parent` property.
+    //     getParent: item => item.parent
+    getParent: PropTypes.func.isRequired,
+
+    // A function to get an item's children.
+    //
+    // Type: getChildren(item: Item) -> [Item]
+    //
+    // Example:
+    //
+    //     // This item's children are stored in its `children` property.
+    //     getChildren: item => item.children
+    getChildren: PropTypes.func.isRequired,
+
+    // A function which takes an item and ArrowExpander component instance and
+    // returns a component, or text, or anything else that React considers
+    // renderable.
+    //
+    // Type: renderItem(item: Item,
+    //                  depth: Number,
+    //                  isFocused: Boolean,
+    //                  arrow: ReactComponent,
+    //                  isExpanded: Boolean) -> ReactRenderable
+    //
+    // Example:
+    //
+    //     renderItem: (item, depth, isFocused, arrow, isExpanded) => {
+    //       let className = "my-tree-item";
+    //       if (isFocused) {
+    //         className += " focused";
+    //       }
+    //       return dom.div(
+    //         {
+    //           className,
+    //           style: { marginLeft: depth * 10 + "px" }
+    //         },
+    //         arrow,
+    //         dom.span({ className: "my-tree-item-label" }, item.label)
+    //       );
+    //     },
+    renderItem: PropTypes.func.isRequired,
+
+    // A function which returns the roots of the tree (forest).
+    //
+    // Type: getRoots() -> [Item]
+    //
+    // Example:
+    //
+    //     // In this case, we only have one top level, root item. You could
+    //     // return multiple items if you have many top level items in your
+    //     // tree.
+    //     getRoots: () => [this.props.rootOfMyTree]
+    getRoots: PropTypes.func.isRequired,
+
+    // A function to get a unique key for the given item. This helps speed up
+    // React's rendering a *TON*.
+    //
+    // Type: getKey(item: Item) -> String
+    //
+    // Example:
+    //
+    //     getKey: item => `my-tree-item-${item.uniqueId}`
+    getKey: PropTypes.func.isRequired,
+
+    // A function to get whether an item is expanded or not. If an item is not
+    // expanded, then it must be collapsed.
+    //
+    // Type: isExpanded(item: Item) -> Boolean
+    //
+    // Example:
+    //
+    //     isExpanded: item => item.expanded,
+    isExpanded: PropTypes.func.isRequired,
+
+    // The height of an item in the tree including margin and padding, in
+    // pixels.
+    itemHeight: PropTypes.number.isRequired,
+
+    // Optional props
+
+    // The currently focused item, if any such item exists.
+    focused: PropTypes.any,
+
+    // Handle when a new item is focused.
+    onFocus: PropTypes.func,
+
+    // The depth to which we should automatically expand new items.
+    autoExpandDepth: PropTypes.number,
+
+    // Optional event handlers for when items are expanded or collapsed. Useful
+    // for dispatching redux events and updating application state, maybe lazily
+    // loading subtrees from a worker, etc.
+    //
+    // Type:
+    //     onExpand(item: Item)
+    //     onCollapse(item: Item)
+    //
+    // Example:
+    //
+    //     onExpand: item => dispatchExpandActionToRedux(item)
+    onExpand: PropTypes.func,
+    onCollapse: PropTypes.func,
+  },
+
+  getDefaultProps() {
+    return {
+      autoExpandDepth: AUTO_EXPAND_DEPTH,
+    };
+  },
+
+  getInitialState() {
+    return {
+      scroll: 0,
+      height: window.innerHeight,
+      seen: new Set(),
+    };
+  },
+
+  componentDidMount() {
+    window.addEventListener("resize", this._updateHeight);
+    this._autoExpand();
+    this._updateHeight();
+  },
+
+  componentWillReceiveProps(nextProps) {
+    this._autoExpand();
+    this._updateHeight();
+  },
+
+  componentWillUnmount() {
+    window.removeEventListener("resize", this._updateHeight);
+  },
+
+  _autoExpand() {
+    if (!this.props.autoExpandDepth) {
+      return;
+    }
+
+    // Automatically expand the first autoExpandDepth levels for new items. Do
+    // not use the usual DFS infrastructure because we don't want to ignore
+    // collapsed nodes.
+    const autoExpand = (item, currentDepth) => {
+      if (currentDepth >= this.props.autoExpandDepth ||
+          this.state.seen.has(item)) {
+        return;
+      }
+
+      this.props.onExpand(item);
+      this.state.seen.add(item);
+
+      const children = this.props.getChildren(item);
+      const length = children.length;
+      for (let i = 0; i < length; i++) {
+        autoExpand(children[i], currentDepth + 1);
+      }
+    };
+
+    const roots = this.props.getRoots();
+    const length = roots.length;
+    for (let i = 0; i < length; i++) {
+      autoExpand(roots[i], 0);
+    }
+  },
+
+  _preventArrowKeyScrolling(e) {
+    switch (e.key) {
+      case "ArrowUp":
+      case "ArrowDown":
+      case "ArrowLeft":
+      case "ArrowRight":
+        e.preventDefault();
+        e.stopPropagation();
+        if (e.nativeEvent) {
+          if (e.nativeEvent.preventDefault) {
+            e.nativeEvent.preventDefault();
+          }
+          if (e.nativeEvent.stopPropagation) {
+            e.nativeEvent.stopPropagation();
+          }
+        }
+    }
+  },
+
+  /**
+   * Updates the state's height based on clientHeight.
+   */
+  _updateHeight() {
+    this.setState({
+      height: this.refs.tree.clientHeight
+    });
+  },
+
+  /**
+   * Perform a pre-order depth-first search from item.
+   */
+  _dfs(item, maxDepth = Infinity, traversal = [], _depth = 0) {
+    traversal.push({ item, depth: _depth });
+
+    if (!this.props.isExpanded(item)) {
+      return traversal;
+    }
+
+    const nextDepth = _depth + 1;
+
+    if (nextDepth > maxDepth) {
+      return traversal;
+    }
+
+    const children = this.props.getChildren(item);
+    const length = children.length;
+    for (let i = 0; i < length; i++) {
+      this._dfs(children[i], maxDepth, traversal, nextDepth);
+    }
+
+    return traversal;
+  },
+
+  /**
+   * Perform a pre-order depth-first search over the whole forest.
+   */
+  _dfsFromRoots(maxDepth = Infinity) {
+    const traversal = [];
+
+    const roots = this.props.getRoots();
+    const length = roots.length;
+    for (let i = 0; i < length; i++) {
+      this._dfs(roots[i], maxDepth, traversal);
+    }
+
+    return traversal;
+  },
+
+  /**
+   * Expands current row.
+   *
+   * @param {Object} item
+   * @param {Boolean} expandAllChildren
+   */
+  _onExpand: oncePerAnimationFrame(function (item, expandAllChildren) {
+    if (this.props.onExpand) {
+      this.props.onExpand(item);
+
+      if (expandAllChildren) {
+        const children = this._dfs(item);
+        const length = children.length;
+        for (let i = 0; i < length; i++) {
+          this.props.onExpand(children[i].item);
+        }
+      }
+    }
+  }),
+
+  /**
+   * Collapses current row.
+   *
+   * @param {Object} item
+   */
+  _onCollapse: oncePerAnimationFrame(function (item) {
+    if (this.props.onCollapse) {
+      this.props.onCollapse(item);
+    }
+  }),
+
+  /**
+   * Sets the passed in item to be the focused item.
+   *
+   * @param {Number} index
+   *        The index of the item in a full DFS traversal (ignoring collapsed
+   *        nodes). Ignored if `item` is undefined.
+   *
+   * @param {Object|undefined} item
+   *        The item to be focused, or undefined to focus no item.
+   */
+  _focus(index, item) {
+    if (item !== undefined) {
+      const itemStartPosition = index * this.props.itemHeight;
+      const itemEndPosition = (index + 1) * this.props.itemHeight;
+
+      // Note that if the height of the viewport (this.state.height) is less
+      // than `this.props.itemHeight`, we could accidentally try and scroll both
+      // up and down in a futile attempt to make both the item's start and end
+      // positions visible. Instead, give priority to the start of the item by
+      // checking its position first, and then using an "else if", rather than
+      // a separate "if", for the end position.
+      if (this.state.scroll > itemStartPosition) {
+        this.refs.tree.scrollTo(0, itemStartPosition);
+      } else if ((this.state.scroll + this.state.height) < itemEndPosition) {
+        this.refs.tree.scrollTo(0, itemEndPosition - this.state.height);
+      }
+    }
+
+    if (this.props.onFocus) {
+      this.props.onFocus(item);
+    }
+  },
+
+  /**
+   * Sets the state to have no focused item.
+   */
+  _onBlur() {
+    this._focus(0, undefined);
+  },
+
+  /**
+   * Fired on a scroll within the tree's container, updates
+   * the stored position of the view port to handle virtual view rendering.
+   *
+   * @param {Event} e
+   */
+  _onScroll: oncePerAnimationFrame(function (e) {
+    this.setState({
+      scroll: Math.max(this.refs.tree.scrollTop, 0),
+      height: this.refs.tree.clientHeight
+    });
+  }),
+
+  /**
+   * Handles key down events in the tree's container.
+   *
+   * @param {Event} e
+   */
+  _onKeyDown(e) {
+    if (this.props.focused == null) {
+      return;
+    }
+
+    // Allow parent nodes to use navigation arrows with modifiers.
+    if (e.altKey || e.ctrlKey || e.shiftKey || e.metaKey) {
+      return;
+    }
+
+    this._preventArrowKeyScrolling(e);
+
+    switch (e.key) {
+      case "ArrowUp":
+        this._focusPrevNode();
+        return;
+
+      case "ArrowDown":
+        this._focusNextNode();
+        return;
+
+      case "ArrowLeft":
+        if (this.props.isExpanded(this.props.focused)
+            && this.props.getChildren(this.props.focused).length) {
+          this._onCollapse(this.props.focused);
+        } else {
+          this._focusParentNode();
+        }
+        return;
+
+      case "ArrowRight":
+        if (!this.props.isExpanded(this.props.focused)) {
+          this._onExpand(this.props.focused);
+        } else {
+          this._focusNextNode();
+        }
+        return;
+    }
+  },
+
+  /**
+   * Sets the previous node relative to the currently focused item, to focused.
+   */
+  _focusPrevNode: oncePerAnimationFrame(function () {
+    // Start a depth first search and keep going until we reach the currently
+    // focused node. Focus the previous node in the DFS, if it exists. If it
+    // doesn't exist, we're at the first node already.
+
+    let prev;
+    let prevIndex;
+
+    const traversal = this._dfsFromRoots();
+    const length = traversal.length;
+    for (let i = 0; i < length; i++) {
+      const item = traversal[i].item;
+      if (item === this.props.focused) {
+        break;
+      }
+      prev = item;
+      prevIndex = i;
+    }
+
+    if (prev === undefined) {
+      return;
+    }
+
+    this._focus(prevIndex, prev);
+  }),
+
+  /**
+   * Handles the down arrow key which will focus either the next child
+   * or sibling row.
+   */
+  _focusNextNode: oncePerAnimationFrame(function () {
+    // Start a depth first search and keep going until we reach the currently
+    // focused node. Focus the next node in the DFS, if it exists. If it
+    // doesn't exist, we're at the last node already.
+
+    const traversal = this._dfsFromRoots();
+    const length = traversal.length;
+    let i = 0;
+
+    while (i < length) {
+      if (traversal[i].item === this.props.focused) {
+        break;
+      }
+      i++;
+    }
+
+    if (i + 1 < traversal.length) {
+      this._focus(i + 1, traversal[i + 1].item);
+    }
+  }),
+
+  /**
+   * Handles the left arrow key, going back up to the current rows'
+   * parent row.
+   */
+  _focusParentNode: oncePerAnimationFrame(function () {
+    const parent = this.props.getParent(this.props.focused);
+    if (!parent) {
+      return;
+    }
+
+    const traversal = this._dfsFromRoots();
+    const length = traversal.length;
+    let parentIndex = 0;
+    for (; parentIndex < length; parentIndex++) {
+      if (traversal[parentIndex].item === parent) {
+        break;
+      }
+    }
+
+    this._focus(parentIndex, parent);
+  }),
+
+  render() {
+    const traversal = this._dfsFromRoots();
+
+    // 'begin' and 'end' are the index of the first (at least partially) visible item
+    // and the index after the last (at least partially) visible item, respectively.
+    // `NUMBER_OF_OFFSCREEN_ITEMS` is removed from `begin` and added to `end` so that
+    // the top and bottom of the page are filled with the `NUMBER_OF_OFFSCREEN_ITEMS`
+    // previous and next items respectively, which helps the user to see fewer empty
+    // gaps when scrolling quickly.
+    const { itemHeight } = this.props;
+    const { scroll, height } = this.state;
+    const begin = Math.max(((scroll / itemHeight) | 0) - NUMBER_OF_OFFSCREEN_ITEMS, 0);
+    const end = Math.ceil((scroll + height) / itemHeight) + NUMBER_OF_OFFSCREEN_ITEMS;
+    const toRender = traversal.slice(begin, end);
+    const topSpacerHeight = begin * itemHeight;
+    const bottomSpacerHeight = Math.max(traversal.length - end, 0) * itemHeight;
+
+    const nodes = [
+      dom.div({
+        key: "top-spacer",
+        style: {
+          padding: 0,
+          margin: 0,
+          height: topSpacerHeight + "px"
+        }
+      })
+    ];
+
+    for (let i = 0; i < toRender.length; i++) {
+      const index = begin + i;
+      const first = index == 0;
+      const last = index == traversal.length - 1;
+      const { item, depth } = toRender[i];
+      nodes.push(TreeNode({
+        key: this.props.getKey(item),
+        index,
+        first,
+        last,
+        item,
+        depth,
+        renderItem: this.props.renderItem,
+        focused: this.props.focused === item,
+        expanded: this.props.isExpanded(item),
+        hasChildren: !!this.props.getChildren(item).length,
+        onExpand: this._onExpand,
+        onCollapse: this._onCollapse,
+        onFocus: () => this._focus(begin + i, item),
+        onFocusedNodeUnmount: () => this.refs.tree && this.refs.tree.focus(),
+      }));
+    }
+
+    nodes.push(dom.div({
+      key: "bottom-spacer",
+      style: {
+        padding: 0,
+        margin: 0,
+        height: bottomSpacerHeight + "px"
+      }
+    }));
+
+    return dom.div(
+      {
+        className: "tree",
+        ref: "tree",
+        onKeyDown: this._onKeyDown,
+        onKeyPress: this._preventArrowKeyScrolling,
+        onKeyUp: this._preventArrowKeyScrolling,
+        onScroll: this._onScroll,
+        style: {
+          padding: 0,
+          margin: 0
+        }
+      },
+      nodes
+    );
+  }
+});
+
+/**
+ * An arrow that displays whether its node is expanded (▼) or collapsed
+ * (▶). When its node has no children, it is hidden.
+ */
+const ArrowExpander = createFactory(createClass({
+  displayName: "ArrowExpander",
+
+  shouldComponentUpdate(nextProps, nextState) {
+    return this.props.item !== nextProps.item
+      || this.props.visible !== nextProps.visible
+      || this.props.expanded !== nextProps.expanded;
+  },
+
+  render() {
+    const attrs = {
+      className: "arrow theme-twisty",
+      onClick: this.props.expanded
+        ? () => this.props.onCollapse(this.props.item)
+        : e => this.props.onExpand(this.props.item, e.altKey)
+    };
+
+    if (this.props.expanded) {
+      attrs.className += " open";
+    }
+
+    if (!this.props.visible) {
+      attrs.style = {
+        visibility: "hidden"
+      };
+    }
+
+    return dom.div(attrs);
+  }
+}));
+
+const TreeNode = createFactory(createClass({
+  componentDidMount() {
+    if (this.props.focused) {
+      this.refs.button.focus();
+    }
+  },
+
+  componentDidUpdate() {
+    if (this.props.focused) {
+      this.refs.button.focus();
+    }
+  },
+
+  componentWillUnmount() {
+    // If this node is being destroyed and has focus, transfer the focus manually
+    // to the parent tree component. Otherwise, the focus will get lost and keyboard
+    // navigation in the tree will stop working. This is a workaround for a XUL bug.
+    // See bugs 1259228 and 1152441 for details.
+    // DE-XUL: Remove this hack once all usages are only in HTML documents.
+    if (this.props.focused) {
+      this.refs.button.blur();
+      if (this.props.onFocusedNodeUnmount) {
+        this.props.onFocusedNodeUnmount();
+      }
+    }
+  },
+
+  _buttonAttrs: {
+    ref: "button",
+    style: {
+      opacity: 0,
+      width: "0 !important",
+      height: "0 !important",
+      padding: "0 !important",
+      outline: "none",
+      MozAppearance: "none",
+      // XXX: Despite resetting all of the above properties (and margin), the
+      // button still ends up with ~79px width, so we set a large negative
+      // margin to completely hide it.
+      MozMarginStart: "-1000px !important",
+    }
+  },
+
+  render() {
+    const arrow = ArrowExpander({
+      item: this.props.item,
+      expanded: this.props.expanded,
+      visible: this.props.hasChildren,
+      onExpand: this.props.onExpand,
+      onCollapse: this.props.onCollapse,
+    });
+
+    let classList = [ "tree-node", "div" ];
+    if (this.props.index % 2) {
+      classList.push("tree-node-odd");
+    }
+    if (this.props.first) {
+      classList.push("tree-node-first");
+    }
+    if (this.props.last) {
+      classList.push("tree-node-last");
+    }
+
+    return dom.div(
+      {
+        className: classList.join(" "),
+        onFocus: this.props.onFocus,
+        onClick: this.props.onFocus,
+        onBlur: this.props.onBlur,
+        "data-expanded": this.props.expanded ? "" : undefined,
+        "data-depth": this.props.depth,
+        style: {
+          padding: 0,
+          margin: 0
+        }
+      },
+
+      this.props.renderItem(this.props.item,
+                            this.props.depth,
+                            this.props.focused,
+                            arrow,
+                            this.props.expanded),
+
+      // XXX: OSX won't focus/blur regular elements even if you set tabindex
+      // unless there is an input/button child.
+      dom.button(this._buttonAttrs)
+    );
+  }
+}));
+
+/**
+ * Create a function that calls the given function `fn` only once per animation
+ * frame.
+ *
+ * @param {Function} fn
+ * @returns {Function}
+ */
+function oncePerAnimationFrame(fn) {
+  let animationId = null;
+  let argsToPass = null;
+  return function (...args) {
+    argsToPass = args;
+    if (animationId !== null) {
+      return;
+    }
+
+    animationId = requestAnimationFrame(() => {
+      fn.call(this, ...argsToPass);
+      animationId = null;
+      argsToPass = null;
+    });
+  };
+}
diff --git a/devtools/client/shared/components/tree/label-cell.js b/devtools/client/shared/components/tree/label-cell.js
new file mode 100644
index 000000000..e14875b4d
--- /dev/null
+++ b/devtools/client/shared/components/tree/label-cell.js
@@ -0,0 +1,66 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { td, span } = React.DOM;
+  const PropTypes = React.PropTypes;
+
+  /**
+   * Render the default cell used for toggle buttons
+   */
+  let LabelCell = React.createClass({
+    displayName: "LabelCell",
+
+    // See the TreeView component for details related
+    // to the 'member' object.
+    propTypes: {
+      member: PropTypes.object.isRequired
+    },
+
+    render: function () {
+      let member = this.props.member;
+      let level = member.level || 0;
+
+      // Compute indentation dynamically. The deeper the item is
+      // inside the hierarchy, the bigger is the left padding.
+      let rowStyle = {
+        "paddingInlineStart": (level * 16) + "px",
+      };
+
+      let iconClassList = ["treeIcon"];
+      if (member.hasChildren && member.loading) {
+        iconClassList.push("devtools-throbber");
+      } else if (member.hasChildren) {
+        iconClassList.push("theme-twisty");
+      }
+      if (member.open) {
+        iconClassList.push("open");
+      }
+
+      return (
+        td({
+          className: "treeLabelCell",
+          key: "default",
+          style: rowStyle},
+          span({ className: iconClassList.join(" ") }),
+          span({
+            className: "treeLabel " + member.type + "Label",
+            "data-level": level
+          }, member.name)
+        )
+      );
+    }
+  });
+
+  // Exports from this module
+  module.exports = LabelCell;
+});
diff --git a/devtools/client/shared/components/tree/moz.build b/devtools/client/shared/components/tree/moz.build
new file mode 100644
index 000000000..a7413f25a
--- /dev/null
+++ b/devtools/client/shared/components/tree/moz.build
@@ -0,0 +1,14 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'label-cell.js',
+    'object-provider.js',
+    'tree-cell.js',
+    'tree-header.js',
+    'tree-row.js',
+    'tree-view.css',
+    'tree-view.js',
+)
diff --git a/devtools/client/shared/components/tree/object-provider.js b/devtools/client/shared/components/tree/object-provider.js
new file mode 100644
index 000000000..58519f81f
--- /dev/null
+++ b/devtools/client/shared/components/tree/object-provider.js
@@ -0,0 +1,90 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  /**
+   * Implementation of the default data provider. A provider is state less
+   * object responsible for transformation data (usually a state) to
+   * a structure that can be directly consumed by the tree-view component.
+   */
+  let ObjectProvider = {
+    getChildren: function (object) {
+      let children = [];
+
+      if (object instanceof ObjectProperty) {
+        object = object.value;
+      }
+
+      if (!object) {
+        return [];
+      }
+
+      if (typeof (object) == "string") {
+        return [];
+      }
+
+      for (let prop in object) {
+        try {
+          children.push(new ObjectProperty(prop, object[prop]));
+        } catch (e) {
+          console.error(e);
+        }
+      }
+      return children;
+    },
+
+    hasChildren: function (object) {
+      if (object instanceof ObjectProperty) {
+        object = object.value;
+      }
+
+      if (!object) {
+        return false;
+      }
+
+      if (typeof object == "string") {
+        return false;
+      }
+
+      if (typeof object !== "object") {
+        return false;
+      }
+
+      return Object.keys(object).length > 0;
+    },
+
+    getLabel: function (object) {
+      return (object instanceof ObjectProperty) ?
+        object.name : null;
+    },
+
+    getValue: function (object) {
+      return (object instanceof ObjectProperty) ?
+        object.value : null;
+    },
+
+    getKey: function (object) {
+      return (object instanceof ObjectProperty) ?
+        object.name : null;
+    },
+
+    getType: function (object) {
+      return (object instanceof ObjectProperty) ?
+        typeof object.value : typeof object;
+    }
+  };
+
+  function ObjectProperty(name, value) {
+    this.name = name;
+    this.value = value;
+  }
+
+  // Exports from this module
+  exports.ObjectProperty = ObjectProperty;
+  exports.ObjectProvider = ObjectProvider;
+});
diff --git a/devtools/client/shared/components/tree/tree-cell.js b/devtools/client/shared/components/tree/tree-cell.js
new file mode 100644
index 000000000..f3c48510f
--- /dev/null
+++ b/devtools/client/shared/components/tree/tree-cell.js
@@ -0,0 +1,101 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { td, span } = React.DOM;
+  const PropTypes = React.PropTypes;
+
+  /**
+   * This template represents a cell in TreeView row. It's rendered
+   * using <td> element (the row is <tr> and the entire tree is <table>).
+   */
+  let TreeCell = React.createClass({
+    displayName: "TreeCell",
+
+    // See TreeView component for detailed property explanation.
+    propTypes: {
+      value: PropTypes.any,
+      decorator: PropTypes.object,
+      id: PropTypes.string.isRequired,
+      member: PropTypes.object.isRequired,
+      renderValue: PropTypes.func.isRequired
+    },
+
+    /**
+     * Optimize cell rendering. Rerender cell content only if
+     * the value or expanded state changes.
+     */
+    shouldComponentUpdate: function (nextProps) {
+      return (this.props.value != nextProps.value) ||
+        (this.props.member.open != nextProps.member.open);
+    },
+
+    getCellClass: function (object, id) {
+      let decorator = this.props.decorator;
+      if (!decorator || !decorator.getCellClass) {
+        return [];
+      }
+
+      // Decorator can return a simple string or array of strings.
+      let classNames = decorator.getCellClass(object, id);
+      if (!classNames) {
+        return [];
+      }
+
+      if (typeof classNames == "string") {
+        classNames = [classNames];
+      }
+
+      return classNames;
+    },
+
+    render: function () {
+      let member = this.props.member;
+      let type = member.type || "";
+      let id = this.props.id;
+      let value = this.props.value;
+      let decorator = this.props.decorator;
+
+      // Compute class name list for the <td> element.
+      let classNames = this.getCellClass(member.object, id) || [];
+      classNames.push("treeValueCell");
+      classNames.push(type + "Cell");
+
+      // Render value using a default render function or custom
+      // provided function from props or a decorator.
+      let renderValue = this.props.renderValue || defaultRenderValue;
+      if (decorator && decorator.renderValue) {
+        renderValue = decorator.renderValue(member.object, id) || renderValue;
+      }
+
+      let props = Object.assign({}, this.props, {
+        object: value,
+      });
+
+      // Render me!
+      return (
+        td({ className: classNames.join(" ") },
+          span({}, renderValue(props))
+        )
+      );
+    }
+  });
+
+  // Default value rendering.
+  let defaultRenderValue = props => {
+    return (
+      props.object + ""
+    );
+  };
+
+  // Exports from this module
+  module.exports = TreeCell;
+});
diff --git a/devtools/client/shared/components/tree/tree-header.js b/devtools/client/shared/components/tree/tree-header.js
new file mode 100644
index 000000000..eec5363dd
--- /dev/null
+++ b/devtools/client/shared/components/tree/tree-header.js
@@ -0,0 +1,100 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Shortcuts
+  const { thead, tr, td, div } = React.DOM;
+  const PropTypes = React.PropTypes;
+
+  /**
+   * This component is responsible for rendering tree header.
+   * It's based on <thead> element.
+   */
+  let TreeHeader = React.createClass({
+    displayName: "TreeHeader",
+
+    // See also TreeView component for detailed info about properties.
+    propTypes: {
+      // Custom tree decorator
+      decorator: PropTypes.object,
+      // True if the header should be visible
+      header: PropTypes.bool,
+      // Array with column definition
+      columns: PropTypes.array
+    },
+
+    getDefaultProps: function () {
+      return {
+        columns: [{
+          id: "default"
+        }]
+      };
+    },
+
+    getHeaderClass: function (colId) {
+      let decorator = this.props.decorator;
+      if (!decorator || !decorator.getHeaderClass) {
+        return [];
+      }
+
+      // Decorator can return a simple string or array of strings.
+      let classNames = decorator.getHeaderClass(colId);
+      if (!classNames) {
+        return [];
+      }
+
+      if (typeof classNames == "string") {
+        classNames = [classNames];
+      }
+
+      return classNames;
+    },
+
+    render: function () {
+      let cells = [];
+      let visible = this.props.header;
+
+      // Render the rest of the columns (if any)
+      this.props.columns.forEach(col => {
+        let cellStyle = {
+          "width": col.width ? col.width : "",
+        };
+
+        let classNames = [];
+
+        if (visible) {
+          classNames = this.getHeaderClass(col.id);
+          classNames.push("treeHeaderCell");
+        }
+
+        cells.push(
+          td({
+            className: classNames.join(" "),
+            style: cellStyle,
+            key: col.id},
+            div({ className: visible ? "treeHeaderCellBox" : "" },
+              visible ? col.title : ""
+            )
+          )
+        );
+      });
+
+      return (
+        thead({}, tr({ className: visible ? "treeHeaderRow" : "" },
+          cells
+        ))
+      );
+    }
+  });
+
+  // Exports from this module
+  module.exports = TreeHeader;
+});
diff --git a/devtools/client/shared/components/tree/tree-row.js b/devtools/client/shared/components/tree/tree-row.js
new file mode 100644
index 000000000..adfb1f3ae
--- /dev/null
+++ b/devtools/client/shared/components/tree/tree-row.js
@@ -0,0 +1,184 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+  const ReactDOM = require("devtools/client/shared/vendor/react-dom");
+
+  // Tree
+  const TreeCell = React.createFactory(require("./tree-cell"));
+  const LabelCell = React.createFactory(require("./label-cell"));
+
+  // Shortcuts
+  const { tr } = React.DOM;
+  const PropTypes = React.PropTypes;
+
+  /**
+   * This template represents a node in TreeView component. It's rendered
+   * using <tr> element (the entire tree is one big <table>).
+   */
+  let TreeRow = React.createClass({
+    displayName: "TreeRow",
+
+    // See TreeView component for more details about the props and
+    // the 'member' object.
+    propTypes: {
+      member: PropTypes.shape({
+        object: PropTypes.obSject,
+        name: PropTypes.sring,
+        type: PropTypes.string.isRequired,
+        rowClass: PropTypes.string.isRequired,
+        level: PropTypes.number.isRequired,
+        hasChildren: PropTypes.bool,
+        value: PropTypes.any,
+        open: PropTypes.bool.isRequired,
+        path: PropTypes.string.isRequired,
+        hidden: PropTypes.bool,
+      }),
+      decorator: PropTypes.object,
+      renderCell: PropTypes.object,
+      renderLabelCell: PropTypes.object,
+      columns: PropTypes.array.isRequired,
+      provider: PropTypes.object.isRequired,
+      onClick: PropTypes.func.isRequired
+    },
+
+    componentWillReceiveProps(nextProps) {
+      // I don't like accessing the underlying DOM elements directly,
+      // but this optimization makes the filtering so damn fast!
+      // The row doesn't have to be re-rendered, all we really need
+      // to do is toggling a class name.
+      // The important part is that DOM elements don't need to be
+      // re-created when they should appear again.
+      if (nextProps.member.hidden != this.props.member.hidden) {
+        let row = ReactDOM.findDOMNode(this);
+        row.classList.toggle("hidden");
+      }
+    },
+
+    /**
+     * Optimize row rendering. If props are the same do not render.
+     * This makes the rendering a lot faster!
+     */
+    shouldComponentUpdate: function (nextProps) {
+      let props = ["name", "open", "value", "loading"];
+      for (let p in props) {
+        if (nextProps.member[props[p]] != this.props.member[props[p]]) {
+          return true;
+        }
+      }
+
+      return false;
+    },
+
+    getRowClass: function (object) {
+      let decorator = this.props.decorator;
+      if (!decorator || !decorator.getRowClass) {
+        return [];
+      }
+
+      // Decorator can return a simple string or array of strings.
+      let classNames = decorator.getRowClass(object);
+      if (!classNames) {
+        return [];
+      }
+
+      if (typeof classNames == "string") {
+        classNames = [classNames];
+      }
+
+      return classNames;
+    },
+
+    render: function () {
+      let member = this.props.member;
+      let decorator = this.props.decorator;
+
+      // Compute class name list for the <tr> element.
+      let classNames = this.getRowClass(member.object) || [];
+      classNames.push("treeRow");
+      classNames.push(member.type + "Row");
+
+      if (member.hasChildren) {
+        classNames.push("hasChildren");
+      }
+
+      if (member.open) {
+        classNames.push("opened");
+      }
+
+      if (member.loading) {
+        classNames.push("loading");
+      }
+
+      if (member.hidden) {
+        classNames.push("hidden");
+      }
+
+      // The label column (with toggle buttons) is usually
+      // the first one, but there might be cases (like in
+      // the Memory panel) where the toggling is done
+      // in the last column.
+      let cells = [];
+
+      // Get components for rendering cells.
+      let renderCell = this.props.renderCell || RenderCell;
+      let renderLabelCell = this.props.renderLabelCell || RenderLabelCell;
+      if (decorator && decorator.renderLabelCell) {
+        renderLabelCell = decorator.renderLabelCell(member.object) ||
+          renderLabelCell;
+      }
+
+      // Render a cell for every column.
+      this.props.columns.forEach(col => {
+        let props = Object.assign({}, this.props, {
+          key: col.id,
+          id: col.id,
+          value: this.props.provider.getValue(member.object, col.id)
+        });
+
+        if (decorator && decorator.renderCell) {
+          renderCell = decorator.renderCell(member.object, col.id);
+        }
+
+        let render = (col.id == "default") ? renderLabelCell : renderCell;
+
+        // Some cells don't have to be rendered. This happens when some
+        // other cells span more columns. Note that the label cells contains
+        // toggle buttons and should be usually there unless we are rendering
+        // a simple non-expandable table.
+        if (render) {
+          cells.push(render(props));
+        }
+      });
+
+      // Render tree row
+      return (
+        tr({
+          className: classNames.join(" "),
+          onClick: this.props.onClick},
+          cells
+        )
+      );
+    }
+  });
+
+  // Helpers
+
+  let RenderCell = props => {
+    return TreeCell(props);
+  };
+
+  let RenderLabelCell = props => {
+    return LabelCell(props);
+  };
+
+  // Exports from this module
+  module.exports = TreeRow;
+});
diff --git a/devtools/client/shared/components/tree/tree-view.css b/devtools/client/shared/components/tree/tree-view.css
new file mode 100644
index 000000000..850533872
--- /dev/null
+++ b/devtools/client/shared/components/tree/tree-view.css
@@ -0,0 +1,157 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+@import url('resource://devtools/client/shared/components/reps/reps.css');
+
+/******************************************************************************/
+/* TreeView Colors */
+
+:root {
+  --tree-link-color: blue;
+  --tree-header-background: #C8D2DC;
+  --tree-header-sorted-background: #AAC3DC;
+}
+
+/******************************************************************************/
+/* TreeView Table*/
+
+.treeTable .treeLabelCell {
+  padding: 2px 0;
+  vertical-align: top;
+  white-space: nowrap;
+}
+
+.treeTable .treeLabelCell::after {
+  content: ":";
+  color: var(--object-color);
+}
+
+.treeTable .treeValueCell {
+  padding: 2px 0;
+  padding-inline-start: 5px;
+  overflow: hidden;
+}
+
+.treeTable .treeLabel {
+  cursor: default;
+  overflow: hidden;
+  padding-inline-start: 4px;
+  white-space: nowrap;
+}
+
+/* No paddding if there is actually no label */
+.treeTable .treeLabel:empty {
+  padding-inline-start: 0;
+}
+
+.treeTable .treeRow.hasChildren > .treeLabelCell > .treeLabel:hover {
+  cursor: pointer;
+  color: var(--tree-link-color);
+  text-decoration: underline;
+}
+
+/* Filtering */
+.treeTable .treeRow.hidden {
+  display: none;
+}
+
+/******************************************************************************/
+/* Toggle Icon */
+
+.treeTable .treeRow .treeIcon {
+  height: 14px;
+  width: 14px;
+  font-size: 10px; /* Set the size of loading spinner */
+  display: inline-block;
+  vertical-align: bottom;
+  margin-inline-start: 3px;
+  padding-top: 1px;
+}
+
+/* All expanded/collapsed styles need to apply on immediate children
+  since there might be nested trees within a tree. */
+.treeTable .treeRow.hasChildren > .treeLabelCell > .treeIcon {
+  cursor: pointer;
+  background-repeat: no-repeat;
+}
+
+/******************************************************************************/
+/* Header */
+
+.treeTable .treeHeaderRow {
+  height: 18px;
+}
+
+.treeTable .treeHeaderCell {
+  cursor: pointer;
+  -moz-user-select: none;
+  border-bottom: 1px solid rgba(0, 0, 0, 0.2);
+  padding: 0 !important;
+  background: linear-gradient(
+          rgba(255, 255, 255, 0.05),
+          rgba(0, 0, 0, 0.05)),
+      radial-gradient(1px 60% at right,
+          rgba(0, 0, 0, 0.8) 0%,
+          transparent 80%) repeat-x var(--tree-header-background);
+  color: var(--theme-body-color);
+  white-space: nowrap;
+}
+
+.treeTable .treeHeaderCellBox {
+  padding: 2px 0;
+  padding-inline-start: 10px;
+  padding-inline-end: 14px;
+}
+
+.treeTable .treeHeaderRow > .treeHeaderCell:first-child > .treeHeaderCellBox {
+  padding: 0;
+}
+
+.treeTable .treeHeaderSorted {
+  background-color: var(--tree-header-sorted-background);
+}
+
+.treeTable .treeHeaderSorted > .treeHeaderCellBox {
+  background: url(chrome://devtools/skin/images/firebug/arrow-down.svg) no-repeat calc(100% - 4px);
+}
+
+.treeTable .treeHeaderSorted.sortedAscending > .treeHeaderCellBox {
+  background-image: url(chrome://devtools/skin/images/firebug/arrow-up.svg);
+}
+
+.treeTable .treeHeaderCell:hover:active {
+  background-image: linear-gradient(
+          rgba(0, 0, 0, 0.1),
+          transparent),
+      radial-gradient(1px 60% at right,
+          rgba(0, 0, 0, 0.8) 0%,
+          transparent 80%);
+}
+
+/******************************************************************************/
+/* Themes */
+
+.theme-light .treeTable .treeRow:hover,
+.theme-dark .treeTable .treeRow:hover {
+  background-color: var(--theme-selection-background-semitransparent) !important;
+}
+
+.theme-firebug .treeTable .treeRow:hover {
+  background-color: var(--theme-body-background);
+}
+
+.theme-light .treeTable .treeLabel,
+.theme-dark .treeTable .treeLabel {
+  color: var(--theme-highlight-pink);
+}
+
+.theme-light .treeTable .treeRow.hasChildren > .treeLabelCell > .treeLabel:hover,
+.theme-dark .treeTable .treeRow.hasChildren > .treeLabelCell > .treeLabel:hover {
+  color: var(--theme-highlight-pink);
+}
+
+.theme-firebug .treeTable .treeLabel {
+  color: var(--theme-body-color);
+}
diff --git a/devtools/client/shared/components/tree/tree-view.js b/devtools/client/shared/components/tree/tree-view.js
new file mode 100644
index 000000000..9fae9addb
--- /dev/null
+++ b/devtools/client/shared/components/tree/tree-view.js
@@ -0,0 +1,352 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Make this available to both AMD and CJS environments
+define(function (require, exports, module) {
+  // ReactJS
+  const React = require("devtools/client/shared/vendor/react");
+
+  // Reps
+  const { ObjectProvider } = require("./object-provider");
+  const TreeRow = React.createFactory(require("./tree-row"));
+  const TreeHeader = React.createFactory(require("./tree-header"));
+
+  // Shortcuts
+  const DOM = React.DOM;
+  const PropTypes = React.PropTypes;
+
+  /**
+   * This component represents a tree view with expandable/collapsible nodes.
+   * The tree is rendered using <table> element where every node is represented
+   * by <tr> element. The tree is one big table where nodes (rows) are properly
+   * indented from the left to mimic hierarchical structure of the data.
+   *
+   * The tree can have arbitrary number of columns and so, might be use
+   * as an expandable tree-table UI widget as well. By default, there is
+   * one column for node label and one for node value.
+   *
+   * The tree is maintaining its (presentation) state, which consists
+   * from list of expanded nodes and list of columns.
+   *
+   * Complete data provider interface:
+   * var TreeProvider = {
+   *   getChildren: function(object);
+   *   hasChildren: function(object);
+   *   getLabel: function(object, colId);
+   *   getValue: function(object, colId);
+   *   getKey: function(object);
+   *   getType: function(object);
+   * }
+   *
+   * Complete tree decorator interface:
+   * var TreeDecorator = {
+   *   getRowClass: function(object);
+   *   getCellClass: function(object, colId);
+   *   getHeaderClass: function(colId);
+   *   renderValue: function(object, colId);
+   *   renderRow: function(object);
+   *   renderCelL: function(object, colId);
+   *   renderLabelCell: function(object);
+   * }
+   */
+  let TreeView = React.createClass({
+    displayName: "TreeView",
+
+    // The only required property (not set by default) is the input data
+    // object that is used to puputate the tree.
+    propTypes: {
+      // The input data object.
+      object: PropTypes.any,
+      className: PropTypes.string,
+      // Data provider (see also the interface above)
+      provider: PropTypes.shape({
+        getChildren: PropTypes.func,
+        hasChildren: PropTypes.func,
+        getLabel: PropTypes.func,
+        getValue: PropTypes.func,
+        getKey: PropTypes.func,
+        getType: PropTypes.func,
+      }).isRequired,
+      // Tree decorator (see also the interface above)
+      decorator: PropTypes.shape({
+        getRowClass: PropTypes.func,
+        getCellClass: PropTypes.func,
+        getHeaderClass: PropTypes.func,
+        renderValue: PropTypes.func,
+        renderRow: PropTypes.func,
+        renderCelL: PropTypes.func,
+        renderLabelCell: PropTypes.func,
+      }),
+      // Custom tree row (node) renderer
+      renderRow: PropTypes.func,
+      // Custom cell renderer
+      renderCell: PropTypes.func,
+      // Custom value renderef
+      renderValue: PropTypes.func,
+      // Custom tree label (including a toggle button) renderer
+      renderLabelCell: PropTypes.func,
+      // Set of expanded nodes
+      expandedNodes: PropTypes.object,
+      // Custom filtering callback
+      onFilter: PropTypes.func,
+      // Custom sorting callback
+      onSort: PropTypes.func,
+      // A header is displayed if set to true
+      header: PropTypes.bool,
+      // Array of columns
+      columns: PropTypes.arrayOf(PropTypes.shape({
+        id: PropTypes.string.isRequired,
+        title: PropTypes.string,
+        width: PropTypes.string
+      }))
+    },
+
+    getDefaultProps: function () {
+      return {
+        object: null,
+        renderRow: null,
+        provider: ObjectProvider,
+        expandedNodes: new Set(),
+        columns: []
+      };
+    },
+
+    getInitialState: function () {
+      return {
+        expandedNodes: this.props.expandedNodes,
+        columns: ensureDefaultColumn(this.props.columns)
+      };
+    },
+
+    // Node expand/collapse
+
+    toggle: function (nodePath) {
+      let nodes = this.state.expandedNodes;
+      if (this.isExpanded(nodePath)) {
+        nodes.delete(nodePath);
+      } else {
+        nodes.add(nodePath);
+      }
+
+      // Compute new state and update the tree.
+      this.setState(Object.assign({}, this.state, {
+        expandedNodes: nodes
+      }));
+    },
+
+    isExpanded: function (nodePath) {
+      return this.state.expandedNodes.has(nodePath);
+    },
+
+    // Event Handlers
+
+    onClickRow: function (nodePath, event) {
+      event.stopPropagation();
+      this.toggle(nodePath);
+    },
+
+    // Filtering & Sorting
+
+    /**
+     * Filter out nodes that don't correspond to the current filter.
+     * @return {Boolean} true if the node should be visible otherwise false.
+     */
+    onFilter: function (object) {
+      let onFilter = this.props.onFilter;
+      return onFilter ? onFilter(object) : true;
+    },
+
+    onSort: function (parent, children) {
+      let onSort = this.props.onSort;
+      return onSort ? onSort(parent, children) : children;
+    },
+
+    // Members
+
+    /**
+     * Return children node objects (so called 'members') for given
+     * parent object.
+     */
+    getMembers: function (parent, level, path) {
+      // Strings don't have children. Note that 'long' strings are using
+      // the expander icon (+/-) to display the entire original value,
+      // but there are no child items.
+      if (typeof parent == "string") {
+        return [];
+      }
+
+      let provider = this.props.provider;
+      let children = provider.getChildren(parent) || [];
+
+      // If the return value is non-array, the children
+      // are being loaded asynchronously.
+      if (!Array.isArray(children)) {
+        return children;
+      }
+
+      children = this.onSort(parent, children) || children;
+
+      return children.map(child => {
+        let key = provider.getKey(child);
+        let nodePath = path + "/" + key;
+        let type = provider.getType(child);
+        let hasChildren = provider.hasChildren(child);
+
+        // Value with no column specified is used for optimization.
+        // The row is re-rendered only if this value changes.
+        // Value for actual column is get when a cell is rendered.
+        let value = provider.getValue(child);
+
+        if (isLongString(value)) {
+          hasChildren = true;
+        }
+
+        // Return value is a 'member' object containing meta-data about
+        // tree node. It describes node label, value, type, etc.
+        return {
+          // An object associated with this node.
+          object: child,
+          // A label for the child node
+          name: provider.getLabel(child),
+          // Data type of the child node (used for CSS customization)
+          type: type,
+          // Class attribute computed from the type.
+          rowClass: "treeRow-" + type,
+          // Level of the child within the hierarchy (top == 0)
+          level: level,
+          // True if this node has children.
+          hasChildren: hasChildren,
+          // Value associated with this node (as provided by the data provider)
+          value: value,
+          // True if the node is expanded.
+          open: this.isExpanded(nodePath),
+          // Node path
+          path: nodePath,
+          // True if the node is hidden (used for filtering)
+          hidden: !this.onFilter(child)
+        };
+      });
+    },
+
+    /**
+     * Render tree rows/nodes.
+     */
+    renderRows: function (parent, level = 0, path = "") {
+      let rows = [];
+      let decorator = this.props.decorator;
+      let renderRow = this.props.renderRow || TreeRow;
+
+      // Get children for given parent node, iterate over them and render
+      // a row for every one. Use row template (a component) from properties.
+      // If the return value is non-array, the children are being loaded
+      // asynchronously.
+      let members = this.getMembers(parent, level, path);
+      if (!Array.isArray(members)) {
+        return members;
+      }
+
+      members.forEach(member => {
+        if (decorator && decorator.renderRow) {
+          renderRow = decorator.renderRow(member.object) || renderRow;
+        }
+
+        let props = Object.assign({}, this.props, {
+          key: member.path,
+          member: member,
+          columns: this.state.columns,
+          onClick: this.onClickRow.bind(this, member.path)
+        });
+
+        // Render single row.
+        rows.push(renderRow(props));
+
+        // If a child node is expanded render its rows too.
+        if (member.hasChildren && member.open) {
+          let childRows = this.renderRows(member.object, level + 1,
+            member.path);
+
+          // If children needs to be asynchronously fetched first,
+          // set 'loading' property to the parent row. Otherwise
+          // just append children rows to the array of all rows.
+          if (!Array.isArray(childRows)) {
+            let lastIndex = rows.length - 1;
+            props.member.loading = true;
+            rows[lastIndex] = React.cloneElement(rows[lastIndex], props);
+          } else {
+            rows = rows.concat(childRows);
+          }
+        }
+      });
+
+      return rows;
+    },
+
+    render: function () {
+      let root = this.props.object;
+      let classNames = ["treeTable"];
+
+      // Use custom class name from props.
+      let className = this.props.className;
+      if (className) {
+        classNames.push(...className.split(" "));
+      }
+
+      // Alright, let's render all tree rows. The tree is one big <table>.
+      let rows = this.renderRows(root, 0, "");
+
+      // This happens when the view needs to do initial asynchronous
+      // fetch for the root object. The tree might provide a hook API
+      // for rendering animated spinner (just like for tree nodes).
+      if (!Array.isArray(rows)) {
+        rows = [];
+      }
+
+      let props = Object.assign({}, this.props, {
+        columns: this.state.columns
+      });
+
+      return (
+        DOM.table({
+          className: classNames.join(" "),
+          cellPadding: 0,
+          cellSpacing: 0},
+          TreeHeader(props),
+          DOM.tbody({},
+            rows
+          )
+        )
+      );
+    }
+  });
+
+  // Helpers
+
+  /**
+   * There should always be at least one column (the one with toggle buttons)
+   * and this function ensures that it's true.
+   */
+  function ensureDefaultColumn(columns) {
+    if (!columns) {
+      columns = [];
+    }
+
+    let defaultColumn = columns.filter(col => col.id == "default");
+    if (defaultColumn.length) {
+      return columns;
+    }
+
+    // The default column is usually the first one.
+    return [{id: "default"}, ...columns];
+  }
+
+  function isLongString(value) {
+    return typeof value == "string" && value.length > 50;
+  }
+
+  // Exports from this module
+  module.exports = TreeView;
+});