Add m-esr52 at 52.6.0

94 files changed, 6683 insertions, 0 deletions

diff --git a/devtools/client/memory/test/browser/.eslintrc.js b/devtools/client/memory/test/browser/.eslintrc.js
new file mode 100644
index 000000000..698ae9181
--- /dev/null
+++ b/devtools/client/memory/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/memory/test/browser/browser.ini b/devtools/client/memory/test/browser/browser.ini
new file mode 100644
index 000000000..dc803a335
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser.ini
@@ -0,0 +1,31 @@
+[DEFAULT]
+tags = devtools devtools-memory
+subsuite = devtools
+support-files =
+  head.js
+  doc_big_tree.html
+  doc_empty.html
+  doc_steady_allocation.html
+  !/devtools/client/framework/test/shared-head.js
+  !/devtools/client/framework/test/shared-redux-head.js
+
+[browser_memory_allocationStackDisplay_01.js]
+    skip-if = debug # bug 1219554
+[browser_memory_displays_01.js]
+[browser_memory_clear_snapshots.js]
+[browser_memory_diff_01.js]
+[browser_memory_dominator_trees_01.js]
+[browser_memory_dominator_trees_02.js]
+[browser_memory_filter_01.js]
+[browser_memory_individuals_01.js]
+[browser_memory_keyboard.js]
+[browser_memory_keyboard-snapshot-list.js]
+[browser_memory_no_allocation_stacks.js]
+[browser_memory_no_auto_expand.js]
+    skip-if = debug # bug 1219554
+[browser_memory_percents_01.js]
+[browser_memory_refresh_does_not_leak.js]
+[browser_memory_simple_01.js]
+[browser_memory_transferHeapSnapshot_e10s_01.js]
+[browser_memory_tree_map-01.js]
+[browser_memory_tree_map-02.js]
diff --git a/devtools/client/memory/test/browser/browser_memory_allocationStackDisplay_01.js b/devtools/client/memory/test/browser/browser_memory_allocationStackDisplay_01.js
new file mode 100644
index 000000000..60cd5c456
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_allocationStackDisplay_01.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test that we can show allocation stack displays in the tree.
+
+"use strict";
+
+const { toggleRecordingAllocationStacks } = require("devtools/client/memory/actions/allocations");
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const censusDisplayActions = require("devtools/client/memory/actions/census-display");
+const { viewState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const { getState, dispatch } = panel.panelWin.gStore;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  dispatch(censusDisplayActions.setCensusDisplay(censusDisplays.invertedAllocationStack));
+  is(getState().censusDisplay.breakdown.by, "allocationStack");
+
+  yield dispatch(toggleRecordingAllocationStacks(front));
+  ok(getState().allocations.recording);
+
+  // Let some allocations build up.
+  yield waitForTime(500);
+
+  yield dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  const names = [...doc.querySelectorAll(".frame-link-function-display-name")];
+  ok(names.length, "Should have rendered some allocation stack tree items");
+  ok(names.some(e => !!e.textContent.trim()),
+     "And at least some of them should have functionDisplayNames");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_clear_snapshots.js b/devtools/client/memory/test/browser/browser_memory_clear_snapshots.js
new file mode 100644
index 000000000..ca577bcd2
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_clear_snapshots.js
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests taking and then clearing snapshots.
+ */
+
+ const { treeMapState } = require("devtools/client/memory/constants");
+ const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+ this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+   const { gStore, document } = panel.panelWin;
+   const { getState, dispatch } = gStore;
+
+   let snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+   is(getState().snapshots.length, 0, "Starts with no snapshots in store");
+   is(snapshotEls.length, 0, "No snapshots visible");
+
+   info("Take two snapshots");
+   takeSnapshot(panel.panelWin);
+   takeSnapshot(panel.panelWin);
+   yield waitUntilState(gStore, state =>
+    state.snapshots.length === 2 &&
+    state.snapshots[0].treeMap && state.snapshots[1].treeMap &&
+    state.snapshots[0].treeMap.state === treeMapState.SAVED &&
+    state.snapshots[1].treeMap.state === treeMapState.SAVED);
+
+   snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+   is(snapshotEls.length, 2, "Two snapshots visible");
+
+   info("Click on Clear Snapshots");
+   yield clearSnapshots(panel.panelWin);
+   is(getState().snapshots.length, 0, "No snapshots in store");
+   snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+   is(snapshotEls.length, 0, "No snapshot visible");
+ });
diff --git a/devtools/client/memory/test/browser/browser_memory_diff_01.js b/devtools/client/memory/test/browser/browser_memory_diff_01.js
new file mode 100644
index 000000000..0deb2a078
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_diff_01.js
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test diffing.
+
+"use strict";
+
+const {
+  snapshotState,
+  diffingState,
+  treeMapState
+} = require("devtools/client/memory/constants");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  ok(!getState().diffing, "Not diffing by default.");
+
+  // Take two snapshots.
+  const takeSnapshotButton = doc.getElementById("take-snapshot");
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+  yield waitForTime(1000);
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+
+  // Enable diffing mode.
+  const diffButton = doc.getElementById("diff-snapshots");
+  EventUtils.synthesizeMouseAtCenter(diffButton, {}, panel.panelWin);
+  yield waitUntilState(store,
+                       state =>
+                         !!state.diffing &&
+                         state.diffing.state === diffingState.SELECTING);
+  ok(true, "Clicking the diffing button put us into the diffing state.");
+  is(getDisplayedSnapshotStatus(doc), "Select the baseline snapshot");
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length === 2 &&
+    state.snapshots[0].treeMap && state.snapshots[1].treeMap &&
+    state.snapshots[0].treeMap.state === treeMapState.SAVED &&
+    state.snapshots[1].treeMap.state === treeMapState.SAVED);
+
+  const listItems = [...doc.querySelectorAll(".snapshot-list-item")];
+  is(listItems.length, 2, "Should have two snapshot list items");
+
+  // Select the first snapshot.
+  EventUtils.synthesizeMouseAtCenter(listItems[0], {}, panel.panelWin);
+  yield waitUntilState(store,
+                       state =>
+                         state.diffing.state === diffingState.SELECTING &&
+                         state.diffing.firstSnapshotId);
+  is(getDisplayedSnapshotStatus(doc),
+     "Select the snapshot to compare to the baseline");
+
+  // Select the second snapshot.
+  EventUtils.synthesizeMouseAtCenter(listItems[1], {}, panel.panelWin);
+  yield waitUntilState(store,
+                       state =>
+                         state.diffing.state === diffingState.TAKING_DIFF);
+  ok(true, "Selecting two snapshots for diffing triggers computing the diff");
+
+  // .startsWith because the ellipsis is lost in translation.
+  ok(getDisplayedSnapshotStatus(doc).startsWith("Computing difference"));
+
+  yield waitUntilState(store,
+                       state => state.diffing.state === diffingState.TOOK_DIFF);
+  ok(true, "And that diff is computed successfully");
+  is(getDisplayedSnapshotStatus(doc), null, "No status text anymore");
+  ok(doc.querySelector(".heap-tree-item"), "And instead we should be showing the tree");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_displays_01.js b/devtools/client/memory/test/browser/browser_memory_displays_01.js
new file mode 100644
index 000000000..b5f9e34d9
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_displays_01.js
@@ -0,0 +1,41 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests that the heap tree renders rows based on the display
+ */
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+const { viewState, censusState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const { gStore, document } = panel.panelWin;
+
+  const { dispatch } = panel.panelWin.gStore;
+
+  function $$(selector) {
+    return [...document.querySelectorAll(selector)];
+  }
+  dispatch(changeView(viewState.CENSUS));
+
+  yield takeSnapshot(panel.panelWin);
+
+  yield waitUntilState(gStore, state =>
+    state.snapshots[0].census &&
+    state.snapshots[0].census.state === censusState.SAVED);
+
+  info("Check coarse type heap view");
+  ["Function", "js::Shape", "Object", "strings"].forEach(findNameCell);
+
+  yield setCensusDisplay(panel.panelWin, censusDisplays.allocationStack);
+  info("Check allocation stack heap view");
+  [L10N.getStr("tree-item.nostack")].forEach(findNameCell);
+
+  function findNameCell(name) {
+    const el = $$(".tree .heap-tree-item-name span")
+      .find(e => e.textContent === name);
+    ok(el, `Found heap tree item cell for ${name}.`);
+  }
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_dominator_trees_01.js b/devtools/client/memory/test/browser/browser_memory_dominator_trees_01.js
new file mode 100644
index 000000000..3380d6e21
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_dominator_trees_01.js
@@ -0,0 +1,147 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test for dominator trees, their focused nodes, and keyboard navigating
+// through nodes across incrementally fetching subtrees.
+
+"use strict";
+
+const {
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  expandDominatorTreeNode,
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_big_tree.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  // Taking snapshots and computing dominator trees is slow :-/
+  requestLongerTimeout(4);
+
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+
+  // Take a snapshot.
+
+  const takeSnapshotButton = doc.getElementById("take-snapshot");
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+
+  // Wait for the dominator tree to be computed and fetched.
+
+  yield waitUntilDominatorTreeState(store, [dominatorTreeState.LOADED]);
+  ok(true, "Computed and fetched the dominator tree.");
+
+  // Expand all the dominator tree nodes that are eagerly fetched, except for
+  // the leaves which will trigger fetching their lazily loaded subtrees.
+
+  const id = getState().snapshots[0].id;
+  const root = getState().snapshots[0].dominatorTree.root;
+  (function expandAllEagerlyFetched(node = root) {
+    if (!node.moreChildrenAvailable || node.children) {
+      dispatch(expandDominatorTreeNode(id, node));
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        expandAllEagerlyFetched(child);
+      }
+    }
+  }());
+
+  // Find the deepest eagerly loaded node: one which has more children but none
+  // of them are loaded.
+
+  const deepest = (function findDeepest(node = root) {
+    if (node.moreChildrenAvailable && !node.children) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findDeepest(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }());
+
+  ok(deepest, "Found the deepest node");
+  ok(!getState().snapshots[0].dominatorTree.expanded.has(deepest.nodeId),
+     "The deepest node should not be expanded");
+
+  // Select the deepest node.
+
+  EventUtils.synthesizeMouseAtCenter(doc.querySelector(`.node-${deepest.nodeId}`),
+                                     {},
+                                     panel.panelWin);
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.focused.nodeId === deepest.nodeId);
+  ok(doc.querySelector(`.node-${deepest.nodeId}`).classList.contains("focused"),
+     "The deepest node should be focused now");
+
+  // Expand the deepest node, which triggers an incremental fetch of its lazily
+  // loaded subtree.
+
+  EventUtils.synthesizeKey("VK_RIGHT", {}, panel.panelWin);
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.expanded.has(deepest.nodeId));
+  is(getState().snapshots[0].dominatorTree.state,
+     dominatorTreeState.INCREMENTAL_FETCHING,
+     "Expanding the deepest node should start an incremental fetch of its subtree");
+  ok(doc.querySelector(`.node-${deepest.nodeId}`).classList.contains("focused"),
+     "The deepest node should still be focused after expansion");
+
+  // Wait for the incremental fetch to complete.
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "And the incremental fetch completes.");
+  ok(doc.querySelector(`.node-${deepest.nodeId}`).classList.contains("focused"),
+     "The deepest node should still be focused after we have loaded its children");
+
+  // Find the most up-to-date version of the node whose children we just
+  // incrementally fetched.
+
+  const newDeepest = (function findNewDeepest(node = getState().snapshots[0].dominatorTree.root) {
+    if (node.nodeId === deepest.nodeId) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findNewDeepest(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }());
+
+  ok(newDeepest, "We found the up-to-date version of deepest");
+  ok(newDeepest.children, "And its children are loaded");
+  ok(newDeepest.children.length, "And there are more than 0 children");
+
+  const firstChild = newDeepest.children[0];
+  ok(firstChild, "deepest should have a first child");
+  ok(doc.querySelector(`.node-${firstChild.nodeId}`),
+     "and the first child should exist in the dom");
+
+  // Select the newly loaded first child by pressing the right arrow once more.
+
+  EventUtils.synthesizeKey("VK_RIGHT", {}, panel.panelWin);
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.focused === firstChild);
+  ok(doc.querySelector(`.node-${firstChild.nodeId}`).classList.contains("focused"),
+     "The first child should now be focused");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_dominator_trees_02.js b/devtools/client/memory/test/browser/browser_memory_dominator_trees_02.js
new file mode 100644
index 000000000..72bc52567
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_dominator_trees_02.js
@@ -0,0 +1,64 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Integration test for mouse interaction in the dominator tree
+
+"use strict";
+
+const {
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+function clickOnNodeArrow(node, panel) {
+  EventUtils.synthesizeMouseAtCenter(node.querySelector(".arrow"),
+                                     {}, panel.panelWin);
+}
+
+this.test = makeMemoryTest(TEST_URL, function* ({ panel }) {
+  // Taking snapshots and computing dominator trees is slow :-/
+  requestLongerTimeout(4);
+
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+
+  // Take a snapshot.
+  const takeSnapshotButton = doc.getElementById("take-snapshot");
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+
+  // Wait for the dominator tree to be computed and fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "Computed and fetched the dominator tree.");
+
+  const root = getState().snapshots[0].dominatorTree.root;
+  ok(getState().snapshots[0].dominatorTree.expanded.has(root.nodeId),
+     "Root node is expanded by default");
+
+  // Click on root arrow to collapse the root element
+  const rootNode = doc.querySelector(`.node-${root.nodeId}`);
+  clickOnNodeArrow(rootNode, panel);
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    !state.snapshots[0].dominatorTree.expanded.has(root.nodeId));
+  ok(true, "Root node collapsed");
+
+  // Click on root arrow to expand it again
+  clickOnNodeArrow(rootNode, panel);
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.expanded.has(root.nodeId));
+  ok(true, "Root node is expanded again");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_filter_01.js b/devtools/client/memory/test/browser/browser_memory_filter_01.js
new file mode 100644
index 000000000..448e2aaa9
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_filter_01.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test that we can show allocation stack displays in the tree.
+
+"use strict";
+
+const {
+  dominatorTreeState,
+  snapshotState,
+  viewState,
+  censusState,
+} = require("devtools/client/memory/constants");
+const { changeViewAndRefresh, changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  const takeSnapshotButton = doc.getElementById("take-snapshot");
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length === 1 &&
+    state.snapshots[0].census &&
+    state.snapshots[0].census.state === censusState.SAVING);
+
+  let filterInput = doc.getElementById("filter");
+  EventUtils.synthesizeMouseAtCenter(filterInput, {}, panel.panelWin);
+  EventUtils.sendString("js::Shape", panel.panelWin);
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length === 1 &&
+    state.snapshots[0].census &&
+    state.snapshots[0].census.state === censusState.SAVING);
+  ok(true, "adding a filter string should trigger census recompute");
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length === 1 &&
+    state.snapshots[0].census &&
+    state.snapshots[0].census.state === censusState.SAVED);
+
+  let nameElem = doc.querySelector(".heap-tree-item-field.heap-tree-item-name");
+  ok(nameElem, "Should get a tree item row with a name");
+  is(nameElem.textContent.trim(), "js::Shape", "the tree item should be the one we filtered for");
+  is(filterInput.value, "js::Shape",
+    "and filter input contains the user value");
+
+  // Now switch the dominator view, then switch back to census view
+  // and check that the filter word is still correctly applied
+  dispatch(changeViewAndRefresh(viewState.DOMINATOR_TREE, heapWorker));
+  ok(true, "change view to dominator tree");
+
+  // Wait for the dominator tree to be computed and fetched.
+  yield waitUntilDominatorTreeState(store, [dominatorTreeState.LOADED]);
+  ok(true, "computed and fetched the dominator tree.");
+
+  dispatch(changeViewAndRefresh(viewState.CENSUS, heapWorker));
+  ok(true, "change view back to census");
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length === 1 &&
+    state.snapshots[0].census &&
+    state.snapshots[0].census.state === censusState.SAVED);
+
+  nameElem = doc.querySelector(".heap-tree-item-field.heap-tree-item-name");
+  filterInput = doc.getElementById("filter");
+
+  ok(nameElem, "Should still get a tree item row with a name");
+  is(nameElem.textContent.trim(), "js::Shape",
+    "the tree item should still be the one we filtered for");
+  is(filterInput.value, "js::Shape",
+    "and filter input still contains the user value");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_individuals_01.js b/devtools/client/memory/test/browser/browser_memory_individuals_01.js
new file mode 100644
index 000000000..eae8248c3
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_individuals_01.js
@@ -0,0 +1,67 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test that we can show census group individuals, and then go back to
+// the previous view.
+
+"use strict";
+
+const {
+  individualsState,
+  viewState,
+  censusState,
+} = require("devtools/client/memory/constants");
+const { changeViewAndRefresh, changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Take a snapshot and wait for the census to finish.
+
+  const takeSnapshotButton = doc.getElementById("take-snapshot");
+  EventUtils.synthesizeMouseAtCenter(takeSnapshotButton, {}, panel.panelWin);
+
+  yield waitUntilState(store, state => {
+    return state.snapshots.length === 1 &&
+           state.snapshots[0].census &&
+           state.snapshots[0].census.state === censusState.SAVED;
+  });
+
+  // Click on the first individuals button found, and wait for the individuals
+  // to be fetched.
+
+  const individualsButton = doc.querySelector(".individuals-button");
+  EventUtils.synthesizeMouseAtCenter(individualsButton, {}, panel.panelWin);
+
+  yield waitUntilState(store, state => {
+    return state.view.state === viewState.INDIVIDUALS &&
+           state.individuals &&
+           state.individuals.state === individualsState.FETCHED;
+  });
+
+  ok(doc.getElementById("shortest-paths"),
+     "Should be showing the shortest paths component");
+  ok(doc.querySelector(".heap-tree-item"),
+     "Should be showing the individuals");
+
+  // Go back to the previous view.
+
+  const popViewButton = doc.getElementById("pop-view-button");
+  ok(popViewButton, "Should be showing the #pop-view-button");
+  EventUtils.synthesizeMouseAtCenter(popViewButton, {}, panel.panelWin);
+
+  yield waitUntilState(store, state => {
+    return state.view.state === viewState.CENSUS;
+  });
+
+  ok(!doc.getElementById("shortest-paths"),
+     "Should not be showing the shortest paths component anymore");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_keyboard-snapshot-list.js b/devtools/client/memory/test/browser/browser_memory_keyboard-snapshot-list.js
new file mode 100644
index 000000000..eb7cb8aca
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_keyboard-snapshot-list.js
@@ -0,0 +1,99 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that using ACCEL+UP/DOWN, the user can navigate between snapshots.
+
+"use strict";
+
+const {
+  snapshotState,
+  viewState,
+  censusState
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ panel }) {
+  // Creating snapshots already takes ~25 seconds on linux 32 debug machines
+  // which makes the test very likely to go over the allowed timeout
+  requestLongerTimeout(2);
+
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  info("Take 3 snapshots");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  yield waitUntilState(store, state =>
+    state.snapshots.length == 3 &&
+    state.snapshots.every(s => s.census && s.census.state === censusState.SAVED));
+  ok(true, "All snapshots censuses are in SAVED state");
+
+  yield waitUntilSnapshotSelected(store, 2);
+  ok(true, "Third snapshot selected after creating all snapshots.");
+
+  info("Press ACCEL+UP key, expect second snapshot selected.");
+  EventUtils.synthesizeKey("VK_UP", { accelKey: true }, panel.panelWin);
+  yield waitUntilSnapshotSelected(store, 1);
+  ok(true, "Second snapshot selected after alt+UP.");
+
+  info("Press ACCEL+UP key, expect first snapshot selected.");
+  EventUtils.synthesizeKey("VK_UP", { accelKey: true }, panel.panelWin);
+  yield waitUntilSnapshotSelected(store, 0);
+  ok(true, "First snapshot is selected after ACCEL+UP");
+
+  info("Check ACCEL+UP is a noop when the first snapshot is selected.");
+  EventUtils.synthesizeKey("VK_UP", { accelKey: true }, panel.panelWin);
+  // We assume the snapshot selection should be synchronous here.
+  is(getSelectedSnapshotIndex(store), 0, "First snapshot is still selected");
+
+  info("Press ACCEL+DOWN key, expect second snapshot selected.");
+  EventUtils.synthesizeKey("VK_DOWN", { accelKey: true }, panel.panelWin);
+  yield waitUntilSnapshotSelected(store, 1);
+  ok(true, "Second snapshot is selected after ACCEL+DOWN");
+
+  info("Click on first node.");
+  let firstNode = doc.querySelector(".tree .heap-tree-item-name");
+  EventUtils.synthesizeMouseAtCenter(firstNode, {}, panel.panelWin);
+  yield waitUntilState(store, state => state.snapshots[1].census.focused ===
+      state.snapshots[1].census.report.children[0]
+  );
+  ok(true, "First root is selected after click.");
+
+  info("Press DOWN key, expect second root focused.");
+  EventUtils.synthesizeKey("VK_DOWN", {}, panel.panelWin);
+  yield waitUntilState(store, state => state.snapshots[1].census.focused ===
+      state.snapshots[1].census.report.children[1]
+  );
+  ok(true, "Second root is selected after pressing DOWN.");
+  is(getSelectedSnapshotIndex(store), 1, "Second snapshot is still selected");
+
+  info("Press UP key, expect second root focused.");
+  EventUtils.synthesizeKey("VK_UP", {}, panel.panelWin);
+  yield waitUntilState(store, state => state.snapshots[1].census.focused ===
+      state.snapshots[1].census.report.children[0]
+  );
+  ok(true, "First root is selected after pressing UP.");
+  is(getSelectedSnapshotIndex(store), 1, "Second snapshot is still selected");
+
+  info("Press ACCEL+DOWN key, expect third snapshot selected.");
+  EventUtils.synthesizeKey("VK_DOWN", { accelKey: true }, panel.panelWin);
+  yield waitUntilSnapshotSelected(store, 2);
+  ok(true, "Thirdˆ snapshot is selected after ACCEL+DOWN");
+
+  info("Check ACCEL+DOWN is a noop when the last snapshot is selected.");
+  EventUtils.synthesizeKey("VK_DOWN", { accelKey: true }, panel.panelWin);
+  // We assume the snapshot selection should be synchronous here.
+  is(getSelectedSnapshotIndex(store), 2, "Third snapshot is still selected");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_keyboard.js b/devtools/client/memory/test/browser/browser_memory_keyboard.js
new file mode 100644
index 000000000..243570f83
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_keyboard.js
@@ -0,0 +1,107 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Bug 1246570 - Check that when pressing on LEFT arrow, the parent tree node
+// gets focused.
+
+"use strict";
+
+const {
+  snapshotState,
+  censusState,
+  viewState
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+function waitUntilFocused(store, node) {
+  return waitUntilState(store, state =>
+      state.snapshots.length === 1 &&
+      state.snapshots[0].census &&
+      state.snapshots[0].census.state === censusState.SAVED &&
+      state.snapshots[0].census.focused &&
+      state.snapshots[0].census.focused === node
+  );
+}
+
+function waitUntilExpanded(store, node) {
+  return waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].census &&
+    state.snapshots[0].census.expanded.has(node.id));
+}
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  is(getState().censusDisplay.breakdown.by, "coarseType");
+
+  yield dispatch(takeSnapshotAndCensus(front, heapWorker));
+  let census = getState().snapshots[0].census;
+  let root1 = census.report.children[0];
+  let root2 = census.report.children[0];
+  let root3 = census.report.children[0];
+  let root4 = census.report.children[0];
+  let child1 = root1.children[0];
+
+  info("Click on first node.");
+  let firstNode = doc.querySelector(".tree .heap-tree-item-name");
+  EventUtils.synthesizeMouseAtCenter(firstNode, {}, panel.panelWin);
+  yield waitUntilFocused(store, root1);
+  ok(true, "First root is selected after click.");
+
+  info("Press DOWN key, expect second root focused.");
+  EventUtils.synthesizeKey("VK_DOWN", {}, panel.panelWin);
+  yield waitUntilFocused(store, root2);
+  ok(true, "Second root is selected after pressing DOWN arrow.");
+
+  info("Press DOWN key, expect third root focused.");
+  EventUtils.synthesizeKey("VK_DOWN", {}, panel.panelWin);
+  yield waitUntilFocused(store, root3);
+  ok(true, "Third root is selected after pressing DOWN arrow.");
+
+  info("Press DOWN key, expect fourth root focused.");
+  EventUtils.synthesizeKey("VK_DOWN", {}, panel.panelWin);
+  yield waitUntilFocused(store, root4);
+  ok(true, "Fourth root is selected after pressing DOWN arrow.");
+
+  info("Press UP key, expect third root focused.");
+  EventUtils.synthesizeKey("VK_UP", {}, panel.panelWin);
+  yield waitUntilFocused(store, root3);
+  ok(true, "Third root is selected after pressing UP arrow.");
+
+  info("Press UP key, expect second root focused.");
+  EventUtils.synthesizeKey("VK_UP", {}, panel.panelWin);
+  yield waitUntilFocused(store, root2);
+  ok(true, "Second root is selected after pressing UP arrow.");
+
+  info("Press UP key, expect first root focused.");
+  EventUtils.synthesizeKey("VK_UP", {}, panel.panelWin);
+  yield waitUntilFocused(store, root1);
+  ok(true, "First root is selected after pressing UP arrow.");
+
+  info("Press RIGHT key");
+  EventUtils.synthesizeKey("VK_RIGHT", {}, panel.panelWin);
+  yield waitUntilExpanded(store, root1);
+  ok(true, "Root node is expanded.");
+
+  info("Press RIGHT key, expect first child focused.");
+  EventUtils.synthesizeKey("VK_RIGHT", {}, panel.panelWin);
+  yield waitUntilFocused(store, child1);
+  ok(true, "First child is selected after pressing RIGHT arrow.");
+
+  info("Press LEFT key, expect first root focused.");
+  EventUtils.synthesizeKey("VK_LEFT", {}, panel.panelWin);
+  yield waitUntilFocused(store, root1);
+  ok(true, "First root is selected after pressing LEFT arrow.");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_no_allocation_stacks.js b/devtools/client/memory/test/browser/browser_memory_no_allocation_stacks.js
new file mode 100644
index 000000000..cd8770285
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_no_allocation_stacks.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test that we can show allocation stack displays in the tree.
+
+"use strict";
+
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const censusDisplayActions = require("devtools/client/memory/actions/census-display");
+const { viewState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const { getState, dispatch } = panel.panelWin.gStore;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  ok(!getState().allocations.recording,
+     "Should not be recording allocagtions");
+
+  yield dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield dispatch(censusDisplayActions.setCensusDisplayAndRefresh(
+    heapWorker,
+    censusDisplays.allocationStack));
+
+  is(getState().censusDisplay.breakdown.by, "allocationStack",
+     "Should be using allocation stack breakdown");
+
+  ok(!getState().allocations.recording,
+     "Should still not be recording allocagtions");
+
+  ok(doc.querySelector(".no-allocation-stacks"),
+     "Because we did not record allocations, the no-allocation-stack warning should be visible");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_no_auto_expand.js b/devtools/client/memory/test/browser/browser_memory_no_auto_expand.js
new file mode 100644
index 000000000..ffd481c74
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_no_auto_expand.js
@@ -0,0 +1,37 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Bug 1221150 - Ensure that census trees do not accidentally auto expand
+// when clicking on the allocation stacks checkbox.
+
+"use strict";
+
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const { viewState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const { getState, dispatch } = panel.panelWin.gStore;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  yield dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  is(getState().allocations.recording, false);
+  const recordingCheckbox = doc.getElementById("record-allocation-stacks-checkbox");
+  EventUtils.synthesizeMouseAtCenter(recordingCheckbox, {}, panel.panelWin);
+  is(getState().allocations.recording, true);
+
+  const nameElems = [...doc.querySelectorAll(".heap-tree-item-field.heap-tree-item-name")];
+
+  for (let el of nameElems) {
+    dumpn(`Found ${el.textContent.trim()}`);
+    is(el.style.marginInlineStart, "0px",
+       "None of the elements should be an indented/expanded child");
+  }
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_percents_01.js b/devtools/client/memory/test/browser/browser_memory_percents_01.js
new file mode 100644
index 000000000..c3ed37530
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_percents_01.js
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Sanity test that we calculate percentages in the tree.
+
+"use strict";
+
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const { viewState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+
+function checkCells(cells) {
+  ok(cells.length > 1, "Should have found some");
+  // Ignore the first header cell.
+  for (let cell of cells.slice(1)) {
+    const percent = cell.querySelector(".heap-tree-percent");
+    ok(percent, "should have a percent cell");
+    ok(percent.textContent.match(/^\d?\d%$/), "should be of the form nn% or n%");
+  }
+}
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const { getState, dispatch } = panel.panelWin.gStore;
+  const doc = panel.panelWin.document;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  yield dispatch(takeSnapshotAndCensus(front, heapWorker));
+  is(getState().censusDisplay.breakdown.by, "coarseType",
+     "Should be using coarse type breakdown");
+
+  const bytesCells = [...doc.querySelectorAll(".heap-tree-item-bytes")];
+  checkCells(bytesCells);
+
+  const totalBytesCells = [...doc.querySelectorAll(".heap-tree-item-total-bytes")];
+  checkCells(totalBytesCells);
+
+  const countCells = [...doc.querySelectorAll(".heap-tree-item-count")];
+  checkCells(countCells);
+
+  const totalCountCells = [...doc.querySelectorAll(".heap-tree-item-total-count")];
+  checkCells(totalCountCells);
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_refresh_does_not_leak.js b/devtools/client/memory/test/browser/browser_memory_refresh_does_not_leak.js
new file mode 100644
index 000000000..7ab768b01
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_refresh_does_not_leak.js
@@ -0,0 +1,108 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that refreshing the page with devtools open does not leak the old
+// windows from previous navigations.
+//
+// IF THIS TEST STARTS FAILING, YOU ARE LEAKING EVERY WINDOW EVER NAVIGATED TO
+// WHILE DEVTOOLS ARE OPEN! THIS IS NOT SPECIFIC TO THE MEMORY TOOL ONLY!
+
+"use strict";
+
+const HeapSnapshotFileUtils = require("devtools/shared/heapsnapshot/HeapSnapshotFileUtils");
+const { getLabelAndShallowSize } = require("devtools/shared/heapsnapshot/DominatorTreeNode");
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_empty.html";
+
+function* getWindowsInSnapshot(front) {
+  dumpn("Taking snapshot.");
+  const path = yield front.saveHeapSnapshot();
+  dumpn("Took snapshot with path = " + path);
+  const snapshot = ChromeUtils.readHeapSnapshot(path);
+  dumpn("Read snapshot into memory, taking census.");
+  const report = snapshot.takeCensus({
+    breakdown: {
+      by: "objectClass",
+      then: { by: "bucket" },
+      other: { by: "count", count: true, bytes: false },
+    }
+  });
+  dumpn("Took census, window count = " + report.Window.count);
+  return report.Window;
+}
+
+const DESCRIPTION = {
+  by: "coarseType",
+  objects: {
+    by: "objectClass",
+    then: { by: "count", count: true, bytes: false },
+    other: { by: "count", count: true, bytes: false },
+  },
+  strings: { by: "count", count: true, bytes: false },
+  scripts: {
+    by: "internalType",
+    then: { by: "count", count: true, bytes: false },
+  },
+  other: {
+    by: "internalType",
+    then: { by: "count", count: true, bytes: false },
+  }
+};
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const heapWorker = panel.panelWin.gHeapAnalysesClient;
+  const front = panel.panelWin.gFront;
+  const store = panel.panelWin.gStore;
+  const { getState, dispatch } = store;
+  const doc = panel.panelWin.document;
+
+  const startWindows = yield getWindowsInSnapshot(front);
+  dumpn("Initial windows found = " + startWindows.map(w => "0x" + w.toString(16)).join(", "));
+  is(startWindows.length, 1);
+
+  yield refreshTab(tab);
+
+  const endWindows = yield getWindowsInSnapshot(front);
+  is(endWindows.length, 1);
+
+  if (endWindows.length === 1) {
+    return;
+  }
+
+  dumpn("Test failed, diagnosing leaking windows.");
+  dumpn("(This may fail if a moving GC has relocated the initial Window objects.)");
+
+  dumpn("Taking full runtime snapshot.");
+  const path = yield front.saveHeapSnapshot({ boundaries: { runtime: true } });
+  dumpn("Full runtime's snapshot path = " + path);
+
+  dumpn("Reading full runtime heap snapshot.");
+  const snapshot = ChromeUtils.readHeapSnapshot(path);
+  dumpn("Done reading full runtime heap snapshot.");
+
+  const dominatorTree = snapshot.computeDominatorTree();
+  const paths = snapshot.computeShortestPaths(dominatorTree.root, startWindows, 50);
+
+  for (let i = 0; i < startWindows.length; i++) {
+    dumpn("Shortest retaining paths for leaking Window 0x" + startWindows[i].toString(16) + " =========================");
+    let j = 0;
+    for (let retainingPath of paths.get(startWindows[i])) {
+      if (retainingPath.find(part => part.predecessor === startWindows[i])) {
+        // Skip paths that loop out from the target window and back to it again.
+        continue;
+      }
+
+      dumpn("    Path #" + (++j) + ": --------------------------------------------------------------------");
+      for (let part of retainingPath) {
+        const { label } = getLabelAndShallowSize(part.predecessor, snapshot, DESCRIPTION);
+        dumpn("        0x" + part.predecessor.toString(16) +
+              " (" + label.join(" > ") + ")");
+        dumpn("               |");
+        dumpn("              " + part.edge);
+        dumpn("               |");
+        dumpn("               V");
+      }
+      dumpn("        0x" + startWindows[i].toString(16) + " (objects > Window)");
+    }
+  }
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_simple_01.js b/devtools/client/memory/test/browser/browser_memory_simple_01.js
new file mode 100644
index 000000000..9eaea2ad2
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_simple_01.js
@@ -0,0 +1,40 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests taking snapshots and default states.
+ */
+
+const TEST_URL = "http://example.com/browser/devtools/client/memory/test/browser/doc_steady_allocation.html";
+const { viewState, censusState } = require("devtools/client/memory/constants");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const { gStore, document } = panel.panelWin;
+  const { getState, dispatch } = gStore;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  let snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+  is(getState().snapshots.length, 0, "Starts with no snapshots in store");
+  is(snapshotEls.length, 0, "No snapshots rendered");
+
+  yield takeSnapshot(panel.panelWin);
+  snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+  is(getState().snapshots.length, 1, "One snapshot was created in store");
+  is(snapshotEls.length, 1, "One snapshot was rendered");
+  ok(snapshotEls[0].classList.contains("selected"), "Only snapshot has `selected` class");
+
+  yield takeSnapshot(panel.panelWin);
+  snapshotEls = document.querySelectorAll("#memory-tool-container .list li");
+  is(getState().snapshots.length, 2, "Two snapshots created in store");
+  is(snapshotEls.length, 2, "Two snapshots rendered");
+  ok(!snapshotEls[0].classList.contains("selected"), "First snapshot no longer has `selected` class");
+  ok(snapshotEls[1].classList.contains("selected"), "Second snapshot has `selected` class");
+
+  yield waitUntilCensusState(gStore, s => s.census, [censusState.SAVED,
+                                                     censusState.SAVED]);
+
+  ok(document.querySelector(".heap-tree-item-name"),
+    "Should have rendered some tree items");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js b/devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js
new file mode 100644
index 000000000..8ebb7622a
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can save a heap snapshot and transfer it over the RDP in e10s
+// where the child process is sandboxed and so we have to use
+// HeapSnapshotFileActor to get the heap snapshot file.
+
+"use strict";
+
+const TEST_URL = "data:text/html,<html><body></body></html>";
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const memoryFront = panel.panelWin.gFront;
+  ok(memoryFront, "Should get the MemoryFront");
+
+  const snapshotFilePath = yield memoryFront.saveHeapSnapshot({
+    // Force a copy so that we go through the HeapSnapshotFileActor's
+    // transferHeapSnapshot request and exercise this code path on e10s.
+    forceCopy: true
+  });
+
+  ok(!!(yield OS.File.stat(snapshotFilePath)),
+     "Should have the heap snapshot file");
+
+  const snapshot = ChromeUtils.readHeapSnapshot(snapshotFilePath);
+  ok(snapshot instanceof HeapSnapshot,
+     "And we should be able to read a HeapSnapshot instance from the file");
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_tree_map-01.js b/devtools/client/memory/test/browser/browser_memory_tree_map-01.js
new file mode 100644
index 000000000..ca564a658
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_tree_map-01.js
@@ -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/. */
+
+// Make sure the canvases are created correctly
+
+"use strict";
+
+const CanvasUtils = require("devtools/client/memory/components/tree-map/canvas-utils");
+const D3_SCRIPT = '<script type="application/javascript" ' +
+                  'src="chrome://devtools/content/shared/vendor/d3.js>';
+const TEST_URL = `data:text/html,<html><body>${D3_SCRIPT}</body></html>`;
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const document = panel.panelWin.document;
+  const window = panel.panelWin;
+  const div = document.createElement("div");
+
+  Object.assign(div.style, {
+    width: "100px",
+    height: "200px",
+    position: "absolute"
+  });
+
+  document.body.appendChild(div);
+
+  info("Create the canvases");
+
+  let canvases = new CanvasUtils(div, 0);
+
+  info("Test the shape of the returned object");
+
+  is(typeof canvases, "object", "Canvases create an object");
+  is(typeof canvases.emit, "function", "Decorated with an EventEmitter");
+  is(typeof canvases.on, "function", "Decorated with an EventEmitter");
+  is(div.children[0], canvases.container, "Div has the container");
+  ok(canvases.main.canvas instanceof window.HTMLCanvasElement,
+    "Creates the main canvas");
+  ok(canvases.zoom.canvas instanceof window.HTMLCanvasElement,
+    "Creates the zoom canvas");
+  ok(canvases.main.ctx instanceof window.CanvasRenderingContext2D,
+    "Creates the main canvas context");
+  ok(canvases.zoom.ctx instanceof window.CanvasRenderingContext2D,
+    "Creates the zoom canvas context");
+
+  info("Test resizing");
+
+  let timesResizeCalled = 0;
+  canvases.on("resize", function () {
+    timesResizeCalled++;
+  });
+
+  let main = canvases.main.canvas;
+  let zoom = canvases.zoom.canvas;
+  let ratio = window.devicePixelRatio;
+
+  is(main.width, 100 * ratio,
+    "Main canvas width is the same as the parent div");
+  is(main.height, 200 * ratio,
+    "Main canvas height is the same as the parent div");
+  is(zoom.width, 100 * ratio,
+    "Zoom canvas width is the same as the parent div");
+  is(zoom.height, 200 * ratio,
+    "Zoom canvas height is the same as the parent div");
+  is(timesResizeCalled, 0,
+    "Resize was not emitted");
+
+  div.style.width = "500px";
+  div.style.height = "700px";
+
+  window.dispatchEvent(new Event("resize"));
+
+  is(main.width, 500 * ratio,
+    "Main canvas width is resized to be the same as the parent div");
+  is(main.height, 700 * ratio,
+    "Main canvas height is resized to be the same as the parent div");
+  is(zoom.width, 500 * ratio,
+    "Zoom canvas width is resized to be the same as the parent div");
+  is(zoom.height, 700 * ratio,
+    "Zoom canvas height is resized to be the same as the parent div");
+  is(timesResizeCalled, 1,
+    "'resize' was emitted was emitted");
+
+  div.style.width = "1100px";
+  div.style.height = "1300px";
+
+  canvases.destroy();
+  window.dispatchEvent(new Event("resize"));
+
+  is(main.width, 500 * ratio,
+    "Main canvas width is not resized after destroy");
+  is(main.height, 700 * ratio,
+    "Main canvas height is not resized after destroy");
+  is(zoom.width, 500 * ratio,
+    "Zoom canvas width is not resized after destroy");
+  is(zoom.height, 700 * ratio,
+    "Zoom canvas height is not resized after destroy");
+  is(timesResizeCalled, 1,
+    "onResize was not called again");
+
+  document.body.removeChild(div);
+});
diff --git a/devtools/client/memory/test/browser/browser_memory_tree_map-02.js b/devtools/client/memory/test/browser/browser_memory_tree_map-02.js
new file mode 100644
index 000000000..15f8b0457
--- /dev/null
+++ b/devtools/client/memory/test/browser/browser_memory_tree_map-02.js
@@ -0,0 +1,161 @@
+/* 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/. */
+
+// Test the drag and zooming behavior
+
+"use strict";
+
+const CanvasUtils = require("devtools/client/memory/components/tree-map/canvas-utils");
+const DragZoom = require("devtools/client/memory/components/tree-map/drag-zoom");
+
+const TEST_URL = "data:text/html,<html><body></body></html>";
+const PIXEL_SCROLL_MODE = 0;
+const PIXEL_DELTA = 10;
+const MAX_RAF_LOOP = 1000;
+
+this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+  const panelWin = panel.panelWin;
+  const panelDoc = panelWin.document;
+  const div = panelDoc.createElement("div");
+
+  Object.assign(div.style, {
+    width: "100px",
+    height: "200px",
+    position: "absolute",
+    left:0,
+    top:0
+  });
+
+  let rafMock = createRAFMock();
+
+  panelDoc.body.appendChild(div);
+
+  let canvases = new CanvasUtils(div, 0);
+  let dragZoom = new DragZoom(canvases.container, 0, rafMock.raf);
+  let style = canvases.container.style;
+
+  info("Check initial state of dragZoom");
+  {
+    is(dragZoom.zoom, 0, "Zooming starts at 0");
+    is(dragZoom.smoothZoom, 0, "Smoothed zooming starts at 0");
+    is(rafMock.timesCalled, 0, "No RAFs have been queued");
+    is(style.transform, "translate(0px, 0px) scale(1)",
+       "No transforms have been done.");
+
+    canvases.container.dispatchEvent(new WheelEvent("wheel", {
+      deltaY: -PIXEL_DELTA,
+      deltaMode: PIXEL_SCROLL_MODE
+    }));
+
+    is(style.transform, "translate(0px, 0px) scale(1.05)",
+       "The div has been slightly scaled.");
+    is(dragZoom.zoom, PIXEL_DELTA * dragZoom.ZOOM_SPEED,
+      "The zoom was increased");
+    ok(floatEquality(dragZoom.smoothZoom, 0.05),
+      "The smooth zoom is between the initial value and the target");
+    is(rafMock.timesCalled, 1, "A RAF has been queued");
+  }
+
+  info("RAF will eventually stop once the smooth values approach the target");
+  {
+    let i;
+    let lastCallCount;
+    for (i = 0; i < MAX_RAF_LOOP; i++) {
+      if (lastCallCount === rafMock.timesCalled) {
+        break;
+      }
+      lastCallCount = rafMock.timesCalled;
+      rafMock.nextFrame();
+    }
+    is(style.transform, "translate(0px, 0px) scale(1.1)",
+       "The scale has been fully applied");
+    is(dragZoom.zoom, dragZoom.smoothZoom,
+      "The smooth and target zoom values match");
+    isnot(MAX_RAF_LOOP, i,
+      "The RAF loop correctly stopped");
+  }
+
+  info("Dragging correctly translates the div");
+  {
+    let initialX = dragZoom.translateX;
+    let initialY = dragZoom.translateY;
+    div.dispatchEvent(new MouseEvent("mousemove", {
+      clientX: 10,
+      clientY: 10,
+    }));
+    div.dispatchEvent(new MouseEvent("mousedown"));
+    div.dispatchEvent(new MouseEvent("mousemove", {
+      clientX: 20,
+      clientY: 20,
+    }));
+    div.dispatchEvent(new MouseEvent("mouseup"));
+
+    is(style.transform, "translate(2.5px, 5px) scale(1.1)",
+      "The style is correctly translated");
+    ok(floatEquality(dragZoom.translateX, 5),
+      "Translate X moved by some pixel amount");
+    ok(floatEquality(dragZoom.translateY, 10),
+      "Translate Y moved by some pixel amount");
+  }
+
+  info("Zooming centers around the mouse");
+  {
+    canvases.container.dispatchEvent(new WheelEvent("wheel", {
+      deltaY: -PIXEL_DELTA,
+      deltaMode: PIXEL_SCROLL_MODE
+    }));
+    // Run through the RAF loop to zoom in towards that value.
+    let lastCallCount;
+    for (let i = 0; i < MAX_RAF_LOOP; i++) {
+      if (lastCallCount === rafMock.timesCalled) {
+        break;
+      }
+      lastCallCount = rafMock.timesCalled;
+      rafMock.nextFrame();
+    }
+    is(style.transform, "translate(8.18182px, 18.1818px) scale(1.2)",
+       "Zooming affects the translation to keep the mouse centered");
+    ok(floatEquality(dragZoom.translateX, 8.181818181818185),
+       "Translate X was affected by the mouse position");
+    ok(floatEquality(dragZoom.translateY, 18.18181818181817),
+       "Translate Y was affected by the mouse position");
+    is(dragZoom.zoom, 0.2, "Zooming starts at 0");
+  }
+
+  dragZoom.destroy();
+
+  info("Scroll isn't tracked after destruction");
+  {
+    let previousZoom = dragZoom.zoom;
+    let previousSmoothZoom = dragZoom.smoothZoom;
+
+    canvases.container.dispatchEvent(new WheelEvent("wheel", {
+      deltaY: -PIXEL_DELTA,
+      deltaMode: PIXEL_SCROLL_MODE
+    }));
+
+    is(dragZoom.zoom, previousZoom,
+      "The zoom stayed the same");
+    is(dragZoom.smoothZoom, previousSmoothZoom,
+      "The smooth zoom stayed the same");
+  }
+
+  info("Translation isn't tracked after destruction");
+  {
+    let initialX = dragZoom.translateX;
+    let initialY = dragZoom.translateY;
+
+    div.dispatchEvent(new MouseEvent("mousedown"));
+    div.dispatchEvent(new MouseEvent("mousemove"), {
+      clientX: 40,
+      clientY: 40,
+    });
+    div.dispatchEvent(new MouseEvent("mouseup"));
+    is(dragZoom.translateX, initialX,
+      "The translationX didn't change");
+    is(dragZoom.translateY, initialY,
+      "The translationY didn't change");
+  }
+  panelDoc.body.removeChild(div);
+});
diff --git a/devtools/client/memory/test/browser/doc_big_tree.html b/devtools/client/memory/test/browser/doc_big_tree.html
new file mode 100644
index 000000000..4ad60402a
--- /dev/null
+++ b/devtools/client/memory/test/browser/doc_big_tree.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+    <body>
+        <script>
+         window.big = (function makeBig(depth = 0) {
+           var big = Array(5);
+           big.fill(undefined);
+           if (depth < 5) {
+             big = big.map(_ => makeBig(depth + 1));
+           }
+           return big;
+         }());
+        </script>
+    </body>
+</html>
diff --git a/devtools/client/memory/test/browser/doc_empty.html b/devtools/client/memory/test/browser/doc_empty.html
new file mode 100644
index 000000000..ef123d8d2
--- /dev/null
+++ b/devtools/client/memory/test/browser/doc_empty.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="utf-8"/>
+    </head>
+    <body>
+        This is an empty window.
+    </body>
+</html>
diff --git a/devtools/client/memory/test/browser/doc_steady_allocation.html b/devtools/client/memory/test/browser/doc_steady_allocation.html
new file mode 100644
index 000000000..65703c878
--- /dev/null
+++ b/devtools/client/memory/test/browser/doc_steady_allocation.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+    <body>
+        <script>
+         var objects = window.objects = [];
+
+         var allocate = this.allocate = function allocate() {
+           for (var i = 0; i < 100; i++)
+             objects.push({});
+           setTimeout(allocate, 10);
+         }
+
+         allocate();
+        </script>
+    </body>
+</html>
diff --git a/devtools/client/memory/test/browser/head.js b/devtools/client/memory/test/browser/head.js
new file mode 100644
index 000000000..cb9b470ff
--- /dev/null
+++ b/devtools/client/memory/test/browser/head.js
@@ -0,0 +1,248 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Load the shared test helpers into this compartment.
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/framework/test/shared-head.js",
+  this);
+
+// Load the shared Redux helpers into this compartment.
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/framework/test/shared-redux-head.js",
+  this);
+
+var { censusDisplays, snapshotState: states } = require("devtools/client/memory/constants");
+var { L10N } = require("devtools/client/memory/utils");
+
+Services.prefs.setBoolPref("devtools.memory.enabled", true);
+
+/**
+ * Open the memory panel for the given tab.
+ */
+this.openMemoryPanel = Task.async(function* (tab) {
+  info("Opening memory panel.");
+  const target = TargetFactory.forTab(tab);
+  const toolbox = yield gDevTools.showToolbox(target, "memory");
+  info("Memory panel shown successfully.");
+  let panel = toolbox.getCurrentPanel();
+  return { tab, panel };
+});
+
+/**
+ * Close the memory panel for the given tab.
+ */
+this.closeMemoryPanel = Task.async(function* (tab) {
+  info("Closing memory panel.");
+  const target = TargetFactory.forTab(tab);
+  const toolbox = gDevTools.getToolbox(target);
+  yield toolbox.destroy();
+  info("Closed memory panel successfully.");
+});
+
+/**
+ * Return a test function that adds a tab with the given url, opens the memory
+ * panel, runs the given generator, closes the memory panel, removes the tab,
+ * and finishes.
+ *
+ * Example usage:
+ *
+ *     this.test = makeMemoryTest(TEST_URL, function* ({ tab, panel }) {
+ *         // Your tests go here...
+ *     });
+ */
+function makeMemoryTest(url, generator) {
+  return Task.async(function* () {
+    waitForExplicitFinish();
+
+    // It can take a long time to save a snapshot to disk, read the snapshots
+    // back from disk, and finally perform analyses on them.
+    requestLongerTimeout(2);
+
+    const tab = yield addTab(url);
+    const results = yield openMemoryPanel(tab);
+
+    try {
+      yield* generator(results);
+    } catch (err) {
+      ok(false, "Got an error: " + DevToolsUtils.safeErrorString(err));
+    }
+
+    yield closeMemoryPanel(tab);
+    yield removeTab(tab);
+
+    finish();
+  });
+}
+
+function dumpn(msg) {
+  dump(`MEMORY-TEST: ${msg}\n`);
+}
+
+/**
+ * Returns a promise that will resolve when the provided store matches
+ * the expected array. expectedStates is an array of dominatorTree states.
+ * Expectations :
+ * - store.getState().snapshots.length == expected.length
+ * - snapshots[i].dominatorTree.state == expected[i]
+ *
+ * @param  {Store} store
+ * @param  {Array<string>} expectedStates [description]
+ * @return {Promise}
+ */
+function waitUntilDominatorTreeState(store, expected) {
+  let predicate = () => {
+    let snapshots = store.getState().snapshots;
+    return snapshots.length === expected.length &&
+            expected.every((state, i) => {
+              return snapshots[i].dominatorTree &&
+              snapshots[i].dominatorTree.state === state;
+            });
+  };
+  info(`Waiting for dominator trees to be of state: ${expected}`);
+  return waitUntilState(store, predicate);
+}
+
+function takeSnapshot(window) {
+  let { gStore, document } = window;
+  let snapshotCount = gStore.getState().snapshots.length;
+  info("Taking snapshot...");
+  document.querySelector(".devtools-toolbar .take-snapshot").click();
+  return waitUntilState(gStore, () => gStore.getState().snapshots.length === snapshotCount + 1);
+}
+
+function clearSnapshots(window) {
+  let { gStore, document } = window;
+  document.querySelector(".devtools-toolbar .clear-snapshots").click();
+  return waitUntilState(gStore, () => gStore.getState().snapshots.every(
+    (snapshot) => snapshot.state !== states.READ)
+  );
+}
+
+/**
+ * Sets the current requested display and waits for the selected snapshot to use
+ * it and complete the new census that entails.
+ */
+function setCensusDisplay(window, display) {
+  info(`Setting census display to ${display}...`);
+  let { gStore, gHeapAnalysesClient } = window;
+  // XXX: Should handle this via clicking the DOM, but React doesn't
+  // fire the onChange event, so just change it in the store.
+  // window.document.querySelector(`.select-display`).value = type;
+  gStore.dispatch(require("devtools/client/memory/actions/census-display")
+                         .setCensusDisplayAndRefresh(gHeapAnalysesClient, display));
+
+  return waitUntilState(window.gStore, () => {
+    let selected = window.gStore.getState().snapshots.find(s => s.selected);
+    return selected.state === states.READ &&
+      selected.census &&
+      selected.census.state === censusState.SAVED &&
+      selected.census.display === display;
+  });
+}
+
+/**
+ * Get the snapshot tatus text currently displayed, or null if none is
+ * displayed.
+ *
+ * @param {Document} document
+ */
+function getDisplayedSnapshotStatus(document) {
+  const status = document.querySelector(".snapshot-status");
+  return status ? status.textContent.trim() : null;
+}
+
+/**
+ * Get the index of the currently selected snapshot.
+ *
+ * @return {Number}
+ */
+function getSelectedSnapshotIndex(store) {
+  let snapshots = store.getState().snapshots;
+  let selectedSnapshot = snapshots.find(s => s.selected);
+  return snapshots.indexOf(selectedSnapshot);
+}
+
+/**
+ * Returns a promise that will resolve when the snapshot with provided index
+ * becomes selected.
+ *
+ * @return {Promise}
+ */
+function waitUntilSnapshotSelected(store, snapshotIndex) {
+  return waitUntilState(store, state =>
+    state.snapshots[snapshotIndex] &&
+    state.snapshots[snapshotIndex].selected === true);
+}
+
+
+/**
+ * Wait until the state has censuses in a certain state.
+ *
+ * @return {Promise}
+ */
+function waitUntilCensusState(store, getCensus, expected) {
+  let predicate = () => {
+    let snapshots = store.getState().snapshots;
+
+    info("Current census state:" +
+             snapshots.map(x => getCensus(x) ? getCensus(x).state : null));
+
+    return snapshots.length === expected.length &&
+           expected.every((state, i) => {
+             let census = getCensus(snapshots[i]);
+             return (state === "*") ||
+                    (!census && !state) ||
+                    (census && census.state === state);
+           });
+  };
+  info(`Waiting for snapshot censuses to be of state: ${expected}`);
+  return waitUntilState(store, predicate);
+}
+
+/**
+ * Mock out the requestAnimationFrame.
+ *
+ * @return {Object}
+ * @function nextFrame
+ *           Call the last queued function
+ * @function raf
+ *           The mocked raf function
+ * @function timesCalled
+ *           How many times the RAF has been called
+ */
+function createRAFMock() {
+  let queuedFns = [];
+  let mock = { timesCalled: 0 };
+
+  mock.nextFrame = function () {
+    let thisQueue = queuedFns;
+    queuedFns = [];
+    for (var i = 0; i < thisQueue.length; i++) {
+      thisQueue[i]();
+    }
+  };
+
+  mock.raf = function (fn) {
+    mock.timesCalled++;
+    queuedFns.push(fn);
+  };
+  return mock;
+}
+
+/**
+ * Test to see if two floats are equivalent.
+ *
+ * @param {Float} a
+ * @param {Float} b
+ * @return {Boolean}
+ */
+function floatEquality(a, b) {
+  const EPSILON = 0.00000000001;
+  const equals = Math.abs(a - b) < EPSILON;
+  if (!equals) {
+    info(`${a} not equal to ${b}`);
+  }
+  return equals;
+}
diff --git a/devtools/client/memory/test/chrome/chrome.ini b/devtools/client/memory/test/chrome/chrome.ini
new file mode 100644
index 000000000..7803bcda3
--- /dev/null
+++ b/devtools/client/memory/test/chrome/chrome.ini
@@ -0,0 +1,20 @@
+[DEFAULT]
+support-files =
+  head.js
+
+[test_CensusTreeItem_01.html]
+[test_DominatorTree_01.html]
+[test_DominatorTree_02.html]
+[test_DominatorTree_03.html]
+[test_DominatorTreeItem_01.html]
+[test_Heap_01.html]
+[test_Heap_02.html]
+[test_Heap_03.html]
+[test_Heap_04.html]
+[test_Heap_05.html]
+[test_List_01.html]
+[test_ShortestPaths_01.html]
+[test_ShortestPaths_02.html]
+[test_SnapshotListItem_01.html]
+[test_Toolbar_01.html]
+[test_TreeMap_01.html]
diff --git a/devtools/client/memory/test/chrome/head.js b/devtools/client/memory/test/chrome/head.js
new file mode 100644
index 000000000..4ca5a7a7e
--- /dev/null
+++ b/devtools/client/memory/test/chrome/head.js
@@ -0,0 +1,335 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+var { BrowserLoader } = Cu.import("resource://devtools/client/shared/browser-loader.js", {});
+var { require } = BrowserLoader({
+  baseURI: "resource://devtools/client/memory/",
+  window
+});
+var { Assert } = require("resource://testing-common/Assert.jsm");
+var Services = require("Services");
+var { Task } = require("devtools/shared/task");
+
+var EXPECTED_DTU_ASSERT_FAILURE_COUNT = 0;
+
+SimpleTest.registerCleanupFunction(function () {
+  if (DevToolsUtils.assertionFailureCount !== EXPECTED_DTU_ASSERT_FAILURE_COUNT) {
+    ok(false, "Should have had the expected number of DevToolsUtils.assert() failures. Expected " +
+       EXPECTED_DTU_ASSERT_FAILURE_COUNT + ", got " + DevToolsUtils.assertionFailureCount);
+  }
+});
+
+var DevToolsUtils = require("devtools/shared/DevToolsUtils");
+var { immutableUpdate } = DevToolsUtils;
+var flags = require("devtools/shared/flags");
+flags.testing = true;
+
+var constants = require("devtools/client/memory/constants");
+var {
+  censusDisplays,
+  diffingState,
+  labelDisplays,
+  dominatorTreeState,
+  snapshotState,
+  viewState,
+  censusState
+} = constants;
+
+const {
+  L10N,
+} = require("devtools/client/memory/utils");
+
+var models = require("devtools/client/memory/models");
+
+var Immutable = require("devtools/client/shared/vendor/immutable");
+var React = require("devtools/client/shared/vendor/react");
+var ReactDOM = require("devtools/client/shared/vendor/react-dom");
+var Heap = React.createFactory(require("devtools/client/memory/components/heap"));
+var CensusTreeItem = React.createFactory(require("devtools/client/memory/components/census-tree-item"));
+var DominatorTreeComponent = React.createFactory(require("devtools/client/memory/components/dominator-tree"));
+var DominatorTreeItem = React.createFactory(require("devtools/client/memory/components/dominator-tree-item"));
+var ShortestPaths = React.createFactory(require("devtools/client/memory/components/shortest-paths"));
+var TreeMap = React.createFactory(require("devtools/client/memory/components/tree-map"));
+var SnapshotListItem = React.createFactory(require("devtools/client/memory/components/snapshot-list-item"));
+var List = React.createFactory(require("devtools/client/memory/components/list"));
+var Toolbar = React.createFactory(require("devtools/client/memory/components/toolbar"));
+
+// All tests are asynchronous.
+SimpleTest.waitForExplicitFinish();
+
+var noop = () => {};
+
+var TEST_CENSUS_TREE_ITEM_PROPS = Object.freeze({
+  item: Object.freeze({
+    bytes: 10,
+    count: 1,
+    totalBytes: 10,
+    totalCount: 1,
+    name: "foo",
+    children: [
+      Object.freeze({
+        bytes: 10,
+        count: 1,
+        totalBytes: 10,
+        totalCount: 1,
+        name: "bar",
+      })
+    ]
+  }),
+  depth: 0,
+  arrow: ">",
+  focused: true,
+  getPercentBytes: () => 50,
+  getPercentCount: () => 50,
+  showSign: false,
+  onViewSourceInDebugger: noop,
+  inverted: false,
+});
+
+// Counter for mock DominatorTreeNode ids.
+var TEST_NODE_ID_COUNTER = 0;
+
+/**
+ * Create a mock DominatorTreeNode for testing, with sane defaults. Override any
+ * property by providing it on `opts`. Optionally pass child nodes as well.
+ *
+ * @param {Object} opts
+ * @param {Array<DominatorTreeNode>?} children
+ *
+ * @returns {DominatorTreeNode}
+ */
+function makeTestDominatorTreeNode(opts, children) {
+  const nodeId = TEST_NODE_ID_COUNTER++;
+
+  const node = Object.assign({
+    nodeId,
+    label: ["other", "SomeType"],
+    shallowSize: 1,
+    retainedSize: (children || []).reduce((size, c) => size + c.retainedSize, 1),
+    parentId: undefined,
+    children,
+    moreChildrenAvailable: true,
+  }, opts);
+
+  if (children && children.length) {
+    children.map(c => c.parentId = node.nodeId);
+  }
+
+  return node;
+}
+
+var TEST_DOMINATOR_TREE = Object.freeze({
+  dominatorTreeId: 666,
+  root: (function makeTree(depth = 0) {
+    let children;
+    if (depth <= 3) {
+      children = [
+        makeTree(depth + 1),
+        makeTree(depth + 1),
+        makeTree(depth + 1),
+      ];
+    }
+    return makeTestDominatorTreeNode({}, children);
+  }()),
+  expanded: new Set(),
+  focused: null,
+  error: null,
+  display: labelDisplays.coarseType,
+  activeFetchRequestCount: null,
+  state: dominatorTreeState.LOADED,
+});
+
+var TEST_DOMINATOR_TREE_PROPS = Object.freeze({
+  dominatorTree: TEST_DOMINATOR_TREE,
+  onLoadMoreSiblings: noop,
+  onViewSourceInDebugger: noop,
+  onExpand: noop,
+  onCollapse: noop,
+});
+
+var TEST_SHORTEST_PATHS_PROPS = Object.freeze({
+  graph: Object.freeze({
+    nodes: [
+      { id: 1, label: ["other", "SomeType"] },
+      { id: 2, label: ["other", "SomeType"] },
+      { id: 3, label: ["other", "SomeType"] },
+    ],
+    edges: [
+      { from: 1, to: 2, name: "1->2" },
+      { from: 1, to: 3, name: "1->3" },
+      { from: 2, to: 3, name: "2->3" },
+    ],
+  }),
+});
+
+var TEST_SNAPSHOT = Object.freeze({
+  id: 1337,
+  selected: true,
+  path: "/fake/path/to/snapshot",
+  census: Object.freeze({
+    report: Object.freeze({
+      objects: Object.freeze({ count: 4, bytes: 400 }),
+      scripts: Object.freeze({ count: 3, bytes: 300 }),
+      strings: Object.freeze({ count: 2, bytes: 200 }),
+      other: Object.freeze({ count: 1, bytes: 100 }),
+    }),
+    display: Object.freeze({
+      displayName: "Test Display",
+      tooltip: "Test display tooltup",
+      inverted: false,
+      breakdown: Object.freeze({
+        by: "coarseType",
+        objects: Object.freeze({ by: "count", count: true, bytes: true }),
+        scripts: Object.freeze({ by: "count", count: true, bytes: true }),
+        strings: Object.freeze({ by: "count", count: true, bytes: true }),
+        other: Object.freeze({ by: "count", count: true, bytes: true }),
+      }),
+    }),
+    state: censusState.SAVED,
+    inverted: false,
+    filter: null,
+    expanded: new Set(),
+    focused: null,
+    parentMap: Object.freeze(Object.create(null))
+  }),
+  dominatorTree: TEST_DOMINATOR_TREE,
+  error: null,
+  imported: false,
+  creationTime: 0,
+  state: snapshotState.READ,
+});
+
+var TEST_HEAP_PROPS = Object.freeze({
+  onSnapshotClick: noop,
+  onLoadMoreSiblings: noop,
+  onCensusExpand: noop,
+  onCensusCollapse: noop,
+  onDominatorTreeExpand: noop,
+  onDominatorTreeCollapse: noop,
+  onCensusFocus: noop,
+  onDominatorTreeFocus: noop,
+  onViewSourceInDebugger: noop,
+  diffing: null,
+  view: { state: viewState.CENSUS, },
+  snapshot: TEST_SNAPSHOT,
+  sizes: Object.freeze({ shortestPathsSize: .5 }),
+  onShortestPathsResize: noop,
+});
+
+var TEST_TOOLBAR_PROPS = Object.freeze({
+  censusDisplays: [
+    censusDisplays.coarseType,
+    censusDisplays.allocationStack,
+    censusDisplays.invertedAllocationStack,
+  ],
+  censusDisplay: censusDisplays.coarseType,
+  onTakeSnapshotClick: noop,
+  onImportClick: noop,
+  onCensusDisplayChange: noop,
+  onToggleRecordAllocationStacks: noop,
+  allocations: models.allocations,
+  onToggleInverted: noop,
+  inverted: false,
+  filterString: null,
+  setFilterString: noop,
+  diffing: null,
+  onToggleDiffing: noop,
+  view: { state: viewState.CENSUS, },
+  onViewChange: noop,
+  labelDisplays: [
+    labelDisplays.coarseType,
+    labelDisplays.allocationStack,
+  ],
+  labelDisplay: labelDisplays.coarseType,
+  onLabelDisplayChange: noop,
+  snapshots: [],
+});
+
+function makeTestCensusNode() {
+  return {
+    name: "Function",
+    bytes: 100,
+    totalBytes: 100,
+    count: 100,
+    totalCount: 100,
+    children: []
+  };
+}
+
+var TEST_TREE_MAP_PROPS = Object.freeze({
+  treeMap: Object.freeze({
+    report: {
+      name: null,
+      bytes: 0,
+      totalBytes: 400,
+      count: 0,
+      totalCount: 400,
+      children: [
+        {
+          name: "objects",
+          bytes: 0,
+          totalBytes: 200,
+          count: 0,
+          totalCount: 200,
+          children: [ makeTestCensusNode(), makeTestCensusNode() ]
+        },
+        {
+          name: "other",
+          bytes: 0,
+          totalBytes: 200,
+          count: 0,
+          totalCount: 200,
+          children: [ makeTestCensusNode(), makeTestCensusNode() ],
+        }
+      ]
+    }
+  })
+});
+
+var TEST_SNAPSHOT_LIST_ITEM_PROPS = Object.freeze({
+  onClick: noop,
+  onSave: noop,
+  onDelete: noop,
+  item: TEST_SNAPSHOT,
+  index: 1234,
+});
+
+function onNextAnimationFrame(fn) {
+  return () =>
+    requestAnimationFrame(() =>
+      requestAnimationFrame(fn));
+}
+
+/**
+ * Render the provided ReactElement in the provided HTML container.
+ * Returns a Promise that will resolve the rendered element as a React
+ * component.
+ */
+function renderComponent(element, container) {
+  return new Promise(resolve => {
+    let component = ReactDOM.render(element, container,
+      onNextAnimationFrame(() => {
+        dumpn("Rendered = " + container.innerHTML);
+        resolve(component);
+      }));
+  });
+}
+
+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(`MEMORY-TEST: ${msg}\n`);
+}
diff --git a/devtools/client/memory/test/chrome/test_CensusTreeItem_01.html b/devtools/client/memory/test/chrome/test_CensusTreeItem_01.html
new file mode 100644
index 000000000..fef996330
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_CensusTreeItem_01.html
@@ -0,0 +1,65 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that children pointers show up at the correct times.
+-->
+<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>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(CensusTreeItem(immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS, {
+               inverted: true,
+               depth: 0,
+             })), container);
+
+             ok(!container.querySelector(".children-pointer"),
+                "Don't show children pointer for roots when we are inverted");
+
+             yield renderComponent(CensusTreeItem(immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS, {
+               inverted: true,
+               depth: 1,
+             })), container);
+
+             ok(container.querySelector(".children-pointer"),
+                "Do show children pointer for non-roots when we are inverted");
+
+             yield renderComponent(CensusTreeItem(immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS, {
+               inverted: false,
+               item: immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS.item, { children: undefined }),
+             })), container);
+
+             ok(!container.querySelector(".children-pointer"),
+                "Don't show children pointer when non-inverted and no children");
+
+             yield renderComponent(CensusTreeItem(immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS, {
+               inverted: false,
+               depth: 0,
+               item: immutableUpdate(TEST_CENSUS_TREE_ITEM_PROPS.item, { children: [{}] }),
+             })), container);
+
+             ok(container.querySelector(".children-pointer"),
+                "Do show children pointer when non-inverted and have children");
+
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_DominatorTreeItem_01.html b/devtools/client/memory/test/chrome/test_DominatorTreeItem_01.html
new file mode 100644
index 000000000..56cba7391
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_DominatorTreeItem_01.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we don't display `JS::ubi::RootList` for the root, and instead show "GC Roots".
+-->
+<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>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(DominatorTreeItem({
+               item: makeTestDominatorTreeNode({ label: ["other", "JS::ubi::RootList"] }),
+               depth: 0,
+               arrow: React.DOM.div(),
+               focused: true,
+               getPercentSize: _ => 50,
+               onViewSourceInDebugger: _ => { },
+             }), container);
+
+             ok(container.textContent.indexOf("JS::ubi::RootList") == -1,
+                "Should not display `JS::ubi::RootList`");
+             ok(container.textContent.indexOf("GC Roots") >= 0,
+                "Should display `GC Roots` instead");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_DominatorTree_01.html b/devtools/client/memory/test/chrome/test_DominatorTree_01.html
new file mode 100644
index 000000000..582576e49
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_DominatorTree_01.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we show a place holder for a subtree we are lazily fetching.
+-->
+<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>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             const root = makeTestDominatorTreeNode({ moreChildrenAvailable: true});
+             ok(!root.children);
+
+             const expanded = new Set();
+             expanded.add(root.nodeId);
+
+             yield renderComponent(DominatorTreeComponent(immutableUpdate(TEST_DOMINATOR_TREE_PROPS, {
+               dominatorTree: immutableUpdate(TEST_DOMINATOR_TREE_PROPS.dominatorTree, {
+                 expanded,
+                 root,
+                 state: dominatorTreeState.INCREMENTAL_FETCHING,
+                 activeFetchRequestCount: 1,
+               }),
+             })), container);
+
+             ok(container.querySelector(".subtree-fetching"),
+                "Expanded nodes with more children available, but no children " +
+                "loaded, should get a placeholder");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_DominatorTree_02.html b/devtools/client/memory/test/chrome/test_DominatorTree_02.html
new file mode 100644
index 000000000..ffdac3263
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_DominatorTree_02.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we show a link to load more children when some (but not all) are loaded.
+-->
+<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>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             const root = makeTestDominatorTreeNode({ moreChildrenAvailable: true }, [
+               makeTestDominatorTreeNode({}),
+             ]);
+             ok(root.children);
+             ok(root.moreChildrenAvailable);
+
+             const expanded = new Set();
+             expanded.add(root.nodeId);
+
+             yield renderComponent(DominatorTreeComponent(immutableUpdate(TEST_DOMINATOR_TREE_PROPS, {
+               dominatorTree: immutableUpdate(TEST_DOMINATOR_TREE_PROPS.dominatorTree, {
+                 expanded,
+                 root,
+               }),
+             })), container);
+
+             ok(container.querySelector(".more-children"),
+                "Should get a link to load more children");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_DominatorTree_03.html b/devtools/client/memory/test/chrome/test_DominatorTree_03.html
new file mode 100644
index 000000000..e9656dad8
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_DominatorTree_03.html
@@ -0,0 +1,75 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that expanded DominatorTreeItems are correctly rendered and updated
+-->
+<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>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+            // simple tree with one root and one child
+            const root = makeTestDominatorTreeNode(
+              { moreChildrenAvailable: false },
+              [
+                makeTestDominatorTreeNode({ moreChildrenAvailable: false }),
+              ]);
+            ok(root.children);
+
+            // root node is expanded
+            const expanded = new Set();
+            expanded.add(root.nodeId);
+
+            let component = yield renderComponent(
+              DominatorTreeComponent(immutableUpdate(
+                TEST_DOMINATOR_TREE_PROPS,
+                {
+                  dominatorTree: immutableUpdate(
+                    TEST_DOMINATOR_TREE_PROPS.dominatorTree,
+                    { expanded, root }
+                  ),
+                })), container);
+            ok(true, "Dominator tree rendered");
+
+            is(container.querySelectorAll(".tree-node").length, 2,
+                "Should display two rows");
+            is(container.querySelectorAll(".arrow.open").length, 1,
+                "Should display one expanded arrow");
+
+            yield setProps(component, immutableUpdate(
+              TEST_DOMINATOR_TREE_PROPS,
+              {
+                dominatorTree: immutableUpdate(
+                  TEST_DOMINATOR_TREE_PROPS.dominatorTree,
+                  { expanded: new Set(), root }
+                )
+              }));
+            ok(true, "Dominator tree props updated to collapse all nodes");
+
+            is(container.querySelectorAll(".tree-node").length, 1,
+                "Should display only one row");
+            is(container.querySelectorAll(".arrow.open").length, 0,
+                "Should display no expanded arrow");
+
+          } catch(e) {
+            ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+          } finally {
+            SimpleTest.finish();
+          }
+        });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Heap_01.html b/devtools/client/memory/test/chrome/test_Heap_01.html
new file mode 100644
index 000000000..5d5e72389
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Heap_01.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that rendering a dominator tree error is handled correctly.
+-->
+<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>
+    <div id="container"></div>
+    <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 {
+             ok(React, "Should get React");
+             ok(Heap, "Should get Heap");
+
+             const errorMessage = "Something went wrong!";
+             const container = document.getElementById("container");
+
+             const props = immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.DOMINATOR_TREE, },
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 dominatorTree: {
+                   error: new Error(errorMessage),
+                   state: dominatorTreeState.ERROR,
+                 }
+               })
+             });
+
+             yield renderComponent(Heap(props), container);
+
+             ok(container.querySelector(".error"), "Should render an error view");
+             ok(container.textContent.indexOf(errorMessage) !== -1,
+                "Should see our error message");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Heap_02.html b/devtools/client/memory/test/chrome/test_Heap_02.html
new file mode 100644
index 000000000..800f1044c
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Heap_02.html
@@ -0,0 +1,78 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the currently selected view is 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>
+    <div id="container"></div>
+    <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 {
+             ok(React, "Should get React");
+             ok(Heap, "Should get Heap");
+
+             const errorMessage = "Something went wrong!";
+             const container = document.getElementById("container");
+
+             // Dominator tree view.
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.DOMINATOR_TREE, },
+             })), container);
+
+             ok(container.querySelector(`[data-state=${dominatorTreeState.LOADED}]`),
+                "Should render the dominator tree.");
+
+             // Census view.
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.CENSUS, },
+             })), container);
+
+             ok(container.querySelector(`[data-state=${censusState.SAVED}]`),
+                "Should render the census.");
+
+             // Diffing view.
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.DIFFING, },
+               snapshot: null,
+               diffing: {
+                 firstSnapshotId: null,
+                 secondSnapshotId: null,
+                 census: null,
+                 error: null,
+                 state: diffingState.SELECTING,
+               },
+             })), container);
+
+             ok(container.querySelector(`[data-state=${diffingState.SELECTING}]`),
+                "Should render the diffing.");
+
+             // Initial view.
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: null,
+               diffing: null,
+             })), container);
+
+             ok(container.querySelector("[data-state=initial]"),
+                "With no snapshot, nor a diffing, should render initial prompt.");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Heap_03.html b/devtools/client/memory/test/chrome/test_Heap_03.html
new file mode 100644
index 000000000..7f0f52255
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Heap_03.html
@@ -0,0 +1,74 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we show a throbber while computing and fetching dominator trees,
+but not in other dominator tree states.
+-->
+<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>
+    <div id="container"></div>
+    <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 container = document.getElementById("container");
+
+             for (let state of [dominatorTreeState.COMPUTING, dominatorTreeState.FETCHING]) {
+               yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+                 view: { state: viewState.DOMINATOR_TREE, },
+                 snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                   dominatorTree: immutableUpdate(TEST_HEAP_PROPS.snapshot.dominatorTree, {
+                     state,
+                     root: null,
+                     dominatorTreeId: state === dominatorTreeState.FETCHING ? 1 : null,
+                   }),
+                 }),
+               })), container);
+
+               ok(container.querySelector(".devtools-throbber"),
+                  `Should show a throbber for state = ${state}`);
+             }
+
+             for (let state of [dominatorTreeState.LOADED, dominatorTreeState.INCREMENTAL_FETCHING]) {
+               yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+                 view: { state: viewState.DOMINATOR_TREE, },
+                 snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                   dominatorTree: immutableUpdate(TEST_HEAP_PROPS.snapshot.dominatorTree, {
+                     state,
+                     activeFetchRequestCount: state === dominatorTreeState.INCREMENTAL_FETCHING ? 1 : undefined,
+                   }),
+                 }),
+               })), container);
+
+               ok(!container.querySelector(".devtools-throbber"),
+                  `Should not show a throbber for state = ${state}`);
+             }
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.DOMINATOR_TREE, },
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 dominatorTree: {
+                   state: dominatorTreeState.ERROR,
+                   error: new Error("example error for testing"),
+                 },
+               }),
+             })), container);
+
+             ok(!container.querySelector(".devtools-throbber"),
+                `Should not show a throbber for ERROR state`);
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Heap_04.html b/devtools/client/memory/test/chrome/test_Heap_04.html
new file mode 100644
index 000000000..ccf4c9c6d
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Heap_04.html
@@ -0,0 +1,121 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we show the "hey you're not recording allocation stacks" message at the appropriate times.
+-->
+<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>
+    <div id="container"></div>
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, {
+                   report: {
+                     bytes: 1,
+                     totalBytes: 1,
+                     count: 1,
+                     totalCount: 1,
+                     id: 1,
+                     parent: undefined,
+                     children: [
+                       {
+                         name: "noStack",
+                         bytes: 1,
+                         totalBytes: 1,
+                         count: 1,
+                         totalCount: 1,
+                         children: undefined,
+                         id: 3,
+                         parent: 1,
+                       }
+                     ]
+                   },
+                   display: censusDisplays.allocationStack,
+                 }),
+               }),
+             })), container);
+
+             ok(container.querySelector(".no-allocation-stacks"),
+                "When there are no allocation stacks, we should show the message");
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, {
+                   report: {
+                     bytes: 1,
+                     totalBytes: 1,
+                     count: 1,
+                     totalCount: 1,
+                     id: 1,
+                     parent: undefined,
+                     children: [
+                       {
+                         name: Cu.getJSTestingFunctions().saveStack(),
+                         bytes: 1,
+                         totalBytes: 1,
+                         count: 1,
+                         totalCount: 1,
+                         children: undefined,
+                         id: 2,
+                         parent: 1,
+                       },
+                       {
+                         name: "noStack",
+                         bytes: 1,
+                         totalBytes: 1,
+                         count: 1,
+                         totalCount: 1,
+                         children: undefined,
+                         id: 3,
+                         parent: 1,
+                       }
+                     ]
+                   },
+                   display: censusDisplays.allocationStack,
+                 }),
+               }),
+             })), container);
+
+             ok(!container.querySelector(".no-allocation-stacks"),
+                "When there are allocation stacks, we should not show the message");
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, {
+                   report: {
+                     bytes: 1,
+                     totalBytes: 1,
+                     count: 1,
+                     totalCount: 1,
+                     id: 1,
+                     parent: undefined,
+                     children: undefined
+                   },
+                   display: censusDisplays.allocationStack,
+                 }),
+               }),
+             })), container);
+
+             ok(!container.querySelector(".no-allocation-stacks"),
+                "When there isn't census data, we should not show the message");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Heap_05.html b/devtools/client/memory/test/chrome/test_Heap_05.html
new file mode 100644
index 000000000..14365e3ab
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Heap_05.html
@@ -0,0 +1,132 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that we show a message when the census results are empty.
+-->
+<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>
+    <div id="container"></div>
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, {
+                   report: {
+                     bytes: 1,
+                     totalBytes: 1,
+                     count: 1,
+                     totalCount: 1,
+                     id: 1,
+                     parent: undefined,
+                     children: [
+                       {
+                         name: Cu.getJSTestingFunctions().saveStack(),
+                         bytes: 1,
+                         totalBytes: 1,
+                         count: 1,
+                         totalCount: 1,
+                         children: undefined,
+                         id: 2,
+                         parent: 1,
+                       },
+                       {
+                         name: "noStack",
+                         bytes: 1,
+                         totalBytes: 1,
+                         count: 1,
+                         totalCount: 1,
+                         children: undefined,
+                         id: 3,
+                         parent: 1,
+                       }
+                     ]
+                   },
+                   display: censusDisplays.allocationStack,
+                 }),
+               }),
+             })), container);
+
+             ok(!container.querySelector(".empty"),
+                "When the report is not empty, we should not show the empty message");
+
+             // Empty Census Report
+
+             const emptyCensus = {
+               report: {
+                 bytes: 0,
+                 totalBytes: 0,
+                 count: 0,
+                 totalCount: 0,
+                 id: 1,
+                 parent: undefined,
+                 children: undefined,
+               },
+               parentMap: Object.create(null),
+               display: censusDisplays.allocationStack,
+               filter: null,
+               expanded: new Immutable.Set(),
+               focused: null,
+               state: censusState.SAVED,
+             };
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, emptyCensus),
+               }),
+             })), container);
+
+             ok(container.querySelector(".empty"),
+                "When the report is empty in census view, we show the empty message");
+             ok(container.textContent.indexOf(L10N.getStr("heapview.empty")) >= 0);
+
+             // Empty Diffing Report
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               view: { state: viewState.DIFFING, },
+               diffing: {
+                 firstSnapshotId: 1,
+                 secondSnapshotId: 2,
+                 census: emptyCensus,
+                 state: diffingState.TOOK_DIFF,
+               },
+               snapshot: null,
+             })), container);
+
+             ok(container.querySelector(".empty"),
+                "When the report is empty in diffing view, the empty message is shown");
+             ok(container.textContent.indexOf(L10N.getStr("heapview.no-difference")) >= 0);
+
+             // Empty Filtered Census
+
+             yield renderComponent(Heap(immutableUpdate(TEST_HEAP_PROPS, {
+               snapshot: immutableUpdate(TEST_HEAP_PROPS.snapshot, {
+                 census: immutableUpdate(TEST_HEAP_PROPS.snapshot.census, immutableUpdate(emptyCensus, {
+                   filter: "zzzz"
+                 })),
+               }),
+             })), container);
+
+             ok(container.querySelector(".empty"),
+                "When the report is empty in census view w/ filter, we show the empty message");
+             ok(container.textContent.indexOf(L10N.getStr("heapview.none-match")) >= 0);
+
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_List_01.html b/devtools/client/memory/test/chrome/test_List_01.html
new file mode 100644
index 000000000..911a7bc77
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_List_01.html
@@ -0,0 +1,74 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test to verify the delete button calls the onDelete handler for an item
+-->
+<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>
+    <div id="container"></div>
+
+    <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 container = document.getElementById("container");
+
+            let deletedSnapshots = [];
+
+            let snapshots = [ TEST_SNAPSHOT, TEST_SNAPSHOT, TEST_SNAPSHOT ]
+              .map((snapshot, index) => immutableUpdate(snapshot, {
+                index: snapshot.index + index
+              }));
+
+            yield renderComponent(
+              List({
+                itemComponent: SnapshotListItem,
+                onClick: noop,
+                onDelete: (item) => deletedSnapshots.push(item),
+                items: snapshots
+              }),
+              container
+            );
+
+            let deleteButtons = container.querySelectorAll('.delete');
+
+            is(container.querySelectorAll('.snapshot-list-item').length, 3,
+              "There are 3 list items\n");
+            is(deletedSnapshots.length, 0,
+              "Not snapshots have been deleted\n");
+
+            deleteButtons[1].click();
+
+            is(deletedSnapshots.length, 1, "One snapshot was deleted\n");
+            is(deletedSnapshots[0], snapshots[1],
+              "Deleted snapshot was added to the deleted list\n");
+
+            deleteButtons[0].click();
+
+            is(deletedSnapshots.length, 2, "Two snapshots were deleted\n");
+            is(deletedSnapshots[1], snapshots[0],
+              "Deleted snapshot was added to the deleted list\n");
+
+            deleteButtons[2].click();
+
+            is(deletedSnapshots.length, 3, "Three snapshots were deleted\n");
+            is(deletedSnapshots[2], snapshots[2],
+              "Deleted snapshot was added to the deleted list\n");
+
+
+          } catch(e) {
+            ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+          } finally {
+            SimpleTest.finish();
+          }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_ShortestPaths_01.html b/devtools/client/memory/test/chrome/test_ShortestPaths_01.html
new file mode 100644
index 000000000..e2ad1867a
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_ShortestPaths_01.html
@@ -0,0 +1,112 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the ShortestPaths component properly renders a graph of the merged shortest paths.
+-->
+<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">
+
+    <script type="application/javascript"
+            src="chrome://devtools/content/shared/vendor/d3.js">
+    </script>
+    <script type="application/javascript"
+            src="chrome://devtools/content/shared/vendor/dagre-d3.js">
+    </script>
+</head>
+<body>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(ShortestPaths(TEST_SHORTEST_PATHS_PROPS), container);
+
+             let found1 = false;
+             let found2 = false;
+             let found3 = false;
+
+             let found1to2 = false;
+             let found1to3 = false;
+             let found2to3 = false;
+
+             const tspans = [...container.querySelectorAll("tspan")];
+             for (let el of tspans) {
+               const text = el.textContent.trim();
+               dumpn("tspan's text = " + text);
+
+               switch (text) {
+                 // Nodes
+
+                 case "other › SomeType @ 0x1": {
+                   ok(!found1, "Should only find node 1 once");
+                   found1 = true;
+                   break;
+                 }
+
+                 case "other › SomeType @ 0x2": {
+                   ok(!found2, "Should only find node 2 once");
+                   found2 = true;
+                   break;
+                 }
+
+                 case "other › SomeType @ 0x3": {
+                   ok(!found3, "Should only find node 3 once");
+                   found3 = true;
+                   break;
+                 }
+
+                 // Edges
+
+                 case "1->2": {
+                   ok(!found1to2, "Should only find edge 1->2 once");
+                   found1to2 = true;
+                   break;
+                 }
+
+                 case "1->3": {
+                   ok(!found1to3, "Should only find edge 1->3 once");
+                   found1to3 = true;
+                   break;
+                 }
+
+                 case "2->3": {
+                   ok(!found2to3, "Should only find edge 2->3 once");
+                   found2to3 = true;
+                   break;
+                 }
+
+                 // Unexpected
+
+                 default: {
+                   ok(false, `Unexpected tspan: ${text}`);
+                   break;
+                 }
+               }
+             }
+
+             ok(found1, "Should have rendered node 1");
+             ok(found2, "Should have rendered node 2");
+             ok(found3, "Should have rendered node 3");
+
+             ok(found1to2, "Should have rendered edge 1->2");
+             ok(found1to3, "Should have rendered edge 1->3");
+             ok(found2to3, "Should have rendered edge 2->3");
+
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_ShortestPaths_02.html b/devtools/client/memory/test/chrome/test_ShortestPaths_02.html
new file mode 100644
index 000000000..cb6d48faa
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_ShortestPaths_02.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the ShortestPaths component renders a suggestion to select a node when there is no graph.
+-->
+<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">
+
+    <script type="application/javascript"
+            src="chrome://devtools/content/shared/vendor/d3.js">
+    </script>
+    <script type="application/javascript"
+            src="chrome://devtools/content/shared/vendor/dagre-d3.js">
+    </script>
+</head>
+<body>
+    <!-- Give the container height so that the whole tree is rendered. -->
+    <div id="container" style="height: 900px;"></div>
+
+    <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 container = document.getElementById("container");
+
+             yield renderComponent(ShortestPaths(immutableUpdate(TEST_SHORTEST_PATHS_PROPS,
+                                                                 { graph: null })),
+                                   container);
+
+             ok(container.textContent.indexOf(L10N.getStr("shortest-paths.select-node")) !== -1,
+                "The node selection prompt is displayed");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_SnapshotListItem_01.html b/devtools/client/memory/test/chrome/test_SnapshotListItem_01.html
new file mode 100644
index 000000000..0081496ce
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_SnapshotListItem_01.html
@@ -0,0 +1,53 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test to verify that the delete button only shows up for a snapshot when it has a
+path.
+-->
+<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>
+    <div id="container"></div>
+
+    <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 container = document.getElementById("container");
+
+            yield renderComponent(
+              SnapshotListItem(TEST_SNAPSHOT_LIST_ITEM_PROPS),
+              container
+            );
+
+            ok(container.querySelector('.delete'),
+               "Should have delete button when there is a path");
+
+            const pathlessProps = immutableUpdate(
+                TEST_SNAPSHOT_LIST_ITEM_PROPS,
+                {item: immutableUpdate(TEST_SNAPSHOT, {path: null})}
+            );
+
+            yield renderComponent(
+              SnapshotListItem(pathlessProps),
+              container
+            );
+
+            ok(!container.querySelector('.delete'),
+               "No delete button should be found if there is no path\n");
+
+          } catch(e) {
+            ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+          } finally {
+            SimpleTest.finish();
+          }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_Toolbar_01.html b/devtools/client/memory/test/chrome/test_Toolbar_01.html
new file mode 100644
index 000000000..57546df83
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_Toolbar_01.html
@@ -0,0 +1,47 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the Toolbar component shows the view switcher only at the appropriate times.
+-->
+<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>
+    <div id="container"></div>
+    <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 container = document.getElementById("container");
+
+             // Census and dominator tree views.
+
+             for (let view of [viewState.CENSUS, viewState.DOMINATOR_TREE]) {
+               yield renderComponent(Toolbar(immutableUpdate(TEST_TOOLBAR_PROPS, {
+                 view: { state: view },
+               })), container);
+
+               ok(container.querySelector("#select-view"),
+                  `The view selector is shown in view = ${view}`);
+             }
+
+             yield renderComponent(Toolbar(immutableUpdate(TEST_TOOLBAR_PROPS, {
+               view: { state: viewState.DIFFING, },
+             })), container);
+
+             ok(!container.querySelector("#select-view"),
+                "The view selector is NOT shown in the DIFFING view");
+           } catch(e) {
+             ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+           } finally {
+             SimpleTest.finish();
+           }
+         });
+        </script>
+    </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/chrome/test_TreeMap_01.html b/devtools/client/memory/test/chrome/test_TreeMap_01.html
new file mode 100644
index 000000000..cdc293854
--- /dev/null
+++ b/devtools/client/memory/test/chrome/test_TreeMap_01.html
@@ -0,0 +1,44 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the Tree Map correctly renders onto 2 managed canvases.
+-->
+<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">
+
+    <script type="application/javascript"
+            src="chrome://devtools/content/shared/vendor/d3.js">
+    </script>
+</head>
+<body>
+  <!-- Give the container height so that the whole tree is rendered. -->
+  <div id="container" style="height: 900px;"></div>
+
+  <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 container = document.getElementById("container");
+
+          yield renderComponent(TreeMap(TEST_TREE_MAP_PROPS), container);
+
+          let treeMapContainer = container.querySelector(".tree-map-container");
+          ok(treeMapContainer, "Component creates a container");
+
+          let canvases = treeMapContainer.querySelectorAll("canvas");
+          is(canvases.length, 2, "Creates 2 canvases");
+
+        } catch(e) {
+          ok(false, "Got an error: " + DevToolsUtils.safeErrorString(e));
+        } finally {
+          SimpleTest.finish();
+        }
+      });
+    </script>
+  </pre>
+</body>
+</html>
diff --git a/devtools/client/memory/test/unit/.eslintrc.js b/devtools/client/memory/test/unit/.eslintrc.js
new file mode 100644
index 000000000..aec096a0f
--- /dev/null
+++ b/devtools/client/memory/test/unit/.eslintrc.js
@@ -0,0 +1,6 @@
+"use strict";
+
+module.exports = {
+  // Extend from the shared list of defined globals for mochitests.
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};
diff --git a/devtools/client/memory/test/unit/head.js b/devtools/client/memory/test/unit/head.js
new file mode 100644
index 000000000..f1335dc3d
--- /dev/null
+++ b/devtools/client/memory/test/unit/head.js
@@ -0,0 +1,128 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+var { console } = Cu.import("resource://gre/modules/Console.jsm", {});
+var { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
+
+var Services = require("Services");
+var DevToolsUtils = require("devtools/shared/DevToolsUtils");
+var flags = require("devtools/shared/flags");
+flags.testing = true;
+flags.wantLogging = true;
+flags.wantVerbose = false;
+
+var { OS } = require("resource://gre/modules/osfile.jsm");
+var { FileUtils } = require("resource://gre/modules/FileUtils.jsm");
+var { TargetFactory } = require("devtools/client/framework/target");
+var promise = require("promise");
+var defer = require("devtools/shared/defer");
+var { Task } = require("devtools/shared/task");
+var { expectState } = require("devtools/server/actors/common");
+var HeapSnapshotFileUtils = require("devtools/shared/heapsnapshot/HeapSnapshotFileUtils");
+var HeapAnalysesClient = require("devtools/shared/heapsnapshot/HeapAnalysesClient");
+var { addDebuggerToGlobal } = require("resource://gre/modules/jsdebugger.jsm");
+var Store = require("devtools/client/memory/store");
+var { L10N } = require("devtools/client/memory/utils");
+var SYSTEM_PRINCIPAL = Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal);
+
+var EXPECTED_DTU_ASSERT_FAILURE_COUNT = 0;
+
+do_register_cleanup(function () {
+  equal(DevToolsUtils.assertionFailureCount, EXPECTED_DTU_ASSERT_FAILURE_COUNT,
+        "Should have had the expected number of DevToolsUtils.assert() failures.");
+});
+
+function dumpn(msg) {
+  dump(`MEMORY-TEST: ${msg}\n`);
+}
+
+function initDebugger() {
+  let global = new Cu.Sandbox(SYSTEM_PRINCIPAL, { freshZone: true });
+  addDebuggerToGlobal(global);
+  return new global.Debugger();
+}
+
+function StubbedMemoryFront() {
+  this.state = "detached";
+  this.recordingAllocations = false;
+  this.dbg = initDebugger();
+}
+
+StubbedMemoryFront.prototype.attach = Task.async(function* () {
+  this.state = "attached";
+});
+
+StubbedMemoryFront.prototype.detach = Task.async(function* () {
+  this.state = "detached";
+});
+
+StubbedMemoryFront.prototype.saveHeapSnapshot = expectState("attached", Task.async(function* () {
+  return ThreadSafeChromeUtils.saveHeapSnapshot({ runtime: true });
+}), "saveHeapSnapshot");
+
+StubbedMemoryFront.prototype.startRecordingAllocations = expectState("attached", Task.async(function* () {
+  this.recordingAllocations = true;
+}));
+
+StubbedMemoryFront.prototype.stopRecordingAllocations = expectState("attached", Task.async(function* () {
+  this.recordingAllocations = false;
+}));
+
+function waitUntilSnapshotState(store, expected) {
+  let predicate = () => {
+    let snapshots = store.getState().snapshots;
+    do_print(snapshots.map(x => x.state));
+    return snapshots.length === expected.length &&
+           expected.every((state, i) => state === "*" || snapshots[i].state === state);
+  };
+  do_print(`Waiting for snapshots to be of state: ${expected}`);
+  return waitUntilState(store, predicate);
+}
+
+function findReportLeafIndex(node, name = null) {
+  if (node.reportLeafIndex && (!name || node.name === name)) {
+    return node.reportLeafIndex;
+  }
+
+  if (node.children) {
+    for (let child of node.children) {
+      const found = findReportLeafIndex(child);
+      if (found) {
+        return found;
+      }
+    }
+  }
+
+  return null;
+}
+
+function waitUntilCensusState(store, getCensus, expected) {
+  let predicate = () => {
+    let snapshots = store.getState().snapshots;
+
+    do_print("Current census state:" +
+             snapshots.map(x => getCensus(x) ? getCensus(x).state : null));
+
+    return snapshots.length === expected.length &&
+           expected.every((state, i) => {
+             let census = getCensus(snapshots[i]);
+             return (state === "*") ||
+                    (!census && !state) ||
+                    (census && census.state === state);
+           });
+  };
+  do_print(`Waiting for snapshots' censuses to be of state: ${expected}`);
+  return waitUntilState(store, predicate);
+}
+
+function* createTempFile() {
+  let file = FileUtils.getFile("TmpD", ["tmp.fxsnapshot"]);
+  file.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, FileUtils.PERMS_FILE);
+  let destPath = file.path;
+  let stat = yield OS.File.stat(destPath);
+  ok(stat.size === 0, "new file is 0 bytes at start");
+  return destPath;
+}
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_01.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_01.js
new file mode 100644
index 000000000..a4e611e84
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_01.js
@@ -0,0 +1,38 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test clearSnapshots deletes snapshots with READ censuses
+
+let { takeSnapshotAndCensus, clearSnapshots } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, actions } = require("devtools/client/memory/constants");
+const { treeMapState } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+  ok(true, "snapshot created");
+
+  ok(true, "dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END)
+  ]);
+  dispatch(clearSnapshots(heapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots events");
+
+  equal(getState().snapshots.length, 0, "no snapshot remaining");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_02.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_02.js
new file mode 100644
index 000000000..bb8c118cd
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_02.js
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test clearSnapshots preserves snapshots with state != READ or ERROR
+
+let { takeSnapshotAndCensus, clearSnapshots, takeSnapshot } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, treeMapState, actions } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  ok(true, "create a snapshot with a census in SAVED state");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  ok(true, "create a snapshot in SAVED state");
+  dispatch(takeSnapshot(front));
+  yield waitUntilSnapshotState(store, [states.SAVED, states.SAVED]);
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED, null]);
+  ok(true, "snapshots created with expected states");
+
+  ok(true, "dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END)
+  ]);
+  dispatch(clearSnapshots(heapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots events");
+
+  equal(getState().snapshots.length, 1, "one snapshot remaining");
+  let remainingSnapshot = getState().snapshots[0];
+  equal(remainingSnapshot.treeMap, undefined,
+    "remaining snapshot doesn't have a treeMap property");
+  equal(remainingSnapshot.census, undefined,
+    "remaining snapshot doesn't have a census property");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_03.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_03.js
new file mode 100644
index 000000000..ae888f858
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_03.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test clearSnapshots deletes snapshots with state ERROR
+
+let { takeSnapshotAndCensus, clearSnapshots } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, treeMapState, actions } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  ok(true, "create a snapshot with a treeMap");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilSnapshotState(store, [states.SAVED]);
+  ok(true, "snapshot created with a SAVED state");
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED]);
+  ok(true, "treeMap created with a SAVED state");
+
+  ok(true, "set snapshot state to error");
+  let id = getState().snapshots[0].id;
+  dispatch({ type: actions.SNAPSHOT_ERROR, id, error: new Error("_") });
+  yield waitUntilSnapshotState(store, [states.ERROR]);
+  ok(true, "snapshot set to error state");
+
+  ok(true, "dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END)
+  ]);
+  dispatch(clearSnapshots(heapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots events");
+  equal(getState().snapshots.length, 0, "error snapshot deleted");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_04.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_04.js
new file mode 100644
index 000000000..f5b316b1a
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_04.js
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test clearSnapshots deletes several snapshots
+
+let { takeSnapshotAndCensus, clearSnapshots } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, actions, treeMapState } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  ok(true, "create 3 snapshots with a saved census");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED, treeMapState.SAVED,
+                              treeMapState.SAVED]);
+  ok(true, "snapshots created with a saved census");
+
+  ok(true, "set first snapshot state to error");
+  let id = getState().snapshots[0].id;
+  dispatch({ type: actions.SNAPSHOT_ERROR, id, error: new Error("_") });
+  yield waitUntilSnapshotState(store,
+    [states.ERROR, states.READ, states.READ]);
+  ok(true, "first snapshot set to error state");
+
+  ok(true, "dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END)
+  ]);
+  dispatch(clearSnapshots(heapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots events");
+
+  equal(getState().snapshots.length, 0, "no snapshot remaining");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_05.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_05.js
new file mode 100644
index 000000000..9b889b3a4
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_05.js
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test clearSnapshots deletes several snapshots
+
+let { takeSnapshotAndCensus, clearSnapshots } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, actions, treeMapState } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  ok(true, "create 2 snapshots with a saved census");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  ok(true, "snapshots created with a saved census");
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED, treeMapState.SAVED]);
+
+  let errorHeapWorker = {
+    deleteHeapSnapshot: function () {
+      return Promise.reject("_");
+    }
+  };
+
+  ok(true, "dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END),
+    waitUntilAction(store, actions.SNAPSHOT_ERROR),
+    waitUntilAction(store, actions.SNAPSHOT_ERROR),
+  ]);
+  dispatch(clearSnapshots(errorHeapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots and snapshot error events");
+  equal(getState().snapshots.length, 0, "no snapshot remaining");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-clear-snapshots_06.js b/devtools/client/memory/test/unit/test_action-clear-snapshots_06.js
new file mode 100644
index 000000000..1ee32bb12
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-clear-snapshots_06.js
@@ -0,0 +1,65 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that clearSnapshots disables diffing when deleting snapshots
+
+const {
+  takeSnapshotAndCensus,
+  clearSnapshots
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  snapshotState: states,
+  actions,
+  treeMapState
+} = require("devtools/client/memory/constants");
+const {
+  toggleDiffing,
+  selectSnapshotForDiffingAndRefresh
+} = require("devtools/client/memory/actions/diffing");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  ok(true, "create 2 snapshots with a saved census");
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED, treeMapState.SAVED]);
+  ok(true, "snapshots created with a saved census");
+
+  dispatch(toggleDiffing());
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[0]));
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[1]));
+
+  ok(getState().diffing, "We should be in diffing view");
+
+  yield waitUntilAction(store, actions.TAKE_CENSUS_DIFF_END);
+  ok(true, "Received TAKE_CENSUS_DIFF_END action");
+
+  ok(true, "Dispatch clearSnapshots action");
+  let deleteEvents = Promise.all([
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_START),
+    waitUntilAction(store, actions.DELETE_SNAPSHOTS_END)
+  ]);
+  dispatch(clearSnapshots(heapWorker));
+  yield deleteEvents;
+  ok(true, "received delete snapshots events");
+
+  ok(getState().snapshots.length === 0, "Snapshots array should be empty");
+  ok(!getState().diffing, "We should no longer be diffing");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-export-snapshot.js b/devtools/client/memory/test/unit/test_action-export-snapshot.js
new file mode 100644
index 000000000..0582abbf0
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-export-snapshot.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test exporting a snapshot to a user specified location on disk.
+
+let { exportSnapshot } = require("devtools/client/memory/actions/io");
+let { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states, actions, treeMapState } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  let destPath = yield createTempFile();
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.treeMap,
+                             [treeMapState.SAVED]);
+
+  let exportEvents = Promise.all([
+    waitUntilAction(store, actions.EXPORT_SNAPSHOT_START),
+    waitUntilAction(store, actions.EXPORT_SNAPSHOT_END)
+  ]);
+  dispatch(exportSnapshot(getState().snapshots[0], destPath));
+  yield exportEvents;
+
+  stat = yield OS.File.stat(destPath);
+  do_print(stat.size);
+  ok(stat.size > 0, "destination file is more than 0 bytes");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-filter-01.js b/devtools/client/memory/test/unit/test_action-filter-01.js
new file mode 100644
index 000000000..e0894606d
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-filter-01.js
@@ -0,0 +1,23 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test setting the filter string.
+
+let { setFilterString } = require("devtools/client/memory/actions/filter");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().filter, null, "no filter by default");
+
+  dispatch(setFilterString("my filter"));
+  equal(getState().filter, "my filter", "now we have the expected filter");
+
+  dispatch(setFilterString(""));
+  equal(getState().filter, null, "no filter again");
+});
diff --git a/devtools/client/memory/test/unit/test_action-filter-02.js b/devtools/client/memory/test/unit/test_action-filter-02.js
new file mode 100644
index 000000000..31d777704
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-filter-02.js
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test that changing filter state properly refreshes the selected census.
+
+let { snapshotState: states, viewState, censusState } = require("devtools/client/memory/constants");
+let { setFilterStringAndRefresh } = require("devtools/client/memory/actions/filter");
+let { takeSnapshotAndCensus, selectSnapshotAndRefresh } = require("devtools/client/memory/actions/snapshot");
+let { setCensusDisplay } = require("devtools/client/memory/actions/census-display");
+let { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  equal(getState().filter, null, "no filter by default");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVED]);
+  ok(true, "saved 3 snapshots and took a census of each of them");
+
+  dispatch(setFilterStringAndRefresh("str", heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVING]);
+  ok(true, "setting filter string should recompute the selected snapshot's census");
+
+  equal(getState().filter, "str", "now inverted");
+
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.filter, null);
+  equal(getState().snapshots[1].census.filter, null);
+  equal(getState().snapshots[2].census.filter, "str");
+
+  dispatch(selectSnapshotAndRefresh(heapWorker, getState().snapshots[1].id));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVING,
+                              censusState.SAVED]);
+  ok(true, "selecting non-inverted census should trigger a recompute");
+
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.filter, null);
+  equal(getState().snapshots[1].census.filter, "str");
+  equal(getState().snapshots[2].census.filter, "str");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-filter-03.js b/devtools/client/memory/test/unit/test_action-filter-03.js
new file mode 100644
index 000000000..4d46d5361
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-filter-03.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that changing filter state in the middle of taking a snapshot results in
+// the properly fitered census.
+
+let { snapshotState: states, censusState, viewState } = require("devtools/client/memory/constants");
+let { setFilterString, setFilterStringAndRefresh } = require("devtools/client/memory/actions/filter");
+let { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+let { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilSnapshotState(store, [states.SAVING]);
+
+  dispatch(setFilterString("str"));
+
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED]);
+  equal(getState().filter, "str",
+        "should want filtered trees");
+  equal(getState().snapshots[0].census.filter, "str",
+        "snapshot-we-were-in-the-middle-of-saving's census should be filtered");
+
+  dispatch(setFilterStringAndRefresh("", heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVING]);
+  ok(true, "changing filter string retriggers census");
+  ok(!getState().filter, "no longer filtering");
+
+  dispatch(setFilterString("obj"));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED]);
+  equal(getState().filter, "obj", "filtering for obj now");
+  equal(getState().snapshots[0].census.filter, "obj",
+        "census-we-were-in-the-middle-of-recomputing should be filtered again");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-import-snapshot-and-census.js b/devtools/client/memory/test/unit/test_action-import-snapshot-and-census.js
new file mode 100644
index 000000000..a7e1d366a
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-import-snapshot-and-census.js
@@ -0,0 +1,98 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests the task creator `importSnapshotAndCensus()` for the whole flow of
+ * importing a snapshot, and its sub-actions.
+ */
+
+let { actions, snapshotState: states, treeMapState } = require("devtools/client/memory/constants");
+let { exportSnapshot, importSnapshotAndCensus } = require("devtools/client/memory/actions/io");
+let { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { subscribe, dispatch, getState } = store;
+
+  let destPath = yield createTempFile();
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+
+  let exportEvents = Promise.all([
+    waitUntilAction(store, actions.EXPORT_SNAPSHOT_START),
+    waitUntilAction(store, actions.EXPORT_SNAPSHOT_END)
+  ]);
+  dispatch(exportSnapshot(getState().snapshots[0], destPath));
+  yield exportEvents;
+
+  // Now import our freshly exported snapshot
+  let snapshotI = 0;
+  let censusI = 0;
+  let snapshotStates = ["IMPORTING", "READING", "READ"];
+  let censusStates = ["SAVING", "SAVED"];
+  let expectStates = () => {
+    let snapshot = getState().snapshots[1];
+    if (!snapshot) {
+      return;
+    }
+    if (snapshotI < snapshotStates.length) {
+      let isCorrectState = snapshot.state === states[snapshotStates[snapshotI]];
+      if (isCorrectState) {
+        ok(true, `Found expected snapshot state ${snapshotStates[snapshotI]}`);
+        snapshotI++;
+      }
+    }
+    if (snapshot.treeMap && censusI < censusStates.length) {
+      if (snapshot.treeMap.state === treeMapState[censusStates[censusI]]) {
+        ok(true, `Found expected census state ${censusStates[censusI]}`);
+        censusI++;
+      }
+    }
+  };
+
+  let unsubscribe = subscribe(expectStates);
+  dispatch(importSnapshotAndCensus(heapWorker, destPath));
+
+  yield waitUntilState(store, () => { return snapshotI === snapshotStates.length &&
+                                      censusI === censusStates.length; });
+  unsubscribe();
+  equal(snapshotI, snapshotStates.length, "importSnapshotAndCensus() produces the correct sequence of states in a snapshot");
+  equal(getState().snapshots[1].state, states.READ, "imported snapshot is in READ state");
+  equal(censusI, censusStates.length, "importSnapshotAndCensus() produces the correct sequence of states in a census");
+  equal(getState().snapshots[1].treeMap.state, treeMapState.SAVED, "imported snapshot is in READ state");
+  ok(getState().snapshots[1].selected, "imported snapshot is selected");
+
+  // Check snapshot data
+  let snapshot1 = getState().snapshots[0];
+  let snapshot2 = getState().snapshots[1];
+
+  equal(snapshot1.treeMap.display, snapshot2.treeMap.display,
+        "imported snapshot has correct display");
+
+  // Clone the census data so we can destructively remove the ID/parents to compare
+  // equal census data
+  let census1 = stripUnique(JSON.parse(JSON.stringify(snapshot1.treeMap.report)));
+  let census2 = stripUnique(JSON.parse(JSON.stringify(snapshot2.treeMap.report)));
+
+  equal(JSON.stringify(census1), JSON.stringify(census2), "Imported snapshot has correct census");
+
+  function stripUnique(obj) {
+    let children = obj.children || [];
+    for (let child of children) {
+      delete child.id;
+      delete child.parent;
+      stripUnique(child);
+    }
+    delete obj.id;
+    delete obj.parent;
+    return obj;
+  }
+});
diff --git a/devtools/client/memory/test/unit/test_action-import-snapshot-dominator-tree.js b/devtools/client/memory/test/unit/test_action-import-snapshot-dominator-tree.js
new file mode 100644
index 000000000..868f22ccf
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-import-snapshot-dominator-tree.js
@@ -0,0 +1,84 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests `importSnapshotAndCensus()` when importing snapshots from the dominator
+ * tree view. The snapshot is expected to be loaded and its dominator tree
+ * should be computed.
+ */
+
+let { snapshotState, dominatorTreeState, viewState, treeMapState } =
+  require("devtools/client/memory/constants");
+let { importSnapshotAndCensus } = require("devtools/client/memory/actions/io");
+let { changeViewAndRefresh } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { subscribe, dispatch, getState } = store;
+
+  dispatch(changeViewAndRefresh(viewState.DOMINATOR_TREE, heapWorker));
+  equal(getState().view.state, viewState.DOMINATOR_TREE,
+        "We should now be in the DOMINATOR_TREE view");
+
+  let i = 0;
+  let expected = [
+    "IMPORTING",
+    "READING",
+    "READ",
+    "treeMap:SAVING",
+    "treeMap:SAVED",
+    "dominatorTree:COMPUTING",
+    "dominatorTree:FETCHING",
+    "dominatorTree:LOADED",
+  ];
+  let expectStates = () => {
+    let snapshot = getState().snapshots[0];
+    if (snapshot && hasExpectedState(snapshot, expected[i])) {
+      ok(true, `Found expected state ${expected[i]}`);
+      i++;
+    }
+  };
+
+  let unsubscribe = subscribe(expectStates);
+  const snapshotPath = yield front.saveHeapSnapshot();
+  dispatch(importSnapshotAndCensus(heapWorker, snapshotPath));
+
+  yield waitUntilState(store, () => i === expected.length);
+  unsubscribe();
+  equal(i, expected.length, "importSnapshotAndCensus() produces the correct " +
+    "sequence of states in a snapshot");
+  equal(getState().snapshots[0].dominatorTree.state, dominatorTreeState.LOADED,
+    "imported snapshot's dominator tree is in LOADED state");
+  ok(getState().snapshots[0].selected, "imported snapshot is selected");
+});
+
+/**
+ * Check that the provided snapshot is in the expected state. The expected state
+ * is a snapshotState by default. If the expected state is prefixed by
+ * dominatorTree, a dominatorTree is expected on the provided snapshot, in the
+ * corresponding state from dominatorTreeState.
+ */
+function hasExpectedState(snapshot, expectedState) {
+  let isDominatorState = expectedState.indexOf("dominatorTree:") === 0;
+  if (isDominatorState) {
+    let state = dominatorTreeState[expectedState.replace("dominatorTree:", "")];
+    return snapshot.dominatorTree && snapshot.dominatorTree.state === state;
+  }
+
+  let isTreeMapState = expectedState.indexOf("treeMap:") === 0;
+  if (isTreeMapState) {
+    let state = treeMapState[expectedState.replace("treeMap:", "")];
+    return snapshot.treeMap && snapshot.treeMap.state === state;
+  }
+
+  let state = snapshotState[expectedState];
+  return snapshot.state === state;
+}
diff --git a/devtools/client/memory/test/unit/test_action-select-snapshot.js b/devtools/client/memory/test/unit/test_action-select-snapshot.js
new file mode 100644
index 000000000..2329ab2fa
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-select-snapshot.js
@@ -0,0 +1,37 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the reducer responding to the action `selectSnapshot(snapshot)`
+ */
+
+let actions = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  yield front.attach();
+  let store = Store();
+
+  for (let i = 0; i < 5; i++) {
+    store.dispatch(actions.takeSnapshot(front));
+  }
+
+  yield waitUntilState(store, ({ snapshots }) => snapshots.length === 5 && snapshots.every(isDone));
+
+  for (let i = 0; i < 5; i++) {
+    do_print(`Selecting snapshot[${i}]`);
+    store.dispatch(actions.selectSnapshot(store.getState().snapshots[i].id));
+    yield waitUntilState(store, ({ snapshots }) => snapshots[i].selected);
+
+    let { snapshots } = store.getState();
+    ok(snapshots[i].selected, `snapshot[${i}] selected`);
+    equal(snapshots.filter(s => !s.selected).length, 4, "All other snapshots are unselected");
+  }
+});
+
+function isDone(s) { return s.state === states.SAVED; }
diff --git a/devtools/client/memory/test/unit/test_action-set-display-and-refresh-01.js b/devtools/client/memory/test/unit/test_action-set-display-and-refresh-01.js
new file mode 100644
index 000000000..570ffdf05
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-set-display-and-refresh-01.js
@@ -0,0 +1,118 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests the task creator `setCensusDisplayAndRefreshAndRefresh()` for display
+ * changing. We test this rather than `setCensusDisplayAndRefresh` directly, as
+ * we use the refresh action in the app itself composed from
+ * `setCensusDisplayAndRefresh`.
+ */
+
+let { censusDisplays, snapshotState: states, censusState, viewState } = require("devtools/client/memory/constants");
+let { setCensusDisplayAndRefresh } = require("devtools/client/memory/actions/census-display");
+let { takeSnapshotAndCensus, selectSnapshotAndRefresh } = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+// We test setting an invalid display, which triggers an assertion failure.
+EXPECTED_DTU_ASSERT_FAILURE_COUNT = 1;
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Test default display with no snapshots
+  equal(getState().censusDisplay.breakdown.by, "coarseType",
+        "default coarseType display selected at start.");
+  dispatch(setCensusDisplayAndRefresh(heapWorker,
+                                      censusDisplays.allocationStack));
+  equal(getState().censusDisplay.breakdown.by, "allocationStack",
+        "display changed with no snapshots");
+
+  // Test invalid displays
+  ok(getState().errors.length === 0, "No error actions in the queue.");
+  dispatch(setCensusDisplayAndRefresh(heapWorker, {}));
+  yield waitUntilState(store, () => getState().errors.length === 1);
+  ok(true, "Emits an error action when passing in an invalid display object");
+
+  equal(getState().censusDisplay.breakdown.by, "allocationStack",
+    "current display unchanged when passing invalid display");
+
+  // Test new snapshots
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.display, censusDisplays.allocationStack,
+        "New snapshot's census uses correct display");
+
+  // Updates when changing display during `SAVING`
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED, censusState.SAVING]);
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.coarseType));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED, censusState.SAVED]);
+  equal(getState().snapshots[1].census.display, censusDisplays.coarseType,
+        "Changing display while saving a snapshot results in a census using the new display");
+
+
+  // Updates when changing display during `SAVING_CENSUS`
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVING]);
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.allocationStack));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVED]);
+  equal(getState().snapshots[2].census.display, censusDisplays.allocationStack,
+        "Display can be changed while saving census, stores updated display in snapshot");
+
+  // Updates census on currently selected snapshot when changing display
+  ok(getState().snapshots[2].selected, "Third snapshot currently selected");
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.coarseType));
+  yield waitUntilState(store, state => state.snapshots[2].census.state === censusState.SAVING);
+  yield waitUntilState(store, state => state.snapshots[2].census.state === censusState.SAVED);
+  equal(getState().snapshots[2].census.display, censusDisplays.coarseType,
+        "Snapshot census updated when changing displays after already generating one census");
+
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.allocationStack));
+  yield waitUntilState(store, state => state.snapshots[2].census.state === censusState.SAVED);
+  equal(getState().snapshots[2].census.display, censusDisplays.allocationStack,
+        "Snapshot census updated when changing displays after already generating one census");
+
+  // Does not update unselected censuses.
+  ok(!getState().snapshots[1].selected, "Second snapshot selected currently");
+  equal(getState().snapshots[1].census.display, censusDisplays.coarseType,
+        "Second snapshot using `coarseType` display still and not yet updated to correct display");
+
+  // Updates to current display when switching to stale snapshot.
+  dispatch(selectSnapshotAndRefresh(heapWorker, getState().snapshots[1].id));
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVING,
+                              censusState.SAVED]);
+  yield waitUntilCensusState(store, snapshot => snapshot.census,
+                             [censusState.SAVED,
+                              censusState.SAVED,
+                              censusState.SAVED]);
+
+  ok(getState().snapshots[1].selected, "Second snapshot selected currently");
+  equal(getState().snapshots[1].census.display, censusDisplays.allocationStack,
+        "Second snapshot using `allocationStack` display and updated to correct display");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-set-display-and-refresh-02.js b/devtools/client/memory/test/unit/test_action-set-display-and-refresh-02.js
new file mode 100644
index 000000000..5be5444d4
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-set-display-and-refresh-02.js
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests the task creator `setCensusDisplayAndRefreshAndRefresh()` for custom
+ * displays.
+ */
+
+let { snapshotState: states, censusState, viewState } = require("devtools/client/memory/constants");
+let { setCensusDisplayAndRefresh } = require("devtools/client/memory/actions/census-display");
+let { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+let { changeView } = require("devtools/client/memory/actions/view");
+
+let CUSTOM = {
+  displayName: "Custom",
+  tooltip: "Custom tooltip",
+  inverted: false,
+  breakdown: {
+    by: "internalType",
+    then: { by: "count", bytes: true, count: false }
+  }
+};
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(setCensusDisplayAndRefresh(heapWorker, CUSTOM));
+  equal(getState().censusDisplay, CUSTOM,
+        "CUSTOM display stored in display state.");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.display, CUSTOM,
+  "New snapshot stored CUSTOM display when done taking census");
+  ok(getState().snapshots[0].census.report.children.length, "Census has some children");
+  // Ensure we don't have `count` in any results
+  ok(getState().snapshots[0].census.report.children.every(c => !c.count),
+     "Census used CUSTOM display without counts");
+  // Ensure we do have `bytes` in the results
+  ok(getState().snapshots[0].census.report.children.every(c => typeof c.bytes === "number"),
+     "Census used CUSTOM display with bytes");
+});
diff --git a/devtools/client/memory/test/unit/test_action-set-display.js b/devtools/client/memory/test/unit/test_action-set-display.js
new file mode 100644
index 000000000..43ea975da
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-set-display.js
@@ -0,0 +1,55 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests the action creator `setCensusDisplay()` for display changing. Does not
+ * test refreshing the census information, check `setCensusDisplayAndRefresh`
+ * action for that.
+ */
+
+let { censusDisplays, snapshotState: states, censusState, viewState } = require("devtools/client/memory/constants");
+let { setCensusDisplay } = require("devtools/client/memory/actions/census-display");
+let { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+// We test setting an invalid display, which triggers an assertion failure.
+EXPECTED_DTU_ASSERT_FAILURE_COUNT = 1;
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Test default display with no snapshots
+  equal(getState().censusDisplay.breakdown.by, "coarseType",
+        "default coarseType display selected at start.");
+
+  dispatch(setCensusDisplay(censusDisplays.allocationStack));
+  equal(getState().censusDisplay.breakdown.by, "allocationStack",
+        "display changed with no snapshots");
+
+  // Test invalid displays
+  try {
+    dispatch(setCensusDisplay({}));
+    ok(false, "Throws when passing in an invalid display object");
+  } catch (e) {
+    ok(true, "Throws when passing in an invalid display object");
+  }
+  equal(getState().censusDisplay.breakdown.by, "allocationStack",
+    "current display unchanged when passing invalid display");
+
+  // Test new snapshots
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+  equal(getState().snapshots[0].census.display, censusDisplays.allocationStack,
+        "New snapshots use the current, non-default display");
+});
diff --git a/devtools/client/memory/test/unit/test_action-take-census.js b/devtools/client/memory/test/unit/test_action-take-census.js
new file mode 100644
index 000000000..3e3d30e8e
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-take-census.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the async reducer responding to the action `takeCensus(heapWorker, snapshot)`
+ */
+
+var { snapshotState: states, censusDisplays, censusState, censusState, viewState } = require("devtools/client/memory/constants");
+var actions = require("devtools/client/memory/actions/snapshot");
+var { changeView } = require("devtools/client/memory/actions/view");
+
+
+function run_test() {
+  run_next_test();
+}
+
+// This tests taking a census on a snapshot that is still being read, which
+// triggers an assertion failure.
+EXPECTED_DTU_ASSERT_FAILURE_COUNT = 1;
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+
+  store.dispatch(changeView(viewState.CENSUS));
+
+  store.dispatch(actions.takeSnapshot(front));
+  yield waitUntilState(store, () => {
+    let snapshots = store.getState().snapshots;
+    return snapshots.length === 1 && snapshots[0].state === states.SAVED;
+  });
+
+  let snapshot = store.getState().snapshots[0];
+  equal(snapshot.census, null, "No census data exists yet on the snapshot.");
+
+  // Test error case of wrong state.
+  store.dispatch(actions.takeCensus(heapWorker, snapshot.id));
+  yield waitUntilState(store, () => store.getState().errors.length === 1);
+
+  dumpn("Found error: " + store.getState().errors[0]);
+  ok(/Assertion failure/.test(store.getState().errors[0]),
+    "Error thrown when taking a census of a snapshot that has not been read.");
+
+  store.dispatch(actions.readSnapshot(heapWorker, snapshot.id));
+  yield waitUntilState(store, () => store.getState().snapshots[0].state === states.READ);
+
+  store.dispatch(actions.takeCensus(heapWorker, snapshot.id));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVING]);
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  snapshot = store.getState().snapshots[0];
+  ok(snapshot.census, "Snapshot has census after saved census");
+  ok(snapshot.census.report.children.length, "Census is in tree node form");
+  equal(snapshot.census.display, censusDisplays.coarseType,
+        "Snapshot stored correct display used for the census");
+
+});
diff --git a/devtools/client/memory/test/unit/test_action-take-snapshot-and-census.js b/devtools/client/memory/test/unit/test_action-take-snapshot-and-census.js
new file mode 100644
index 000000000..77c3b8e38
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-take-snapshot-and-census.js
@@ -0,0 +1,58 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the task creator `takeSnapshotAndCensus()` for the whole flow of
+ * taking a snapshot, and its sub-actions.
+ */
+
+let { snapshotState: states, treeMapState } = require("devtools/client/memory/constants");
+let actions = require("devtools/client/memory/actions/snapshot");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+
+  let snapshotI = 0;
+  let censusI = 0;
+  let snapshotStates = ["SAVING", "SAVED", "READING", "READ"];
+  let censusStates = ["SAVING", "SAVED"];
+  let expectStates = () => {
+    let snapshot = store.getState().snapshots[0];
+    if (!snapshot) {
+      return;
+    }
+    if (snapshotI < snapshotStates.length) {
+      let isCorrectState = snapshot.state === states[snapshotStates[snapshotI]];
+      if (isCorrectState) {
+        ok(true, `Found expected snapshot state ${snapshotStates[snapshotI]}`);
+        snapshotI++;
+      }
+    }
+    if (snapshot.treeMap && censusI < censusStates.length) {
+      if (snapshot.treeMap.state === treeMapState[censusStates[censusI]]) {
+        ok(true, `Found expected census state ${censusStates[censusI]}`);
+        censusI++;
+      }
+    }
+  };
+
+
+  let unsubscribe = store.subscribe(expectStates);
+  store.dispatch(actions.takeSnapshotAndCensus(front, heapWorker));
+
+  yield waitUntilState(store, () => { return snapshotI === snapshotStates.length &&
+                                      censusI === censusStates.length; });
+  unsubscribe();
+
+  ok(true, "takeSnapshotAndCensus() produces the correct sequence of states in a snapshot");
+  let snapshot = store.getState().snapshots[0];
+  ok(snapshot.treeMap, "snapshot has tree map census data");
+  ok(snapshot.selected, "snapshot is selected");
+});
diff --git a/devtools/client/memory/test/unit/test_action-take-snapshot.js b/devtools/client/memory/test/unit/test_action-take-snapshot.js
new file mode 100644
index 000000000..c05583b22
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-take-snapshot.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the async reducer responding to the action `takeSnapshot(front)`
+ */
+
+let actions = require("devtools/client/memory/actions/snapshot");
+let { snapshotState: states } = require("devtools/client/memory/constants");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  yield front.attach();
+  let store = Store();
+
+  let unsubscribe = store.subscribe(checkState);
+
+  let foundPendingState = false;
+  let foundDoneState = false;
+
+  function checkState() {
+    let { snapshots } = store.getState();
+    let lastSnapshot = snapshots[snapshots.length - 1];
+
+    if (lastSnapshot.state === states.SAVING) {
+      foundPendingState = true;
+      ok(foundPendingState, "Got state change for pending heap snapshot request");
+      ok(!lastSnapshot.path, "Snapshot does not yet have a path");
+      ok(!lastSnapshot.census, "Has no census data when loading");
+    }
+    else if (lastSnapshot.state === states.SAVED) {
+      foundDoneState = true;
+      ok(foundDoneState, "Got state change for completed heap snapshot request");
+      ok(foundPendingState, "SAVED state occurs after SAVING state");
+      ok(lastSnapshot.path, "Snapshot fetched with a path");
+      ok(snapshots.every(s => s.selected === (s.id === lastSnapshot.id)),
+        "Only recent snapshot is selected");
+    }
+  }
+
+  for (let i = 0; i < 4; i++) {
+    store.dispatch(actions.takeSnapshot(front));
+    yield waitUntilState(store, () => foundPendingState && foundDoneState);
+
+    // reset state trackers
+    foundDoneState = foundPendingState = false;
+  }
+
+  unsubscribe();
+});
diff --git a/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-01.js b/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-01.js
new file mode 100644
index 000000000..cd015557d
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-01.js
@@ -0,0 +1,82 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that changing displays with different inverted state properly
+// refreshes the selected census.
+
+const {
+  censusDisplays,
+  snapshotState: states,
+  censusState,
+  viewState
+} = require("devtools/client/memory/constants");
+const {
+  setCensusDisplayAndRefresh
+} = require("devtools/client/memory/actions/census-display");
+const {
+  takeSnapshotAndCensus,
+  selectSnapshotAndRefresh,
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Select a non-inverted display.
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.allocationStack));
+  equal(getState().censusDisplay.inverted, false, "not inverted by default");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED,
+                                                    censusState.SAVED]);
+  ok(true, "saved 3 snapshots and took a census of each of them");
+
+  // Select an inverted display.
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.invertedAllocationStack));
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED,
+                                                    censusState.SAVING]);
+  ok(true, "toggling inverted should recompute the selected snapshot's census");
+
+  equal(getState().censusDisplay.inverted, true, "now inverted");
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED,
+                                                    censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.display.inverted, false);
+  equal(getState().snapshots[1].census.display.inverted, false);
+  equal(getState().snapshots[2].census.display.inverted, true);
+
+  dispatch(selectSnapshotAndRefresh(heapWorker, getState().snapshots[1].id));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVING,
+                                                    censusState.SAVED]);
+  ok(true, "selecting non-inverted census should trigger a recompute");
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED,
+                                                    censusState.SAVED]);
+
+  equal(getState().snapshots[0].census.display.inverted, false);
+  equal(getState().snapshots[1].census.display.inverted, true);
+  equal(getState().snapshots[2].census.display.inverted, true);
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-02.js b/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-02.js
new file mode 100644
index 000000000..f0cdba264
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-toggle-inverted-and-refresh-02.js
@@ -0,0 +1,58 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test that changing inverted state in the middle of taking a snapshot results
+// in an inverted census.
+
+const { censusDisplays, snapshotState: states, censusState, viewState } = require("devtools/client/memory/constants");
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const {
+  setCensusDisplay,
+  setCensusDisplayAndRefresh,
+} = require("devtools/client/memory/actions/census-display");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  dispatch(setCensusDisplay(censusDisplays.allocationStack));
+  equal(getState().censusDisplay.inverted, false,
+        "Should not have an inverted census display");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilSnapshotState(store, [states.SAVING]);
+
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.invertedAllocationStack));
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  ok(getState().censusDisplay.inverted,
+     "should want inverted trees");
+  ok(getState().snapshots[0].census.display.inverted,
+     "snapshot-we-were-in-the-middle-of-saving's census should be inverted");
+
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.allocationStack));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVING]);
+  ok(true, "toggling inverted retriggers census");
+  ok(!getState().censusDisplay.inverted, "no longer inverted");
+
+  dispatch(setCensusDisplayAndRefresh(heapWorker, censusDisplays.invertedAllocationStack));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+  ok(getState().censusDisplay.inverted, "inverted again");
+  ok(getState().snapshots[0].census.display.inverted,
+     "census-we-were-in-the-middle-of-recomputing should be inverted again");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action-toggle-inverted.js b/devtools/client/memory/test/unit/test_action-toggle-inverted.js
new file mode 100644
index 000000000..665e5d822
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-toggle-inverted.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test toggling the top level inversion state of the tree.
+
+const { censusDisplays } = require("devtools/client/memory/constants");
+const { setCensusDisplay } = require("devtools/client/memory/actions/census-display");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(setCensusDisplay(censusDisplays.allocationStack));
+  equal(getState().censusDisplay.inverted, false,
+        "not inverted initially");
+
+  dispatch(setCensusDisplay(censusDisplays.invertedAllocationStack));
+  equal(getState().censusDisplay.inverted, true, "now inverted after toggling");
+
+  dispatch(setCensusDisplay(censusDisplays.allocationStack));
+  equal(getState().censusDisplay.inverted, false,
+        "not inverted again after toggling again");
+});
diff --git a/devtools/client/memory/test/unit/test_action-toggle-recording-allocations.js b/devtools/client/memory/test/unit/test_action-toggle-recording-allocations.js
new file mode 100644
index 000000000..ebbc17173
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action-toggle-recording-allocations.js
@@ -0,0 +1,42 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Test toggling the recording of allocation stacks.
+ */
+
+let { toggleRecordingAllocationStacks } = require("devtools/client/memory/actions/allocations");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().allocations.recording, false, "not recording by default");
+  equal(getState().allocations.togglingInProgress, false,
+        "not in the process of toggling by default");
+
+  dispatch(toggleRecordingAllocationStacks(front));
+  yield waitUntilState(store, () => getState().allocations.togglingInProgress);
+  ok(true, "`togglingInProgress` set to true when toggling on");
+  yield waitUntilState(store, () => !getState().allocations.togglingInProgress);
+
+  equal(getState().allocations.recording, true, "now we are recording");
+  ok(front.recordingAllocations, "front is recording too");
+
+  dispatch(toggleRecordingAllocationStacks(front));
+  yield waitUntilState(store, () => getState().allocations.togglingInProgress);
+  ok(true, "`togglingInProgress` set to true when toggling off");
+  yield waitUntilState(store, () => !getState().allocations.togglingInProgress);
+
+  equal(getState().allocations.recording, false, "now we are not recording");
+  ok(front.recordingAllocations, "front is not recording anymore");
+
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action_diffing_01.js b/devtools/client/memory/test/unit/test_action_diffing_01.js
new file mode 100644
index 000000000..24893581e
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action_diffing_01.js
@@ -0,0 +1,29 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test toggling of diffing.
+
+const { toggleDiffing } = require("devtools/client/memory/actions/diffing");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().diffing, null, "not diffing by default");
+
+  dispatch(toggleDiffing());
+  ok(getState().diffing, "now diffing after toggling");
+
+  dispatch(toggleDiffing());
+  equal(getState().diffing, null, "not diffing again after toggling again");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action_diffing_02.js b/devtools/client/memory/test/unit/test_action_diffing_02.js
new file mode 100644
index 000000000..fc68cee65
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action_diffing_02.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that toggling diffing unselects all snapshots.
+
+const { snapshotState, censusState, viewState } = require("devtools/client/memory/constants");
+const { toggleDiffing } = require("devtools/client/memory/actions/diffing");
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  equal(getState().diffing, null, "not diffing by default");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED,
+                                                    censusState.SAVED]);
+
+  ok(getState().snapshots.some(s => s.selected),
+     "One of the new snapshots is selected");
+
+  dispatch(toggleDiffing());
+  ok(getState().diffing, "now diffing after toggling");
+
+  for (let s of getState().snapshots) {
+    ok(!s.selected,
+       "No snapshot should be selected after entering diffing mode");
+  }
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action_diffing_03.js b/devtools/client/memory/test/unit/test_action_diffing_03.js
new file mode 100644
index 000000000..3dd901724
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action_diffing_03.js
@@ -0,0 +1,104 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test selecting snapshots for diffing.
+
+const { diffingState, snapshotState, viewState } = require("devtools/client/memory/constants");
+const {
+  toggleDiffing,
+  selectSnapshotForDiffing
+} = require("devtools/client/memory/actions/diffing");
+const { takeSnapshot } = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+// We test that you (1) cannot select a snapshot that is not in a diffable
+// state, and (2) cannot select more than 2 snapshots for diffing. Both attempts
+// trigger assertion failures.
+EXPECTED_DTU_ASSERT_FAILURE_COUNT = 2;
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+  equal(getState().diffing, null, "not diffing by default");
+
+  dispatch(takeSnapshot(front, heapWorker));
+  dispatch(takeSnapshot(front, heapWorker));
+  dispatch(takeSnapshot(front, heapWorker));
+
+  yield waitUntilSnapshotState(store, [snapshotState.SAVED,
+                                       snapshotState.SAVED,
+                                       snapshotState.SAVED]);
+  dispatch(takeSnapshot(front));
+
+  // Start diffing.
+  dispatch(toggleDiffing());
+  ok(getState().diffing, "now diffing after toggling");
+  equal(getState().diffing.firstSnapshotId, null,
+        "no first snapshot selected");
+  equal(getState().diffing.secondSnapshotId, null,
+        "no second snapshot selected");
+  equal(getState().diffing.state, diffingState.SELECTING,
+        "should be in diffing state SELECTING");
+
+  // Can't select a snapshot that is not in a diffable state.
+  equal(getState().snapshots[3].state, snapshotState.SAVING,
+        "the last snapshot is still in the process of being saved");
+  dumpn("Expecting exception:");
+  let threw = false;
+  try {
+    dispatch(selectSnapshotForDiffing(getState().snapshots[3]));
+  } catch (error) {
+    threw = true;
+  }
+  ok(threw, "Should not be able to select snapshots that aren't ready for diffing");
+
+  // Select first snapshot for diffing.
+  dispatch(selectSnapshotForDiffing(getState().snapshots[0]));
+  ok(getState().diffing, "now diffing after toggling");
+  equal(getState().diffing.firstSnapshotId, getState().snapshots[0].id,
+        "first snapshot selected");
+  equal(getState().diffing.secondSnapshotId, null,
+        "no second snapshot selected");
+  equal(getState().diffing.state, diffingState.SELECTING,
+        "should still be in diffing state SELECTING");
+
+  // Can't diff first snapshot with itself; this is a noop.
+  dispatch(selectSnapshotForDiffing(getState().snapshots[0]));
+  ok(getState().diffing, "still diffing");
+  equal(getState().diffing.firstSnapshotId, getState().snapshots[0].id,
+        "first snapshot still selected");
+  equal(getState().diffing.secondSnapshotId, null,
+        "still no second snapshot selected");
+  equal(getState().diffing.state, diffingState.SELECTING,
+        "should still be in diffing state SELECTING");
+
+  // Select second snapshot for diffing.
+  dispatch(selectSnapshotForDiffing(getState().snapshots[1]));
+  ok(getState().diffing, "still diffing");
+  equal(getState().diffing.firstSnapshotId, getState().snapshots[0].id,
+        "first snapshot still selected");
+  equal(getState().diffing.secondSnapshotId, getState().snapshots[1].id,
+        "second snapshot selected");
+
+  // Can't select more than two snapshots for diffing.
+  dumpn("Expecting exception:");
+  threw = false;
+  try {
+    dispatch(selectSnapshotForDiffing(getState().snapshots[2]));
+  } catch (error) {
+    threw = true;
+  }
+  ok(threw, "Can't select more than two snapshots for diffing");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action_diffing_04.js b/devtools/client/memory/test/unit/test_action_diffing_04.js
new file mode 100644
index 000000000..2c3cd098b
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action_diffing_04.js
@@ -0,0 +1,78 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we compute census diffs.
+
+const {
+  diffingState,
+  snapshotState,
+  viewState
+} = require("devtools/client/memory/constants");
+const {
+  toggleDiffing,
+  selectSnapshotForDiffingAndRefresh
+} = require("devtools/client/memory/actions/diffing");
+const {
+  takeSnapshot,
+  readSnapshot
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+  dispatch(changeView(viewState.CENSUS));
+
+  equal(getState().diffing, null, "not diffing by default");
+
+  const s1 = yield dispatch(takeSnapshot(front, heapWorker));
+  const s2 = yield dispatch(takeSnapshot(front, heapWorker));
+  const s3 = yield dispatch(takeSnapshot(front, heapWorker));
+  dispatch(readSnapshot(heapWorker, s1));
+  dispatch(readSnapshot(heapWorker, s2));
+  dispatch(readSnapshot(heapWorker, s3));
+  yield waitUntilSnapshotState(store, [snapshotState.READ,
+                                       snapshotState.READ,
+                                       snapshotState.READ]);
+
+  dispatch(toggleDiffing());
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[0]));
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[1]));
+
+  ok(getState().diffing, "We should be diffing.");
+  equal(getState().diffing.firstSnapshotId, getState().snapshots[0].id,
+        "First snapshot selected.");
+  equal(getState().diffing.secondSnapshotId, getState().snapshots[1].id,
+        "Second snapshot selected.");
+
+  yield waitUntilState(store,
+                       state =>
+                         state.diffing.state === diffingState.TAKING_DIFF);
+  ok(true,
+     "Selecting two snapshots for diffing should trigger computing a diff.");
+
+  yield waitUntilState(store,
+                       state => state.diffing.state === diffingState.TOOK_DIFF);
+  ok(true, "And then the diff should complete.");
+  ok(getState().diffing.census, "And we should have a census.");
+  ok(getState().diffing.census.report, "And that census should have a report.");
+  equal(getState().diffing.census.display, getState().censusDisplay,
+        "And that census should have the correct display");
+  equal(getState().diffing.census.filter, getState().filter,
+        "And that census should have the correct filter");
+  equal(getState().diffing.census.display.inverted,
+        getState().censusDisplay.inverted,
+        "And that census should have the correct inversion");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_action_diffing_05.js b/devtools/client/memory/test/unit/test_action_diffing_05.js
new file mode 100644
index 000000000..e4a1491ac
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_action_diffing_05.js
@@ -0,0 +1,112 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we recompute census diffs at the appropriate times.
+
+const {
+  diffingState,
+  snapshotState,
+  censusDisplays,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  setCensusDisplayAndRefresh,
+} = require("devtools/client/memory/actions/census-display");
+const {
+  toggleDiffing,
+  selectSnapshotForDiffingAndRefresh,
+} = require("devtools/client/memory/actions/diffing");
+const {
+  setFilterStringAndRefresh,
+} = require("devtools/client/memory/actions/filter");
+const {
+  takeSnapshot,
+  readSnapshot,
+} = require("devtools/client/memory/actions/snapshot");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+  dispatch(changeView(viewState.CENSUS));
+
+  yield dispatch(setCensusDisplayAndRefresh(heapWorker,
+                                        censusDisplays.allocationStack));
+  equal(getState().censusDisplay.inverted, false,
+        "not inverted at start");
+
+  equal(getState().diffing, null, "not diffing by default");
+
+  const s1 = yield dispatch(takeSnapshot(front, heapWorker));
+  const s2 = yield dispatch(takeSnapshot(front, heapWorker));
+  const s3 = yield dispatch(takeSnapshot(front, heapWorker));
+  dispatch(readSnapshot(heapWorker, s1));
+  dispatch(readSnapshot(heapWorker, s2));
+  dispatch(readSnapshot(heapWorker, s3));
+  yield waitUntilSnapshotState(store, [snapshotState.READ,
+                                       snapshotState.READ,
+                                       snapshotState.READ]);
+
+  yield dispatch(toggleDiffing());
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[0]));
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker,
+                                              getState().snapshots[1]));
+  yield waitUntilState(store,
+                       state => state.diffing.state === diffingState.TOOK_DIFF);
+
+  const shouldTriggerRecompute = [
+    {
+      name: "toggling inversion",
+      func: () => dispatch(setCensusDisplayAndRefresh(
+        heapWorker,
+        censusDisplays.invertedAllocationStack))
+    },
+    {
+      name: "filtering",
+      func: () => dispatch(setFilterStringAndRefresh("scr", heapWorker))
+    },
+    {
+      name: "changing displays",
+      func: () =>
+        dispatch(setCensusDisplayAndRefresh(heapWorker,
+                                            censusDisplays.coarseType))
+    }
+  ];
+
+  for (let { name, func } of shouldTriggerRecompute) {
+    dumpn(`Testing that "${name}" triggers a diff recompute`);
+    func();
+
+    yield waitUntilState(store,
+                         state =>
+                           state.diffing.state === diffingState.TAKING_DIFF);
+    ok(true, "triggered diff recompute.");
+
+    yield waitUntilState(store,
+                         state =>
+                           state.diffing.state === diffingState.TOOK_DIFF);
+    ok(true, "And then the diff should complete.");
+    ok(getState().diffing.census, "And we should have a census.");
+    ok(getState().diffing.census.report,
+       "And that census should have a report.");
+    equal(getState().diffing.census.display,
+          getState().censusDisplay,
+          "And that census should have the correct display");
+    equal(getState().diffing.census.filter, getState().filter,
+          "And that census should have the correct filter");
+    equal(getState().diffing.census.display.inverted,
+          getState().censusDisplay.inverted,
+          "And that census should have the correct inversion");
+  }
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_01.js b/devtools/client/memory/test/unit/test_dominator_trees_01.js
new file mode 100644
index 000000000..5fcf441d4
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_01.js
@@ -0,0 +1,61 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can compute and fetch the dominator tree for a snapshot.
+
+let {
+  snapshotState: states,
+  dominatorTreeState,
+  treeMapState,
+} = require("devtools/client/memory/constants");
+let {
+  takeSnapshotAndCensus,
+  computeAndFetchDominatorTree,
+} = require("devtools/client/memory/actions/snapshot");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+  ok(!getState().snapshots[0].dominatorTree,
+     "There shouldn't be a dominator tree model yet since it is not computed " +
+     "until we switch to the dominators view.");
+
+  // Change to the dominator tree view.
+  dispatch(computeAndFetchDominatorTree(heapWorker, getState().snapshots[0].id));
+  ok(getState().snapshots[0].dominatorTree,
+     "Should now have a dominator tree model for the selected snapshot");
+
+  // Wait for the dominator tree to start being computed.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.COMPUTING);
+  ok(true, "The dominator tree started computing");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is computing, we should not have its root");
+
+  // Wait for the dominator tree to finish computing and start being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+  ok(true, "The dominator tree started fetching");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is fetching, we should not have its root");
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The dominator tree was fetched");
+  ok(getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is loaded, we should have its root");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_02.js b/devtools/client/memory/test/unit/test_dominator_trees_02.js
new file mode 100644
index 000000000..b35961004
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_02.js
@@ -0,0 +1,64 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that selecting the dominator tree view automatically kicks off fetching
+// and computing dominator trees.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+  treeMapState,
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeViewAndRefresh
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+  ok(!getState().snapshots[0].dominatorTree,
+     "There shouldn't be a dominator tree model yet since it is not computed " +
+     "until we switch to the dominators view.");
+
+  dispatch(changeViewAndRefresh(viewState.DOMINATOR_TREE, heapWorker));
+  ok(getState().snapshots[0].dominatorTree,
+     "Should now have a dominator tree model for the selected snapshot");
+
+  // Wait for the dominator tree to start being computed.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.COMPUTING);
+  ok(true, "The dominator tree started computing");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is computing, we should not have its root");
+
+  // Wait for the dominator tree to finish computing and start being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+  ok(true, "The dominator tree started fetching");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is fetching, we should not have its root");
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The dominator tree was fetched");
+  ok(getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is loaded, we should have its root");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_03.js b/devtools/client/memory/test/unit/test_dominator_trees_03.js
new file mode 100644
index 000000000..09e6477f4
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_03.js
@@ -0,0 +1,61 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that selecting the dominator tree view and then taking a snapshot
+// properly kicks off fetching and computing dominator trees.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+  equal(getState().view.state, viewState.DOMINATOR_TREE,
+        "We should now be in the DOMINATOR_TREE view");
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  // Wait for the dominator tree to start being computed.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] && state.snapshots[0].dominatorTree);
+  equal(getState().snapshots[0].dominatorTree.state,
+        dominatorTreeState.COMPUTING,
+        "The dominator tree started computing");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is computing, we should not have its root");
+
+  // Wait for the dominator tree to finish computing and start being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+  ok(true, "The dominator tree started fetching");
+  ok(!getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is fetching, we should not have its root");
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The dominator tree was fetched");
+  ok(getState().snapshots[0].dominatorTree.root,
+     "When the dominator tree is loaded, we should have its root");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_04.js b/devtools/client/memory/test/unit/test_dominator_trees_04.js
new file mode 100644
index 000000000..ba375c354
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_04.js
@@ -0,0 +1,69 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that selecting the dominator tree view while in the middle of taking a
+// snapshot properly kicks off fetching and computing dominator trees.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+
+  for (let intermediateSnapshotState of [states.SAVING,
+                                         states.READING,
+                                         states.READ]) {
+    dumpn(`Testing switching to the DOMINATOR_TREE view in the middle of the ${intermediateSnapshotState} snapshot state`);
+
+    let store = Store();
+    let { getState, dispatch } = store;
+
+    dispatch(takeSnapshotAndCensus(front, heapWorker));
+    yield waitUntilSnapshotState(store, [intermediateSnapshotState]);
+
+    dispatch(changeView(viewState.DOMINATOR_TREE));
+    equal(getState().view.state, viewState.DOMINATOR_TREE,
+          "We should now be in the DOMINATOR_TREE view");
+
+    // Wait for the dominator tree to start being computed.
+    yield waitUntilState(store, state =>
+      state.snapshots[0] && state.snapshots[0].dominatorTree);
+    equal(getState().snapshots[0].dominatorTree.state,
+          dominatorTreeState.COMPUTING,
+          "The dominator tree started computing");
+    ok(!getState().snapshots[0].dominatorTree.root,
+       "When the dominator tree is computing, we should not have its root");
+
+    // Wait for the dominator tree to finish computing and start being fetched.
+    yield waitUntilState(store, state =>
+      state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+    ok(true, "The dominator tree started fetching");
+    ok(!getState().snapshots[0].dominatorTree.root,
+       "When the dominator tree is fetching, we should not have its root");
+
+    // Wait for the dominator tree to finish being fetched.
+    yield waitUntilState(store, state =>
+      state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+    ok(true, "The dominator tree was fetched");
+    ok(getState().snapshots[0].dominatorTree.root,
+       "When the dominator tree is loaded, we should have its root");
+  }
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_05.js b/devtools/client/memory/test/unit/test_dominator_trees_05.js
new file mode 100644
index 000000000..42ea13e18
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_05.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that changing the currently selected snapshot to a snapshot that does
+// not have a dominator tree will automatically compute and fetch one for it.
+
+let {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+  treeMapState,
+} = require("devtools/client/memory/constants");
+let {
+  takeSnapshotAndCensus,
+  selectSnapshotAndRefresh,
+} = require("devtools/client/memory/actions/snapshot");
+
+let { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED,
+                                                    treeMapState.SAVED]);
+
+  ok(getState().snapshots[1].selected, "The second snapshot is selected");
+
+  // Change to the dominator tree view.
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[1].dominatorTree &&
+    state.snapshots[1].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The second snapshot's dominator tree was fetched");
+
+  // Select the first snapshot.
+  dispatch(selectSnapshotAndRefresh(heapWorker, getState().snapshots[0].id));
+
+  // And now the first snapshot should have its dominator tree fetched and
+  // computed because of the new selection.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The first snapshot's dominator tree was fetched");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_06.js b/devtools/client/memory/test/unit/test_dominator_trees_06.js
new file mode 100644
index 000000000..78f869102
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_06.js
@@ -0,0 +1,127 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can incrementally fetch a subtree of a dominator tree.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus,
+  selectSnapshotAndRefresh,
+  fetchImmediatelyDominated,
+} = require("devtools/client/memory/actions/snapshot");
+const DominatorTreeLazyChildren
+  = require("devtools/client/memory/dominator-tree-lazy-children");
+
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(getState().snapshots[0].dominatorTree.root,
+     "The dominator tree was fetched");
+
+  // Find a node that has children, but none of them are loaded.
+
+  function findNode(node) {
+    if (node.moreChildrenAvailable && !node.children) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findNode(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }
+
+  const oldRoot = getState().snapshots[0].dominatorTree.root;
+  const oldNode = findNode(oldRoot);
+  ok(oldNode,
+     "Should have found a node with children that are not loaded since we " +
+     "only send partial dominator trees across initially and load the rest " +
+     "on demand");
+  ok(oldNode !== oldRoot, "But the node should not be the root");
+
+  const lazyChildren = new DominatorTreeLazyChildren(oldNode.nodeId, 0);
+  dispatch(fetchImmediatelyDominated(heapWorker, getState().snapshots[0].id, lazyChildren));
+
+  equal(getState().snapshots[0].dominatorTree.state,
+        dominatorTreeState.INCREMENTAL_FETCHING,
+        "Fetching immediately dominated children should put us in the " +
+        "INCREMENTAL_FETCHING state");
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true,
+     "The dominator tree should go back to LOADED after the incremental " +
+     "fetching is done.");
+
+  const newRoot = getState().snapshots[0].dominatorTree.root;
+  ok(oldRoot !== newRoot,
+     "When we insert new nodes, we get a new tree");
+  equal(oldRoot.children.length, newRoot.children.length,
+        "The new tree's root should have the same number of children as the " +
+        "old root's");
+
+  let differentChildrenCount = 0;
+  for (let i = 0; i < oldRoot.children.length; i++) {
+    if (oldRoot.children[i] !== newRoot.children[i]) {
+      differentChildrenCount++;
+    }
+  }
+  equal(differentChildrenCount, 1,
+        "All subtrees except the subtree we inserted incrementally fetched " +
+        "children into should be the same because we use persistent updates");
+
+  // Find the new node which has the children inserted.
+
+  function findNewNode(node) {
+    if (node.nodeId === oldNode.nodeId) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findNewNode(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }
+
+  const newNode = findNewNode(newRoot);
+  ok(newNode, "Should find the node in the new tree again");
+  ok(newNode !== oldNode, "We did not mutate the old node in place, instead created a new node");
+  ok(newNode.children, "And the new node should have the children attached");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_07.js b/devtools/client/memory/test/unit/test_dominator_trees_07.js
new file mode 100644
index 000000000..9121fc878
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_07.js
@@ -0,0 +1,146 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can incrementally fetch two subtrees in the same dominator tree
+// concurrently. This exercises the activeFetchRequestCount machinery.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+} = require("devtools/client/memory/constants");
+const {
+  takeSnapshotAndCensus,
+  selectSnapshotAndRefresh,
+  fetchImmediatelyDominated,
+} = require("devtools/client/memory/actions/snapshot");
+const DominatorTreeLazyChildren
+  = require("devtools/client/memory/dominator-tree-lazy-children");
+
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(getState().snapshots[0].dominatorTree.root,
+     "The dominator tree was fetched");
+
+  // Find a node that has more children.
+
+  function findNode(node) {
+    if (node.moreChildrenAvailable && !node.children) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findNode(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }
+
+  const oldRoot = getState().snapshots[0].dominatorTree.root;
+  const oldNode = findNode(oldRoot);
+  ok(oldNode, "Should have found a node with more children.");
+
+  // Find another node that has more children.
+  function findNodeRev(node) {
+    if (node.moreChildrenAvailable && !node.children) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children.slice().reverse()) {
+        const found = findNodeRev(child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }
+
+  const oldNode2 = findNodeRev(oldRoot);
+  ok(oldNode2, "Should have found another node with more children.");
+  ok(oldNode !== oldNode2,
+     "The second node should not be the same as the first one");
+
+  // Fetch both subtrees concurrently.
+  dispatch(fetchImmediatelyDominated(heapWorker, getState().snapshots[0].id,
+                                     new DominatorTreeLazyChildren(oldNode.nodeId, 0)));
+  dispatch(fetchImmediatelyDominated(heapWorker, getState().snapshots[0].id,
+                                     new DominatorTreeLazyChildren(oldNode2.nodeId, 0)));
+
+  equal(getState().snapshots[0].dominatorTree.state,
+        dominatorTreeState.INCREMENTAL_FETCHING,
+        "Fetching immediately dominated children should put us in the " +
+        "INCREMENTAL_FETCHING state");
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true,
+     "The dominator tree should go back to LOADED after the incremental " +
+     "fetching is done.");
+
+  const newRoot = getState().snapshots[0].dominatorTree.root;
+  ok(oldRoot !== newRoot,
+     "When we insert new nodes, we get a new tree");
+
+  // Find the new node which has the children inserted.
+
+  function findNodeWithId(id, node) {
+    if (node.nodeId === id) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = findNodeWithId(id, child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+
+    return null;
+  }
+
+  const newNode = findNodeWithId(oldNode.nodeId, newRoot);
+  ok(newNode, "Should find the node in the new tree again");
+  ok(newNode !== oldNode,
+     "We did not mutate the old node in place, instead created a new node");
+  ok(newNode.children.length,
+     "And the new node should have the new children attached");
+
+  const newNode2 = findNodeWithId(oldNode2.nodeId, newRoot);
+  ok(newNode2, "Should find the second node in the new tree again");
+  ok(newNode2 !== oldNode2,
+     "We did not mutate the second old node in place, instead created a new node");
+  ok(newNode2.children,
+     "And the new node should have the new children attached");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_08.js b/devtools/client/memory/test/unit/test_dominator_trees_08.js
new file mode 100644
index 000000000..27f35180c
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_08.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can change the display with which we describe a dominator tree
+// and that the dominator tree is re-fetched.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+  labelDisplays,
+  treeMapState
+} = require("devtools/client/memory/constants");
+const {
+  setLabelDisplayAndRefresh
+} = require("devtools/client/memory/actions/label-display");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+const {
+  takeSnapshotAndCensus,
+  computeAndFetchDominatorTree,
+} = require("devtools/client/memory/actions/snapshot");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+  ok(!getState().snapshots[0].dominatorTree,
+     "There shouldn't be a dominator tree model yet since it is not computed " +
+     "until we switch to the dominators view.");
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+
+  ok(getState().labelDisplay,
+     "We have a default display for describing nodes in a dominator tree");
+  equal(getState().labelDisplay,
+        labelDisplays.coarseType,
+        "and the default is coarse type");
+  equal(getState().labelDisplay,
+        getState().snapshots[0].dominatorTree.display,
+        "and the newly computed dominator tree has that display");
+
+  // Switch to the allocationStack display.
+  dispatch(setLabelDisplayAndRefresh(
+    heapWorker,
+    labelDisplays.allocationStack));
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+  ok(true,
+     "switching display types caused the dominator tree to be fetched " +
+     "again.");
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  equal(getState().snapshots[0].dominatorTree.display,
+        labelDisplays.allocationStack,
+        "The new dominator tree's display is allocationStack");
+  equal(getState().labelDisplay,
+        labelDisplays.allocationStack,
+        "as is our requested dominator tree display");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_09.js b/devtools/client/memory/test/unit/test_dominator_trees_09.js
new file mode 100644
index 000000000..c1d1f7495
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_09.js
@@ -0,0 +1,78 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can change the display with which we describe a dominator tree
+// while the dominator tree is in the middle of being fetched.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+  labelDisplays,
+  treeMapState,
+} = require("devtools/client/memory/constants");
+const {
+  setLabelDisplayAndRefresh
+} = require("devtools/client/memory/actions/label-display");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+const {
+  takeSnapshotAndCensus,
+  computeAndFetchDominatorTree,
+} = require("devtools/client/memory/actions/snapshot");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.treeMap, [treeMapState.SAVED]);
+  ok(!getState().snapshots[0].dominatorTree,
+     "There shouldn't be a dominator tree model yet since it is not computed " +
+     "until we switch to the dominators view.");
+
+  // Wait for the dominator tree to start fetching.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+
+  ok(getState().labelDisplay,
+     "We have a default display for describing nodes in a dominator tree");
+  equal(getState().labelDisplay,
+        labelDisplays.coarseType,
+        "and the default is coarse type");
+  equal(getState().labelDisplay,
+        getState().snapshots[0].dominatorTree.display,
+        "and the newly computed dominator tree has that display");
+
+  // Switch to the allocationStack display while we are still fetching the
+  // dominator tree.
+  dispatch(setLabelDisplayAndRefresh(
+    heapWorker,
+    labelDisplays.allocationStack));
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+
+  equal(getState().snapshots[0].dominatorTree.display,
+        labelDisplays.allocationStack,
+        "The new dominator tree's display is allocationStack");
+  equal(getState().labelDisplay,
+        labelDisplays.allocationStack,
+        "as is our requested dominator tree display");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_dominator_trees_10.js b/devtools/client/memory/test/unit/test_dominator_trees_10.js
new file mode 100644
index 000000000..f7cf86a10
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_dominator_trees_10.js
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we maintain focus of the selected dominator tree node across
+// changing breakdowns for labeling them.
+
+let {
+  snapshotState: states,
+  dominatorTreeState,
+  labelDisplays,
+  viewState,
+} = require("devtools/client/memory/constants");
+let {
+  takeSnapshotAndCensus,
+  focusDominatorTreeNode,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+const {
+  setLabelDisplayAndRefresh,
+} = require("devtools/client/memory/actions/label-display");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.DOMINATOR_TREE));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+
+  // Wait for the dominator tree to finish being fetched.
+  yield waitUntilState(store, state =>
+    state.snapshots[0] &&
+    state.snapshots[0].dominatorTree &&
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The dominator tree was fetched");
+
+  const root = getState().snapshots[0].dominatorTree.root;
+  ok(root, "When the dominator tree is loaded, we should have its root");
+
+  dispatch(focusDominatorTreeNode(getState().snapshots[0].id, root));
+  equal(root, getState().snapshots[0].dominatorTree.focused,
+        "The root should be focused.");
+
+  equal(getState().labelDisplay, labelDisplays.coarseType,
+        "Using labelDisplays.coarseType by default");
+  dispatch(setLabelDisplayAndRefresh(heapWorker,
+                                             labelDisplays.allocationStack));
+  equal(getState().labelDisplay, labelDisplays.allocationStack,
+        "Using labelDisplays.allocationStack now");
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING);
+  ok(true, "We started re-fetching the dominator tree");
+
+  yield waitUntilState(store, state =>
+    state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED);
+  ok(true, "The dominator tree was loaded again");
+
+  ok(getState().snapshots[0].dominatorTree.focused,
+     "Still have a focused node");
+  equal(getState().snapshots[0].dominatorTree.focused.nodeId, root.nodeId,
+        "Focused node is the same as before");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_01.js b/devtools/client/memory/test/unit/test_individuals_01.js
new file mode 100644
index 000000000..36971a7dc
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_01.js
@@ -0,0 +1,76 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Basic test for switching to the individuals view.
+
+const {
+  censusState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().individuals, null,
+        "no individuals state by default");
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root);
+  ok(reportLeafIndex, "Should get a reportLeafIndex");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().snapshots[0].census.display.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  // Wait for each expected state.
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_02.js b/devtools/client/memory/test/unit/test_individuals_02.js
new file mode 100644
index 000000000..9e23e2c4f
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_02.js
@@ -0,0 +1,88 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test switching to the individuals view when we are in the middle of computing
+// a dominator tree.
+
+const {
+  censusState,
+  dominatorTreeState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+  computeDominatorTree,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().individuals, null,
+        "no individuals state by default");
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root);
+  ok(reportLeafIndex, "Should get a reportLeafIndex");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().snapshots[0].census.display.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  // Start computing a dominator tree.
+
+  dispatch(computeDominatorTree(heapWorker, snapshotId));
+  equal(getState().snapshots[0].dominatorTree.state,
+        dominatorTreeState.COMPUTING,
+        "Should be computing dominator tree");
+
+  // Fetch individuals in the middle of computing the dominator tree.
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  // Wait for each expected state.
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_03.js b/devtools/client/memory/test/unit/test_individuals_03.js
new file mode 100644
index 000000000..54460b737
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_03.js
@@ -0,0 +1,106 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test switching to the individuals view when we are in the diffing view.
+
+const {
+  censusState,
+  diffingState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+  popViewAndRefresh,
+} = require("devtools/client/memory/actions/view");
+const {
+  selectSnapshotForDiffingAndRefresh,
+} = require("devtools/client/memory/actions/diffing");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Take two snapshots and diff them from each other.
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED,
+                                                    censusState.SAVED]);
+
+  dispatch(changeView(viewState.DIFFING));
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker, getState().snapshots[0]));
+  dispatch(selectSnapshotForDiffingAndRefresh(heapWorker, getState().snapshots[1]));
+
+  yield waitUntilState(store, state => {
+    return state.diffing &&
+           state.diffing.state === diffingState.TOOK_DIFF;
+  });
+  ok(getState().diffing.census);
+
+  // Fetch individuals.
+
+  const root = getState().diffing.census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root);
+  ok(reportLeafIndex, "Should get a reportLeafIndex");
+
+  const snapshotId = getState().diffing.secondSnapshotId;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().censusDisplay.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  // Pop the view back to the diffing.
+
+  dispatch(popViewAndRefresh(heapWorker));
+
+  yield waitUntilState(store, state => {
+    return state.diffing &&
+      state.diffing.state === diffingState.TOOK_DIFF;
+  });
+
+  ok(getState().diffing.census.report,
+     "We have our census diff again after popping back to the last view");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_04.js b/devtools/client/memory/test/unit/test_individuals_04.js
new file mode 100644
index 000000000..c160d555f
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_04.js
@@ -0,0 +1,89 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test showing individual Array objects.
+
+const {
+  censusState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+const {
+  setFilterString,
+} = require("devtools/client/memory/actions/filter");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(setFilterString("Array"));
+
+  // Take a snapshot and wait for the census to finish.
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  // Fetch individuals.
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root, "Array");
+  ok(reportLeafIndex, "Should get a reportLeafIndex for Array");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().censusDisplay.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  // Assert that all the individuals are `Array`s.
+
+  for (let node of getState().individuals.nodes) {
+    dumpn("Checking node: " + node.label.join(" > "));
+    ok(node.label.find(part => part === "Array"),
+       "The node should be an Array node");
+  }
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_05.js b/devtools/client/memory/test/unit/test_individuals_05.js
new file mode 100644
index 000000000..1f8873826
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_05.js
@@ -0,0 +1,82 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test showing individual objects that do not have allocation stacks.
+
+const {
+  censusState,
+  viewState,
+  individualsState,
+  censusDisplays,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+const {
+  setCensusDisplay,
+} = require("devtools/client/memory/actions/census-display");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(setCensusDisplay(censusDisplays.invertedAllocationStack));
+
+  // Take a snapshot and wait for the census to finish.
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  // Fetch individuals.
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root, "noStack");
+  ok(reportLeafIndex, "Should get a reportLeafIndex for noStack");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().censusDisplay.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_individuals_06.js b/devtools/client/memory/test/unit/test_individuals_06.js
new file mode 100644
index 000000000..6147b8181
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_individuals_06.js
@@ -0,0 +1,84 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test that clearing the current individuals' snapshot leaves the individuals
+// view.
+
+const {
+  censusState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+  clearSnapshots,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+const EXPECTED_INDIVIDUAL_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  // Take a snapshot and wait for the census to finish.
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  // Fetch individuals.
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root);
+  ok(reportLeafIndex, "Should get a reportLeafIndex");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().censusDisplay.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                            reportLeafIndex));
+
+  for (let state of EXPECTED_INDIVIDUAL_STATES) {
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+  }
+
+  ok(getState().individuals, "Should have individuals state");
+  ok(getState().individuals.nodes, "Should have individuals nodes");
+  ok(getState().individuals.nodes.length > 0,
+     "Should have a positive number of nodes");
+
+  dispatch(clearSnapshots(heapWorker));
+
+  equal(getState().view.state, viewState.CENSUS,
+        "Went back to census view");
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_pop_view_01.js b/devtools/client/memory/test/unit/test_pop_view_01.js
new file mode 100644
index 000000000..9e6a17095
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_pop_view_01.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test popping views from each intermediate individuals model state.
+
+const {
+  censusState,
+  viewState,
+  individualsState,
+} = require("devtools/client/memory/constants");
+const {
+  fetchIndividuals,
+  takeSnapshotAndCensus,
+} = require("devtools/client/memory/actions/snapshot");
+const {
+  changeView,
+  popViewAndRefresh,
+} = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+const TEST_STATES = [
+  individualsState.COMPUTING_DOMINATOR_TREE,
+  individualsState.FETCHING,
+  individualsState.FETCHED,
+];
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  const { getState, dispatch } = store;
+
+  equal(getState().individuals, null,
+        "no individuals state by default");
+
+  dispatch(changeView(viewState.CENSUS));
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  const root = getState().snapshots[0].census.report;
+  ok(root, "Should have a census");
+
+  const reportLeafIndex = findReportLeafIndex(root);
+  ok(reportLeafIndex, "Should get a reportLeafIndex");
+
+  const snapshotId = getState().snapshots[0].id;
+  ok(snapshotId, "Should have a snapshot id");
+
+  const breakdown = getState().snapshots[0].census.display.breakdown;
+  ok(breakdown, "Should have a breakdown");
+
+  for (let state of TEST_STATES) {
+    dumpn(`Testing popping back to the old view from state = ${state}`);
+
+    dispatch(fetchIndividuals(heapWorker, snapshotId, breakdown,
+                              reportLeafIndex));
+
+    // Wait for the expected test state.
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.INDIVIDUALS &&
+             s.individuals &&
+             s.individuals.state === state;
+    });
+    ok(true, `Reached state = ${state}`);
+
+    // Pop back to the CENSUS state.
+    dispatch(popViewAndRefresh(heapWorker));
+    yield waitUntilState(store, s => {
+      return s.view.state === viewState.CENSUS;
+    });
+    ok(!getState().individuals, "Should no longer have individuals");
+  }
+
+  heapWorker.destroy();
+  yield front.detach();
+});
diff --git a/devtools/client/memory/test/unit/test_tree-map-01.js b/devtools/client/memory/test/unit/test_tree-map-01.js
new file mode 100644
index 000000000..15d9a765a
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_tree-map-01.js
@@ -0,0 +1,57 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const { drawBox } = require("devtools/client/memory/components/tree-map/draw");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let fillRectValues, strokeRectValues;
+  let ctx = {
+    fillRect: (...args) => fillRectValues = args,
+    strokeRect: (...args) => strokeRectValues = args
+  };
+  let node = {
+    x: 20,
+    y: 30,
+    dx: 50,
+    dy: 70,
+    type: "other",
+    depth: 2
+  };
+  let padding = [10, 10];
+  let borderWidth = () => 1;
+  let dragZoom = {
+    offsetX: 0,
+    offsetY: 0,
+    zoom: 0
+  };
+  drawBox(ctx, node, borderWidth, dragZoom, padding);
+  ok(true, JSON.stringify([ctx, fillRectValues, strokeRectValues]));
+  equal(ctx.fillStyle, "hsl(210,60%,70%)", "The fillStyle is set");
+  equal(ctx.strokeStyle, "hsl(210,60%,35%)", "The strokeStyle is set");
+  equal(ctx.lineWidth, 1, "The lineWidth is set");
+  deepEqual(fillRectValues, [10.5, 20.5, 49, 69], "Draws a filled rectangle");
+  deepEqual(strokeRectValues, [10.5, 20.5, 49, 69], "Draws a stroked rectangle");
+
+
+  dragZoom.zoom = 0.5;
+
+  drawBox(ctx, node, borderWidth, dragZoom, padding);
+  ok(true, JSON.stringify([ctx, fillRectValues, strokeRectValues]));
+  deepEqual(fillRectValues, [15.5, 30.5, 74, 104],
+    "Draws a zoomed filled rectangle");
+  deepEqual(strokeRectValues, [15.5, 30.5, 74, 104],
+    "Draws a zoomed stroked rectangle");
+
+  dragZoom.offsetX = 110;
+  dragZoom.offsetY = 130;
+
+  drawBox(ctx, node, borderWidth, dragZoom, padding);
+  deepEqual(fillRectValues, [-94.5, -99.5, 74, 104],
+    "Draws a zoomed and offset filled rectangle");
+  deepEqual(strokeRectValues, [-94.5, -99.5, 74, 104],
+    "Draws a zoomed and offset stroked rectangle");
+});
diff --git a/devtools/client/memory/test/unit/test_tree-map-02.js b/devtools/client/memory/test/unit/test_tree-map-02.js
new file mode 100644
index 000000000..4f7200f0a
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_tree-map-02.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { drawText } = require("devtools/client/memory/components/tree-map/draw");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  // Mock out the Canvas2dContext
+  let ctx = {
+    fillText: (...args) => fillTextValues.push(args),
+    measureText: (text) => {
+      let width = text ? text.length * 10 : 0;
+      return { width };
+    }
+  };
+  let node = {
+    x: 20,
+    y: 30,
+    dx: 500,
+    dy: 70,
+    name: "Example Node",
+    totalBytes: 1200,
+    totalCount: 100
+  };
+  let ratio = 0;
+  let borderWidth = () => 1;
+  let dragZoom = {
+    offsetX: 0,
+    offsetY: 0,
+    zoom: 0
+  };
+  let fillTextValues = [];
+  let padding = [10, 10];
+
+  drawText(ctx, node, borderWidth, ratio, dragZoom, padding);
+  deepEqual(fillTextValues[0], ["Example Node", 11.5, 21.5],
+    "Fills in the full node name");
+  deepEqual(fillTextValues[1], ["1KiB 100 count", 141.5, 21.5],
+    "Includes the full byte and count information");
+
+  fillTextValues = [];
+  node.dx = 250;
+  drawText(ctx, node, borderWidth, ratio, dragZoom, padding);
+
+  deepEqual(fillTextValues[0], ["Example Node", 11.5, 21.5],
+    "Fills in the full node name");
+  deepEqual(fillTextValues[1], undefined,
+    "Drops off the byte and count information if not enough room");
+
+  fillTextValues = [];
+  node.dx = 100;
+  drawText(ctx, node, borderWidth, ratio, dragZoom, padding);
+
+  deepEqual(fillTextValues[0], ["Exampl...", 11.5, 21.5],
+    "Cuts the name with ellipsis");
+  deepEqual(fillTextValues[1], undefined,
+    "Drops off the byte and count information if not enough room");
+
+  fillTextValues = [];
+  node.dx = 40;
+  drawText(ctx, node, borderWidth, ratio, dragZoom, padding);
+
+  deepEqual(fillTextValues[0], ["...", 11.5, 21.5],
+    "Shows only ellipsis when smaller");
+  deepEqual(fillTextValues[1], undefined,
+    "Drops off the byte and count information if not enough room");
+
+  fillTextValues = [];
+  node.dx = 20;
+  drawText(ctx, node, borderWidth, ratio, dragZoom, padding);
+
+  deepEqual(fillTextValues[0], undefined,
+    "Draw nothing when not enough room");
+  deepEqual(fillTextValues[1], undefined,
+    "Drops off the byte and count information if not enough room");
+});
diff --git a/devtools/client/memory/test/unit/test_utils-get-snapshot-totals.js b/devtools/client/memory/test/unit/test_utils-get-snapshot-totals.js
new file mode 100644
index 000000000..c4560fb07
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_utils-get-snapshot-totals.js
@@ -0,0 +1,72 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests that we use the correct snapshot aggregate value
+ * in `utils.getSnapshotTotals(snapshot)`
+ */
+
+const { censusDisplays, snapshotState: states, viewState, censusState } = require("devtools/client/memory/constants");
+const { getSnapshotTotals } = require("devtools/client/memory/utils");
+const { takeSnapshotAndCensus } = require("devtools/client/memory/actions/snapshot");
+const { setCensusDisplayAndRefresh } = require("devtools/client/memory/actions/census-display");
+const { changeView } = require("devtools/client/memory/actions/view");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let front = new StubbedMemoryFront();
+  let heapWorker = new HeapAnalysesClient();
+  yield front.attach();
+  let store = Store();
+  let { getState, dispatch } = store;
+
+  dispatch(changeView(viewState.CENSUS));
+
+  yield dispatch(setCensusDisplayAndRefresh(heapWorker,
+                                            censusDisplays.allocationStack));
+
+  dispatch(takeSnapshotAndCensus(front, heapWorker));
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+
+  ok(!getState().snapshots[0].census.display.inverted, "Snapshot is not inverted");
+
+  let census = getState().snapshots[0].census;
+  let result = aggregate(census.report);
+  let totalBytes = result.bytes;
+  let totalCount = result.count;
+
+  ok(totalBytes > 0, "counted up bytes in the census");
+  ok(totalCount > 0, "counted up count in the census");
+
+  result = getSnapshotTotals(getState().snapshots[0].census);
+  equal(totalBytes, result.bytes, "getSnapshotTotals reuslted in correct bytes");
+  equal(totalCount, result.count, "getSnapshotTotals reuslted in correct count");
+
+  dispatch(setCensusDisplayAndRefresh(heapWorker,
+                                      censusDisplays.invertedAllocationStack));
+
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVING]);
+  yield waitUntilCensusState(store, s => s.census, [censusState.SAVED]);
+  ok(getState().snapshots[0].census.display.inverted, "Snapshot is inverted");
+
+  result = getSnapshotTotals(getState().snapshots[0].census);
+  equal(totalBytes, result.bytes,
+        "getSnapshotTotals reuslted in correct bytes when inverted");
+  equal(totalCount, result.count,
+        "getSnapshotTotals reuslted in correct count when inverted");
+});
+
+function aggregate(report) {
+  let totalBytes = report.bytes;
+  let totalCount = report.count;
+  for (let child of (report.children || [])) {
+    let { bytes, count } = aggregate(child);
+    totalBytes += bytes;
+    totalCount += count;
+  }
+  return { bytes: totalBytes, count: totalCount };
+}
diff --git a/devtools/client/memory/test/unit/test_utils.js b/devtools/client/memory/test/unit/test_utils.js
new file mode 100644
index 000000000..f6deddfc9
--- /dev/null
+++ b/devtools/client/memory/test/unit/test_utils.js
@@ -0,0 +1,70 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Tests the task creator `takeSnapshotAndCensus()` for the whole flow of
+ * taking a snapshot, and its sub-actions. Tests the formatNumber and
+ * formatPercent methods.
+ */
+
+let utils = require("devtools/client/memory/utils");
+let { snapshotState: states, viewState } = require("devtools/client/memory/constants");
+let { Preferences } = require("resource://gre/modules/Preferences.jsm");
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  let s1 = utils.createSnapshot({ view: { state: viewState.CENSUS } });
+  let s2 = utils.createSnapshot({ view: { state: viewState.CENSUS } });
+  equal(s1.state, states.SAVING, "utils.createSnapshot() creates snapshot in saving state");
+  ok(s1.id !== s2.id, "utils.createSnapshot() creates snapshot with unique ids");
+
+  let custom = { by: "internalType", then: { by: "count", bytes: true }};
+  Preferences.set("devtools.memory.custom-census-displays", JSON.stringify({ "My Display": custom }));
+
+  equal(utils.getCustomCensusDisplays()["My Display"].by, custom.by,
+        "utils.getCustomCensusDisplays() returns custom displays");
+
+  ok(true, "test formatNumber util functions");
+  equal(utils.formatNumber(12), "12", "formatNumber returns 12 for 12");
+
+  equal(utils.formatNumber(0), "0", "formatNumber returns 0 for 0");
+  equal(utils.formatNumber(-0), "0", "formatNumber returns 0 for -0");
+  equal(utils.formatNumber(+0), "0", "formatNumber returns 0 for +0");
+
+  equal(utils.formatNumber(1234567), "1 234 567",
+    "formatNumber adds a space every 3rd digit");
+  equal(utils.formatNumber(12345678), "12 345 678",
+    "formatNumber adds a space every 3rd digit");
+  equal(utils.formatNumber(123456789), "123 456 789",
+    "formatNumber adds a space every 3rd digit");
+
+  equal(utils.formatNumber(12, true), "+12",
+    "formatNumber can display number sign");
+  equal(utils.formatNumber(-12, true), "-12",
+    "formatNumber can display number sign (negative)");
+
+  ok(true, "test formatPercent util functions");
+  equal(utils.formatPercent(12), "12%", "formatPercent returns 12% for 12");
+  equal(utils.formatPercent(12345), "12 345%",
+    "formatPercent returns 12 345% for 12345");
+
+  equal(utils.formatAbbreviatedBytes(12), "12B", "Formats bytes");
+  equal(utils.formatAbbreviatedBytes(12345), "12KiB", "Formats kilobytes");
+  equal(utils.formatAbbreviatedBytes(12345678), "11MiB", "Formats megabytes");
+  equal(utils.formatAbbreviatedBytes(12345678912), "11GiB", "Formats gigabytes");
+
+  equal(utils.hslToStyle(0.5, 0.6, 0.7),
+    "hsl(180,60%,70%)", "hslToStyle converts an array to a style string");
+  equal(utils.hslToStyle(0, 0, 0),
+    "hsl(0,0%,0%)", "hslToStyle converts an array to a style string");
+  equal(utils.hslToStyle(1, 1, 1),
+    "hsl(360,100%,100%)", "hslToStyle converts an array to a style string");
+
+  equal(utils.lerp(5, 7, 0), 5, "lerp return first number for 0");
+  equal(utils.lerp(5, 7, 1), 7, "lerp return second number for 1");
+  equal(utils.lerp(5, 7, 0.5), 6, "lerp interpolates the numbers for 0.5");
+});
diff --git a/devtools/client/memory/test/unit/xpcshell.ini b/devtools/client/memory/test/unit/xpcshell.ini
new file mode 100644
index 000000000..dade269c3
--- /dev/null
+++ b/devtools/client/memory/test/unit/xpcshell.ini
@@ -0,0 +1,56 @@
+[DEFAULT]
+tags = devtools devtools-memory
+head = head.js ../../../framework/test/shared-redux-head.js
+tail =
+firefox-appdir = browser
+skip-if = toolkit == 'android'
+
+[test_action_diffing_01.js]
+[test_action_diffing_02.js]
+[test_action_diffing_03.js]
+[test_action_diffing_04.js]
+[test_action_diffing_05.js]
+[test_action-clear-snapshots_01.js]
+[test_action-clear-snapshots_02.js]
+[test_action-clear-snapshots_03.js]
+[test_action-clear-snapshots_04.js]
+[test_action-clear-snapshots_05.js]
+[test_action-clear-snapshots_06.js]
+[test_action-export-snapshot.js]
+[test_action-filter-01.js]
+[test_action-filter-02.js]
+[test_action-filter-03.js]
+[test_action-import-snapshot-and-census.js]
+[test_action-import-snapshot-dominator-tree.js]
+[test_action-select-snapshot.js]
+[test_action-set-display.js]
+[test_action-set-display-and-refresh-01.js]
+[test_action-set-display-and-refresh-02.js]
+[test_action-take-census.js]
+[test_action-take-snapshot.js]
+[test_action-take-snapshot-and-census.js]
+[test_action-toggle-inverted.js]
+[test_action-toggle-inverted-and-refresh-01.js]
+[test_action-toggle-inverted-and-refresh-02.js]
+[test_action-toggle-recording-allocations.js]
+[test_dominator_trees_01.js]
+[test_dominator_trees_02.js]
+[test_dominator_trees_03.js]
+[test_dominator_trees_04.js]
+[test_dominator_trees_05.js]
+[test_dominator_trees_06.js]
+[test_dominator_trees_07.js]
+[test_dominator_trees_08.js]
+[test_dominator_trees_09.js]
+[test_dominator_trees_10.js]
+[test_individuals_01.js]
+[test_individuals_02.js]
+[test_individuals_03.js]
+[test_individuals_04.js]
+[test_individuals_05.js]
+[test_individuals_06.js]
+[test_pop_view_01.js]
+[test_tree-map-01.js]
+[test_tree-map-02.js]
+[test_utils.js]
+[test_utils-get-snapshot-totals.js]