Add m-esr52 at 52.6.0

6 files changed, 1524 insertions, 0 deletions

diff --git a/devtools/shared/pretty-fast/UPGRADING.md b/devtools/shared/pretty-fast/UPGRADING.md
new file mode 100644
index 000000000..9758096eb
--- /dev/null
+++ b/devtools/shared/pretty-fast/UPGRADING.md
@@ -0,0 +1,11 @@
+# UPGRADING
+
+1. `git clone https://github.com/mozilla/pretty-fast.git`
+
+2. Copy `pretty-fast/pretty-fast.js` to `devtools/shared/pretty-fast/pretty-fast.js`
+
+3. Copy `pretty-fast/test.js` to `devtools/shared/pretty-fast/tests/unit/test.js`
+
+4. If necessary, upgrade acorn (see devtools/shared/acorn/UPGRADING.md)
+
+5. Replace `acorn/dist/` with `acorn/` in pretty-fast.js.
\ No newline at end of file
diff --git a/devtools/shared/pretty-fast/moz.build b/devtools/shared/pretty-fast/moz.build
new file mode 100644
index 000000000..3c72c8ff6
--- /dev/null
+++ b/devtools/shared/pretty-fast/moz.build
@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPCSHELL_TESTS_MANIFESTS += ['tests/unit/xpcshell.ini']
+
+DevToolsModules(
+    'pretty-fast.js',
+)
diff --git a/devtools/shared/pretty-fast/pretty-fast.js b/devtools/shared/pretty-fast/pretty-fast.js
new file mode 100644
index 000000000..838a7b348
--- /dev/null
+++ b/devtools/shared/pretty-fast/pretty-fast.js
@@ -0,0 +1,873 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2; fill-column: 80 -*- */
+/*
+ * Copyright 2013 Mozilla Foundation and contributors
+ * Licensed under the New BSD license. See LICENSE.md or:
+ * http://opensource.org/licenses/BSD-2-Clause
+ */
+(function (root, factory) {
+  "use strict";
+
+  if (typeof define === "function" && define.amd) {
+    define(factory);
+  } else if (typeof exports === "object") {
+    module.exports = factory();
+  } else {
+    root.prettyFast = factory();
+  }
+}(this, function () {
+  "use strict";
+
+  var acorn = this.acorn || require("acorn/acorn");
+  var sourceMap = this.sourceMap || require("source-map");
+  var SourceNode = sourceMap.SourceNode;
+
+  // If any of these tokens are seen before a "[" token, we know that "[" token
+  // is the start of an array literal, rather than a property access.
+  //
+  // The only exception is "}", which would need to be disambiguated by
+  // parsing. The majority of the time, an open bracket following a closing
+  // curly is going to be an array literal, so we brush the complication under
+  // the rug, and handle the ambiguity by always assuming that it will be an
+  // array literal.
+  var PRE_ARRAY_LITERAL_TOKENS = {
+    "typeof": true,
+    "void": true,
+    "delete": true,
+    "case": true,
+    "do": true,
+    "=": true,
+    "in": true,
+    "{": true,
+    "*": true,
+    "/": true,
+    "%": true,
+    "else": true,
+    ";": true,
+    "++": true,
+    "--": true,
+    "+": true,
+    "-": true,
+    "~": true,
+    "!": true,
+    ":": true,
+    "?": true,
+    ">>": true,
+    ">>>": true,
+    "<<": true,
+    "||": true,
+    "&&": true,
+    "<": true,
+    ">": true,
+    "<=": true,
+    ">=": true,
+    "instanceof": true,
+    "&": true,
+    "^": true,
+    "|": true,
+    "==": true,
+    "!=": true,
+    "===": true,
+    "!==": true,
+    ",": true,
+
+    "}": true
+  };
+
+  /**
+   * Determines if we think that the given token starts an array literal.
+   *
+   * @param Object token
+   *        The token we want to determine if it is an array literal.
+   * @param Object lastToken
+   *        The last token we added to the pretty printed results.
+   *
+   * @returns Boolean
+   *          True if we believe it is an array literal, false otherwise.
+   */
+  function isArrayLiteral(token, lastToken) {
+    if (token.type.label != "[") {
+      return false;
+    }
+    if (!lastToken) {
+      return true;
+    }
+    if (lastToken.type.isAssign) {
+      return true;
+    }
+    return !!PRE_ARRAY_LITERAL_TOKENS[
+      lastToken.type.keyword || lastToken.type.label
+    ];
+  }
+
+  // If any of these tokens are followed by a token on a new line, we know that
+  // ASI cannot happen.
+  var PREVENT_ASI_AFTER_TOKENS = {
+    // Binary operators
+    "*": true,
+    "/": true,
+    "%": true,
+    "+": true,
+    "-": true,
+    "<<": true,
+    ">>": true,
+    ">>>": true,
+    "<": true,
+    ">": true,
+    "<=": true,
+    ">=": true,
+    "instanceof": true,
+    "in": true,
+    "==": true,
+    "!=": true,
+    "===": true,
+    "!==": true,
+    "&": true,
+    "^": true,
+    "|": true,
+    "&&": true,
+    "||": true,
+    ",": true,
+    ".": true,
+    "=": true,
+    "*=": true,
+    "/=": true,
+    "%=": true,
+    "+=": true,
+    "-=": true,
+    "<<=": true,
+    ">>=": true,
+    ">>>=": true,
+    "&=": true,
+    "^=": true,
+    "|=": true,
+    // Unary operators
+    "delete": true,
+    "void": true,
+    "typeof": true,
+    "~": true,
+    "!": true,
+    "new": true,
+    // Function calls and grouped expressions
+    "(": true
+  };
+
+  // If any of these tokens are on a line after the token before it, we know
+  // that ASI cannot happen.
+  var PREVENT_ASI_BEFORE_TOKENS = {
+    // Binary operators
+    "*": true,
+    "/": true,
+    "%": true,
+    "<<": true,
+    ">>": true,
+    ">>>": true,
+    "<": true,
+    ">": true,
+    "<=": true,
+    ">=": true,
+    "instanceof": true,
+    "in": true,
+    "==": true,
+    "!=": true,
+    "===": true,
+    "!==": true,
+    "&": true,
+    "^": true,
+    "|": true,
+    "&&": true,
+    "||": true,
+    ",": true,
+    ".": true,
+    "=": true,
+    "*=": true,
+    "/=": true,
+    "%=": true,
+    "+=": true,
+    "-=": true,
+    "<<=": true,
+    ">>=": true,
+    ">>>=": true,
+    "&=": true,
+    "^=": true,
+    "|=": true,
+    // Function calls
+    "(": true
+  };
+
+  /**
+   * Determines if Automatic Semicolon Insertion (ASI) occurs between these
+   * tokens.
+   *
+   * @param Object token
+   *        The current token.
+   * @param Object lastToken
+   *        The last token we added to the pretty printed results.
+   *
+   * @returns Boolean
+   *          True if we believe ASI occurs.
+   */
+  function isASI(token, lastToken) {
+    if (!lastToken) {
+      return false;
+    }
+    if (token.loc.start.line === lastToken.loc.start.line) {
+      return false;
+    }
+    if (PREVENT_ASI_AFTER_TOKENS[
+      lastToken.type.label || lastToken.type.keyword
+    ]) {
+      return false;
+    }
+    if (PREVENT_ASI_BEFORE_TOKENS[token.type.label || token.type.keyword]) {
+      return false;
+    }
+    return true;
+  }
+
+  /**
+   * Determine if we have encountered a getter or setter.
+   *
+   * @param Object token
+   *        The current token. If this is a getter or setter, it would be the
+   *        property name.
+   * @param Object lastToken
+   *        The last token we added to the pretty printed results. If this is a
+   *        getter or setter, it would be the `get` or `set` keyword
+   *        respectively.
+   * @param Array stack
+   *        The stack of open parens/curlies/brackets/etc.
+   *
+   * @returns Boolean
+   *          True if this is a getter or setter.
+   */
+  function isGetterOrSetter(token, lastToken, stack) {
+    return stack[stack.length - 1] == "{"
+      && lastToken
+      && lastToken.type.label == "name"
+      && (lastToken.value == "get" || lastToken.value == "set")
+      && token.type.label == "name";
+  }
+
+  /**
+   * Determine if we should add a newline after the given token.
+   *
+   * @param Object token
+   *        The token we are looking at.
+   * @param Array stack
+   *        The stack of open parens/curlies/brackets/etc.
+   *
+   * @returns Boolean
+   *          True if we should add a newline.
+   */
+  function isLineDelimiter(token, stack) {
+    if (token.isArrayLiteral) {
+      return true;
+    }
+    var ttl = token.type.label;
+    var top = stack[stack.length - 1];
+    return ttl == ";" && top != "("
+      || ttl == "{"
+      || ttl == "," && top != "("
+      || ttl == ":" && (top == "case" || top == "default");
+  }
+
+  /**
+   * Append the necessary whitespace to the result after we have added the given
+   * token.
+   *
+   * @param Object token
+   *        The token that was just added to the result.
+   * @param Function write
+   *        The function to write to the pretty printed results.
+   * @param Array stack
+   *        The stack of open parens/curlies/brackets/etc.
+   *
+   * @returns Boolean
+   *          Returns true if we added a newline to result, false in all other
+   *          cases.
+   */
+  function appendNewline(token, write, stack) {
+    if (isLineDelimiter(token, stack)) {
+      write("\n", token.loc.start.line, token.loc.start.column);
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Determines if we need to add a space between the last token we added and
+   * the token we are about to add.
+   *
+   * @param Object token
+   *        The token we are about to add to the pretty printed code.
+   * @param Object lastToken
+   *        The last token added to the pretty printed code.
+   */
+  function needsSpaceAfter(token, lastToken) {
+    if (lastToken) {
+      if (lastToken.type.isLoop) {
+        return true;
+      }
+      if (lastToken.type.isAssign) {
+        return true;
+      }
+      if (lastToken.type.binop != null) {
+        return true;
+      }
+
+      var ltt = lastToken.type.label;
+      if (ltt == "?") {
+        return true;
+      }
+      if (ltt == ":") {
+        return true;
+      }
+      if (ltt == ",") {
+        return true;
+      }
+      if (ltt == ";") {
+        return true;
+      }
+
+      var ltk = lastToken.type.keyword;
+      if (ltk != null) {
+        if (ltk == "break" || ltk == "continue" || ltk == "return") {
+          return token.type.label != ";";
+        }
+        if (ltk != "debugger"
+            && ltk != "null"
+            && ltk != "true"
+            && ltk != "false"
+            && ltk != "this"
+            && ltk != "default") {
+          return true;
+        }
+      }
+
+      if (ltt == ")" && (token.type.label != ")"
+                         && token.type.label != "]"
+                         && token.type.label != ";"
+                         && token.type.label != ","
+                         && token.type.label != ".")) {
+        return true;
+      }
+    }
+
+    if (token.type.isAssign) {
+      return true;
+    }
+    if (token.type.binop != null) {
+      return true;
+    }
+    if (token.type.label == "?") {
+      return true;
+    }
+
+    return false;
+  }
+
+  /**
+   * Add the required whitespace before this token, whether that is a single
+   * space, newline, and/or the indent on fresh lines.
+   *
+   * @param Object token
+   *        The token we are about to add to the pretty printed code.
+   * @param Object lastToken
+   *        The last token we added to the pretty printed code.
+   * @param Boolean addedNewline
+   *        Whether we added a newline after adding the last token to the pretty
+   *        printed code.
+   * @param Function write
+   *        The function to write pretty printed code to the result SourceNode.
+   * @param Object options
+   *        The options object.
+   * @param Number indentLevel
+   *        The number of indents deep we are.
+   * @param Array stack
+   *        The stack of open curlies, brackets, etc.
+   */
+  function prependWhiteSpace(token, lastToken, addedNewline, write, options,
+                             indentLevel, stack) {
+    var ttk = token.type.keyword;
+    var ttl = token.type.label;
+    var newlineAdded = addedNewline;
+    var ltt = lastToken ? lastToken.type.label : null;
+
+    // Handle whitespace and newlines after "}" here instead of in
+    // `isLineDelimiter` because it is only a line delimiter some of the
+    // time. For example, we don't want to put "else if" on a new line after
+    // the first if's block.
+    if (lastToken && ltt == "}") {
+      if (ttk == "while" && stack[stack.length - 1] == "do") {
+        write(" ",
+              lastToken.loc.start.line,
+              lastToken.loc.start.column);
+      } else if (ttk == "else" ||
+                 ttk == "catch" ||
+                 ttk == "finally") {
+        write(" ",
+              lastToken.loc.start.line,
+              lastToken.loc.start.column);
+      } else if (ttl != "(" &&
+                 ttl != ";" &&
+                 ttl != "," &&
+                 ttl != ")" &&
+                 ttl != ".") {
+        write("\n",
+              lastToken.loc.start.line,
+              lastToken.loc.start.column);
+        newlineAdded = true;
+      }
+    }
+
+    if (isGetterOrSetter(token, lastToken, stack)) {
+      write(" ",
+            lastToken.loc.start.line,
+            lastToken.loc.start.column);
+    }
+
+    if (ttl == ":" && stack[stack.length - 1] == "?") {
+      write(" ",
+            lastToken.loc.start.line,
+            lastToken.loc.start.column);
+    }
+
+    if (lastToken && ltt != "}" && ttk == "else") {
+      write(" ",
+            lastToken.loc.start.line,
+            lastToken.loc.start.column);
+    }
+
+    function ensureNewline() {
+      if (!newlineAdded) {
+        write("\n",
+              lastToken.loc.start.line,
+              lastToken.loc.start.column);
+        newlineAdded = true;
+      }
+    }
+
+    if (isASI(token, lastToken)) {
+      ensureNewline();
+    }
+
+    if (decrementsIndent(ttl, stack)) {
+      ensureNewline();
+    }
+
+    if (newlineAdded) {
+      if (ttk == "case" || ttk == "default") {
+        write(repeat(options.indent, indentLevel - 1),
+              token.loc.start.line,
+              token.loc.start.column);
+      } else {
+        write(repeat(options.indent, indentLevel),
+              token.loc.start.line,
+              token.loc.start.column);
+      }
+    } else if (needsSpaceAfter(token, lastToken)) {
+      write(" ",
+            lastToken.loc.start.line,
+            lastToken.loc.start.column);
+    }
+  }
+
+  /**
+   * Repeat the `str` string `n` times.
+   *
+   * @param String str
+   *        The string to be repeated.
+   * @param Number n
+   *        The number of times to repeat the string.
+   *
+   * @returns String
+   *          The repeated string.
+   */
+  function repeat(str, n) {
+    var result = "";
+    while (n > 0) {
+      if (n & 1) {
+        result += str;
+      }
+      n >>= 1;
+      str += str;
+    }
+    return result;
+  }
+
+  /**
+   * Make sure that we output the escaped character combination inside string
+   * literals instead of various problematic characters.
+   */
+  var sanitize = (function () {
+    var escapeCharacters = {
+      // Backslash
+      "\\": "\\\\",
+      // Newlines
+      "\n": "\\n",
+      // Carriage return
+      "\r": "\\r",
+      // Tab
+      "\t": "\\t",
+      // Vertical tab
+      "\v": "\\v",
+      // Form feed
+      "\f": "\\f",
+      // Null character
+      "\0": "\\0",
+      // Single quotes
+      "'": "\\'"
+    };
+
+    var regExpString = "("
+      + Object.keys(escapeCharacters)
+              .map(function (c) { return escapeCharacters[c]; })
+              .join("|")
+      + ")";
+    var escapeCharactersRegExp = new RegExp(regExpString, "g");
+
+    return function (str) {
+      return str.replace(escapeCharactersRegExp, function (_, c) {
+        return escapeCharacters[c];
+      });
+    };
+  }());
+  /**
+   * Add the given token to the pretty printed results.
+   *
+   * @param Object token
+   *        The token to add.
+   * @param Function write
+   *        The function to write pretty printed code to the result SourceNode.
+   */
+  function addToken(token, write) {
+    if (token.type.label == "string") {
+      write("'" + sanitize(token.value) + "'",
+            token.loc.start.line,
+            token.loc.start.column);
+    } else if (token.type.label == "regexp") {
+      write(String(token.value.value),
+            token.loc.start.line,
+            token.loc.start.column);
+    } else {
+      write(String(token.value != null ? token.value : token.type.label),
+            token.loc.start.line,
+            token.loc.start.column);
+    }
+  }
+
+  /**
+   * Returns true if the given token type belongs on the stack.
+   */
+  function belongsOnStack(token) {
+    var ttl = token.type.label;
+    var ttk = token.type.keyword;
+    return ttl == "{"
+      || ttl == "("
+      || ttl == "["
+      || ttl == "?"
+      || ttk == "do"
+      || ttk == "switch"
+      || ttk == "case"
+      || ttk == "default";
+  }
+
+  /**
+   * Returns true if the given token should cause us to pop the stack.
+   */
+  function shouldStackPop(token, stack) {
+    var ttl = token.type.label;
+    var ttk = token.type.keyword;
+    var top = stack[stack.length - 1];
+    return ttl == "]"
+      || ttl == ")"
+      || ttl == "}"
+      || (ttl == ":" && (top == "case" || top == "default" || top == "?"))
+      || (ttk == "while" && top == "do");
+  }
+
+  /**
+   * Returns true if the given token type should cause us to decrement the
+   * indent level.
+   */
+  function decrementsIndent(tokenType, stack) {
+    return tokenType == "}"
+      || (tokenType == "]" && stack[stack.length - 1] == "[\n");
+  }
+
+  /**
+   * Returns true if the given token should cause us to increment the indent
+   * level.
+   */
+  function incrementsIndent(token) {
+    return token.type.label == "{"
+      || token.isArrayLiteral
+      || token.type.keyword == "switch";
+  }
+
+  /**
+   * Add a comment to the pretty printed code.
+   *
+   * @param Function write
+   *        The function to write pretty printed code to the result SourceNode.
+   * @param Number indentLevel
+   *        The number of indents deep we are.
+   * @param Object options
+   *        The options object.
+   * @param Boolean block
+   *        True if the comment is a multiline block style comment.
+   * @param String text
+   *        The text of the comment.
+   * @param Number line
+   *        The line number to comment appeared on.
+   * @param Number column
+   *        The column number the comment appeared on.
+   */
+  function addComment(write, indentLevel, options, block, text, line, column) {
+    var indentString = repeat(options.indent, indentLevel);
+
+    write(indentString, line, column);
+    if (block) {
+      write("/*");
+      write(text
+            .split(new RegExp("/\n" + indentString + "/", "g"))
+            .join("\n" + indentString));
+      write("*/");
+    } else {
+      write("//");
+      write(text);
+    }
+    write("\n");
+  }
+
+  /**
+   * The main function.
+   *
+   * @param String input
+   *        The ugly JS code we want to pretty print.
+   * @param Object options
+   *        The options object. Provides configurability of the pretty
+   *        printing. Properties:
+   *          - url: The URL string of the ugly JS code.
+   *          - indent: The string to indent code by.
+   *
+   * @returns Object
+   *          An object with the following properties:
+   *            - code: The pretty printed code string.
+   *            - map: A SourceMapGenerator instance.
+   */
+  return function prettyFast(input, options) {
+    // The level of indents deep we are.
+    var indentLevel = 0;
+
+    // We will accumulate the pretty printed code in this SourceNode.
+    var result = new SourceNode();
+
+    /**
+     * Write a pretty printed string to the result SourceNode.
+     *
+     * We buffer our writes so that we only create one mapping for each line in
+     * the source map. This enhances performance by avoiding extraneous mapping
+     * serialization, and flattening the tree that
+     * `SourceNode#toStringWithSourceMap` will have to recursively walk. When
+     * timing how long it takes to pretty print jQuery, this optimization
+     * brought the time down from ~390 ms to ~190ms!
+     *
+     * @param String str
+     *        The string to be added to the result.
+     * @param Number line
+     *        The line number the string came from in the ugly source.
+     * @param Number column
+     *        The column number the string came from in the ugly source.
+     */
+    var write = (function () {
+      var buffer = [];
+      var bufferLine = -1;
+      var bufferColumn = -1;
+      return function write(str, line, column) {
+        if (line != null && bufferLine === -1) {
+          bufferLine = line;
+        }
+        if (column != null && bufferColumn === -1) {
+          bufferColumn = column;
+        }
+        buffer.push(str);
+
+        if (str == "\n") {
+          var lineStr = "";
+          for (var i = 0, len = buffer.length; i < len; i++) {
+            lineStr += buffer[i];
+          }
+          result.add(new SourceNode(bufferLine, bufferColumn, options.url,
+                                    lineStr));
+          buffer.splice(0, buffer.length);
+          bufferLine = -1;
+          bufferColumn = -1;
+        }
+      };
+    }());
+
+    // Whether or not we added a newline on after we added the last token.
+    var addedNewline = false;
+
+    // The current token we will be adding to the pretty printed code.
+    var token;
+
+    // Shorthand for token.type.label, so we don't have to repeatedly access
+    // properties.
+    var ttl;
+
+    // Shorthand for token.type.keyword, so we don't have to repeatedly access
+    // properties.
+    var ttk;
+
+    // The last token we added to the pretty printed code.
+    var lastToken;
+
+    // Stack of token types/keywords that can affect whether we want to add a
+    // newline or a space. We can make that decision based on what token type is
+    // on the top of the stack. For example, a comma in a parameter list should
+    // be followed by a space, while a comma in an object literal should be
+    // followed by a newline.
+    //
+    // Strings that go on the stack:
+    //
+    //   - "{"
+    //   - "("
+    //   - "["
+    //   - "[\n"
+    //   - "do"
+    //   - "?"
+    //   - "switch"
+    //   - "case"
+    //   - "default"
+    //
+    // The difference between "[" and "[\n" is that "[\n" is used when we are
+    // treating "[" and "]" tokens as line delimiters and should increment and
+    // decrement the indent level when we find them.
+    var stack = [];
+
+    // Pass through acorn's tokenizer and append tokens and comments into a
+    // single queue to process.  For example, the source file:
+    //
+    //     foo
+    //     // a
+    //     // b
+    //     bar
+    //
+    // After this process, tokenQueue has the following token stream:
+    //
+    //     [ foo, '// a', '// b', bar]
+    var tokenQueue = [];
+
+    var tokens = acorn.tokenizer(input, {
+      locations: true,
+      sourceFile: options.url,
+      onComment: function (block, text, start, end, startLoc, endLoc) {
+        tokenQueue.push({
+          type: {},
+          comment: true,
+          block: block,
+          text: text,
+          loc: { start: startLoc, end: endLoc }
+        });
+      }
+    });
+
+    for (;;) {
+      token = tokens.getToken();
+      tokenQueue.push(token);
+      if (token.type.label == "eof") {
+        break;
+      }
+    }
+
+    for (var i = 0; i < tokenQueue.length; i++) {
+      token = tokenQueue[i];
+
+      if (token.comment) {
+        var commentIndentLevel = indentLevel;
+        if (lastToken && (lastToken.loc.end.line == token.loc.start.line)) {
+          commentIndentLevel = 0;
+          write(" ");
+        }
+        addComment(write, commentIndentLevel, options, token.block, token.text,
+                   token.loc.start.line, token.loc.start.column);
+        addedNewline = true;
+        continue;
+      }
+
+      ttk = token.type.keyword;
+      ttl = token.type.label;
+
+      if (ttl == "eof") {
+        if (!addedNewline) {
+          write("\n");
+        }
+        break;
+      }
+
+      token.isArrayLiteral = isArrayLiteral(token, lastToken);
+
+      if (belongsOnStack(token)) {
+        if (token.isArrayLiteral) {
+          stack.push("[\n");
+        } else {
+          stack.push(ttl || ttk);
+        }
+      }
+
+      if (decrementsIndent(ttl, stack)) {
+        indentLevel--;
+        if (ttl == "}"
+            && stack.length > 1
+            && stack[stack.length - 2] == "switch") {
+          indentLevel--;
+        }
+      }
+
+      prependWhiteSpace(token, lastToken, addedNewline, write, options,
+                        indentLevel, stack);
+      addToken(token, write);
+
+      // If the next token is going to be a comment starting on the same line,
+      // then no need to add one here
+      var nextToken = tokenQueue[i + 1];
+      if (!nextToken || !nextToken.comment || token.loc.end.line != nextToken.loc.start.line) {
+        addedNewline = appendNewline(token, write, stack);
+      }
+
+      if (shouldStackPop(token, stack)) {
+        stack.pop();
+        if (token == "}" && stack.length
+            && stack[stack.length - 1] == "switch") {
+          stack.pop();
+        }
+      }
+
+      if (incrementsIndent(token)) {
+        indentLevel++;
+      }
+
+      // Acorn's tokenizer re-uses tokens, so we have to copy the last token on
+      // every iteration. We follow acorn's lead here, and reuse the lastToken
+      // object the same way that acorn reuses the token object. This allows us
+      // to avoid allocations and minimize GC pauses.
+      if (!lastToken) {
+        lastToken = { loc: { start: {}, end: {} } };
+      }
+      lastToken.start = token.start;
+      lastToken.end = token.end;
+      lastToken.loc.start.line = token.loc.start.line;
+      lastToken.loc.start.column = token.loc.start.column;
+      lastToken.loc.end.line = token.loc.end.line;
+      lastToken.loc.end.column = token.loc.end.column;
+      lastToken.type = token.type;
+      lastToken.value = token.value;
+      lastToken.isArrayLiteral = token.isArrayLiteral;
+    }
+
+    return result.toStringWithSourceMap({ file: options.url });
+  };
+
+}.bind(this)));
diff --git a/devtools/shared/pretty-fast/tests/unit/head_pretty-fast.js b/devtools/shared/pretty-fast/tests/unit/head_pretty-fast.js
new file mode 100644
index 000000000..abde4b197
--- /dev/null
+++ b/devtools/shared/pretty-fast/tests/unit/head_pretty-fast.js
@@ -0,0 +1,49 @@
+"use strict";
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var Cu = Components.utils;
+var Cr = Components.results;
+
+const { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
+
+this.sourceMap = require("source-map");
+this.acorn = require("acorn/acorn");
+this.prettyFast = require("devtools/shared/pretty-fast/pretty-fast");
+const { console } = Cu.import("resource://gre/modules/Console.jsm", {});
+
+// Register a console listener, so console messages don't just disappear
+// into the ether.
+var errorCount = 0;
+var listener = {
+  observe: function (aMessage) {
+    errorCount++;
+    try {
+      // If we've been given an nsIScriptError, then we can print out
+      // something nicely formatted, for tools like Emacs to pick up.
+      var scriptError = aMessage.QueryInterface(Ci.nsIScriptError);
+      dump(aMessage.sourceName + ":" + aMessage.lineNumber + ": " +
+           scriptErrorFlagsToKind(aMessage.flags) + ": " +
+           aMessage.errorMessage + "\n");
+      var string = aMessage.errorMessage;
+    } catch (x) {
+      // Be a little paranoid with message, as the whole goal here is to lose
+      // no information.
+      try {
+        var string = "" + aMessage.message;
+      } catch (x) {
+        var string = "<error converting error message to string>";
+      }
+    }
+
+    // Ignored until they are fixed in bug 1242968.
+    if (string.includes("JavaScript Warning")) {
+      return;
+    }
+
+    do_throw("head_pretty-fast.js got console message: " + string + "\n");
+  }
+};
+
+var consoleService = Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService);
+consoleService.registerListener(listener);
+
diff --git a/devtools/shared/pretty-fast/tests/unit/test.js b/devtools/shared/pretty-fast/tests/unit/test.js
new file mode 100644
index 000000000..b462726a2
--- /dev/null
+++ b/devtools/shared/pretty-fast/tests/unit/test.js
@@ -0,0 +1,572 @@
+/* -*- Mode: js; tab-width: 2; indent-tabs-mode: nil; js-indent-level: 2; fill-column: 80 -*- */
+
+"use strict";
+
+/*
+ * Copyright 2013 Mozilla Foundation and contributors
+ * Licensed under the New BSD license. See LICENSE.md or:
+ * http://opensource.org/licenses/BSD-2-Clause
+ */
+var prettyFast = this.prettyFast || require("./pretty-fast");
+
+var testCases = [
+
+  {
+    name: "Simple function",
+    input: "function foo() { bar(); }",
+    output: "function foo() {\n" +
+            "  bar();\n" +
+            "}\n",
+    mappings: [
+      // function foo() {
+      {
+        inputLine: 1,
+        outputLine: 1
+      },
+      // bar();
+      {
+        inputLine: 1,
+        outputLine: 2
+      },
+      // }
+      {
+        inputLine: 1,
+        outputLine: 3
+      },
+    ]
+  },
+
+  {
+    name: "Nested function",
+    input: "function foo() { function bar() { debugger; } bar(); }",
+    output: "function foo() {\n" +
+            "  function bar() {\n" +
+            "    debugger;\n" +
+            "  }\n" +
+            "  bar();\n" +
+            "}\n",
+    mappings: [
+      // function bar() {
+      {
+        inputLine: 1,
+        outputLine: 2
+      },
+      // debugger;
+      {
+        inputLine: 1,
+        outputLine: 3
+      },
+      // bar();
+      {
+        inputLine: 1,
+        outputLine: 5
+      },
+    ]
+  },
+
+  {
+    name: "Immediately invoked function expression",
+    input: "(function(){thingy()}())",
+    output: "(function () {\n" +
+            "  thingy()\n" +
+            "}())\n"
+  },
+
+  {
+    name: "Single line comment",
+    input: "// Comment\n" +
+           "function foo() { bar(); }\n",
+    output: "// Comment\n" +
+            "function foo() {\n" +
+            "  bar();\n" +
+            "}\n",
+    mappings: [
+      // // Comment
+      {
+        inputLine: 1,
+        outputLine: 1
+      }
+    ]
+  },
+
+  {
+    name: "Multi line comment",
+    input: "/* Comment\n" +
+           "more comment */\n" +
+           "function foo() { bar(); }\n",
+    output: "/* Comment\n" +
+            "more comment */\n" +
+            "function foo() {\n" +
+            "  bar();\n" +
+            "}\n",
+    mappings: [
+      // /* Comment
+      {
+        inputLine: 1,
+        outputLine: 1
+      },
+      // \nmore comment */
+      {
+        inputLine: 1,
+        outputLine: 2
+      }
+    ]
+  },
+
+  {
+    name: "Null assignment",
+    input: "var i=null;\n",
+    output: "var i = null;\n",
+    mappings: [
+      {
+        inputLine: 1,
+        outputLine: 1
+      }
+    ]
+  },
+
+  {
+    name: "Undefined assignment",
+    input: "var i=undefined;\n",
+    output: "var i = undefined;\n"
+  },
+
+  {
+    name: "Void 0 assignment",
+    input: "var i=void 0;\n",
+    output: "var i = void 0;\n"
+  },
+
+  {
+    name: "This property access",
+    input: "var foo=this.foo;\n",
+    output: "var foo = this.foo;\n"
+  },
+
+  {
+    name: "True assignment",
+    input: "var foo=true;\n",
+    output: "var foo = true;\n"
+  },
+
+  {
+    name: "False assignment",
+    input: "var foo=false;\n",
+    output: "var foo = false;\n"
+  },
+
+  {
+    name: "For loop",
+    input: "for (var i = 0; i < n; i++) { console.log(i); }",
+    output: "for (var i = 0; i < n; i++) {\n" +
+            "  console.log(i);\n" +
+            "}\n",
+    mappings: [
+      // for (var i = 0; i < n; i++) {
+      {
+        inputLine: 1,
+        outputLine: 1
+      },
+      // console.log(i);
+      {
+        inputLine: 1,
+        outputLine: 2
+      },
+    ]
+  },
+
+  {
+    name: "String with semicolon",
+    input: "var foo = ';';\n",
+    output: "var foo = ';';\n"
+  },
+
+  {
+    name: "String with quote",
+    input: "var foo = \"'\";\n",
+    output: "var foo = '\\'';\n"
+  },
+
+  {
+    name: "Function calls",
+    input: "var result=func(a,b,c,d);",
+    output: "var result = func(a, b, c, d);\n"
+  },
+
+  {
+    name: "Regexp",
+    input: "var r=/foobar/g;",
+    output: "var r = /foobar/g;\n"
+  },
+
+  {
+    name: "In operator",
+    input: "if(foo in bar){doThing()}",
+    output: "if (foo in bar) {\n" +
+            "  doThing()\n" +
+            "}\n"
+  },
+
+  {
+    name: "With statement",
+    input: "with(obj){crock()}",
+    output: "with (obj) {\n" +
+            "  crock()\n" +
+            "}\n"
+  },
+
+  {
+    name: "New expression",
+    input: "var foo=new Foo();",
+    output: "var foo = new Foo();\n"
+  },
+
+  {
+    name: "Continue/break statements",
+    input: "while(1){if(x){continue}if(y){break}if(z){break foo}}",
+    output: "while (1) {\n" +
+            "  if (x) {\n" +
+            "    continue\n" +
+            "  }\n" +
+            "  if (y) {\n" +
+            "    break\n" +
+            "  }\n" +
+            "  if (z) {\n" +
+            "    break foo\n" +
+            "  }\n" +
+            "}\n"
+  },
+
+  {
+    name: "Instanceof",
+    input: "var a=x instanceof y;",
+    output: "var a = x instanceof y;\n"
+  },
+
+  {
+    name: "Binary operators",
+    input: "var a=5*30;var b=5>>3;",
+    output: "var a = 5 * 30;\n" +
+            "var b = 5 >> 3;\n"
+  },
+
+  {
+    name: "Delete",
+    input: "delete obj.prop;",
+    output: "delete obj.prop;\n"
+  },
+
+  {
+    name: "Try/catch/finally statement",
+    input: "try{dangerous()}catch(e){handle(e)}finally{cleanup()}",
+    output: "try {\n" +
+            "  dangerous()\n" +
+            "} catch (e) {\n" +
+            "  handle(e)\n" +
+            "} finally {\n" +
+            "  cleanup()\n" +
+            "}\n"
+  },
+
+  {
+    name: "If/else statement",
+    input: "if(c){then()}else{other()}",
+    output: "if (c) {\n" +
+            "  then()\n" +
+            "} else {\n" +
+            "  other()\n" +
+            "}\n"
+  },
+
+  {
+    name: "If/else without curlies",
+    input: "if(c) a else b",
+    output: "if (c) a else b\n"
+  },
+
+  {
+    name: "Objects",
+    input: "var o={a:1,\n" +
+           "       b:2};",
+    output: "var o = {\n" +
+            "  a: 1,\n" +
+            "  b: 2\n" +
+            "};\n",
+    mappings: [
+      // a: 1,
+      {
+        inputLine: 1,
+        outputLine: 2
+      },
+      // b: 2
+      {
+        inputLine: 2,
+        outputLine: 3
+      },
+    ]
+  },
+
+  {
+    name: "Do/while loop",
+    input: "do{x}while(y)",
+    output: "do {\n" +
+            "  x\n" +
+            "} while (y)\n"
+  },
+
+  {
+    name: "Arrays",
+    input: "var a=[1,2,3];",
+    output: "var a = [\n" +
+            "  1,\n" +
+            "  2,\n" +
+            "  3\n" +
+            "];\n"
+  },
+
+  {
+    name: "Code that relies on ASI",
+    input: "var foo = 10\n" +
+           "var bar = 20\n" +
+           "function g() {\n" +
+           "  a()\n" +
+           "  b()\n" +
+           "}",
+    output: "var foo = 10\n" +
+            "var bar = 20\n" +
+            "function g() {\n" +
+            "  a()\n" +
+            "  b()\n" +
+            "}\n"
+  },
+
+  {
+    name: "Ternary operator",
+    input: "bar?baz:bang;",
+    output: "bar ? baz : bang;\n"
+  },
+
+  {
+    name: "Switch statements",
+    input: "switch(x){case a:foo();break;default:bar()}",
+    output: "switch (x) {\n" +
+            "  case a:\n" +
+            "    foo();\n" +
+            "    break;\n" +
+            "  default:\n" +
+            "    bar()\n" +
+            "}\n"
+  },
+
+  {
+    name: "Multiple single line comments",
+    input: "function f() {\n" +
+           "  // a\n" +
+           "  // b\n" +
+           "  // c\n" +
+           "}\n",
+    output: "function f() {\n" +
+            "  // a\n" +
+            "  // b\n" +
+            "  // c\n" +
+            "}\n",
+  },
+
+  {
+    name: "Indented multiline comment",
+    input: "function foo() {\n" +
+           "  /**\n" +
+           "   * java doc style comment\n" +
+           "   * more comment\n" +
+           "   */\n" +
+           "  bar();\n" +
+           "}\n",
+    output: "function foo() {\n" +
+            "  /**\n" +
+            "   * java doc style comment\n" +
+            "   * more comment\n" +
+            "   */\n" +
+            "  bar();\n" +
+            "}\n",
+  },
+
+  {
+    name: "ASI return",
+    input: "function f() {\n" +
+           "  return\n" +
+           "  {}\n" +
+           "}\n",
+    output: "function f() {\n" +
+            "  return\n" +
+            "  {\n" +
+            "  }\n" +
+            "}\n",
+  },
+
+  {
+    name: "Non-ASI property access",
+    input: "[1,2,3]\n" +
+           "[0]",
+    output: "[\n" +
+            "  1,\n" +
+            "  2,\n" +
+            "  3\n" +
+            "]\n" +
+            "[0]\n"
+  },
+
+  {
+    name: "Non-ASI in",
+    input: "'x'\n" +
+           "in foo",
+    output: "'x' in foo\n"
+  },
+
+  {
+    name: "Non-ASI function call",
+    input: "f\n" +
+           "()",
+    output: "f()\n"
+  },
+
+  {
+    name: "Non-ASI new",
+    input: "new\n" +
+           "F()",
+    output: "new F()\n"
+  },
+
+  {
+    name: "Getter and setter literals",
+    input: "var obj={get foo(){return this._foo},set foo(v){this._foo=v}}",
+    output: "var obj = {\n" +
+            "  get foo() {\n" +
+            "    return this._foo\n" +
+            "  },\n" +
+            "  set foo(v) {\n" +
+            "    this._foo = v\n" +
+            "  }\n" +
+            "}\n"
+  },
+
+  {
+    name: "Escaping backslashes in strings",
+    input: "'\\\\'\n",
+    output: "'\\\\'\n"
+  },
+
+  {
+    name: "Escaping carriage return in strings",
+    input: "'\\r'\n",
+    output: "'\\r'\n"
+  },
+
+  {
+    name: "Escaping tab in strings",
+    input: "'\\t'\n",
+    output: "'\\t'\n"
+  },
+
+  {
+    name: "Escaping vertical tab in strings",
+    input: "'\\v'\n",
+    output: "'\\v'\n"
+  },
+
+  {
+    name: "Escaping form feed in strings",
+    input: "'\\f'\n",
+    output: "'\\f'\n"
+  },
+
+  {
+    name: "Escaping null character in strings",
+    input: "'\\0'\n",
+    output: "'\\0'\n"
+  },
+
+  {
+    name: "Bug 977082 - space between grouping operator and dot notation",
+    input: "JSON.stringify(3).length;\n" +
+           "([1,2,3]).length;\n" +
+           "(new Date()).toLocaleString();\n",
+    output: "JSON.stringify(3).length;\n" +
+            "([1,\n" +
+            "2,\n" +
+            "3]).length;\n" +
+            "(new Date()).toLocaleString();\n"
+  },
+
+  {
+    name: "Bug 975477 don't move end of line comments to next line",
+    input: "switch (request.action) {\n" +
+           "  case 'show': //$NON-NLS-0$\n" +
+           "    if (localStorage.hideicon !== 'true') { //$NON-NLS-0$\n" +
+           "      chrome.pageAction.show(sender.tab.id);\n" +
+           "    }\n" +
+           "    break;\n" +
+           "  case 'hide': /*Multiline\n" +
+           "    Comment */" +
+           "    break;\n" +
+           "  default:\n" +
+           "    console.warn('unknown request'); //$NON-NLS-0$\n" +
+           "    // don't respond if you don't understand the message.\n" +
+           "    return;\n" +
+           "}\n",
+    output: "switch (request.action) {\n" +
+            "  case 'show': //$NON-NLS-0$\n" +
+            "    if (localStorage.hideicon !== 'true') { //$NON-NLS-0$\n" +
+            "      chrome.pageAction.show(sender.tab.id);\n" +
+            "    }\n" +
+            "    break;\n" +
+            "  case 'hide': /*Multiline\n" +
+            "    Comment */\n" +
+            "    break;\n" +
+            "  default:\n" +
+            "    console.warn('unknown request'); //$NON-NLS-0$\n" +
+            "    // don't respond if you don't understand the message.\n" +
+            "    return;\n" +
+            "}\n"
+  }
+
+];
+
+var sourceMap = this.sourceMap || require("source-map");
+
+function run_test() {
+  testCases.forEach(function (test) {
+    console.log(test.name);
+
+    var actual = prettyFast(test.input, {
+      indent: "  ",
+      url: "test.js"
+    });
+
+    if (actual.code !== test.output) {
+      throw new Error("Expected:\n" + test.output
+                      + "\nGot:\n" + actual.code);
+    }
+
+    if (test.mappings) {
+      var smc = new sourceMap.SourceMapConsumer(actual.map.toJSON());
+      test.mappings.forEach(function (m) {
+        var query = { line: m.outputLine, column: 0 };
+        var original = smc.originalPositionFor(query);
+        if (original.line != m.inputLine) {
+          throw new Error("Querying:\n" + JSON.stringify(query, null, 2) + "\n"
+                          + "Expected line:\n" + m.inputLine + "\n"
+                          + "Got:\n" + JSON.stringify(original, null, 2));
+        }
+      });
+    }
+  });
+  console.log("✓ All tests pass!");
+}
+
+// Only run the tests if this is node and we are running this file
+// directly. (Firefox's test runner will import this test file, and then call
+// run_test itself.)
+if (typeof require == "function" && typeof module == "object"
+    && require.main === module) {
+  run_test();
+}
diff --git a/devtools/shared/pretty-fast/tests/unit/xpcshell.ini b/devtools/shared/pretty-fast/tests/unit/xpcshell.ini
new file mode 100644
index 000000000..cb92b1825
--- /dev/null
+++ b/devtools/shared/pretty-fast/tests/unit/xpcshell.ini
@@ -0,0 +1,8 @@
+[DEFAULT]
+tags = devtools
+head = head_pretty-fast.js
+tail =
+firefox-appdir = browser
+skip-if = toolkit == 'android'
+
+[test.js]