From a60287328199ecae2122600990237ee6c9452b8c Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Fri, 20 Mar 2015 20:05:29 +1100
Subject: [PATCH] update to latest acorn, better array shortcuts, don't add
 code frame to error message

---
 src/babel/api/browser.js                      |   2 +-
 src/babel/generation/source-map.js            |   2 +-
 src/babel/helpers/code-frame.js               |  73 ++++++------
 src/babel/helpers/parse.js                    |   7 +-
 src/babel/transformation/file/index.js        |  24 ++--
 .../transformation/file/option-parsers.js     |   4 +
 src/babel/transformation/file/options.json    |  15 ++-
 .../transformation/templates/for-of-loose.js  |   2 +-
 .../templates/sliced-to-array-loose.js        |  14 +++
 .../templates/sliced-to-array.js              |   7 +-
 .../transformation/templates/to-array.js      |   2 +-
 .../templates/to-consumable-array.js          |   2 +-
 .../transformers/internal/validation.js       |   4 +
 src/babel/traversal/index.js                  |   5 +-
 src/babel/traversal/path/index.js             |  29 +++--
 src/babel/traversal/scope.js                  |   7 +-
 src/babel/types/index.js                      |   1 +
 src/babel/util.js                             |   3 +-
 ...es-not-bind-this-from-standard-function.js |   5 -
 .../es6-for-of-loose/identifier/expected.js   |   2 +-
 .../es6-for-of-loose/ignore-cases/expected.js |   2 +-
 .../es6-for-of-loose/let/expected.js          |   2 +-
 .../member-expression/expected.js             |   2 +-
 .../es6-for-of-loose/multiple/expected.js     |   4 +-
 .../es6-for-of-loose/var/expected.js          |   2 +-
 .../es6-spread/arguments-array/expected.js    |   3 +-
 .../es6-spread/arguments-concat/expected.js   |   3 +-
 .../array-literal-first/expected.js           |   4 +-
 .../array-literal-middle/expected.js          |   4 +-
 .../array-literal-multiple/expected.js        |   4 +-
 .../es6-spread/array-literals/expected.js     |   4 +-
 .../expected.js                               |   4 +-
 .../expected.js                               |   4 +-
 .../expected.js                               |   6 +-
 .../expected.js                               |   6 +-
 .../es6-spread/method-call-first/expected.js  |   4 +-
 .../es6-spread/method-call-middle/expected.js |   4 +-
 .../method-call-multiple-args/expected.js     |   4 +-
 .../method-call-multiple/expected.js          |   4 +-
 .../method-call-single-arg/expected.js        |   4 +-
 .../es6-spread/new-expression/expected.js     |   8 +-
 .../transformation/es6-spread/options.json    |   7 +-
 .../es6-spread/single/expected.js             |   4 +-
 test/util.js                                  |   4 +-
 vendor/acorn/acorn.js                         | 110 +++++++++---------
 vendor/acorn/test/tests-harmony.js            | 107 +++++++++++++++++
 46 files changed, 322 insertions(+), 202 deletions(-)
 create mode 100644 src/babel/transformation/templates/sliced-to-array-loose.js
 delete mode 100644 test/fixtures/esnext/es6-arrow-functions/does-not-bind-this-from-standard-function.js

diff --git a/src/babel/api/browser.js b/src/babel/api/browser.js
index 82671a3712..8611775061 100644
--- a/src/babel/api/browser.js
+++ b/src/babel/api/browser.js
@@ -5,7 +5,7 @@ transform.version = require("../../../package").version;
 transform.transform = transform;
 
 transform.run = function (code, opts = {}) {
-  opts.sourceMap = "inline";
+  opts.sourceMaps = "inline";
   return new Function(transform(code, opts).code)();
 };
 
diff --git a/src/babel/generation/source-map.js b/src/babel/generation/source-map.js
index 1ce084a365..2f6407ca41 100644
--- a/src/babel/generation/source-map.js
+++ b/src/babel/generation/source-map.js
@@ -6,7 +6,7 @@ export default class SourceMap {
     this.position = position;
     this.opts     = opts;
 
-    if (opts.sourceMap) {
+    if (opts.sourceMaps) {
       this.map = new sourceMap.SourceMapGenerator({
         file: opts.sourceMapName,
         sourceRoot: opts.sourceRoot
diff --git a/src/babel/helpers/code-frame.js b/src/babel/helpers/code-frame.js
index 8f24c61502..c7c6a1e061 100644
--- a/src/babel/helpers/code-frame.js
+++ b/src/babel/helpers/code-frame.js
@@ -3,15 +3,13 @@ import repeating from "repeating";
 import jsTokens from "js-tokens";
 import esutils from "esutils";
 import chalk from "chalk";
-import ary from "lodash/function/ary";
 
 var defs = {
   string:     chalk.red,
-  punctuator: chalk.white.bold,
+  punctuator: chalk.bold,
   curly:      chalk.green,
   parens:     chalk.blue.bold,
   square:     chalk.yellow,
-  name:       chalk.white,
   keyword:    chalk.cyan,
   number:     chalk.magenta,
   regex:      chalk.magenta,
@@ -19,50 +17,51 @@ var defs = {
   invalid:    chalk.inverse
 };
 
-var newline = /\r\n|[\n\r\u2028\u2029]/;
+const NEWLINE = /\r\n|[\n\r\u2028\u2029]/;
 
-var highlight = function (text) {
-  var tokenType = function (match) {
-    var token = jsTokens.matchToToken(match);
-    if (token.type === "name" && esutils.keyword.isReservedWordES6(token.value)) {
-      return "keyword";
+function getTokenType(match) {
+  var token = jsTokens.matchToToken(match);
+  if (token.type === "name" && esutils.keyword.isReservedWordES6(token.value)) {
+    return "keyword";
+  }
+
+  if (token.type === "punctuator") {
+    switch (token.value) {
+      case "{":
+      case "}":
+        return "curly";
+      case "(":
+      case ")":
+        return "parens";
+      case "[":
+      case "]":
+        return "square";
     }
+  }
 
-    if (token.type === "punctuator") {
-      switch (token.value) {
-        case "{":
-        case "}":
-          return "curly";
-        case "(":
-        case ")":
-          return "parens";
-        case "[":
-        case "]":
-          return "square";
-      }
+  return token.type;
+}
+
+function highlight(text) {
+  return text.replace(jsTokens, function (...args) {
+    var type = getTokenType(args);
+    var colorize = defs[type];
+    if (colorize) {
+      return args[0].split(NEWLINE).map(str => colorize(str)).join("\n");
+    } else {
+      return args[0];
     }
-
-    return token.type;
-  };
-
-  return text.replace(jsTokens, function (match) {
-    var type = tokenType(arguments);
-    if (type in defs) {
-      var colorize = ary(defs[type], 1);
-      return match.split(newline).map(colorize).join("\n");
-    }
-    return match;
   });
-};
+}
 
-export default function (lines: number, lineNumber: number, colNumber: number, color?): string {
+export default function (lines: number, lineNumber: number, colNumber: number, opts?): string {
   colNumber = Math.max(colNumber, 0);
 
-  if (color && chalk.supportsColor) {
+  if (opts.highlightCode && chalk.supportsColor) {
     lines = highlight(lines);
   }
 
-  lines = lines.split(newline);
+  lines = lines.split(NEWLINE);
 
   var start = Math.max(lineNumber - 3, 0);
   var end   = Math.min(lines.length, lineNumber + 3);
@@ -72,7 +71,7 @@ export default function (lines: number, lineNumber: number, colNumber: number, c
     end = lines.length;
   }
 
-  return "\n" + lineNumbers(lines.slice(start, end), {
+  return lineNumbers(lines.slice(start, end), {
     start: start + 1,
     before: "  ",
     after: " | ",
diff --git a/src/babel/helpers/parse.js b/src/babel/helpers/parse.js
index 89001810d0..1a6459497d 100644
--- a/src/babel/helpers/parse.js
+++ b/src/babel/helpers/parse.js
@@ -40,11 +40,12 @@ export default function (opts, code, callback) {
     if (!err._babel) {
       err._babel = true;
 
-      var message = `${opts.filename}: ${err.message}`;
+      var message = err.message = `${opts.filename}: ${err.message}`;
 
       var loc = err.loc;
       if (loc) {
-        message += codeFrame(code, loc.line, loc.column + 1, opts.highlightErrors);
+        err.codeFrame = codeFrame(code, loc.line, loc.column + 1, opts);
+        message += "\n" + err.codeFrame;
       }
 
       if (err.stack) {
@@ -55,8 +56,6 @@ export default function (opts, code, callback) {
           // `err.stack` may be a readonly property in some environments
         }
       }
-
-      err.message = message;
     }
 
     throw err;
diff --git a/src/babel/transformation/file/index.js b/src/babel/transformation/file/index.js
index 94135bf91d..65eefee04f 100644
--- a/src/babel/transformation/file/index.js
+++ b/src/babel/transformation/file/index.js
@@ -65,6 +65,7 @@ export default class File {
     "to-array",
     "to-consumable-array",
     "sliced-to-array",
+    "sliced-to-array-loose",
     "object-without-properties",
     "has-own",
     "slice",
@@ -111,11 +112,15 @@ export default class File {
       var optionParser = optionParsers[option.type];
       if (optionParser) val = optionParser(key, val);
 
-      opts[key] = val;
+      if (option.alias) {
+        opts[option.alias] ||= val;
+      } else {
+        opts[key] = val;
+      }
     }
 
     if (opts.inputSourceMap) {
-      opts.sourceMap = true;
+      opts.sourceMaps = true;
     }
 
     // normalize windows path separators to unix
@@ -382,9 +387,9 @@ export default class File {
     //
 
     var parseOpts = {
-      highlightErrors: opts.highlightErrors,
-      filename:        opts.filename,
-      plugins:         {}
+      highlightCode: opts.highlightCode,
+      filename:      opts.filename,
+      plugins:       {}
     };
 
     var features = parseOpts.features = {};
@@ -448,9 +453,8 @@ export default class File {
     var stack = this.transformerStack;
     for (var i = 0; i < stack.length; i++) {
       var transformer = stack[i].transformer;
-      if (transformer[key]) {
-        transformer[key](this);
-      }
+      var fn = transformer[key];
+      if (fn) fn(this);
     }
   }
 
@@ -527,11 +531,11 @@ export default class File {
 
     result.map = this.mergeSourceMap(result.map);
 
-    if (opts.sourceMap === "inline" || opts.sourceMap === "both") {
+    if (opts.sourceMaps === "inline" || opts.sourceMaps === "both") {
       result.code += "\n" + convertSourceMap.fromObject(result.map).toComment();
     }
 
-    if (opts.sourceMap === "inline") {
+    if (opts.sourceMaps === "inline") {
       result.map = null;
     }
 
diff --git a/src/babel/transformation/file/option-parsers.js b/src/babel/transformation/file/option-parsers.js
index a0a2cc33d2..d1ee8feba9 100644
--- a/src/babel/transformation/file/option-parsers.js
+++ b/src/babel/transformation/file/option-parsers.js
@@ -12,6 +12,10 @@ export function transformerList(key, val) {
 }
 
 export function boolean(key, val) {
+  return !!val;
+}
+
+export function booleanString(key, val) {
   return util.booleanify(val);
 }
 
diff --git a/src/babel/transformation/file/options.json b/src/babel/transformation/file/options.json
index 9b18d54e15..06f04ef7fe 100644
--- a/src/babel/transformation/file/options.json
+++ b/src/babel/transformation/file/options.json
@@ -19,8 +19,12 @@
 
   },
 
-  "highlightErrors": {
-    "description": "ANSI syntax highlight error messages",
+  "highlightTheme": {
+    "hidden": true
+  },
+
+  "highlightCode": {
+    "description": "ANSI syntax highlight code frames",
     "type": "boolean",
     "default": true
   },
@@ -135,7 +139,12 @@
   },
 
   "sourceMap": {
-    "type": "string",
+    "alias": "sourceMaps",
+    "hidden": true
+  },
+
+  "sourceMaps": {
+    "type": "booleanString",
     "default": false,
     "shorthand": "s"
   },
diff --git a/src/babel/transformation/templates/for-of-loose.js b/src/babel/transformation/templates/for-of-loose.js
index 9b463868ce..14c0c7e437 100644
--- a/src/babel/transformation/templates/for-of-loose.js
+++ b/src/babel/transformation/templates/for-of-loose.js
@@ -1,5 +1,5 @@
 for (var LOOP_OBJECT = OBJECT,
-         IS_ARRAY = Array.isArray(LOOP_OBJECT),
+         IS_ARRAY = LOOP_OBJECT && LOOP_OBJECT.constructor === Array,
          INDEX = 0,
          LOOP_OBJECT = IS_ARRAY ? LOOP_OBJECT : LOOP_OBJECT[Symbol.iterator]();;) {
   var ID;
diff --git a/src/babel/transformation/templates/sliced-to-array-loose.js b/src/babel/transformation/templates/sliced-to-array-loose.js
new file mode 100644
index 0000000000..b6d8868843
--- /dev/null
+++ b/src/babel/transformation/templates/sliced-to-array-loose.js
@@ -0,0 +1,14 @@
+(function (arr, i) {
+  if (arr && arr.constructor === Array) {
+    return arr;
+  } else if (Symbol.iterator in Object(arr)) {
+    var _arr = [];
+    for (var _iterator = arr[Symbol.iterator](), _step; !(_step = _iterator.next()).done;) {
+      _arr.push(_step.value);
+      if (i && _arr.length === i) break;
+    }
+    return _arr;
+  } else {
+    throw new TypeError("Invalid attempt to destructure non-iterable instance");
+  }
+});
diff --git a/src/babel/transformation/templates/sliced-to-array.js b/src/babel/transformation/templates/sliced-to-array.js
index aac859f7f4..c35f18e903 100644
--- a/src/babel/transformation/templates/sliced-to-array.js
+++ b/src/babel/transformation/templates/sliced-to-array.js
@@ -1,5 +1,5 @@
 (function (arr, i) {
-  if (Array.isArray(arr)) {
+  if (arr && arr.constructor === Array) {
     return arr;
   } else if (Symbol.iterator in Object(arr)) {
     // this is an expanded form of `for...of` that properly supports abrupt completions of
@@ -17,9 +17,8 @@
     var _d = false;
     var _e = undefined;
     try {
-      for (var _i = arr[Symbol.iterator](), _s; !(_n (_s = _i.next()).done); _n = true) {
-        var val = _s.value;
-        _arr.push(_step.value);
+      for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) {
+        _arr.push(_s.value);
         if (i && _arr.length === i) break;
       }
     } catch (err) {
diff --git a/src/babel/transformation/templates/to-array.js b/src/babel/transformation/templates/to-array.js
index c479b65446..42b81bd483 100644
--- a/src/babel/transformation/templates/to-array.js
+++ b/src/babel/transformation/templates/to-array.js
@@ -1,3 +1,3 @@
 (function (arr) {
-  return Array.isArray(arr) ? arr : Array.from(arr);
+  return arr && arr.constructor === Array ? arr : Array.from(arr);
 });
diff --git a/src/babel/transformation/templates/to-consumable-array.js b/src/babel/transformation/templates/to-consumable-array.js
index 9e042dadf1..711657e96b 100644
--- a/src/babel/transformation/templates/to-consumable-array.js
+++ b/src/babel/transformation/templates/to-consumable-array.js
@@ -1,5 +1,5 @@
 (function (arr) {
-  if (Array.isArray(arr)) {
+  if (arr && arr.constructor === Array) {
     for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i];
     return arr2;
   } else {
diff --git a/src/babel/transformation/transformers/internal/validation.js b/src/babel/transformation/transformers/internal/validation.js
index 87119f6380..c21b524294 100644
--- a/src/babel/transformation/transformers/internal/validation.js
+++ b/src/babel/transformation/transformers/internal/validation.js
@@ -1,6 +1,10 @@
 import * as messages from "../../../messages";
 import * as t from "../../../types";
 
+export var metadata = {
+  readOnly: true
+};
+
 export function ForOfStatement(node, parent, scope, file) {
   var left = node.left;
   if (t.isVariableDeclaration(left)) {
diff --git a/src/babel/traversal/index.js b/src/babel/traversal/index.js
index fa68811939..0f0a5db68c 100644
--- a/src/babel/traversal/index.js
+++ b/src/babel/traversal/index.js
@@ -38,8 +38,9 @@ traverse.node = function (node, opts, scope, state, parentPath) {
 };
 
 const CLEAR_KEYS = [
-  "trailingComments", "leadingComments", "_declarations", "extendedRange",
-  "_paths", "tokens", "range", "start", "end", "loc", "raw"
+  "trailingComments", "leadingComments", "extendedRange",
+  "_declarations", "_scopeInfo" ,"_paths",
+  "tokens", "range", "start", "end", "loc", "raw"
 ];
 
 function clearNode(node) {
diff --git a/src/babel/traversal/path/index.js b/src/babel/traversal/path/index.js
index 64fed848f0..40248f93c4 100644
--- a/src/babel/traversal/path/index.js
+++ b/src/babel/traversal/path/index.js
@@ -5,6 +5,7 @@ import isString from "lodash/lang/isString";
 import traverse from "../index";
 import includes from "lodash/collection/includes";
 import assign from "lodash/object/assign";
+import extend from "lodash/object/extend";
 import Scope from "../scope";
 import * as t from "../../types";
 
@@ -158,7 +159,6 @@ export default class TraversalPath {
       }
 
       this.flatten();
-      // TODO: duplicate internal path metadata across the new node paths
     }
   }
 
@@ -210,15 +210,24 @@ export default class TraversalPath {
     return this.shouldStop;
   }
 
-  get(key) {
-    var node = this.node;
-    var container = node[key];
-    if (Array.isArray(container)) {
-      return container.map((_, i) => {
-        return TraversalPath.get(this, this.context, node, container, i);
-      });
-    } else {
-      return TraversalPath.get(this, this.context, node, node, key);
+  get(key: string): TraversalPath {
+    var parts = key.split(".");
+    if (parts.length === 1) { // "foo.bar"
+      var node = this.node;
+      var container = node[key];
+      if (Array.isArray(container)) {
+        return container.map((_, i) => {
+          return TraversalPath.get(this, this.context, node, container, i);
+        });
+      } else {
+        return TraversalPath.get(this, this.context, node, node, key);
+      }
+    } else { // "foo"
+      var path = this;
+      for (var i = 0; i > parts.length; i++) {
+        path = path.get(parts[i]);
+      }
+      return path;
     }
   }
 
diff --git a/src/babel/traversal/scope.js b/src/babel/traversal/scope.js
index 6c75615e70..ba3364b6a4 100644
--- a/src/babel/traversal/scope.js
+++ b/src/babel/traversal/scope.js
@@ -294,6 +294,7 @@ export default class Scope {
     } else if (i) {
       args.push(t.literal(i));
       helperName = "sliced-to-array";
+      if (this.file.isLoose("es6.forOf")) helperName += "-loose";
     }
     return t.callExpression(file.addHelper(helperName), args);
   }
@@ -400,14 +401,14 @@ export default class Scope {
 
     //
 
-    var info = path.getData("scopeInfo");
+    var info = this.block._scopeInfo;
     if (info) return extend(this, info);
 
-    info = path.setData("scopeInfo", {
+    info = this.block._scopeInfo = {
       bindings: object(),
       globals:  object(),
       uids:     object()
-    });
+    };
 
     extend(this, info);
 
diff --git a/src/babel/types/index.js b/src/babel/types/index.js
index f1d8c6318a..cc93dbb9df 100644
--- a/src/babel/types/index.js
+++ b/src/babel/types/index.js
@@ -282,6 +282,7 @@ export function inheritsComments(child: Object, parent: Object): Object {
 
 export function inherits(child: Object, parent: Object): Object {
   child._declarations = parent._declarations;
+  child._scopeInfo    = parent._scopeInfo;
   child.range         = parent.range;
   child.start         = parent.start;
   child.loc           = parent.loc;
diff --git a/src/babel/util.js b/src/babel/util.js
index c61fef5ba9..61bccf1410 100644
--- a/src/babel/util.js
+++ b/src/babel/util.js
@@ -1,5 +1,6 @@
 import "./patch";
 
+import escapeRegExp from "lodash/string/escapeRegExp";
 import buildDebug from "debug/node";
 import cloneDeep from "lodash/lang/cloneDeep";
 import isBoolean from "lodash/lang/isBoolean";
@@ -43,7 +44,7 @@ export function list(val: string): Array<string> {
 
 export function regexify(val: any): RegExp {
   if (!val) return new RegExp(/.^/);
-  if (Array.isArray(val)) val = val.join("|");
+  if (Array.isArray(val)) val = new RegExp(val.map(escapeRegExp).join("|"), "i");
   if (isString(val)) return minimatch.makeRe(val, { nocase: true });
   if (isRegExp(val)) return val;
   throw new TypeError("illegal type for regexify");
diff --git a/test/fixtures/esnext/es6-arrow-functions/does-not-bind-this-from-standard-function.js b/test/fixtures/esnext/es6-arrow-functions/does-not-bind-this-from-standard-function.js
deleted file mode 100644
index 6f3ffee93a..0000000000
--- a/test/fixtures/esnext/es6-arrow-functions/does-not-bind-this-from-standard-function.js
+++ /dev/null
@@ -1,5 +0,0 @@
-var dynamicThisGetter = () => function () { return this; };
-assert.equal(
-  '(' + dynamicThisGetter.toString() + ')',
-  '(function () {\n  return function () {\n    return this;\n  };\n})'
-);
diff --git a/test/fixtures/transformation/es6-for-of-loose/identifier/expected.js b/test/fixtures/transformation/es6-for-of-loose/identifier/expected.js
index cb83442b64..0d8a45e609 100644
--- a/test/fixtures/transformation/es6-for-of-loose/identifier/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/identifier/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = arr, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   if (_isArray) {
     if (_i >= _iterator.length) break;
     i = _iterator[_i++];
diff --git a/test/fixtures/transformation/es6-for-of-loose/ignore-cases/expected.js b/test/fixtures/transformation/es6-for-of-loose/ignore-cases/expected.js
index d7576bf4f7..58cd9b98e6 100644
--- a/test/fixtures/transformation/es6-for-of-loose/ignore-cases/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/ignore-cases/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = foo, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = foo, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   var _ref;
 
   if (_isArray) {
diff --git a/test/fixtures/transformation/es6-for-of-loose/let/expected.js b/test/fixtures/transformation/es6-for-of-loose/let/expected.js
index 24b278f864..246b378924 100644
--- a/test/fixtures/transformation/es6-for-of-loose/let/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/let/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = arr, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   var _ref;
 
   if (_isArray) {
diff --git a/test/fixtures/transformation/es6-for-of-loose/member-expression/expected.js b/test/fixtures/transformation/es6-for-of-loose/member-expression/expected.js
index 10c85b30a2..cc864f5fe8 100644
--- a/test/fixtures/transformation/es6-for-of-loose/member-expression/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/member-expression/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = arr, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   if (_isArray) {
     if (_i >= _iterator.length) break;
     obj.prop = _iterator[_i++];
diff --git a/test/fixtures/transformation/es6-for-of-loose/multiple/expected.js b/test/fixtures/transformation/es6-for-of-loose/multiple/expected.js
index f3a251f396..fb5e478b26 100644
--- a/test/fixtures/transformation/es6-for-of-loose/multiple/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/multiple/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = arr, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   var _ref;
 
   if (_isArray) {
@@ -15,7 +15,7 @@ for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator
   var i = _ref;
 }
 
-for (var _iterator2 = numbers, _isArray2 = Array.isArray(_iterator2), _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : _iterator2[Symbol.iterator]();;) {
+for (var _iterator2 = numbers, _isArray2 = _iterator2 && _iterator2.constructor === Array, _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : _iterator2[Symbol.iterator]();;) {
   var _ref2;
 
   if (_isArray2) {
diff --git a/test/fixtures/transformation/es6-for-of-loose/var/expected.js b/test/fixtures/transformation/es6-for-of-loose/var/expected.js
index 24b278f864..246b378924 100644
--- a/test/fixtures/transformation/es6-for-of-loose/var/expected.js
+++ b/test/fixtures/transformation/es6-for-of-loose/var/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-for (var _iterator = arr, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+for (var _iterator = arr, _isArray = _iterator && _iterator.constructor === Array, _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
   var _ref;
 
   if (_isArray) {
diff --git a/test/fixtures/transformation/es6-spread/arguments-array/expected.js b/test/fixtures/transformation/es6-spread/arguments-array/expected.js
index 705f37c31e..18aecfa027 100644
--- a/test/fixtures/transformation/es6-spread/arguments-array/expected.js
+++ b/test/fixtures/transformation/es6-spread/arguments-array/expected.js
@@ -1,8 +1,7 @@
 "use strict";
 
-var _slice = Array.prototype.slice;
 function foo() {
-  return bar([].concat(_slice.call(arguments)));
+  return bar([].concat(babelHelpers.slice.call(arguments)));
 }
 
 function bar(one, two, three) {
diff --git a/test/fixtures/transformation/es6-spread/arguments-concat/expected.js b/test/fixtures/transformation/es6-spread/arguments-concat/expected.js
index a95f66cf85..23468169cb 100644
--- a/test/fixtures/transformation/es6-spread/arguments-concat/expected.js
+++ b/test/fixtures/transformation/es6-spread/arguments-concat/expected.js
@@ -1,8 +1,7 @@
 "use strict";
 
-var _slice = Array.prototype.slice;
 function foo() {
-  return bar.apply(undefined, ["test"].concat(_slice.call(arguments)));
+  return bar.apply(undefined, ["test"].concat(babelHelpers.slice.call(arguments)));
 }
 
 function bar(one, two, three) {
diff --git a/test/fixtures/transformation/es6-spread/array-literal-first/expected.js b/test/fixtures/transformation/es6-spread/array-literal-first/expected.js
index 4fe049cf69..65e76aebc6 100644
--- a/test/fixtures/transformation/es6-spread/array-literal-first/expected.js
+++ b/test/fixtures/transformation/es6-spread/array-literal-first/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-var lyrics = [].concat(_toConsumableArray(parts), ["head", "and", "toes"]);
+var lyrics = [].concat(babelHelpers.toConsumableArray(parts), ["head", "and", "toes"]);
diff --git a/test/fixtures/transformation/es6-spread/array-literal-middle/expected.js b/test/fixtures/transformation/es6-spread/array-literal-middle/expected.js
index a4a19d29d0..91292cb698 100644
--- a/test/fixtures/transformation/es6-spread/array-literal-middle/expected.js
+++ b/test/fixtures/transformation/es6-spread/array-literal-middle/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-var a = [b].concat(_toConsumableArray(c), [d]);
+var a = [b].concat(babelHelpers.toConsumableArray(c), [d]);
diff --git a/test/fixtures/transformation/es6-spread/array-literal-multiple/expected.js b/test/fixtures/transformation/es6-spread/array-literal-multiple/expected.js
index 8190d877aa..a9e349d03b 100644
--- a/test/fixtures/transformation/es6-spread/array-literal-multiple/expected.js
+++ b/test/fixtures/transformation/es6-spread/array-literal-multiple/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-var a = [b].concat(_toConsumableArray(c), [d, e], _toConsumableArray(f));
+var a = [b].concat(babelHelpers.toConsumableArray(c), [d, e], babelHelpers.toConsumableArray(f));
diff --git a/test/fixtures/transformation/es6-spread/array-literals/expected.js b/test/fixtures/transformation/es6-spread/array-literals/expected.js
index 5881ce581e..436c91026b 100644
--- a/test/fixtures/transformation/es6-spread/array-literals/expected.js
+++ b/test/fixtures/transformation/es6-spread/array-literals/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-var lyrics = ["head", "and", "toes"].concat(_toConsumableArray(parts));
+var lyrics = ["head", "and", "toes"].concat(babelHelpers.toConsumableArray(parts));
diff --git a/test/fixtures/transformation/es6-spread/contexted-computed-method-call-multiple-args/expected.js b/test/fixtures/transformation/es6-spread/contexted-computed-method-call-multiple-args/expected.js
index 2acacbf97d..93e7396960 100644
--- a/test/fixtures/transformation/es6-spread/contexted-computed-method-call-multiple-args/expected.js
+++ b/test/fixtures/transformation/es6-spread/contexted-computed-method-call-multiple-args/expected.js
@@ -2,6 +2,4 @@
 
 var _obj;
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-(_obj = obj)[method].apply(_obj, [foo, bar].concat(_toConsumableArray(args)));
+(_obj = obj)[method].apply(_obj, [foo, bar].concat(babelHelpers.toConsumableArray(args)));
diff --git a/test/fixtures/transformation/es6-spread/contexted-computed-method-call-single-arg/expected.js b/test/fixtures/transformation/es6-spread/contexted-computed-method-call-single-arg/expected.js
index 90d4042576..e1a10318ec 100644
--- a/test/fixtures/transformation/es6-spread/contexted-computed-method-call-single-arg/expected.js
+++ b/test/fixtures/transformation/es6-spread/contexted-computed-method-call-single-arg/expected.js
@@ -2,6 +2,4 @@
 
 var _obj;
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-(_obj = obj)[method].apply(_obj, _toConsumableArray(args));
+(_obj = obj)[method].apply(_obj, babelHelpers.toConsumableArray(args));
diff --git a/test/fixtures/transformation/es6-spread/contexted-method-call-multiple-args/expected.js b/test/fixtures/transformation/es6-spread/contexted-method-call-multiple-args/expected.js
index 8918047bf1..97f2cdfdf0 100644
--- a/test/fixtures/transformation/es6-spread/contexted-method-call-multiple-args/expected.js
+++ b/test/fixtures/transformation/es6-spread/contexted-method-call-multiple-args/expected.js
@@ -2,7 +2,5 @@
 
 var _foob, _foob$test;
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-(_foob = foob).add.apply(_foob, [foo, bar].concat(_toConsumableArray(numbers)));
-(_foob$test = foob.test).add.apply(_foob$test, [foo, bar].concat(_toConsumableArray(numbers)));
+(_foob = foob).add.apply(_foob, [foo, bar].concat(babelHelpers.toConsumableArray(numbers)));
+(_foob$test = foob.test).add.apply(_foob$test, [foo, bar].concat(babelHelpers.toConsumableArray(numbers)));
diff --git a/test/fixtures/transformation/es6-spread/contexted-method-call-single-arg/expected.js b/test/fixtures/transformation/es6-spread/contexted-method-call-single-arg/expected.js
index 68e7049991..868a092240 100644
--- a/test/fixtures/transformation/es6-spread/contexted-method-call-single-arg/expected.js
+++ b/test/fixtures/transformation/es6-spread/contexted-method-call-single-arg/expected.js
@@ -2,7 +2,5 @@
 
 var _foob, _foob$test;
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-(_foob = foob).add.apply(_foob, _toConsumableArray(numbers));
-(_foob$test = foob.test).add.apply(_foob$test, _toConsumableArray(numbers));
+(_foob = foob).add.apply(_foob, babelHelpers.toConsumableArray(numbers));
+(_foob$test = foob.test).add.apply(_foob$test, babelHelpers.toConsumableArray(numbers));
diff --git a/test/fixtures/transformation/es6-spread/method-call-first/expected.js b/test/fixtures/transformation/es6-spread/method-call-first/expected.js
index 958db15bb1..b21bb56b0b 100644
--- a/test/fixtures/transformation/es6-spread/method-call-first/expected.js
+++ b/test/fixtures/transformation/es6-spread/method-call-first/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-add.apply(undefined, _toConsumableArray(numbers).concat([foo, bar]));
+add.apply(undefined, babelHelpers.toConsumableArray(numbers).concat([foo, bar]));
diff --git a/test/fixtures/transformation/es6-spread/method-call-middle/expected.js b/test/fixtures/transformation/es6-spread/method-call-middle/expected.js
index 3ad75de3cc..aa58d4b763 100644
--- a/test/fixtures/transformation/es6-spread/method-call-middle/expected.js
+++ b/test/fixtures/transformation/es6-spread/method-call-middle/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-add.apply(undefined, [foo].concat(_toConsumableArray(numbers), [bar]));
+add.apply(undefined, [foo].concat(babelHelpers.toConsumableArray(numbers), [bar]));
diff --git a/test/fixtures/transformation/es6-spread/method-call-multiple-args/expected.js b/test/fixtures/transformation/es6-spread/method-call-multiple-args/expected.js
index 1e2cedd9c4..b05198cb1f 100644
--- a/test/fixtures/transformation/es6-spread/method-call-multiple-args/expected.js
+++ b/test/fixtures/transformation/es6-spread/method-call-multiple-args/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-add.apply(undefined, [foo, bar].concat(_toConsumableArray(numbers)));
+add.apply(undefined, [foo, bar].concat(babelHelpers.toConsumableArray(numbers)));
diff --git a/test/fixtures/transformation/es6-spread/method-call-multiple/expected.js b/test/fixtures/transformation/es6-spread/method-call-multiple/expected.js
index c07763c6b3..efbcb25bb6 100644
--- a/test/fixtures/transformation/es6-spread/method-call-multiple/expected.js
+++ b/test/fixtures/transformation/es6-spread/method-call-multiple/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-add.apply(undefined, [foo].concat(_toConsumableArray(numbers), [bar, what], _toConsumableArray(test)));
+add.apply(undefined, [foo].concat(babelHelpers.toConsumableArray(numbers), [bar, what], babelHelpers.toConsumableArray(test)));
diff --git a/test/fixtures/transformation/es6-spread/method-call-single-arg/expected.js b/test/fixtures/transformation/es6-spread/method-call-single-arg/expected.js
index f697e3b8f5..3b817b4f15 100644
--- a/test/fixtures/transformation/es6-spread/method-call-single-arg/expected.js
+++ b/test/fixtures/transformation/es6-spread/method-call-single-arg/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-add.apply(undefined, _toConsumableArray(numbers));
+add.apply(undefined, babelHelpers.toConsumableArray(numbers));
diff --git a/test/fixtures/transformation/es6-spread/new-expression/expected.js b/test/fixtures/transformation/es6-spread/new-expression/expected.js
index de0426cd6f..6f963d42dd 100644
--- a/test/fixtures/transformation/es6-spread/new-expression/expected.js
+++ b/test/fixtures/transformation/es6-spread/new-expression/expected.js
@@ -1,8 +1,4 @@
 "use strict";
 
-var _applyConstructor = function (Constructor, args) { var instance = Object.create(Constructor.prototype); var result = Constructor.apply(instance, args); return result != null && (typeof result == "object" || typeof result == "function") ? result : instance; };
-
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-_applyConstructor(Numbers, _toConsumableArray(nums));
-_applyConstructor(Numbers, [1].concat(_toConsumableArray(nums)));
+babelHelpers.applyConstructor(Numbers, babelHelpers.toConsumableArray(nums));
+babelHelpers.applyConstructor(Numbers, [1].concat(babelHelpers.toConsumableArray(nums)));
diff --git a/test/fixtures/transformation/es6-spread/options.json b/test/fixtures/transformation/es6-spread/options.json
index b8b90ecb11..02c3a96413 100644
--- a/test/fixtures/transformation/es6-spread/options.json
+++ b/test/fixtures/transformation/es6-spread/options.json
@@ -1,3 +1,4 @@
-{
-  "blacklist": ["es6.tailCall"]
-}
+{
+  "externalHelpers": true,
+  "blacklist": ["es6.tailCall"]
+}
diff --git a/test/fixtures/transformation/es6-spread/single/expected.js b/test/fixtures/transformation/es6-spread/single/expected.js
index 74a812d890..68249fd331 100644
--- a/test/fixtures/transformation/es6-spread/single/expected.js
+++ b/test/fixtures/transformation/es6-spread/single/expected.js
@@ -1,5 +1,3 @@
 "use strict";
 
-var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
-
-[].concat(_toConsumableArray(foo));
+[].concat(babelHelpers.toConsumableArray(foo));
diff --git a/test/util.js b/test/util.js
index 2562750dc2..88276ffbc3 100644
--- a/test/util.js
+++ b/test/util.js
@@ -78,8 +78,8 @@ suite("util", function () {
     assert.deepEqual(util.regexify(false), /.^/);
     assert.deepEqual(util.regexify(null), /.^/);
     assert.deepEqual(util.regexify(""), /.^/);
-    assert.deepEqual(util.regexify(["foo", "bar"]), /foo|bar/);
-    assert.deepEqual(util.regexify("foobar"), /foobar/);
+    assert.deepEqual(util.regexify(["foo", "bar"]), /foo|bar/i);
+    assert.deepEqual(util.regexify("foobar"), /^(?:(?=.)foobar)$/i);
     assert.deepEqual(util.regexify(/foobar/), /foobar/);
 
     assert.throws(function () {
diff --git a/vendor/acorn/acorn.js b/vendor/acorn/acorn.js
index 68b94cf405..77432428a9 100644
--- a/vendor/acorn/acorn.js
+++ b/vendor/acorn/acorn.js
@@ -243,6 +243,7 @@
     this.label = label;
     this.keyword = conf.keyword;
     this.beforeExpr = !!conf.beforeExpr;
+    this.startsExpr = !!conf.startsExpr;
     this.rightAssociative = !!conf.rightAssociative;
     this.isLoop = !!conf.isLoop;
     this.isAssign = !!conf.isAssign;
@@ -255,21 +256,21 @@
   function binop(name, prec) {
     return new TokenType(name, {beforeExpr: true, binop: prec});
   }
-  var beforeExpr = {beforeExpr: true};
+  var beforeExpr = {beforeExpr: true}, startsExpr = {startsExpr: true};;
 
   var tt = exports.tokTypes = {
-    num: new TokenType("num"),
-    regexp: new TokenType("regexp"),
-    string: new TokenType("string"),
-    name: new TokenType("name"),
+    num: new TokenType("num", startsExpr),
+    regexp: new TokenType("regexp", startsExpr),
+    string: new TokenType("string", startsExpr),
+    name: new TokenType("name", startsExpr),
     eof: new TokenType("eof"),
 
     // Punctuation token types.
-    bracketL: new TokenType("[", beforeExpr),
+    bracketL: new TokenType("[", {beforeExpr: true, startsExpr: true}),
     bracketR: new TokenType("]"),
-    braceL: new TokenType("{", beforeExpr),
+    braceL: new TokenType("{", {beforeExpr: true, startsExpr: true}),
     braceR: new TokenType("}"),
-    parenL: new TokenType("(", beforeExpr),
+    parenL: new TokenType("(", {beforeExpr: true, startsExpr: true}),
     parenR: new TokenType(")"),
     comma: new TokenType(",", beforeExpr),
     semi: new TokenType(";", beforeExpr),
@@ -279,8 +280,8 @@
     arrow: new TokenType("=>", beforeExpr),
     template: new TokenType("template"),
     ellipsis: new TokenType("...", beforeExpr),
-    backQuote: new TokenType("`"),
-    dollarBraceL: new TokenType("${", beforeExpr),
+    backQuote: new TokenType("`", startsExpr),
+    dollarBraceL: new TokenType("${", {beforeExpr: true, startsExpr: true}),
 
     // Operators. These carry several kinds of properties to help the
     // parser use them properly (the presence of these properties is
@@ -298,8 +299,8 @@
 
     eq: new TokenType("=", {beforeExpr: true, isAssign: true}),
     assign: new TokenType("_=", {beforeExpr: true, isAssign: true}),
-    incDec: new TokenType("++/--", {prefix: true, postfix: true}),
-    prefix: new TokenType("prefix", {beforeExpr: true, prefix: true}),
+    incDec: new TokenType("++/--", {prefix: true, postfix: true, startsExpr: true}),
+    prefix: new TokenType("prefix", {beforeExpr: true, prefix: true, startsExpr: true}),
     logicalOR: binop("||", 1),
     logicalAND: binop("&&", 2),
     bitwiseOR: binop("|", 3),
@@ -308,7 +309,7 @@
     equality: binop("==/!=", 6),
     relational: binop("</>", 7),
     bitShift: binop("<</>>", 8),
-    plusMin: new TokenType("+/-", {beforeExpr: true, binop: 9, prefix: true}),
+    plusMin: new TokenType("+/-", {beforeExpr: true, binop: 9, prefix: true, startsExpr: true}),
     modulo: binop("%", 10),
     star: binop("*", 10),
     slash: binop("/", 10),
@@ -347,22 +348,22 @@
   kw("const");
   kw("while", {isLoop: true});
   kw("with");
-  kw("new", beforeExpr);
-  kw("this");
-  kw("super");
+  kw("new", {beforeExpr: true, startsExpr: true});
+  kw("this", startsExpr);
+  kw("super", startsExpr);
   kw("class");
   kw("extends", beforeExpr);
   kw("export");
   kw("import");
-  kw("yield", beforeExpr);
-  kw("null");
-  kw("true");
-  kw("false");
+  kw("yield", {beforeExpr: true, startsExpr: true});
+  kw("null", startsExpr);
+  kw("true", startsExpr);
+  kw("false", startsExpr);
   kw("in", {beforeExpr: true, binop: 7});
   kw("instanceof", {beforeExpr: true, binop: 7});
-  kw("typeof", {beforeExpr: true, prefix: true});
-  kw("void", {beforeExpr: true, prefix: true});
-  kw("delete", {beforeExpr: true, prefix: true});
+  kw("typeof", {beforeExpr: true, prefix: true, startsExpr: true});
+  kw("void", {beforeExpr: true, prefix: true, startsExpr: true});
+  kw("delete", {beforeExpr: true, prefix: true, startsExpr: true});
 
   // This is a trick taken from Esprima. It turns out that, on
   // non-Chrome browsers, to check whether a string is in a set, a
@@ -1125,13 +1126,15 @@
       if (this.options.ecmaVersion >= 6) validFlags = /^[gmsiyu]*$/;
       if (!validFlags.test(mods)) this.raise(start, "Invalid regular expression flag");
       if (mods.indexOf('u') >= 0 && !regexpUnicodeSupport) {
-        // Replace each astral symbol and every Unicode code point
-        // escape sequence that represents such a symbol with a single
-        // ASCII symbol to avoid throwing on regular expressions that
+        // Replace each astral symbol and every Unicode escape sequence that
+        // possibly represents an astral symbol or a paired surrogate with a
+        // single ASCII symbol to avoid throwing on regular expressions that
         // are only valid in combination with the `/u` flag.
-        tmp = tmp
-          .replace(/\\u\{([0-9a-fA-F]+)\}/g, "x")
-          .replace(/[\uD800-\uDBFF][\uDC00-\uDFFF]/g, "x");
+        // Note: replacing with the ASCII symbol `x` might cause false
+        // negatives in unlikely scenarios. For example, `[\u{61}-b]` is a
+        // perfectly valid pattern that is equivalent to `[a-b]`, but it would
+        // be replaced by `[x-b]` which throws an error.
+        tmp = tmp.replace(/\\u([a-fA-F0-9]{4})|\\u\{([0-9a-fA-F]+)\}|[\uD800-\uDBFF][\uDC00-\uDFFF]/g, "x")
       }
     }
     // Detect invalid regular expressions.
@@ -1604,24 +1607,23 @@
   // Convert list of expression atoms to binding list.
 
   pp.toAssignableList = function(exprList, isBinding) {
-    if (exprList.length) {
-      for (var i = 0; i < exprList.length - 1; i++) {
-        this.toAssignable(exprList[i], isBinding);
-      }
-      var last = exprList[exprList.length - 1];
-      switch (last.type) {
-        case "RestElement":
-          break;
-        case "SpreadElement":
-          last.type = "RestElement";
-          var arg = last.argument;
-          this.toAssignable(arg, isBinding);
-          if (arg.type !== "Identifier" && arg.type !== "MemberExpression" && arg.type !== "ArrayPattern")
-            this.unexpected(arg.start);
-          break;
-        default:
-          this.toAssignable(last, isBinding);
-      }
+    var end = exprList.length;
+    if (end) {
+      var last = exprList[end - 1];
+      if (last && last.type == "RestElement") {
+        --end;
+      } else if (last && last.type == "SpreadElement") {
+        last.type = "RestElement";
+        var arg = last.argument;
+        this.toAssignable(arg, isBinding);
+        if (arg.type !== "Identifier" && arg.type !== "MemberExpression" && arg.type !== "ArrayPattern")
+          this.unexpected(arg.start);
+        --end;
+       }
+     }
+    for (var i = 0; i < end; i++) {
+      var elt = exprList[i];
+      if (elt) this.toAssignable(elt, isBinding);
     }
     return exprList;
   };
@@ -2193,6 +2195,8 @@
         decl.init = this.parseMaybeAssign(noIn);
       } else if (kind === tt._const && !(this.type === tt._in || (this.options.ecmaVersion >= 6 && this.isContextual("of")))) {
         this.unexpected();
+      } else if (decl.id.type != "Identifier") {
+        this.raise(this.lastTokEnd, "Complex binding patterns require an initialization value");
       } else {
         decl.init = null;
       }
@@ -2634,12 +2638,10 @@
       if (this.options.ecmaVersion >= 6) {
         prop.method = false;
         prop.shorthand = false;
-        if (isPattern || refShorthandDefaultPos) {
+        if (isPattern || refShorthandDefaultPos)
           start = this.currentPos();
-        }
-        if (!isPattern) {
+        if (!isPattern)
           isGenerator = this.eat(tt.star);
-        }
       }
       if (this.options.features["es7.asyncFunctions"] && this.isContextual("async")) {
         if (isGenerator || isPattern) this.unexpected();
@@ -2680,6 +2682,10 @@
     } else if (this.options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
       prop.kind = "init";
       if (isPattern) {
+        if (this.isKeyword(prop.key.name) ||
+              (this.strict && (isStrictBadIdWord(prop.key.name) || isStrictReservedWord(prop.key.name))) ||
+              (!this.options.allowReserved && this.isReservedWord(prop.key.name)))
+            this.raise(prop.key.start, "Binding " + prop.key.name);
         prop.value = this.parseMaybeDefault(start, prop.key);
       } else if (this.type === tt.eq && refShorthandDefaultPos) {
         if (!refShorthandDefaultPos.start)
@@ -3040,7 +3046,7 @@
   pp.parseYield = function() {
     var node = this.startNode();
     this.next();
-    if (this.type == tt.semi || this.canInsertSemicolon()) {
+    if (this.type == tt.semi || this.canInsertSemicolon() || (this.type != tt.star && !this.type.startsExpr)) {
       node.delegate = false;
       node.argument = null;
     } else {
diff --git a/vendor/acorn/test/tests-harmony.js b/vendor/acorn/test/tests-harmony.js
index 72154470c7..9399254a06 100644
--- a/vendor/acorn/test/tests-harmony.js
+++ b/vendor/acorn/test/tests-harmony.js
@@ -5989,6 +5989,53 @@ test("var x = { *test () { yield *v } };", {
   locations: true
 });
 
+test("function* foo() { console.log(yield); }", {
+  body: [
+    {
+      id: {
+        name: "foo",
+        type: "Identifier",
+      },
+      generator: true,
+      expression: false,
+      params: [],
+      body: {
+        body: [
+          {
+            expression: {
+              callee: {
+                object: {
+                  name: "console",
+                  type: "Identifier",
+                },
+                property: {
+                  name: "log",
+                  type: "Identifier",
+                },
+                computed: false,
+                type: "MemberExpression",
+              },
+              arguments: [
+                {
+                  delegate: false,
+                  argument: null,
+                  type: "YieldExpression",
+                }
+              ],
+              type: "CallExpression",
+            },
+            type: "ExpressionStatement",
+          }
+        ],
+        type: "BlockStatement",
+      },
+      type: "FunctionDeclaration",
+    }
+  ],
+  sourceType: "script",
+  type: "Program"
+}, {ecmaVersion: 6})
+
 test("function* t() {}", {
   type: "Program",
   body: [{
@@ -13814,6 +13861,34 @@ test("/[a-z]/u", {
   ecmaVersion: 6
 });
 
+test("/[\\uD834\\uDF06-\\uD834\\uDF08a-z]/u", {
+  type: "Program",
+  body: [
+    {
+      type: "ExpressionStatement",
+      expression: {
+        type: "Literal",
+        regex: {
+          pattern: "[\\uD834\\uDF06-\\uD834\\uDF08a-z]",
+          flags: "u"
+        },
+        loc: {
+          start: {
+            line: 1,
+            column: 0
+          },
+          end: {
+            line: 1,
+            column: 33
+          }
+        }
+      }
+    }
+  ]
+}, {
+  locations: true,
+  ecmaVersion: 6
+});
 
 test("do {} while (false) foo();", {
   type: "Program",
@@ -15419,6 +15494,36 @@ test("let {x} = y", {
   "end": 11
 }, {ecmaVersion: 6})
 
+test("[x,,] = 1", {
+  type: "Program",
+  body: [
+    {
+      type: "ExpressionStatement",
+      expression: {
+        type: "AssignmentExpression",
+        operator: "=",
+        left: {
+          type: "ArrayPattern",
+          elements: [
+            {
+              type: "Identifier",
+              name: "x"
+            },
+            null
+          ]
+        },
+        right: {
+          type: "Literal",
+          value: 1,
+          raw: "1"
+        }
+      }
+    }
+  ]
+}, {ecmaVersion: 6});
+
+testFail("let [x]", "Complex binding patterns require an initialization value (1:7)", {ecmaVersion: 6})
+testFail("var [x]", "Complex binding patterns require an initialization value (1:7)", {ecmaVersion: 6})
 testFail("var _𖫵 = 11;", "Unexpected character '𖫵' (1:5)", {ecmaVersion: 6});
 testFail("var 𫠞_ = 12;", "Unexpected character '𫠞' (1:4)", {ecmaVersion: 6});
 testFail("var 𫠝_ = 10;", "Unexpected character '𫠝' (1:4)", {ecmaVersion: 5});
@@ -15431,3 +15536,5 @@ testFail("'use strict'; [...eval] = arr", "Assigning to eval in strict mode (1:1
 testFail("'use strict'; ({eval = defValue} = obj)", "Assigning to eval in strict mode (1:16)", {ecmaVersion: 6});
 
 testFail("[...eval] = arr", "Assigning to eval in strict mode (1:4)", {ecmaVersion: 6, sourceType: "module"});
+
+testFail("function* y({yield}) {}", "Binding yield (1:13)", {ecmaVersion: 6});