v5.6.12

This is necessary in order to retain correct function arity and to have
completely correct semantics. Sometimes features are tied together so much
that they would require so much desugaring to retain the correct semantics
that they'd be equivalent to... the normal transpiled output.

.babelrc

@@ -2,5 +2,6 @@
   "stage": 0,
   "loose": ["all"],
   "blacklist": ["es6.tailCall"],
-  "optional": ["optimisation.flow.forOf"]
+  "optional": ["optimisation.flow.forOf"],
+  "plugins": ["./tools/build-plugins/protect"]
 }

.eslintrc

@@ -18,7 +18,8 @@
     "new-cap": 0,
     "no-loop-func": 0,
     "no-unreachable": 0,
-    "no-labels": 0
+    "no-labels": 0,
+    "no-process-exit": 0
   },
   "env": {
     "node": true

CHANGELOG.md

@@ -13,6 +13,66 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
 
+## 5.6.12
+
+ * **Bug Fix**
+  * Fix finding parent for top-level shadowed functions.
+
+## 5.6.11
+
+ ** **Internal**
+  * Merge `es6.parameters.rest` and `es6.parameters.default` transformers. See commit [c0fd4c1f9e0b18231f585c4fa793e4cb0e01aed1](https://github.com/babel/babel/commit/c0fd4c1f9e0b18231f585c4fa793e4cb0e01aed1) for more info.
+
+## 5.6.10
+
+ * **Bug Fix**
+  * Fix faulty internal require check.
+ * **Polish**
+  * Add support for trailing commas in arrow function parameter lists.
+
+## 5.6.8
+
+ * **Bug Fix**
+  * Fix binary expressions colliding with unary expression operators in compact mode.
+  * Fix node properties being set to `null` when using computed properties.
+
+## 5.6.7
+
+ * **Bug Fix**
+  * Fix hoisting of `ForXStatement` `left` `var`s when inserting a block scoping IIFE.
+ * **Polish**
+  * Combine all leading computed property initialisers into the root object in loose mode.
+ * **Internal**
+  * Deprecate returning of replacement strings from visitor methods.
+
+## 5.6.6
+
+ * **Bug Fix**
+  * Fix weird parser bug where `void` type annotations were being parsed as keywords causing the tokeniser to lose track of context.
+
+## 5.6.5
+
+ * **Bug Fix**
+  * Fix nested functions causing rest parameter optimisation to not properly detect when it should deopt on a reference.
+ * **Internal**
+  * Update Regenerator `0.8.31`.
+
+## 5.6.4
+
+ * **Internal**
+  * Add `ParenthesizedExpression` node type.
+
+## 5.6.3
+
+ * **Bug Fix**
+  * Fix rest parameter array allocation loop being incorrectly aliased.
+
+## 5.6.2
+
+ * **Bug Fix**
+  * Fix method key literals not turning into computed member expression in loose mode.
+  * Elect rest parameters in spread element position as candidates instead of replacing them in place.
+
 ## 5.6.0
 
  * **Bug Fix**

CONTRIBUTING.md

@@ -113,8 +113,6 @@ your [`$PATH`](http://unix.stackexchange.com/questions/26047/how-to-correctly-ad
 
 + [js-tokens](http://ghub.io/js-tokens) This is used to get tokens for syntax error highlighting.
 
-+ [leven](http://ghub.io/leven) A levenstein algorithm to determine how close a word is to another. This is used to offer suggestions when using the utility.undeclaredVariableCheck transformer.
-
 + [line-numbers](http://ghub.io/line-numbers) Used to produce the code frames in syntax errors.
 
 + [lodash](http://ghub.io/lodash) Used for various utilities.

Makefile

@@ -24,7 +24,7 @@ clean-core:
 	rm -rf lib
 
 lint:
-	eslint src/babel
+	eslint src/babel packages/babel-cli/bin
 
 build:
 	mkdir -p dist

index.js

@@ -0,0 +1 @@
+module.exports = require("./lib/babel/api/node.js");

package.json

@@ -1,12 +1,11 @@
 {
   "name": "babel-core",
   "description": "A compiler for writing next generation JavaScript",
-  "version": "5.6.2",
+  "version": "5.6.12",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
   "license": "MIT",
   "repository": "babel/babel",
-  "main": "lib/babel/api/node.js",
   "browser": {
     "./lib/babel/api/register/node.js": "./lib/babel/api/register/browser.js"
   },
@@ -31,7 +30,7 @@
     "acorn-jsx": "^1.0.0",
     "ast-types": "~0.7.0",
     "babel-plugin-constant-folding": "^1.0.1",
-    "babel-plugin-dead-code-elimination": "^1.0.1",
+    "babel-plugin-dead-code-elimination": "^1.0.2",
     "babel-plugin-eval": "^1.0.1",
     "babel-plugin-inline-environment-variables": "^1.0.1",
     "babel-plugin-jscript": "^1.0.1",
@@ -57,14 +56,14 @@
     "home-or-tmp": "^1.0.0",
     "is-integer": "^1.0.4",
     "js-tokens": "1.0.1",
-    "leven": "^1.0.1",
     "line-numbers": "0.2.0",
     "lodash": "^3.6.0",
     "minimatch": "^2.0.3",
     "output-file-sync": "^1.1.0",
+    "path-exists": "^1.0.0",
     "path-is-absolute": "^1.0.0",
     "private": "^0.1.6",
-    "regenerator": "0.8.30",
+    "regenerator": "0.8.31",
     "regexpu": "^1.1.2",
     "repeating": "^1.1.2",
     "resolve": "^1.1.6",
@@ -77,7 +76,7 @@
     "trim-right": "^1.0.0"
   },
   "devDependencies": {
-    "babel": "5.5.7",
+    "babel": "5.6.10",
     "browserify": "^9.0.8",
     "chai": "^2.2.0",
     "eslint": "^0.21.2",

packages/babel-cli/bin/babel-plugin/index.js

@@ -1,9 +1,10 @@
 #!/usr/bin/env node
 
-var readline = require("readline");
-var child    = require("child_process");
-var path     = require("path");
-var fs       = require("fs");
+var pathExists = require("path-exists");
+var readline   = require("readline");
+var child      = require("child_process");
+var path       = require("path");
+var fs         = require("fs");
 
 function spawn(cmd, args, callback) {
   console.log(">", cmd, args);
@@ -34,7 +35,7 @@ function spawnMultiple(cmds) {
 }
 
 function template(name, data) {
-  var source = fs.readFileSync(__dirname + "/templates/" + name, "utf8");
+  var source = fs.readFileSync(path.join(__dirname, "templates", name), "utf8");
   source = source.replace(/[A-Z_]+/g, function (key) {
     return data[key] === undefined ? key : data[key];
   });
@@ -98,7 +99,7 @@ var cmds = {
 
         write("README.md", template("README.md", templateData));
 
-        if (!fs.existsSync("src")) {
+        if (!pathExists.sync("src")) {
           fs.mkdirSync("src");
           write("src/index.js", template("index.js", templateData));
         }

packages/babel-cli/bin/babel/dir.js

@@ -1,4 +1,5 @@
 var outputFileSync = require("output-file-sync");
+var pathExists     = require("path-exists");
 var chokidar       = require("chokidar");
 var slash          = require("slash");
 var path           = require("path");
@@ -6,7 +7,7 @@ var util           = require("./util");
 var fs             = require("fs");
 var _              = require("lodash");
 
-module.exports = function (commander, filenames, opts) {
+module.exports = function (commander, filenames) {
   var write = function (src, relative) {
     // remove extension and then append back on .js
     relative = relative.replace(/\.(\w*?)$/, "") + ".js";
@@ -41,7 +42,7 @@ module.exports = function (commander, filenames, opts) {
   };
 
   var handle = function (filename) {
-    if (!fs.existsSync(filename)) return;
+    if (!pathExists.sync(filename)) return;
 
     var stat = fs.statSync(filename);
 

packages/babel-cli/bin/babel/file.js

@@ -1,4 +1,5 @@
 var convertSourceMap = require("convert-source-map");
+var pathExists       = require("path-exists");
 var sourceMap        = require("source-map");
 var chokidar         = require("chokidar");
 var slash            = require("slash");
@@ -100,7 +101,7 @@ module.exports = function (commander, filenames, opts) {
     results = [];
 
     _.each(filenames, function (filename) {
-      if (!fs.existsSync(filename)) return;
+      if (!pathExists.sync(filename)) return;
 
       var stat = fs.statSync(filename);
       if (stat.isDirectory()) {

packages/babel-cli/bin/babel/index.js

@@ -1,6 +1,9 @@
 #!/usr/bin/env node
 
+require("babel-core");
+
 var moduleFormatters = require("babel-core/lib/babel/transformation/modules");
+var pathExists       = require("path-exists");
 var commander        = require("commander");
 var transform        = require("babel-core").transform;
 var kebabCase        = require("lodash/string/kebabCase");
@@ -9,7 +12,6 @@ var util             = require("babel-core").util;
 var uniq             = require("lodash/array/uniq");
 var each             = require("lodash/collection/each");
 var keys             = require("lodash/object/keys");
-var fs               = require("fs");
 var glob             = require("glob");
 
 each(options, function (option, key) {
@@ -88,7 +90,7 @@ var filenames = commander.args.reduce(function (globbed, input) {
 filenames = uniq(filenames);
 
 each(filenames, function (filename) {
-  if (!fs.existsSync(filename)) {
+  if (!pathExists.sync(filename)) {
     errors.push(filename + " doesn't exist");
   }
 });

packages/babel-cli/package.json

@@ -1,14 +1,14 @@
 {
   "name": "babel",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "5.6.1",
+  "version": "5.6.11",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
   "license": "MIT",
   "repository": "babel/babel",
   "preferGlobal": true,
   "dependencies": {
-    "babel-core": "^5.6.1",
+    "babel-core": "^5.6.11",
     "chokidar": "^1.0.0",
     "commander": "^2.6.0",
     "convert-source-map": "^1.1.0",
@@ -16,6 +16,7 @@
     "glob": "^5.0.5",
     "lodash": "^3.2.0",
     "output-file-sync": "^1.1.0",
+    "path-exists": "^1.0.0",
     "path-is-absolute": "^1.0.0",
     "source-map": "^0.4.0",
     "slash": "^1.0.0"

packages/babel-runtime/package.json

@@ -1,7 +1,7 @@
 {
   "name": "babel-runtime",
   "description": "babel selfContained runtime",
-  "version": "5.6.1",
+  "version": "5.6.11",
   "license": "MIT",
   "repository": "babel/babel",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",

src/acorn/plugins/flow.js

@@ -1,3 +1,4 @@
+Error.stackTraceLimit = Infinity;
 var acorn = require("../src/index")
 
 var pp = acorn.Parser.prototype
@@ -41,8 +42,11 @@ pp.flow_parseDeclareFunction = function (node) {
   typeNode.rest = tmp.rest
   this.expect(tt.parenR)
 
+  var oldInType = this.inType
+  this.inType = true
   this.expect(tt.colon)
   typeNode.returnType = this.flow_parseType()
+  this.inType = oldInType
 
   typeContainer.typeAnnotation = this.finishNode(typeNode, "FunctionTypeAnnotation")
   id.typeAnnotation = this.finishNode(typeContainer, "TypeAnnotation")
@@ -352,12 +356,6 @@ pp.flow_parseGenericType = function (start, id) {
   return this.finishNode(node, "GenericTypeAnnotation")
 }
 
-pp.flow_parseVoidType = function () {
-  var node = this.startNode()
-  this.expect(tt._void)
-  return this.finishNode(node, "VoidTypeAnnotation")
-}
-
 pp.flow_parseTypeofType = function () {
   var node = this.startNode()
   this.expect(tt._typeof)
@@ -411,6 +409,9 @@ pp.flow_identToTypeAnnotation = function (start, node, id) {
     case "any":
       return this.finishNode(node, "AnyTypeAnnotation")
 
+    case "void":
+      return this.finishNode(node, "VoidTypeAnnotation")
+
     case "bool":
     case "boolean":
       return this.finishNode(node, "BooleanTypeAnnotation")
@@ -524,14 +525,8 @@ pp.flow_parsePrimaryType = function () {
       return this.finishNode(node, "StringLiteralTypeAnnotation")
 
     default:
-      if (this.type.keyword) {
-        switch (this.type.keyword) {
-          case "void":
-            return this.flow_parseVoidType()
-
-          case "typeof":
-            return this.flow_parseTypeofType()
-        }
+      if (this.type.keyword === "typeof") {
+        return this.flow_parseTypeofType()
       }
   }
 
@@ -694,6 +689,18 @@ acorn.plugins.flow = function (instance) {
     }
   })
 
+  // don't consider `void` to be a keyword as then it'll use the void token type
+  // and set startExpr
+  instance.extend("isKeyword", function (inner) {
+    return function(name) {
+      if (this.inType && name === "void") {
+        return false
+      } else {
+        return inner.call(this, name)
+      }
+    }
+  })
+
   instance.extend("readToken", function (inner) {
     return function(code) {
       if (this.inType && (code === 62 || code === 60)) {

src/acorn/src/expression.js

@@ -432,9 +432,18 @@ pp.parseParenAndDistinguishExpression = function(start, isAsync, canBeArrow) {
     }
 
     let innerStart = this.markPosition(), exprList = [], first = true
-    let refShorthandDefaultPos = {start: 0}, spreadStart, innerParenStart
+    let refShorthandDefaultPos = {start: 0}, spreadStart, innerParenStart, optionalCommaStart
     while (this.type !== tt.parenR) {
-      first ? first = false : this.expect(tt.comma)
+      if (first) {
+        first = false;
+      } else {
+        this.expect(tt.comma)
+        if (this.type === tt.parenR && this.options.features["es7.trailingFunctionCommas"]) {
+          optionalCommaStart = this.start
+          break
+        }
+      }
+
       if (this.type === tt.ellipsis) {
         let spreadNodeStart = this.markPosition()
         spreadStart = this.start
@@ -462,6 +471,7 @@ pp.parseParenAndDistinguishExpression = function(start, isAsync, canBeArrow) {
         this.unexpected(this.lastTokStart)
       }
     }
+    if (optionalCommaStart) this.unexpected(optionalCommaStart)
     if (spreadStart) this.unexpected(spreadStart)
     if (refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start)
 

src/acorn/src/lookahead.js

@@ -19,7 +19,11 @@ var STATE_KEYS = [
   "exprAllowed",
   "potentialArrowAt",
   "currLine",
-  "input"
+  "input",
+  "inType",
+  "inFunction",
+  "inGenerator",
+  "labels"
 ];
 
 pp.getState = function () {
@@ -29,6 +33,7 @@ pp.getState = function () {
     state[key] = this[key]
   }
   state.context = this.context.slice()
+  state.labels = this.labels.slice()
   return state
 };
 

src/acorn/src/state.js

@@ -4,11 +4,11 @@ import {lineBreak} from "./whitespace"
 
 export function Parser(options, input, startPos) {
   this.options = options
-  this.loadPlugins(this.options.plugins)
   this.sourceFile = this.options.sourceFile || null
   this.isKeyword = keywords[this.options.ecmaVersion >= 6 ? 6 : 5]
   this.isReservedWord = reservedWords[this.options.ecmaVersion]
   this.input = input
+  this.loadPlugins(this.options.plugins)
 
   // Set up token state
 

src/acorn/src/tokentype.js

@@ -112,7 +112,7 @@ kw("case", beforeExpr)
 kw("catch")
 kw("continue")
 kw("debugger")
-kw("default")
+kw("default", beforeExpr)
 kw("do", {isLoop: true})
 kw("else", beforeExpr)
 kw("finally")

src/babel/api/register/cache.js

@@ -1,6 +1,7 @@
 import path from "path";
 import fs from "fs";
 import homeOrTmp from "home-or-tmp";
+import pathExists from "path-exists";
 
 const FILENAME = process.env.BABEL_CACHE_PATH || path.join(homeOrTmp, ".babel.json");
 var data = {};
@@ -15,7 +16,7 @@ export function load() {
   process.on("exit", save);
   process.nextTick(save);
 
-  if (!fs.existsSync(FILENAME)) return;
+  if (!pathExists.sync(FILENAME)) return;
 
   try {
     data = JSON.parse(fs.readFileSync(FILENAME));

src/babel/generation/buffer.js

@@ -54,9 +54,10 @@ export default class Buffer {
     this.space();
   }
 
-  space() {
-    if (this.format.compact) return;
-    if (this.buf && !this.isLast(" ") && !this.isLast("\n")) {
+  space(force?) {
+    if (!force && this.format.compact) return;
+
+    if (force || this.buf && !this.isLast(" ") && !this.isLast("\n")) {
       this.push(" ");
     }
   }
@@ -155,8 +156,12 @@ export default class Buffer {
     this.buf += str;
   }
 
-  endsWith(str) {
-    return this.buf.slice(-str.length) === str;
+  endsWith(str, buf = this.buf) {
+    if (str.length === 1) {
+      return buf[buf.length - 1] === str;
+    } else {
+      return buf.slice(-str.length) === str;
+    }
   }
 
   isLast(cha) {

src/babel/generation/generators/classes.js

@@ -1,5 +1,5 @@
 export function ClassDeclaration(node, print) {
-  print.list(node.decorators);
+  print.list(node.decorators, { separator: "" });
   this.push("class");
 
   if (node.id) {
@@ -43,7 +43,7 @@ export function ClassBody(node, print) {
 
 
 export function ClassProperty(node, print) {
-  print.list(node.decorators);
+  print.list(node.decorators, { separator: "" });
 
   if (node.static) this.push("static ");
   print.plain(node.key);
@@ -58,7 +58,7 @@ export function ClassProperty(node, print) {
 }
 
 export function MethodDefinition(node, print) {
-  print.list(node.decorators);
+  print.list(node.decorators, { separator: "" });
 
   if (node.static) {
     this.push("static ");

src/babel/generation/generators/expressions.js

@@ -2,19 +2,19 @@ import isNumber from "lodash/lang/isNumber";
 import * as t from "../../types";
 
 export function UnaryExpression(node, print) {
-  var hasSpace = /[a-z]$/.test(node.operator);
+  var needsSpace = /[a-z]$/.test(node.operator);
   var arg = node.argument;
 
   if (t.isUpdateExpression(arg) || t.isUnaryExpression(arg)) {
-    hasSpace = true;
+    needsSpace = true;
   }
 
   if (t.isUnaryExpression(arg) && arg.operator === "!") {
-    hasSpace = false;
+    needsSpace = false;
   }
 
   this.push(node.operator);
-  if (hasSpace) this.push(" ");
+  if (needsSpace) this.push(" ");
   print.plain(node.argument);
 }
 
@@ -24,6 +24,12 @@ export function DoExpression(node, print) {
   print.plain(node.body);
 }
 
+export function ParenthesizedExpression(node, print) {
+  this.push("(");
+  print.plain(node.expression);
+  this.push(")");
+}
+
 export function UpdateExpression(node, print) {
   if (node.prefix) {
     this.push(node.operator);
@@ -77,19 +83,16 @@ export function CallExpression(node, print) {
 
   this.push("(");
 
-  var separator = ",";
-
-  var isPrettyCall = node._prettyCall && !this.format.retainLines;
+  var isPrettyCall = node._prettyCall && !this.format.retainLines && !this.format.compact;
 
+  var separator;
   if (isPrettyCall) {
-    separator += "\n";
+    separator = ",\n";
     this.newline();
     this.indent();
-  } else {
-    separator += " ";
   }
 
-  print.list(node.arguments, { separator: separator });
+  print.list(node.arguments, { separator });
 
   if (isPrettyCall) {
     this.newline();
@@ -135,9 +138,23 @@ export function AssignmentPattern(node, print) {
 export function AssignmentExpression(node, print) {
   // todo: add cases where the spaces can be dropped when in compact mode
   print.plain(node.left);
-  this.push(" ");
+
+  var spaces = node.operator === "in" || node.operator === "instanceof";
+  spaces = true; // todo: https://github.com/babel/babel/issues/1835
+  this.space(spaces);
+
   this.push(node.operator);
-  this.push(" ");
+
+  if (!spaces) {
+    // space is mandatory to avoid outputting <!--
+    // http://javascript.spec.whatwg.org/#comment-syntax
+    spaces = node.operator === "<" &&
+             t.isUnaryExpression(node.right, { prefix: true, operator: "!" }) &&
+             t.isUnaryExpression(node.right.argument, { prefix: true, operator: "--" });
+  }
+
+  this.space(spaces);
+
   print.plain(node.right);
 }
 

src/babel/generation/generators/methods.js

@@ -42,7 +42,7 @@ export function _method(node, print) {
   }
 
   this._params(value, print);
-  this.push(" ");
+  this.space();
   print.plain(value.body);
 }
 

src/babel/generation/generators/statements.js

@@ -33,13 +33,13 @@ export function ForStatement(node, print) {
   this.push(";");
 
   if (node.test) {
-    this.push(" ");
+    this.space();
     print.plain(node.test);
   }
   this.push(";");
 
   if (node.update) {
-    this.push(" ");
+    this.space();
     print.plain(node.update);
   }
 
@@ -190,16 +190,29 @@ export function VariableDeclaration(node, print, parent) {
     }
   }
 
-  var sep = ",";
+  //
+  // use a pretty separator when we aren't in compact mode, have initializers and don't have retainLines on
+  // this will format declarations like:
+  //
+  //   var foo = "bar", bar = "foo";
+  //
+  // into
+  //
+  //   var foo = "bar",
+  //       bar = "foo";
+  //
+
+  var sep;
   if (!this.format.compact && !this.format.concise && hasInits && !this.format.retainLines) {
-    sep += `\n${repeating(" ", node.kind.length + 1)}`;
-  } else {
-    sep += " ";
+    sep = `,\n${repeating(" ", node.kind.length + 1)}`;
   }
 
+  //
+
   print.list(node.declarations, { separator: sep });
 
   if (t.isFor(parent)) {
+    // don't give semicolons to these nodes since they'll be inserted in the parent generator
     if (parent.left === node || parent.init === node) return;
   }
 

src/babel/generation/generators/types.js

@@ -33,6 +33,8 @@ export function ObjectExpression(node, print) {
 export { ObjectExpression as ObjectPattern };
 
 export function Property(node, print) {
+  print.list(node.decorators, { separator: "" });
+
   if (node.method || node.kind === "get" || node.kind === "set") {
     this._method(node, print);
   } else {
@@ -80,7 +82,7 @@ export function ArrayExpression(node, print) {
       // both (all) of the holes.
       this.push(",");
     } else {
-      if (i > 0) this.push(" ");
+      if (i > 0) this.space();
       print.plain(elem);
       if (i < len - 1) this.push(",");
     }

src/babel/generation/index.js

@@ -128,8 +128,7 @@ class CodeGenerator {
     // catch up to this nodes newline if we're behind
     if (node.loc && this.format.retainLines && this.buffer.buf) {
       var needsParens = false;
-      if (!leftParenPrinted && parent &&
-          this.position.line < node.loc.start.line && t.isTerminatorless(parent)) {
+      if (!leftParenPrinted && parent && this.position.line < node.loc.start.line && t.isTerminatorless(parent)) {
         needsParens = true;
         this._push("(");
       }

src/babel/generation/node/printer.js

@@ -18,7 +18,11 @@ export default class NodePrinter {
   }
 
   list(items, opts = {}) {
-    if (opts.separator == null) opts.separator = ", ";
+    if (opts.separator == null) {
+      opts.separator = ",";
+      if (!this.generator.format.compact) opts.separator += " ";
+    }
+
     return this.join(items, opts);
   }
 

src/babel/tools/protect.js

@@ -0,0 +1,9 @@
+import path from "path";
+
+var root = path.resolve(__dirname, "../../../");
+
+export default function (module) {
+  if (module.parent && module.parent.filename.indexOf(root) !== 0) {
+    throw new Error("Don't hotlink internal Babel files.");
+  }
+}

src/babel/transformation/file/logger.js

@@ -4,6 +4,8 @@ import buildDebug from "debug/node";
 var verboseDebug = buildDebug("babel:verbose");
 var generalDebug = buildDebug("babel");
 
+var seenDeprecatedMessages = [];
+
 export default class Logger {
   constructor(file: File, filename: string) {
     this.filename = filename;
@@ -25,9 +27,17 @@ export default class Logger {
   }
 
   deprecate(msg) {
-    if (!this.file.opts.suppressDeprecationMessages) {
-      console.error(this._buildMessage(msg));
-    }
+    if (this.file.opts.suppressDeprecationMessages) return;
+
+    msg = this._buildMessage(msg);
+
+    // already seen this message
+    if (seenDeprecatedMessages.indexOf(msg) >= 0) return;
+
+    // make sure we don't see it again
+    seenDeprecatedMessages.push(msg);
+
+    console.error(msg);
   }
 
   verbose(msg: string) {

src/babel/transformation/file/options/resolve-rc.js

@@ -3,16 +3,15 @@ import { normaliseOptions } from "./index";
 import merge from "../../../helpers/merge";
 import path from "path";
 import fs from "fs";
+import pathExists from "path-exists";
 
 var cache = {};
 var jsons = {};
 
 function exists(filename) {
-  if (!fs.existsSync) return false;
-
   var cached = cache[filename];
   if (cached != null) return cached;
-  return cache[filename] = fs.existsSync(filename);
+  return cache[filename] = pathExists.sync(filename);
 }
 
 export default function (loc, opts = {}) {

src/babel/transformation/templates/helper-define-property.js

@@ -1,8 +1,18 @@
 (function (obj, key, value) {
-  return Object.defineProperty(obj, key, {
-    value: value,
-    enumerable: true,
-    configurable: true,
-    writable: true
-  });
+  // Shortcircuit the slow defineProperty path when possible.
+  // We are trying to avoid issues where setters defined on the
+  // prototype cause side effects under the fast path of simple
+  // assignment. By checking for existence of the property with
+  // the in operator, we can optimize most of this overhead away.
+  if (key in obj) {
+    Object.defineProperty(obj, key, {
+      value: value,
+      enumerable: true,
+      configurable: true,
+      writable: true
+    });
+  } else {
+    obj[key] = value;
+  }
+  return obj;
 });

src/babel/transformation/templates/helper-sliced-to-array.js

@@ -1,7 +1,7 @@
-(function (arr, i) {
-  if (Array.isArray(arr)) {
-    return arr;
-  } else if (Symbol.iterator in Object(arr)) {
+(function () {
+  // Broken out into a separate function to avoid deoptimizations due to the try/catch for the
+  // array iterator case.
+  function sliceIterator(arr, i) {
     // this is an expanded form of `for...of` that properly supports abrupt completions of
     // iterators etc. variable names have been minimised to reduce the size of this massive
     // helper. sometimes spec compliancy is annoying :(
@@ -32,7 +32,15 @@
       }
     }
     return _arr;
-  } else {
-    throw new TypeError("Invalid attempt to destructure non-iterable instance");
   }
-});
+
+  return function (arr, i) {
+    if (Array.isArray(arr)) {
+      return arr;
+    } else if (Symbol.iterator in Object(arr)) {
+      return sliceIterator(arr, i);
+    } else {
+      throw new TypeError("Invalid attempt to destructure non-iterable instance");
+    }
+  };
+})();

src/babel/transformation/transformers/deprecated.json

@@ -8,5 +8,8 @@
   "utility.inlineExpressions": "minification.constantFolding",
   "utility.deadCodeElimination": "minification.deadCodeElimination",
   "utility.removeConsoleCalls": "minification.removeConsole",
-  "utility.removeDebugger": "minification.removeDebugger"
+  "utility.removeDebugger": "minification.removeDebugger",
+
+  "es6.parameters.rest": "es6.parameters",
+  "es6.parameters.default": "es6.parameters"
 }

src/babel/transformation/transformers/es6/block-scoping.js

@@ -162,6 +162,7 @@ var hoistVarDeclarationsVisitor = {
     } else if (this.isFor()) {
       if (isVar(node.left, node)) {
         node.left = node.left.declarations[0].id;
+        self.pushDeclar(node.left);
       }
     } else if (isVar(node, parent)) {
       return self.pushDeclar(node).map(t.expressionStatement);

src/babel/transformation/transformers/es6/destructuring.js

@@ -70,7 +70,15 @@ export var visitor = {
       let pattern = node.params[i];
       if (!t.isPattern(pattern)) continue;
 
-      var ref = node.params[i] = scope.generateUidIdentifier("ref");
+      var ref = scope.generateUidIdentifier("ref");
+      if (t.isAssignmentPattern(pattern)) {
+        var _pattern = pattern;
+        pattern = pattern.left;
+        _pattern.left = ref;
+      } else {
+        node.params[i] = ref;
+      }
+
       t.inherits(ref, pattern);
 
       var destructuring = new DestructuringTransformer({

src/babel/transformation/transformers/es6/parameters/default.js

@@ -1,7 +1,7 @@
-import callDelegate from "../../helpers/call-delegate";
-import getFunctionArity from "../../helpers/get-function-arity";
-import * as util from  "../../../util";
-import * as t from "../../../types";
+import callDelegate from "../../../helpers/call-delegate";
+import getFunctionArity from "../../../helpers/get-function-arity";
+import * as util from  "../../../../util";
+import * as t from "../../../../types";
 
 var hasDefaults = function (node) {
   for (var i = 0; i < node.params.length; i++) {
@@ -38,7 +38,7 @@ export var visitor = {
 
     //
     var argsIdentifier = t.identifier("arguments");
-    argsIdentifier._shadowedFunctionLiteral = true;
+    argsIdentifier._shadowedFunctionLiteral = this;
 
     // push a default parameter definition
     function pushDefNode(left, right, i) {

src/babel/transformation/transformers/es6/parameters/index.js

@@ -0,0 +1,10 @@
+import * as visitors from "../../../../traversal/visitors";
+
+import * as def from "./default";
+import * as rest from "./rest";
+
+export var metadata = {
+  group: "builtin-advanced"
+};
+
+export var visitor = visitors.merge([rest.visitor, def.visitor]);

src/babel/transformation/transformers/es6/parameters/rest.js

@@ -1,5 +1,5 @@
-import * as util from  "../../../util";
-import * as t from "../../../types";
+import * as util from  "../../../../util";
+import * as t from "../../../../types";
 
 var memberExpressionOptimisationVisitor = {
   Scope(node, parent, scope, state) {
@@ -12,9 +12,10 @@ var memberExpressionOptimisationVisitor = {
   Function(node, parent, scope, state) {
     // skip over functions as whatever `arguments` we reference inside will refer
     // to the wrong function
+    var oldNoOptimise = state.noOptimise;
     state.noOptimise = true;
     this.traverse(memberExpressionOptimisationVisitor, state);
-    state.noOptimise = false;
+    state.noOptimise = oldNoOptimise;
     this.skip();
   },
 
@@ -27,7 +28,9 @@ var memberExpressionOptimisationVisitor = {
     // is this a referenced identifier and is it referencing the rest parameter?
     if (node.name !== state.name) return;
 
-    if (!state.noOptimise) {
+    if (state.noOptimise) {
+      state.deopted = true;
+    } else {
       if (this.parentPath.isMemberExpression({ computed: true, object: node })) {
         // if we know that this member expression is referencing a number then we can safely
         // optimise it
@@ -46,11 +49,7 @@ var memberExpressionOptimisationVisitor = {
           return;
         }
       }
-    }
 
-    if (state.noOptimise) {
-      state.deopted = true;
-    } else {
       state.references.push(this);
     }
   }
@@ -85,7 +84,7 @@ export var visitor = {
     var argsId = t.identifier("arguments");
 
     // otherwise `arguments` will be remapped in arrow functions
-    argsId._shadowedFunctionLiteral = true;
+    argsId._shadowedFunctionLiteral = this;
 
     // support patterns
     if (t.isPattern(rest)) {
@@ -100,7 +99,6 @@ export var visitor = {
     }
 
     // check and optimise for extremely common cases
-
     var state = {
       references: [],
       offset:     node.params.length,
@@ -135,6 +133,9 @@ export var visitor = {
       state.references = state.references.concat(state.candidates);
     }
 
+    // deopt shadowed functions as transforms like regenerator may try touch the allocation loop
+    state.deopted = state.deopted || !!node.shadow;
+
     //
 
     var start = t.literal(node.params.length);
@@ -173,13 +174,13 @@ export var visitor = {
       LEN:        len
     });
 
-    if (!state.deopted) {
+    if (state.deopted) {
+      loop._blockHoist = node.params.length + 1;
+      node.body.body.unshift(loop);
+    } else {
       // perform allocation at the lowest common denominator of all references
+      loop._blockHoist = 1;
       this.getEarliestCommonAncestorFrom(state.references).getStatementParent().insertBefore(loop);
-      return;
     }
-
-    loop._blockHoist = node.params.length + 1;
-    node.body.body.unshift(loop);
   }
 };

src/babel/transformation/transformers/es6/properties.computed.js

@@ -1,9 +1,7 @@
 import * as t from "../../../types";
 
 function loose(node, body, objId) {
-  for (var i = 0; i < node.properties.length; i++) {
-    var prop = node.properties[i];
-
+  for (var prop of (node.properties: Array)) {
     body.push(t.expressionStatement(
       t.assignmentExpression(
         "=",
@@ -15,31 +13,15 @@ function loose(node, body, objId) {
 }
 
 function spec(node, body, objId, initProps, file) {
-  var props = node.properties;
-
-  // add all non-computed properties and `__proto__` properties to the initializer
-
-  var broken = false;
-
-  for (let i = 0; i < props.length; i++) {
-    let prop = props[i];
-
-    if (prop.computed) {
-      broken = true;
-    }
-
-    if (prop.kind !== "init" || !broken || t.isLiteral(t.toComputedKey(prop, prop.key), { value: "__proto__" })) {
-      initProps.push(prop);
-      props[i] = null;
-    }
-  }
-
   // add a simple assignment for all Symbol member expressions due to symbol polyfill limitations
   // otherwise use Object.defineProperty
 
-  for (let i = 0; i < props.length; i++) {
-    let prop = props[i];
-    if (!prop) continue;
+  for (let prop of (node.properties: Array)) {
+    // this wont work with Object.defineProperty
+    if (t.isLiteral(t.toComputedKey(prop), { value: "__proto__" })) {
+      initProps.push(prop);
+      continue;
+    }
 
     let key = prop.key;
     if (t.isIdentifier(key) && !prop.computed) {
@@ -68,14 +50,34 @@ export var visitor = {
     exit(node, parent, scope, file) {
       var hasComputed = false;
 
-      for (var prop of (node.properties: Array)) {
+      for (let prop of (node.properties: Array)) {
         hasComputed = t.isProperty(prop, { computed: true, kind: "init" });
         if (hasComputed) break;
       }
 
       if (!hasComputed) return;
 
+      // put all getters/setters into the first object expression as well as all initialisers up
+      // to the first computed property
+
       var initProps = [];
+      var stopInits = false;
+
+      node.properties = node.properties.filter(function (prop) {
+        if (prop.computed) {
+          stopInits = true;
+        }
+
+        if (prop.kind !== "init" || !stopInits) {
+          initProps.push(prop);
+          return false;
+        } else {
+          return true;
+        }
+      });
+
+      //
+
       var objId = scope.generateUidIdentifierBasedOnNode(parent);
 
       //

src/babel/transformation/transformers/es6/spread.js

@@ -43,6 +43,10 @@ function build(props, scope) {
   return nodes;
 }
 
+export var metadata = {
+  group: "builtin-advanced"
+};
+
 export var visitor = {
   ArrayExpression(node, parent, scope) {
     var elements = node.elements;

src/babel/transformation/transformers/es6/tail-call.js

@@ -211,7 +211,7 @@ class TailCallTransformer {
       var decl = t.variableDeclarator(this.argumentsId);
       if (this.argumentsId) {
         decl.init = t.identifier("arguments");
-        decl.init._shadowedFunctionLiteral = true;
+        decl.init._shadowedFunctionLiteral = this.path;
       }
       topVars.push(decl);
     }

src/babel/transformation/transformers/index.js

@@ -46,9 +46,6 @@ export default {
   "es6.regex.sticky":                      require("./es6/regex.sticky"),
   "es6.regex.unicode":                     require("./es6/regex.unicode"),
   "es6.constants":                         require("./es6/constants"),
-  "es6.parameters.rest":                   require("./es6/parameters.rest"),
-  "es6.spread":                            require("./es6/spread"),
-  "es6.parameters.default":                require("./es6/parameters.default"),
   "es7.exportExtensions":                  require("./es7/export-extensions"),
   "spec.protoToAssign":                    require("babel-plugin-proto-to-assign"),
   "es7.doExpressions":                     require("./es7/do-expressions"),
@@ -57,6 +54,8 @@ export default {
   "spec.undefinedToVoid":                  require("babel-plugin-undefined-to-void"),
 
   //- builtin-advanced
+  "es6.spread":                            require("./es6/spread"),
+  "es6.parameters":                        require("./es6/parameters"),
   "es6.destructuring":                     require("./es6/destructuring"),
   "es6.blockScoping":                      require("./es6/block-scoping"),
   "es6.spec.blockScoping":                 require("./es6/spec.block-scoping"),

src/babel/transformation/transformers/internal/shadow-functions.js

@@ -8,7 +8,30 @@ function remap(path, key, create) {
   // ensure that we're shadowed
   if (!path.inShadow()) return;
 
-  var fnPath = path.findParent((path) => !path.is("shadow") && (path.isFunction() || path.isProgram()));
+  var shadowFunction = path.node._shadowedFunctionLiteral;
+  var currentFunction;
+
+  var fnPath = path.findParent(function (path) {
+    if (path.isProgram() || path.isFunction()) {
+      // catch current function in case this is the shadowed one and we can ignore it
+      currentFunction = currentFunction || path;
+    }
+
+    if (path.isProgram()) {
+      return true;
+    } else if (path.isFunction()) {
+      if (shadowFunction) {
+        return path === shadowFunction || path.node === shadowFunction.node;
+      } else {
+        return !path.is("shadow");
+      }
+    }
+
+    return false;
+  });
+
+  // no point in realiasing if we're in this function
+  if (fnPath === currentFunction) return;
 
   var cached = fnPath.getData(key);
   if (cached) return cached;
@@ -28,7 +51,7 @@ export var visitor = {
   },
 
   ReferencedIdentifier(node) {
-    if (node.name === "arguments" && !node._shadowedFunctionLiteral) {
+    if (node.name === "arguments") {
       return remap(this, "arguments", () => t.identifier("arguments"));
     }
   }

src/babel/traversal/path/context.js

@@ -230,6 +230,7 @@ export function unshiftContext(context) {
  */
 
 export function setup(parentPath, container, listKey, key) {
+  this.inList    = !!listKey;
   this.listKey   = listKey;
   this.parentKey = listKey || key;
   this.container = container;

src/babel/traversal/path/index.js

@@ -21,6 +21,7 @@ export default class NodePath {
     this.context            = null;
     this.container          = null;
     this.listKey            = null;
+    this.inList             = false;
     this.parentKey          = null;
     this.key                = null;
     this.node               = null;

src/babel/traversal/path/inference/index.js

@@ -1,3 +1,4 @@
+import type NodePath from "./index";
 import * as inferers from "./inferers";
 import * as t from "../../../types";
 
@@ -61,9 +62,11 @@ export function _getTypeAnnotation(): ?Object {
  * Description
  */
 
-export function isBaseType(baseName: string): boolean {
-  var type = this.getTypeAnnotation();
+export function isBaseType(baseName: string, soft?): boolean {
+  return _isBaseType(baseName, this.getTypeAnnotation(), soft);
+}
 
+function _isBaseType(baseName: string, type?, soft?): boolean {
   if (baseName === "string") {
     return t.isStringTypeAnnotation(type);
   } else if (baseName === "number") {
@@ -74,8 +77,47 @@ export function isBaseType(baseName: string): boolean {
     return t.isAnyTypeAnnotation(type);
   } else if (baseName === "mixed") {
     return t.isMixedTypeAnnotation(type);
+  } else if (baseName === "void") {
+    return t.isVoidTypeAnnotation(type);
   } else {
-    throw new Error(`Unknown base type ${baseName}`);
+    if (soft) {
+      return false;
+    } else {
+      throw new Error(`Unknown base type ${baseName}`);
+    }
+  }
+}
+
+/**
+ * Description
+ */
+
+export function couldBeBaseType(name: string): boolean {
+  var type = this.getTypeAnnotation();
+  if (t.isAnyTypeAnnotation(type)) return true;
+
+  if (t.isUnionTypeAnnotation(type)) {
+    for (var type2 of (type.types: Array)) {
+      if (t.isAnyTypeAnnotation(type2) || _isBaseType(name, type2, true)) {
+        return true;
+      }
+    }
+    return false;
+  } else {
+    return _isBaseType(name, type, true);
+  }
+}
+
+/**
+ * Description
+ */
+
+export function baseTypeStrictlyMatches(right: NodePath) {
+  var left = this.getTypeAnnotation();
+  right = right.getTypeAnnotation();
+
+  if (!t.isAnyTypeAnnotation() && t.isFlowBaseAnnotation(left)) {
+    return right.type === left.type;
   }
 }
 

src/babel/traversal/path/inference/inferers.js

@@ -140,7 +140,7 @@ export function ObjectExpression() {
 
 //
 
-export function ArrayExpression () {
+export function ArrayExpression() {
   return t.genericTypeAnnotation(t.identifier("Array"));
 }
 

src/babel/traversal/path/lib/hoister.js

@@ -122,7 +122,7 @@ export default class PathHoister {
     if (parent.isJSXElement() && this.path.container === parent.node.children) {
       // turning the `span` in `<div><span /></div>` to an expression so we need to wrap it with
       // an expression container
-      uid = t.jSXExpressionContainer(uid);
+      uid = t.JSXExpressionContainer(uid);
     }
 
     this.path.replaceWith(uid);

src/babel/traversal/path/replacement.js

@@ -92,14 +92,14 @@ export function replaceWith(replacement, whateverAllowed) {
     return;
   }
 
+  if (this.isProgram() && !t.isProgram(replacement)) {
+    throw new Error("You can only replace a Program root node with another Program node");
+  }
+
   // normalise inserting an entire AST
   if (t.isProgram(replacement) && !this.isProgram()) {
     replacement = replacement.body;
     whateverAllowed = true;
-  } else {
-    if (this.isProgram()) {
-      throw new Error("You can only replace a Program root node with another Program node");
-    }
   }
 
   if (Array.isArray(replacement)) {
@@ -112,6 +112,13 @@ export function replaceWith(replacement, whateverAllowed) {
 
   if (typeof replacement === "string") {
     if (whateverAllowed) {
+      this.hub.file.log.deprecate("Returning a string from a visitor method will be removed in the future. String " +
+                                  "building is NOT a substitute for AST generation. String building leads to " +
+                                  "terrible performance due to the additional parsing overhead and will lead to " +
+                                  "extremely brittle transformers. For those extreme cases where you're dealing " +
+                                  "with strings from a foreign source you may continue to use " +
+                                  "`path.replaceWithSourceString(code)`. Please don't abuse this. Bad plugins " +
+                                  "hurt the ecosystem.");
       return this.replaceWithSourceString(replacement);
     } else {
       throw new Error("Don't use `path.replaceWith()` with a string, use `path.replaceWithSourceString()`");

src/babel/traversal/visitors.js

@@ -126,6 +126,8 @@ export function merge(visitors) {
   var rootVisitor = {};
 
   for (var visitor of (visitors: Array)) {
+    explode(visitor);
+
     for (var type in visitor) {
       var nodeVisitor = rootVisitor[type] = rootVisitor[type] || {};
       mergePair(nodeVisitor, visitor[type]);

src/babel/types/alias-keys.json

@@ -71,6 +71,7 @@
   "MetaProperty":              ["Expression"],
   "NewExpression":             ["Expression"],
   "ObjectExpression":          ["Expression"],
+  "ParenthesizedExpression":   ["Expression"],
   "SequenceExpression":        ["Expression"],
   "TaggedTemplateExpression":  ["Expression"],
   "ThisExpression":            ["Expression"],

src/babel/types/flow.js

@@ -112,5 +112,9 @@ export function createTypeAnnotationBasedOnTypeof(type) {
     return t.genericTypeAnnotation(t.identifier("Function"));
   } else if (type === "object") {
     return t.genericTypeAnnotation(t.identifier("Object"));
+  } else if (type === "symbol") {
+    return t.genericTypeAnnotation(t.identifier("Symbol"));
+  } else {
+    throw new Error("Invalid typeof value");
   }
 }

src/babel/types/index.js

@@ -108,7 +108,7 @@ each(t.VISITOR_KEYS, function (keys, type) {
 });
 
 each(t.BUILDER_KEYS, function (keys, type) {
-  t[type[0].toLowerCase() + type.slice(1)] = function () {
+  var builder = function () {
     var node = {};
     node.start = null;
     node.type = type;
@@ -123,6 +123,9 @@ each(t.BUILDER_KEYS, function (keys, type) {
 
     return node;
   };
+
+  t[type] = builder;
+  t[type[0].toLowerCase() + type.slice(1)] = builder;
 });
 
 /*

src/babel/types/validators.js

@@ -23,7 +23,7 @@ export function isReferenced(node: Object, parent: Object): boolean {
   switch (parent.type) {
     // yes: PARENT[NODE]
     // yes: NODE.child
-    // no: parent.CHILD
+    // no: parent.NODE
     case "MemberExpression":
     case "JSXMemberExpression":
       if (parent.property === node && parent.computed) {
@@ -73,21 +73,17 @@ export function isReferenced(node: Object, parent: Object): boolean {
         return parent.local === node;
       }
 
-    // no: import NODE from "foo";
-    case "ImportDefaultSpecifier":
-      return false;
-
-    // no: import * as NODE from "foo";
-    case "ImportNamespaceSpecifier":
-      return false;
-
     // no: <div NODE="foo" />
     case "JSXAttribute":
       return parent.name !== node;
 
+    // no: import NODE from "foo";
+    // no: import * as NODE from "foo";
     // no: import { NODE as foo } from "foo";
     // no: import { foo as NODE } from "foo";
     // no: import NODE from "bar";
+    case "ImportDefaultSpecifier":
+    case "ImportNamespaceSpecifier":
     case "ImportSpecifier":
       return false;
 
@@ -112,12 +108,16 @@ export function isReferenced(node: Object, parent: Object): boolean {
     case "RestElement":
       return false;
 
-    // no: [NODE = foo] = [];
-    // yes: [foo = NODE] = [];
+    // yes: left = NODE;
+    // no: NODE = right;
     case "AssignmentExpression":
-    case "AssignmentPattern":
       return parent.right === node;
 
+    // no: [NODE = foo] = [];
+    // no: [foo = NODE] = [];
+    case "AssignmentPattern":
+      return false;
+
     // no: [NODE] = [];
     // no: ({ NODE }) = [];
     case "ObjectPattern":
@@ -195,7 +195,7 @@ export function isImmutable(node: Object): boolean {
 
   if (t.isLiteral(node)) {
     if (node.regex) {
-      // regexes are mutable
+      // regexs are mutable
       return false;
     } else {
       // immutable!

src/babel/types/visitor-keys.json

@@ -46,6 +46,7 @@
   "Noop":                      [],
   "ObjectExpression":          ["properties"],
   "ObjectPattern":             ["properties", "typeAnnotation"],
+  "ParenthesizedExpression":   ["expression"],
   "Program":                   ["body"],
   "Property":                  ["key", "value", "decorators"],
   "RestElement":               ["argument", "typeAnnotation"],

src/babel/util.js

@@ -18,6 +18,7 @@ import has from "lodash/object/has";
 import fs from "fs";
 import * as t from "./types";
 import slash from "slash";
+import pathExists from "path-exists";
 
 export { inherits, inspect } from "util";
 
@@ -182,7 +183,7 @@ function loadTemplates() {
   var templates = {};
 
   var templatesLoc = path.join(__dirname, "transformation/templates");
-  if (!fs.existsSync(templatesLoc)) {
+  if (!pathExists.sync(templatesLoc)) {
     throw new ReferenceError(messages.get("missingTemplatesDirectory"));
   }
 

test/acorn/tests-babel.js

@@ -3374,6 +3374,49 @@ test("class Foo { bar(a,) { } }", {
   features: { "es7.trailingFunctionCommas": true }
 });
 
+test("(x, y, ) => 1;", {
+  start: 0,
+  body: [{
+    start: 0,
+    expression: {
+      start: 0,
+      id: null,
+      generator: false,
+      expression: true,
+      params: [
+        {
+          start: 1,
+          name: "x",
+          type: "Identifier",
+          end: 2
+        },
+        {
+          start: 4,
+          name: "y",
+          type: "Identifier",
+          end: 5
+        }
+      ],
+      body: {
+        start: 12,
+        value: 1,
+        raw: "1",
+        type: "Literal",
+        end: 13
+      },
+      type: "ArrowFunctionExpression",
+      end: 13
+    },
+    type: "ExpressionStatement",
+    end: 14
+  }],
+  type: "Program",
+  end: 14
+}, {
+  ecmaVersion: 7,
+  features: { "es7.trailingFunctionCommas": true }
+});
+
 testFail("log(,);", "Unexpected token (1:4)", {
   ecmaVersion: 7,
   features: { "es7.trailingFunctionCommas": true }
@@ -3383,3 +3426,8 @@ testFail("function log(,) { }", "Unexpected token (1:13)", {
   ecmaVersion: 7,
   features: { "es7.trailingFunctionCommas": true }
 });
+
+testFail("('foo',)", "Unexpected token (1:7)", {
+  ecmaVersion: 7,
+  features: { "es7.trailingFunctionCommas": true }
+});

test/acorn/tests-flow.js

@@ -11148,3 +11148,9 @@ for (var ns in fbTestFixture) {
     });
   }
 }
+
+test("<Foo foo={function (): void {}} />", {}, {
+  ecmaVersion: 6,
+  sourceType: "module",
+  plugins: { jsx: true, flow: true },
+});

test/acorn/tests-harmony.js

@@ -15328,3 +15328,5 @@ test("({ ['__proto__']: 1, __proto__: 2 })", {}, {ecmaVersion: 6});
 test("({ __proto__() { return 1 }, __proto__: 2 })", {}, {ecmaVersion: 6});
 test("({ get __proto__() { return 1 }, __proto__: 2 })", {}, {ecmaVersion: 6});
 test("({ __proto__, __proto__: 2 })", {}, {ecmaVersion: 6});
+
+test("export default /foo/", {}, {ecmaVersion: 6, sourceType: "module"});

test/core/_helper.js

@@ -1,8 +1,9 @@
-var esvalid = require("esvalid");
-var util    = require("../../lib/babel/util");
-var path    = require("path");
-var fs      = require("fs");
-var _       = require("lodash");
+var pathExists = require("path-exists");
+var esvalid    = require("esvalid");
+var util       = require("../../lib/babel/util");
+var path       = require("path");
+var fs         = require("fs");
+var _          = require("lodash");
 
 var humanize = function (val, noext) {
   if (noext) val = path.basename(val, path.extname(val));
@@ -10,7 +11,7 @@ var humanize = function (val, noext) {
 };
 
 var readFile = exports.readFile = function (filename) {
-  if (fs.existsSync(filename)) {
+  if (pathExists.sync(filename)) {
     var file = fs.readFileSync(filename, "utf8").trim();
     file = file.replace(/\r\n/g, "\n");
     return file;
@@ -31,7 +32,7 @@ exports.esvalid = function (ast, code, loc) {
 };
 
 exports.assertVendor = function (name) {
-  if (!fs.existsSync(__dirname + "/../../vendor/" + name)) {
+  if (!pathExists.sync(__dirname + "/../../vendor/" + name)) {
     console.error("No vendor/" + name + " - run `make bootstrap`");
     process.exit(1);
   }
@@ -130,13 +131,13 @@ exports.get = function (entryName, entryLoc) {
       suite.tests.push(test);
 
       var sourceMappingsLoc = taskDir + "/source-mappings.json";
-      if (fs.existsSync(sourceMappingsLoc)) {
+      if (pathExists.sync(sourceMappingsLoc)) {
         test.options.sourceMap = true;
         test.sourceMappings = require(sourceMappingsLoc);
       }
 
       var sourceMap = taskDir + "/source-map.json";
-      if (fs.existsSync(sourceMap)) {
+      if (pathExists.sync(sourceMap)) {
         test.options.sourceMap = true;
         test.sourceMap = require(sourceMap);
       }

test/core/api.js

@@ -219,7 +219,7 @@ suite("api", function () {
 
     function getModuleNameTest(moduleFormat, expected) {
       var result = transform("foo('bar');", {
-        filename: "foo/bar/index",
+        filename: "/foo/bar/index",
         modules: moduleFormat,
         moduleIds: true,
         getModuleId: function (name) {
@@ -232,7 +232,7 @@ suite("api", function () {
 
     test("amd", function () {
       var expected = [
-        "define('foo/bar', ['exports'], function (exports) {",
+        "define('/foo/bar', ['exports'], function (exports) {",
         "  'use strict';",
         "",
         "  foo('bar');",
@@ -246,7 +246,7 @@ suite("api", function () {
       var expected = [
         "(function (global, factory) {",
         "  if (typeof define === 'function' && define.amd) {",
-        "    define('foo/bar', ['exports'], factory);",
+        "    define('/foo/bar', ['exports'], factory);",
         "  } else if (typeof exports !== 'undefined') {",
         "    factory(exports);",
         "  } else {",
@@ -268,7 +268,7 @@ suite("api", function () {
 
     test("system", function () {
       var expected = [
-        "System.register('foo/bar', [], function (_export) {",
+        "System.register('/foo/bar', [], function (_export) {",
         "  'use strict';",
         "",
         "  return {",

test/core/bin.js

@@ -9,6 +9,7 @@ var child          = require("child_process");
 var path           = require("path");
 var chai           = require("chai");
 var fs             = require("fs");
+var pathExists     = require("path-exists");
 var _              = require("lodash");
 
 var fixtureLoc = __dirname + "/fixtures/bin";
@@ -16,7 +17,7 @@ var tmpLoc = __dirname + "/tmp";
 
 var readDir = function (loc) {
   var files = {};
-  if (fs.existsSync(loc)) {
+  if (pathExists.sync(loc)) {
     _.each(readdir(loc), function (filename) {
       var contents = helper.readFile(loc + "/" + filename);
       files[filename] = contents;
@@ -112,7 +113,7 @@ var buildTest = function (binName, testName, opts) {
 
 var clear = function () {
   process.chdir(__dirname);
-  if (fs.existsSync(tmpLoc)) rimraf.sync(tmpLoc);
+  if (pathExists.sync(tmpLoc)) rimraf.sync(tmpLoc);
   fs.mkdirSync(tmpLoc);
   process.chdir(tmpLoc);
 };
@@ -132,11 +133,11 @@ _.each(fs.readdirSync(fixtureLoc), function (binName) {
       };
 
       var optionsLoc = testLoc + "/options.json"
-      if (fs.existsSync(optionsLoc)) _.merge(opts, require(optionsLoc));
+      if (pathExists.sync(optionsLoc)) _.merge(opts, require(optionsLoc));
 
       _.each(["stdout", "stdin", "stderr"], function (key) {
         var loc = testLoc + "/" + key + ".txt";
-        if (fs.existsSync(loc)) {
+        if (pathExists.sync(loc)) {
           opts[key] = helper.readFile(loc);
         } else {
           opts[key] = opts[key] || "";

test/core/fixtures/generation/types/Decorator/actual.js

@@ -0,0 +1,31 @@
+var obj = {
+  @foo
+  @bar
+  foo: "bar",
+
+  @foo
+  @bar
+  foo() {},
+
+  @foo
+  get foo() {},
+
+  @bar
+  set bar(foo) {}
+};
+
+class Foo {
+  @foo
+  @bar
+  foo() {}
+
+  @foo
+  @bar
+  foo() {}
+
+  @foo
+  get foo() {}
+
+  @bar
+  set bar(foo) {}
+}

test/core/fixtures/generation/types/Decorator/expected.js

@@ -0,0 +1,31 @@
+var obj = {
+  @foo
+  @bar
+  foo: "bar",
+
+  @foo
+  @bar
+  foo() {},
+
+  @foo
+  get foo() {},
+
+  @bar
+  set bar(foo) {}
+};
+
+class Foo {
+  @foo
+  @bar
+  foo() {}
+
+  @foo
+  @bar
+  foo() {}
+
+  @foo
+  get foo() {}
+
+  @bar
+  set bar(foo) {}
+}

test/core/fixtures/transformation/es6.parameters/rest-async-function/actual.js

@@ -0,0 +1,7 @@
+var fn = async (...rest) => rest;
+
+var fn = async (...rest) => {
+  if (true) {
+    rest;
+  }
+};

test/core/fixtures/transformation/es6.parameters/rest-async-function/expected.js

@@ -0,0 +1,39 @@
+"use strict";
+
+var _this = this;
+
+var fn = function fn() {
+  for (var _len = arguments.length, rest = Array(_len), _key = 0; _key < _len; _key++) {
+    rest[_key] = arguments[_key];
+  }
+
+  return regeneratorRuntime.async(function fn$(context$1$0) {
+    while (1) switch (context$1$0.prev = context$1$0.next) {
+      case 0:
+        return context$1$0.abrupt("return", rest);
+
+      case 1:
+      case "end":
+        return context$1$0.stop();
+    }
+  }, null, _this);
+};
+
+var fn = function fn() {
+  for (var _len2 = arguments.length, rest = Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
+    rest[_key2] = arguments[_key2];
+  }
+
+  return regeneratorRuntime.async(function fn$(context$1$0) {
+    while (1) switch (context$1$0.prev = context$1$0.next) {
+      case 0:
+        if (true) {
+          rest;
+        }
+
+      case 1:
+      case "end":
+        return context$1$0.stop();
+    }
+  }, null, _this);
+};

test/core/fixtures/transformation/es6.parameters/rest-async-function/options.json

@@ -0,0 +1,3 @@
+{
+  "stage": 0
+}

test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/actual.js

@@ -41,3 +41,12 @@ function r(...rest){
   if (lol) rest;
   rest;
 }
+
+// nested functions
+function a(...args) {
+  return function() {
+    function b() {}
+
+    console.log("Shouldn't args be from a's scope?", args);
+  };
+}

test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/expected.js

@@ -64,3 +64,16 @@ function r() {
   if (lol) rest;
   rest;
 }
+
+// nested functions
+function a() {
+  for (var _len6 = arguments.length, args = Array(_len6), _key6 = 0; _key6 < _len6; _key6++) {
+    args[_key6] = arguments[_key6];
+  }
+
+  return function () {
+    function b() {}
+
+    console.log("Shouldn't args be from a's scope?", args);
+  };
+}

test/core/fixtures/transformation/es6.parameters/rest-nested-iife/actual.js

@@ -0,0 +1,6 @@
+function broken(x, ...foo) {
+  if (true) {
+    class Foo extends Bar { }
+    return hello(...foo)
+  }
+}

test/core/fixtures/transformation/es6.parameters/rest-nested-iife/expected.js

@@ -0,0 +1,35 @@
+"use strict";
+
+var _get = function get(_x, _x2, _x3) { var _again = true; _function: while (_again) { var object = _x, property = _x2, receiver = _x3; desc = parent = getter = undefined; _again = false; if (object === null) object = Function.prototype; var desc = Object.getOwnPropertyDescriptor(object, property); if (desc === undefined) { var parent = Object.getPrototypeOf(object); if (parent === null) { return undefined; } else { _x = parent; _x2 = property; _x3 = receiver; _again = true; continue _function; } } else if ("value" in desc) { return desc.value; } else { var getter = desc.get; if (getter === undefined) { return undefined; } return getter.call(receiver); } } };
+
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) subClass.__proto__ = superClass; }
+
+function broken(x) {
+  for (var _len = arguments.length, foo = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+    foo[_key - 1] = arguments[_key];
+  }
+
+  if (true) {
+    var _ret = (function () {
+      var Foo = (function (_Bar) {
+        function Foo() {
+          _classCallCheck(this, Foo);
+
+          _get(Object.getPrototypeOf(Foo.prototype), "constructor", this).apply(this, arguments);
+        }
+
+        _inherits(Foo, _Bar);
+
+        return Foo;
+      })(Bar);
+
+      return {
+        v: hello.apply(undefined, foo)
+      };
+    })();
+
+    if (typeof _ret === "object") return _ret.v;
+  }
+}

test/core/fixtures/transformation/es6.properties.computed-loose/coerce/actual.js

@@ -0,0 +1,4 @@
+var obj = {
+  foo: "bar",
+  [bar]: "foo"
+};

test/core/fixtures/transformation/es6.properties.computed-loose/coerce/expected.js

@@ -0,0 +1,7 @@
+"use strict";
+
+var _obj;
+
+var obj = (_obj = {
+  foo: "bar"
+}, _obj[bar] = "foo", _obj);

test/core/fixtures/transformation/es6.properties.computed-loose/options.json

@@ -1,3 +1,4 @@
 {
+  "blacklist": ["es5.properties.mutators"],
   "loose": ["es6.properties.computed"]
 }

test/core/fixtures/transformation/es6.properties.computed-loose/two/actual.js

@@ -1,4 +1,4 @@
 var obj = {
   first: "first",
-  ["second"]: "second",
+  [second]: "second",
 };

test/core/fixtures/transformation/es6.properties.computed-loose/two/expected.js

@@ -2,4 +2,6 @@
 
 var _obj;
 
-var obj = (_obj = {}, _obj.first = "first", _obj["second"] = "second", _obj);
+var obj = (_obj = {
+  first: "first"
+}, _obj[second] = "second", _obj);

test/core/fixtures/transformation/es7.trailing-function-commas/arrow-function/actual.js

@@ -0,0 +1 @@
+(x, y, ) => {};

test/core/fixtures/transformation/es7.trailing-function-commas/arrow-function/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+
+(function (x, y) {});