v1.12.20

Remove comments

.hound.yml

@@ -0,0 +1,3 @@
+java_script:
+  enabled: true
+  config_file: .jshintrc

.npmignore

@@ -8,4 +8,4 @@ Makefile
 .*
 dist
 tests.json
-!README.md
+CHANGELOG.md

CHANGELOG.md

@@ -1,3 +1,88 @@
+# 1.12.20
+
+ * Append `sourceMappingURL` when using `bin/6to5` and output sourcemaps.
+
+# 1.12.19
+
+ * Add `comments` option and `--remove-comments` flag. Thanks @[webpro](htps://github.com/webpro)!
+ * Embed `regenerator`.
+
+# 1.12.18
+
+ * Use `global` reference instead of `window`.
+
+# 1.12.17
+
+ * Add `moduleName`, `sourceRoot` and `filenameRelative` options - thanks @[darvelo](https://github.com/darvelo)!
+ * Traversal optimisations.
+
+# 1.12.16
+
+ * Fix comments not being retained from `MethodDefinition` in classes.
+ * Add temporal dead zone in default parameters.
+
+# 1.12.15
+
+ * Update `acorn-6to5`.
+
+# 1.12.14
+
+ * Fix duplicate let scoping in functions.
+ * Make JSX whitespace more React-compliant.
+ * Add `_memberExpressionKeywords` transformer that turns keyword identifiers to computed literals.
+ * Upgrade `regenerator-6to5`.
+
+# 1.12.13
+
+ * Support duplicate constants within different block scopes.
+ * Fix for-head duplication testing and replacement.
+ * Support `raw` property on tagged template literals.
+
+# 1.12.12
+
+ * Make scope tracker more reliable to handle all edgecases.
+
+# 1.12.11
+
+ * Block scope classes.
+ * Fix generation of integer `Literal`s in `MemberExpression`.
+
+# 1.12.10
+
+ * Fix let scoping var hoisting.
+
+# 1.12.9
+
+ * Escape unicode characters when generating string `Literal`s.
+ * Fix semicolons being output for statements in `ExportDeclaration`.
+ * Fix `WithStatement` missing parenthesis.
+
+# 1.12.8
+
+ * Temporarily forbid `AssignmentExpression` destructuring outside of `ExpressionStatement`.
+
+# 1.12.7
+
+ * Update to latest `acorn-6to5`.
+
+# 1.12.6
+
+ * Update to latest `acorn-6to5`.
+
+# 1.12.5
+
+ * Fix excessive whitespace trimming resulting in innaccurate sourcemap line.
+
+# 1.12.4
+
+ * Add `doc` folder for documentation.
+
+# 1.12.3
+
+ * Support generator comprehensions.
+ * Use `Array.from` instead of `Array.prototype.slice` in spread transformer.
+ * Support spread in `NewExpression`s.
+
 # 1.12.2
 
  * Upgrade `matcha` to `0.6.0` and `browserify` to `6.3.2`.

CONTRIBUTING.md

@@ -0,0 +1,31 @@
+# Contributing
+
+ * **General**
+   * No ES6 syntax features or methods, exclusively ES5.
+   * Max of five arguments for functions
+   * Max depth of four nested blocks
+   * 2-spaced soft tabs
+ * **Naming**
+   * CamelCase all class names
+   * camelBack all variable names
+ * **Spacing**
+   * 80 character line max
+   * Spaces after all keywords
+   * Spaces before all left curly braces
+ * **Comments**
+   * Use JSDoc-style comments for methods
+   * Single-line comments for ambiguous code
+ * **Quotes**
+   * Always use double quotes
+   * Only use single quotes when the string contains a double quote
+ * **Declaration**
+   * No unused variables
+   * No pollution of global variables and prototypes
+
+## Testing
+
+    $ make test
+
+## Linting
+
+    $ make lint

README.md

@@ -24,492 +24,6 @@
   </a>
 </p>
 
-**6to5** turns ES6 code into vanilla ES5, so you can use ES6 features **today.**
+**6to5** turns ES6+ code into vanilla ES5, so you can use next generation features **today.**
 
- - **Readable** - formatting is retained if possible so your generated code is as similar as possible.
- - **Extensible** - with a large range of [plugins](#plugins) and **browser support**.
- - **Lossless** - **source map support** so you can debug your compiled code with ease.
- - **Compact** - maps directly to the equivalent ES5 with **no runtime**[\*](#generators).
-
-## Installation
-
-It's as easy as:
-
-    $ npm install -g 6to5
-
-## Table of Contents
-
-- [Features](#features)
-- [Usage](#usage)
-  - [Plugins](#plugins)
-  - [CLI](#cli)
-  - [Node](#node-1)
-  - [Browser](#browser)
-- [Modules](#modules)
-- [Caveats](#caveats)
-- [Polyfill](#polyfill)
-- [Optional runtime](#optional-runtime)
-- [React/JSX](#reactjsx)
-- [Differences](#differences)
-
-## [Features](FEATURES.md)
-
- - [Array comprehension](FEATURES.md#array-comprehension)
- - [Async functions](FEATURES.md#async-functions) via [regenerator](https://github.com/facebook/regenerator)
- - [Arrow functions](FEATURES.md#arrow-functions)
- - [Classes](FEATURES.md#classes)
- - [Computed property names](FEATURES.md#computed-property-names)
- - [Constants](FEATURES.md#constants)
- - [Default parameters](FEATURES.md#default-parameters)
- - [Destructuring](FEATURES.md#destructuring)
- - [For-of](FEATURES.md#for-of)
- - [Generators](FEATURES.md#generators) via [regenerator](https://github.com/facebook/regenerator)
- - [Let scoping](FEATURES.md#let-scoping)
- - [Modules](FEATURES.md#modules)
- - [Numeric literals](FEATURES.md#numeric-literals)
- - [Property method assignment](FEATURES.md#property-method-assignment)
- - [Property name shorthand](FEATURES.md#property-name-shorthand)
- - [Rest parameters](FEATURES.md#rest-parameters)
- - [Spread](FEATURES.md#spread)
- - [Template literals](FEATURES.md#template-literals)
- - [Unicode regex](FEATURES.md#unicode-regex)
-
-## Usage
-
-### Plugins
-
- - [Broccoli](https://github.com/very-geek/broccoli-6to5-transpiler)
- - [Browserify](https://github.com/6to5/6to5-browserify)
- - [Brunch](https://github.com/es128/6to5-brunch)
- - [Duo](https://github.com/bdo-labs/duo6to5)
- - [Connect](https://github.com/6to5/6to5-connect)
- - [Gulp](https://github.com/sindresorhus/gulp-6to5)
- - [Grunt](https://github.com/sindresorhus/grunt-6to5)
- - [Jade](https://github.com/Apoxx/jade-6to5)
- - [Jest](https://github.com/6to5/6to5-jest)
- - [Karma](https://github.com/shuhei/karma-6to5-preprocessor)
- - [Mocha](https://github.com/6to5/6to5-mocha)
- - [Rails](https://github.com/6to5/6to5-rails)
- - [webpack](https://github.com/Couto/6to5-loader)
-
-### CLI
-
-Compile the file `script.js` and output it to stdout.
-
-    $ 6to5 script.js
-
-Compile the file `script.js` and output it to `script-compiled.js`.
-
-    $ 6to5 script.js --out-file script-compiled.js
-
-Compile the file `script.js` and output it to `script-compiled.js` and save a
-source map to `script-compiled.js.map`.
-
-    $ 6to5 script.js --source-maps --out-file script-compiled.js
-
-Compile the file `script.js` and output it to `script-compiled.js` with a source
-map embedded in a comment at the bottom.
-
-    $ 6to5 script.js --source-maps-inline --out-file script-compiled.js
-
-Compile the entire `src` directory and output it to the `lib` directory.
-
-    $ 6to5 src --out-dir lib
-
-Compile the entire `src` directory and output it to the one concatenated file.
-
-    $ 6to5 src --out-file script-compiled.js
-
-Pipe a file in via stdin and output it to `script-compiled.js`
-
-    $ 6to5 --out-file script-compiled.js < script.js
-
-#### Node
-
-Launch a repl.
-
-    $ 6to5-node
-
-Evaluate code.
-
-    $ 6to5-node -e "class Test { }"
-
-Compile and run `test.js`.
-
-    $ 6to5-node test
-
-### Node
-
-```javascript
-var to5 = require("6to5");
-
-var result = to5.transform("code();", options);
-result.code;
-result.map;
-result.ast;
-
-to5.transformFileSync("filename.js", options).code;
-
-to5.transformFile("filename.js", options, function (err, result) {
-
-});
-```
-
-##### Options
-
-```javascript
-{
-  // Filename for use in errors etc.
-  // Default: "unknown"
-  filename: "filename",
-
-  // List of transformers to EXCLUDE.
-  // Run `6to5 --help` to see a full list of transformers.
-  blacklist: [],
-
-  // List of transformers to ONLY use.
-  // Run `6to5 --help` to see a full list of transformers.
-  whitelist: [],
-
-  // Module formatter to use
-  // Run `6to5 --help` to see a full list of module formatters.
-  // Default: "common"
-  modules: "common",
-
-  // If truthy, adds a `map` property to returned output.
-  // If set to "inline", a comment with a sourceMappingURL directive is added to
-  // the bottom of the returned code.
-  // Default: false
-  sourceMap: true,
-
-  // Set `file` on returned source map.
-  // Default: `filename` option.
-  sourceMapName: "filename",
-
-  // Set `sources[0]` on returned source map.
-  // Default: `filename` option.
-  sourceFileName: "filename",
-
-  // Optionally replace all 6to5 helper declarations with a referenece to this
-  // variable. If set to `true` then the default namespace is used "to5Runtime".
-  // Default: false
-  runtime: true
-}
-```
-
-#### Require hook
-
-All subsequent files required by node with the extensions `.es6` and `.js` will
-be transformed by 6to5. The polyfill specified in [Polyfill](#polyfill) is also
-required.
-
-```javascript
-require("6to5/register");
-```
-
-**NOTE:** By default all requires to `node_modules` will be ignored. You can
-override this by passing an ignore regex via:
-
-```javascript
-require("6to5/register")({
-  // This will override `node_modules` ignoring - you can alternatively pass
-  // a regex
-  ignore: false
-});
-```
-
-##### Options
-
-```javascript
-require("6to5/register")({
-  // Optional ignore regex - if any filenames **do** match this regex then they
-  // aren't compiled
-  ignore: /regex/,
-
-  // Optional only regex - if any filenames **don't** match this regex then they
-  // aren't compiled
-  only: /my_es6_folder/,
-
-  // See options above for usage
-  whitelist: [],
-  blacklist: [],
-
-  // This will remove the currently hooked extensions of .es6 and .js so you'll
-  // have to add them back if you want them to be used again.
-  extensions: [".js", ".es6"]
-});
-```
-
-### Browser
-
-A browser version of 6to5 is available from `browser.js` inside the 6to5
-directory in an npm release.
-
-#### Scripts
-
-While it's not recommended for serious use, when the browser version is included
-all scripts with the type `text/ecmascript-6` and `text/6to5` are automatically
-compiled and ran.
-
-For example:
-
-```html
-<script src="node_modules/6to5/browser.js"></script>
-<script type="text/6to5">
-class Test {
-  test() {
-    return "test";
-  }
-}
-
-var test = new Test;
-test.test();
-</script>
-```
-
-#### Build
-
-You can build a browser version of the compiler by running the following in the
-6to5 directory:
-
-    $ make build
-
-This will output the files `dist/6to5.js` and `dist/6to5.min.js`.
-
-#### API
-
-```javascript
-to5.transform("class Test {}").code;
-```
-
-#### Test
-
-To test 6to5 in your browser run:
-
-    $ make test-browser
-
-And open `test/browser.html` in your browser if it doesn't open automatically.
-
-## [Modules](MODULES.md)
-
-See [Modules - Common](MODULES.md#common-default) for documentation on the
-default module formatting.
-
-Alternatively see [Modules](MODULES.md) for all other supported module formatting types.
-
-## Caveats
-
-### For-of
-
-A polyfill is required for for-of functionality that implements `Symbol` and
-adds `prototype[Symbol.iterator]` behaviour to built-ins. Using the polyfills
-specified in [polyfill](#polyfill) suffices.
-
-### Classes
-
-Built-in classes such as `Date`, `Array` and `DOM` cannot be subclassed due to
-limitations in ES5 implementations.
-
-If you're inheriting from a class then static properties are inherited from it
-via [\_\_proto\_\_](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/proto),
-this is widely supported but you may run into problems with much older browsers.
-
-**NOTE:** `__proto__` is not supported on IE <= 9 so static properties
-**will not** be inherited. A possible workaround is to use `super();`:
-
-```javascript
-class Foo {
-  static foo() {
-
-  }
-}
-
-class Bar extends Foo {
-  static foo() {
-    super();
-  }
-}
-```
-
-### Generators
-
-The [regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js)
-and an [ES6 polyfill](#polyfill) are required in order for generators to work.
-
-## Polyfill
-
-6to5 includes a polyfill that includes the
-[regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js) and the
-[es6-shim](https://github.com/paulmillr/es6-shim) and
-[es6-symbol](https://github.com/medikoo/es6-symbol) polyfills.
-
-### Node
-
-```javascript
-require("6to5/polyfill");
-```
-
-### Browser
-
-Available from the `browser-polyfill.js` file within the 6to5 directory of an
-npm release.
-
-## Optional runtime
-
-6to5 has a few helper functions that'll be placed at the top of the generated
-code if needed so it's not inlined multiple times throughout that file. This may
-become an issue if you have multiple files, especially when you're sending them
-to the browser. gzip alleviates most of this concern but it's still not ideal.
-
-You can tell 6to5 to not place any declarations at the top of your files and
-instead just point them to a reference contained within the runtime.
-
-Simply use the following option if you're using the [Node API](#node-1):
-
-```javascript
-{
-  runtime: true
-}
-```
-
-or the following flag if you're using the [CLI](#cli):
-
-    $ 6to5 --runtime
-
-Then just include the runtime before your generated code.
-
-### Getting the runtime
-
-You can get the runtime via either:
-
-    $ 6to5-runtime
-
-or
-
-```javascript
-require("6to5").runtime();
-```
-
-or from an npm release in `runtime.js` from the 6to5 directory.
-
-### Customising namespace
-
-You can also customise the runtime namespace by passing an optional namespace
-argument:
-
-```javascript
-require("6to5").runtime("myCustomNamespace");
-```
-
-    $ 6to5-runtime myCustomNamespace
-
-See [Options - runtime](#options) for documentation on changing the reference in
-generated code.
-
-## React/JSX
-
-6to5 has built-in support for React v0.12. Tags are automatically transformed to
-their equivalent `React.createElement(...)` and `displayName` is automatically
-inferred and added to all `React.createClass` calls.
-
-To disable this behaviour add `react` to your blacklist.
-
-## Differences
-
-### Philosophy
-
-The fundamental concept behind 6to5 is that the generated code must be close as
-possible to the original, retaining all the same formatting and readability.
-
-Many other transpilers are just concerned with making the code work while 6to5
-is concerned with making sure it works **and** is readable at the same time.
-
-For example, given the following array comprehension:
-
-```javascript
-var seattlers = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }];
-```
-
-is generated to the following with 6to5:
-
-```javascript
-var seattlers = customers.filter(function (c) {
-  return c.city == "Seattle";
-}).map(function (c) {
-  return {
-    name: c.name,
-    age: c.age
-  };
-});
-```
-
-The following is what Traceur generates:
-
-```javascript
-var seattlers = (function() {
-  var c;
-  var $__20 = 0,
-      $__21 = [];
-  for (var $__22 = customers[$traceurRuntime.toProperty(Symbol.iterator)](),
-      $__23; !($__23 = $__22.next()).done; ) {
-    c = $__23.value;
-    if (c.city == "Seattle")
-      $traceurRuntime.setProperty($__21, $__20++, {
-        name: c.name,
-        age: c.age
-      });
-  }
-  return $__21;
-}());
-```
-
-As you can tell, it's not very pretty, unreadable even. Instead of mapping
-directly to a runtime, like other transpilers, 6to5 maps directly to the
-equivalent ES5.
-
-I'm not saying 6to5 is for everyone or even suited for everything. Traceur is
-better suited if you'd like a full ES6 environment with polyfills and all.
-
-### Comparison to other transpilers
-
-|                              | 6to5 | Traceur | esnext | es6now | es6-transpiler | jstransform |
-| ---------------------------- | ---- | ------- | ------ | ------ | -------------- | ----------- |
-| No runtime                   | ✓    |         |        |        | ✓              | ✓           |
-| Source maps                  | ✓    | ✓       | ✓      |        | ✓              | ✓           |
-| No compiler global pollution | ✓    |         | ✓      |        | ✓              | ✓           |
-| Arrow functions              | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Classes                      | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Computed property names      | ✓    | ✓       | ✓      | ✓      | ✓              |             |
-| Constants                    | ✓    | ✓       |        |        | ✓              |             |
-| Default parameters           | ✓    | ✓       | ✓      | ✓      | ✓              |             |
-| Destructuring                | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| For-of                       | ✓    | ✓       | ✓      | ✓      | ✓              |             |
-| Generators                   | ✓    | ✓       | ✓      |        |                |             |
-| Let scoping                  | ✓    | ✓       |        |        | ✓              |             |
-| Modules                      | ✓    | ✓       |        | ✓      |                |             |
-| Property method assignment   | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Property name shorthand      | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Rest parameters              | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Spread                       | ✓    | ✓       | ✓      | ✓      | ✓              |             |
-| Template literals            | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
-| Unicode regex                | ✓    | ✓       |        |        | ✓              |             |
-
-#### [Traceur](https://github.com/google/traceur-compiler)
-
-Traceur requires quite a bulky runtime (~75KB) and produces quite verbose code.
-While this can be trimmed down by selectively building the runtime, it's an
-unneccesary step when a runtime can be eliminated entirely.
-
-#### [es6now](https://github.com/zenparsing/es6now)
-
-es6now doesn't output sourcemaps. This is cited as a positive as line-to-line
-mapping is the goal. This however obviously doesn't retain column mapping
-resulting in the output code not being very pleasant.
-
-#### [es6-transpiler](https://github.com/termi/es6-transpiler)
-
-The es6-transpiler compiler requires shims to operate which pollutes the global
-scope resulting in possible collisions.
-
-es6-transpiler maps line-by-line, just like es6now, this results in the same
-issues such as lack of column information and unpleasant code output.
+For more information view the [documentation](https://6to5.github.io).

bin/6to5/dir.js

@@ -19,7 +19,9 @@ module.exports = function (commander, filenames, opts) {
     mkdirp.sync(up);
 
     if (commander.sourceMaps) {
-      fs.writeFileSync(dest + ".map", JSON.stringify(data.map));
+      var mapLoc = dest + ".map";
+      data.code = util.addSourceMappingUrl(data.code, mapLoc);
+      fs.writeFileSync(mapLoc, JSON.stringify(data.map));
     }
 
     fs.writeFileSync(dest, data.code);

bin/6to5/file.js

@@ -56,7 +56,9 @@ module.exports = function (commander, filenames) {
 
     if (commander.outFile) {
       if (commander.sourceMaps) {
-        fs.writeFileSync(commander.outFile + ".map", JSON.stringify(result.map));
+        var mapLoc = commander.outFile + ".map";
+        result.code = util.addSourceMappingUrl(result.code, mapLoc);
+        fs.writeFileSync(mapLoc, JSON.stringify(result.map));
       }
 
       fs.writeFileSync(commander.outFile, result.code);

bin/6to5/index.js

@@ -17,6 +17,7 @@ commander.option("-w, --whitelist [whitelist]", "Whitelist of transformers to ON
 commander.option("-b, --blacklist [blacklist]", "Blacklist of transformers to NOT use", util.list);
 commander.option("-o, --out-file [out]", "Compile all input files into a single file");
 commander.option("-d, --out-dir [out]", "Compile an input directory of modules into an output directory");
+commander.option("-c, --remove-comments", "Remove comments from the compiled code", false);
 
 commander.on("--help", function(){
   var outKeys = function (title, obj) {
@@ -88,6 +89,7 @@ exports.opts = {
   blacklist:     commander.blacklist,
   whitelist:     commander.whitelist,
   sourceMap:     commander.sourceMaps || commander.sourceMapsInline,
+  comments:      !commander.removeComments,
   runtime:       commander.runtime,
   modules:       commander.modules
 };

bin/6to5/util.js

@@ -1,6 +1,7 @@
 var readdir = require("fs-readdir-recursive");
 var index   = require("./index");
 var util    = require("../../lib/6to5/util");
+var path    = require("path");
 var to5     = require("../../lib/6to5");
 var fs      = require("fs");
 var _       = require("lodash");
@@ -11,6 +12,10 @@ exports.readdirFilter = function (filename) {
   });
 };
 
+exports.addSourceMappingUrl = function (code, loc) {
+  return code + "\n//# sourceMappingURL=" + path.basename(loc);
+};
+
 exports.transform = function (filename, code, opts) {
   opts = _.extend(opts || {}, index.opts);
   opts.filename = filename;

bin/_6to5-node

@@ -1,10 +1,10 @@
 #!/usr/bin/env node
 
 var commander = require("commander");
-var util      = require("../lib/6to5/util");
 var path      = require("path");
 var repl      = require("repl");
 var to5       = require("../lib/6to5");
+var util      = require("../lib/6to5/util");
 var vm        = require("vm");
 var _         = require("lodash");
 

doc/browser.md

@@ -0,0 +1,61 @@
+# Browser
+
+A browser version of 6to5 is available from `browser.js` inside the 6to5
+directory in an npm release.
+
+## Scripts
+
+While it's not recommended for serious use, when the browser version is included
+all scripts with the type `text/ecmascript-6` and `text/6to5` are automatically
+compiled and ran.
+
+For example:
+
+```html
+<script src="node_modules/6to5/browser.js"></script>
+<script type="text/6to5">
+class Test {
+  test() {
+    return "test";
+  }
+}
+
+var test = new Test;
+test.test();
+</script>
+```
+
+## Build
+
+You can build a browser version of the compiler by running the following in the
+6to5 directory:
+
+    $ make build
+
+This will output the files `dist/6to5.js` and `dist/6to5.min.js`.
+
+## Test
+
+To test 6to5 in your browser run:
+
+    $ make test-browser
+
+And open `test/browser.html` in your browser if it doesn't open automatically.
+
+## API
+
+### to5.transform(code, [opts])
+
+See [options](usage.md#options) for additional documentation.
+
+```javascript
+to5.transform("class Test {}").code;
+```
+
+### to5.run(code, [opts])
+
+See [options](usage.md#options) for additional documentation.
+
+```javascript
+to5.run("class Test {}");
+```

doc/caveats.md

@@ -0,0 +1,43 @@
+# Caveats
+
+## Async/Generators
+
+The [regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js)
+and an [ES6 polyfill](polyfill.md) are required in order for generators to work.
+
+## Classes
+
+Built-in classes such as `Date`, `Array` and `DOM` cannot be subclassed due to
+limitations in ES5 implementations.
+
+If you're inheriting from a class then static properties are inherited from it
+via [\_\_proto\_\_](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/proto),
+this is widely supported but you may run into problems with much older browsers.
+
+**NOTE:** `__proto__` is not supported on IE <= 9 so static properties
+**will not** be inherited. A possible workaround is to use `super();`:
+
+```javascript
+class Foo {
+  static foo() {
+
+  }
+}
+
+class Bar extends Foo {
+  static foo() {
+    super();
+  }
+}
+```
+
+## For-of
+
+A polyfill is required for for-of functionality that implements `Symbol` and
+adds `prototype[Symbol.iterator]` behaviour to built-ins. Using the polyfills
+specified in [polyfill](polyfill.md) suffices.
+
+## Spread
+
+An [ES6 polyfill](polyfill.md) is required in order for spread to work. More
+specifically a polyfill for `Array.from`.

doc/differences.md

@@ -0,0 +1,103 @@
+# Differences
+
+## Philosophy
+
+The fundamental concept behind 6to5 is that the generated code must be close as
+possible to the original, retaining all the same formatting and readability.
+
+Many other transpilers are just concerned with making the code work while 6to5
+is concerned with making sure it works **and** is readable at the same time.
+
+For example, given the following array comprehension:
+
+```javascript
+var seattlers = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }];
+```
+
+is generated to the following with 6to5:
+
+```javascript
+var seattlers = customers.filter(function (c) {
+  return c.city == "Seattle";
+}).map(function (c) {
+  return {
+    name: c.name,
+    age: c.age
+  };
+});
+```
+
+The following is what Traceur generates:
+
+```javascript
+var seattlers = (function() {
+  var c;
+  var $__20 = 0,
+      $__21 = [];
+  for (var $__22 = customers[$traceurRuntime.toProperty(Symbol.iterator)](),
+      $__23; !($__23 = $__22.next()).done; ) {
+    c = $__23.value;
+    if (c.city == "Seattle")
+      $traceurRuntime.setProperty($__21, $__20++, {
+        name: c.name,
+        age: c.age
+      });
+  }
+  return $__21;
+}());
+```
+
+As you can tell, it's not very pretty, unreadable even. Instead of mapping
+directly to a runtime, like other transpilers, 6to5 maps directly to the
+equivalent ES5.
+
+I'm not saying 6to5 is for everyone or even suited for everything. Traceur is
+better suited if you'd like a full ES6 environment with polyfills and all.
+
+## Comparison to other transpilers
+
+|                              | 6to5 | Traceur | esnext | es6now | es6-transpiler | jstransform |
+| ---------------------------- | ---- | ------- | ------ | ------ | -------------- | ----------- |
+| No runtime                   | ✓    |         |        |        | ✓              | ✓           |
+| Source maps                  | ✓    | ✓       | ✓      |        | ✓              | ✓           |
+| No compiler global pollution | ✓    |         | ✓      |        | ✓              | ✓           |
+| Browser support              | ✓    | ✓       | ✓      |        |                |             |
+| Array comprehension          | ✓    | ✓       |        |        | ✓              |             |
+| Arrow functions              | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Async functions              | ✓    | ✓       | ✓      |        |                |             |
+| Classes                      | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Computed property names      | ✓    | ✓       | ✓      | ✓      | ✓              |             |
+| Constants                    | ✓    | ✓       |        |        | ✓              |             |
+| Default parameters           | ✓    | ✓       | ✓      | ✓      | ✓              |             |
+| Destructuring                | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| For-of                       | ✓    | ✓       | ✓      | ✓      | ✓              |             |
+| Generators                   | ✓    | ✓       | ✓      |        |                |             |
+| Generator comprehension      | ✓    | ✓       |        |        |                |             |
+| Let scoping                  | ✓    | ✓       |        |        | ✓              |             |
+| Modules                      | ✓    | ✓       |        | ✓      |                |             |
+| Property method assignment   | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Property name shorthand      | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Rest parameters              | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Spread                       | ✓    | ✓       | ✓      | ✓      | ✓              |             |
+| Template literals            | ✓    | ✓       | ✓      | ✓      | ✓              | ✓           |
+| Unicode regex                | ✓    | ✓       |        |        | ✓              |             |
+
+### [Traceur](https://github.com/google/traceur-compiler)
+
+Traceur requires quite a bulky runtime (~75KB) and produces quite verbose code.
+While this can be trimmed down by selectively building the runtime, it's an
+unneccesary step when a runtime can be eliminated entirely.
+
+### [es6now](https://github.com/zenparsing/es6now)
+
+es6now doesn't output sourcemaps. This is cited as a positive as line-to-line
+mapping is the goal. This however obviously doesn't retain column mapping
+resulting in the output code not being very pleasant.
+
+### [es6-transpiler](https://github.com/termi/es6-transpiler)
+
+The es6-transpiler compiler requires shims to operate which pollutes the global
+scope resulting in possible collisions.
+
+es6-transpiler maps line-by-line, just like es6now, this results in the same
+issues such as lack of column information and unpleasant code output.

doc/features.md

@@ -3,7 +3,32 @@
 ## Array comprehension
 
 ```javascript
-[for (i of [1, 2, 3]) i * i]; // [1, 4, 9]
+var results = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }]
+```
+
+## Arrow functions
+
+```javascript
+// Expression bodies
+var odds = evens.map(v => v + 1);
+var nums = evens.map((v, i) => v + i);
+
+// Statement bodies
+nums.forEach(v => {
+  if (v % 5 === 0)
+    fives.push(v);
+});
+
+// Lexical this
+var bob = {
+  _name: "Bob",
+  _friends: [],
+  printFriends() {
+    this._friends.forEach(f => {
+      console.log(this._name + " knows " + f);
+    });
+  }
+};
 ```
 
 ## Async functions
@@ -16,31 +41,27 @@ async function chainAnimationsAsync(elem, animations) {
 }
 ```
 
-## Arrow functions
-
-```javascript
-arr.map(x => x * x);
-```
-
-## Let scoping
-
-```javascript
-for (let i in arr) {
-  let v = arr[i];
-}
-```
-
 ## Classes
 
 ```javascript
-class Foo extends Bar {
-  constructor() { }
+class SkinnedMesh extends THREE.Mesh {
+  constructor(geometry, materials) {
+    super(geometry, materials);
 
-  foo() { }
+    this.idMatrix = SkinnedMesh.defaultMatrix();
+    this.bones = [];
+    this.boneMatrices = [];
+    //...
+  }
 
-  get bar() { }
+  update(camera) {
+    //...
+    super.update();
+  }
 
-  set bar() { }
+  static defaultMatrix() {
+    return new THREE.Matrix4();
+  }
 }
 ```
 
@@ -70,16 +91,35 @@ var MULTIPLIER; // error
 ## Default parameters
 
 ```javascript
-function foo(bar = "foo") {
-  return bar + "bar";
+function f(x, y = 12) {
+  // y is 12 if not passed (or passed as undefined)
+  return x + y;
 }
+f(3) == 15
 ```
 
 ## Destructuring
 
 ```javascript
-var [a, [b], c, d] = ["hello", [", ", "junk"], ["world"]];
-console.log(a + b + c); // hello, world
+// list matching
+var [a, , b] = [1,2,3];
+
+// object matching
+var { op: a, lhs: { op: b }, rhs: c } = getASTNode();
+
+// object matching shorthand
+// binds `op`, `lhs` and `rhs` in scope
+var { op, lhs, rhs } = getASTNode();
+
+// Can be used in parameter position
+function g({ name: x }) {
+  console.log(x);
+}
+g({ name: 5 });
+
+// Fail-soft destructuring
+var [a] = [];
+a === undefined;
 ```
 
 ## For-of
@@ -93,11 +133,27 @@ for (var i of [1, 2, 3]) {
 ## Generators
 
 ```javascript
+
+```
+
+## Generator comprehension
+
+```javascript
+
+```
+
+## Let scoping
+
+```javascript
+for (let i in arr) {
+  let v = arr[i];
+}
 ```
 
 ## Modules
 
 ```javascript
+
 ```
 
 ## Numeric literals
@@ -136,23 +192,21 @@ function f(x, y) {
 ## Rest parameters
 
 ```javascript
-function printList(name, ...items) {
-  console.log("list %s has the following items", name);
-  items.forEach(function (item) {
-    console.log(item);
-  });
+function f(x, ...y) {
+  // y is an Array
+  return x * y.length;
 }
+f(3, "hello", true) == 6
 ```
 
 ## Spread
 
 ```javascript
-function add(x, y) {
-  return x + y;
+function f(x, y, z) {
+  return x + y + z;
 }
-
-var numbers = [5, 10];
-add(...numbers); // 15
+// Pass each elem of array as argument
+f(...[1,2,3]) == 6
 ```
 
 ## Template literals

doc/index.md

@@ -0,0 +1,54 @@
+**6to5** turns ES6+ code into vanilla ES5, so you can use next generation features **today.**
+
+ - **Readable** - formatting is retained if possible so your generated code is as similar as possible.
+ - **Extensible** - with a large range of [plugins](plugins.md) and **browser support**.
+ - **Lossless** - **source map support** so you can debug your compiled code with ease.
+ - **Compact** - maps directly to the equivalent ES5 with **no runtime**[\*](caveats.md#generators).
+
+## Installation
+
+It's as easy as:
+
+    $ npm install -g 6to5
+
+## Usage
+
+Once you've installed 6to5, there are multiple paths you can take depending on
+how you want to use it.
+
+6to5 will simply compile your ES6+ script to ES5 if you pass it as an argument
+to the command-line tool `6to5`:
+
+    $ 6to5 script.js
+
+If you have a file written using ES6+ and you just want to run it, `6to5-node`
+has you covered:
+
+    $ 6to5-node script.js
+
+And it doesn't end here! To see all the ways you can use 6to5, check out the
+[Usage](http://6to5.github.io/usage.html) page.
+
+## [Features](features.md)
+
+ - [Array comprehension](features.md#array-comprehension)
+ - [Async functions](features.md#async-functions) via [regenerator](https://github.com/facebook/regenerator)
+ - [Arrow functions](features.md#arrow-functions)
+ - [Classes](features.md#classes)
+ - [Computed property names](features.md#computed-property-names)
+ - [Constants](features.md#constants)
+ - [Default parameters](features.md#default-parameters)
+ - [Destructuring](features.md#destructuring)
+ - [For-of](features.md#for-of)
+ - [Generators](features.md#generators) via [regenerator](https://github.com/facebook/regenerator)
+ - [Generator comprehension](features.md#generator-comprehension)
+ - [Let scoping](features.md#let-scoping)
+ - [Modules](features.md#modules)
+ - [Numeric literals](features.md#numeric-literals)
+ - [Property method assignment](features.md#property-method-assignment)
+ - [Property name shorthand](features.md#property-name-shorthand)
+ - [React/JSX](react.md)
+ - [Rest parameters](features.md#rest-parameters)
+ - [Spread](features.md#spread)
+ - [Template literals](features.md#template-literals)
+ - [Unicode regex](features.md#unicode-regex)

doc/modules.md

@@ -66,7 +66,7 @@ export function bar() {
 **Out**
 
 ```javascript
-define(["exports", "foo"], function (exports, _foo) {
+define("filename", ["exports", "foo"], function (exports, _foo) {
   exports.bar = bar;
 
   var foo = _foo.default;
@@ -94,7 +94,7 @@ export function bar() {
 ```javascript
 (function (factory) {
   if (typeof define === "function" && define.amd) {
-    define(["exports", "foo"], factory);
+    define("filename", ["exports", "foo"], factory);
   } else if (typeof exports !== "undefined") {
     factory(exports, require("foo"));
   }
@@ -111,7 +111,6 @@ export function bar() {
 
 ### Ignore
 
-
 **In**
 
 ```javascript

doc/optional-runtime.md

@@ -0,0 +1,51 @@
+# Optional runtime
+
+6to5 has a few helper functions that'll be placed at the top of the generated
+code if needed so it's not inlined multiple times throughout that file. This may
+become an issue if you have multiple files, especially when you're sending them
+to the browser. gzip alleviates most of this concern but it's still not ideal.
+
+You can tell 6to5 to not place any declarations at the top of your files and
+instead just point them to a reference contained within the runtime.
+
+Simply use the following option if you're using the [Node API](usage.md#node):
+
+```javascript
+{
+  runtime: true
+}
+```
+
+or the following flag if you're using the [CLI](usage.md#cli):
+
+    $ 6to5 --runtime
+
+Then just include the runtime before your generated code.
+
+## Getting the runtime
+
+You can get the runtime via either:
+
+    $ 6to5-runtime
+
+or
+
+```javascript
+require("6to5").runtime();
+```
+
+or from an npm release in `runtime.js` from the 6to5 directory.
+
+## Customising namespace
+
+You can also customise the runtime namespace by passing an optional namespace
+argument:
+
+```javascript
+require("6to5").runtime("myCustomNamespace");
+```
+
+    $ 6to5-runtime myCustomNamespace
+
+See [Options - runtime](usage.md#options) for documentation on changing the
+reference in generated code.

doc/plugins.md

@@ -0,0 +1,17 @@
+# Plugins
+
+ - [Broccoli](https://github.com/very-geek/broccoli-6to5-transpiler)
+ - [Browserify](https://github.com/6to5/6to5-browserify)
+ - [Brunch](https://github.com/es128/6to5-brunch)
+ - [Duo](https://github.com/bdo-labs/duo6to5)
+ - [Connect](https://github.com/6to5/6to5-connect)
+ - [Gobble](https://github.com/gobblejs/gobble-6to5)
+ - [Gulp](https://github.com/sindresorhus/gulp-6to5)
+ - [Grunt](https://github.com/sindresorhus/grunt-6to5)
+ - [Jade](https://github.com/Apoxx/jade-6to5)
+ - [Jest](https://github.com/6to5/6to5-jest)
+ - [JSXHint](https://github.com/STRML/JSXHint) (A wrapper around JSHint to allow linting of JSX files)
+ - [Karma](https://github.com/shuhei/karma-6to5-preprocessor)
+ - [Mocha](https://github.com/6to5/6to5-mocha)
+ - [Rails](https://github.com/josh/sprockets-es6) or via [browserify-rails](https://github.com/6to5/6to5-rails)
+ - [webpack](https://github.com/Couto/6to5-loader)

doc/polyfill.md

@@ -0,0 +1,17 @@
+# Polyfill
+
+6to5 includes a polyfill that includes the
+[regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js) and the
+[es6-shim](https://github.com/paulmillr/es6-shim) and
+[es6-symbol](https://github.com/medikoo/es6-symbol) polyfills.
+
+## Node
+
+```javascript
+require("6to5/polyfill");
+```
+
+## Browser
+
+Available from the `browser-polyfill.js` file within the 6to5 directory of an
+npm release.

doc/react.md

@@ -0,0 +1,16 @@
+# React/JSX
+
+6to5 has built-in support for React v0.12. Tags are automatically transformed to
+their equivalent `React.createElement(...)` and `displayName` is automatically
+inferred and added to all `React.createClass` calls.
+
+## Blacklist
+
+To disable this behaviour add `react` to your blacklist:
+
+```javascript
+to5.transform("code", { blacklist: ["react"] });
+```
+
+
+    $ 6to5 --blacklist react

doc/usage.md

@@ -0,0 +1,176 @@
+# Usage
+
+## CLI
+
+Compile the file `script.js` and output it to stdout.
+
+    $ 6to5 script.js
+
+Compile the file `script.js` and output it to `script-compiled.js`.
+
+    $ 6to5 script.js --out-file script-compiled.js
+
+Compile the file `script.js` and output it to `script-compiled.js` and save a
+source map to `script-compiled.js.map`.
+
+    $ 6to5 script.js --source-maps --out-file script-compiled.js
+
+Compile the file `script.js` and output it to `script-compiled.js` with a source
+map embedded in a comment at the bottom.
+
+    $ 6to5 script.js --source-maps-inline --out-file script-compiled.js
+
+Compile the entire `src` directory and output it to the `lib` directory.
+
+    $ 6to5 src --out-dir lib
+
+Compile the entire `src` directory and output it to the one concatenated file.
+
+    $ 6to5 src --out-file script-compiled.js
+
+Pipe a file in via stdin and output it to `script-compiled.js`
+
+    $ 6to5 --out-file script-compiled.js < script.js
+
+### Node
+
+Launch a repl.
+
+    $ 6to5-node
+
+Evaluate code.
+
+    $ 6to5-node -e "class Test { }"
+
+Compile and run `test.js`.
+
+    $ 6to5-node test
+
+## Node
+
+```javascript
+var to5 = require("6to5");
+```
+
+### to5.transform(code, [opts]);
+
+```javascript
+var result = to5.transform("code();", options);
+result.code;
+result.map;
+result.ast;
+```
+
+### to5.transformFileSync(filename, [opts])
+
+```javascript
+to5.transformFileSync("filename.js", options).code;
+```
+
+### to5.transformFile(filename, [opts], callback)
+
+```javascript
+to5.transformFile("filename.js", options, function (err, result) {
+  result.code;
+});
+```
+
+#### Options
+
+```javascript
+{
+  // Filename for use in errors etc.
+  // Default: "unknown"
+  filename: "filename",
+
+  // Filename relative to `sourceRoot`
+  // Default: `filename` option.
+  filenameRelative: "",
+
+  // List of transformers to EXCLUDE.
+  // Run `6to5 --help` to see a full list of transformers.
+  blacklist: [],
+
+  // List of transformers to ONLY use.
+  // Run `6to5 --help` to see a full list of transformers.
+  whitelist: [],
+
+  // Module formatter to use
+  // Run `6to5 --help` to see a full list of module formatters.
+  // Default: "common"
+  modules: "common",
+
+  // If truthy, adds a `map` property to returned output.
+  // If set to "inline", a comment with a sourceMappingURL directive is added to
+  // the bottom of the returned code.
+  // Default: false
+  sourceMap: true,
+
+  // Set `file` on returned source map.
+  // Default: `filenameRelative` option.
+  sourceMapName: "filename",
+
+  // Set `sources[0]` on returned source map.
+  // Default: `filenameRelative` option.
+  sourceFileName: "filename",
+
+  // The root from which all sources are relative
+  sourceRoot: "assets/scripts",
+
+  // Optional prefix for the AMD module formatter that will be prepend to the
+  // filename on module definitions
+  moduleRoot: "my-app",
+
+  // Optionally replace all 6to5 helper declarations with a referenece to this
+  // variable. If set to `true` then the default namespace is used "to5Runtime".
+  // Default: false
+  runtime: true,
+
+  // Output comments in generated output
+  // Default: true
+  comments: false
+}
+```
+
+### Require hook
+
+All subsequent files required by node with the extensions `.es6` and `.js` will
+be transformed by 6to5. The polyfill specified in [Polyfill](polyfill.md) is
+also required.
+
+```javascript
+require("6to5/register");
+```
+
+**NOTE:** By default all requires to `node_modules` will be ignored. You can
+override this by passing an ignore regex via:
+
+```javascript
+require("6to5/register")({
+  // This will override `node_modules` ignoring - you can alternatively pass
+  // a regex
+  ignore: false
+});
+```
+
+#### Options
+
+```javascript
+require("6to5/register")({
+  // Optional ignore regex - if any filenames **do** match this regex then they
+  // aren't compiled
+  ignore: /regex/,
+
+  // Optional only regex - if any filenames **don't** match this regex then they
+  // aren't compiled
+  only: /my_es6_folder/,
+
+  // See options above for usage
+  whitelist: [],
+  blacklist: [],
+
+  // This will remove the currently hooked extensions of .es6 and .js so you'll
+  // have to add them back if you want them to be used again.
+  extensions: [".js", ".es6"]
+});
+```

lib/6to5/browser.js

@@ -2,13 +2,6 @@ var transform = module.exports = require("./transformation/transform");
 
 transform.transform = transform;
 
-transform.eval = function (code, opts) {
-  opts = opts || {};
-  opts.filename = opts.filename || "eval";
-  opts.sourceMap = "inline";
-  return eval(transform(code, opts).code);
-};
-
 transform.run = function (code, opts) {
   opts = opts || {};
   opts.sourceMap = "inline";
@@ -19,7 +12,7 @@ transform.load = function (url, callback, opts, hold) {
   opts = opts || {};
   opts.filename = opts.filename || url;
 
-  var xhr = window.ActiveXObject ? new window.ActiveXObject("Microsoft.XMLHTTP") : new window.XMLHttpRequest();
+  var xhr = global.ActiveXObject ? new global.ActiveXObject("Microsoft.XMLHTTP") : new global.XMLHttpRequest();
   xhr.open("GET", url, true);
   if ("overrideMimeType" in xhr) xhr.overrideMimeType("text/plain");
 
@@ -67,7 +60,7 @@ var runScripts = function () {
     }
   };
 
-  var _scripts = window.document.getElementsByTagName("script");
+  var _scripts = global.document.getElementsByTagName("script");
   for (var i in _scripts) {
     var _script = _scripts[i];
     if (types.indexOf(_script.type) >= 0) scripts.push(_script);
@@ -80,8 +73,8 @@ var runScripts = function () {
   exec();
 };
 
-if (window.addEventListener) {
-  window.addEventListener("DOMContentLoaded", runScripts, false);
-} else {
-  window.attachEvent("onload", runScripts);
+if (global.addEventListener) {
+  global.addEventListener("DOMContentLoaded", runScripts, false);
+} else if (global.attachEvent) {
+  global.attachEvent("onload", runScripts);
 }

lib/6to5/file.js

@@ -18,7 +18,8 @@ function File(opts) {
   this.ast          = {};
 }
 
-File.declarations = ["extends", "class-props", "slice"];
+File.declarations = ["extends", "class-props", "slice", "apply-constructor",
+                     "tagged-template-literal"];
 
 File.normaliseOptions = function (opts) {
   opts = _.cloneDeep(opts || {});
@@ -28,17 +29,23 @@ File.normaliseOptions = function (opts) {
     blacklist:  [],
     whitelist:  [],
     sourceMap:  false,
+    comments:   true,
     filename:   "unknown",
     modules:    "common",
-    runtime:    false
+    runtime:    false,
+    code:       true
   });
 
   // normalise windows path separators to unix
   opts.filename = opts.filename.replace(/\\/g, "/");
 
   _.defaults(opts, {
-    sourceFileName: opts.filename,
-    sourceMapName:  opts.filename
+    filenameRelative: opts.filename
+  });
+
+  _.defaults(opts, {
+    sourceFileName: opts.filenameRelative,
+    sourceMapName:  opts.filenameRelative
   });
 
   if (opts.runtime === true) {
@@ -142,6 +149,14 @@ File.prototype.generate = function () {
   var opts = this.opts;
   var ast  = this.ast;
 
+  if (!opts.code) {
+    return {
+      code: "",
+      map:  null,
+      ast:  ast
+    };
+  }
+
   var result = generate(ast, opts, this.code);
 
   if (this.shebang) {
@@ -153,6 +168,8 @@ File.prototype.generate = function () {
     result.code += "\n" + util.sourceMapToComment(result.map);
   }
 
+  result.ast = result;
+
   return result;
 };
 

lib/6to5/generation/buffer.js

@@ -76,6 +76,8 @@ Buffer.prototype.newline = function (i, removeLast) {
   }
 
   if (_.isNumber(i)) {
+    if (this.endsWith(util.repeat(i, "\n"))) return;
+
     var self = this;
     _.times(i, function () {
       self.newline(null, removeLast);
@@ -86,7 +88,7 @@ Buffer.prototype.newline = function (i, removeLast) {
   if (removeLast && this.isLast("\n")) this.removeLast("\n");
 
   this.removeLast(" ");
-  this.buf = this.buf.replace(/\n(\s+)$/, "\n");
+  this.buf = this.buf.replace(/\n +$/, "\n");
   this._push("\n");
 };
 

lib/6to5/generation/generator.js

@@ -35,34 +35,30 @@ _.each(Buffer.prototype, function (fn, key) {
 });
 
 CodeGenerator.normaliseOptions = function (opts) {
-  opts = opts.format || {};
-
-  opts = _.merge({
+  return _.merge({
     parentheses: true,
     semicolons: true,
-    comments: true,
+    comments: opts.comments == null || opts.comments,
     compact: false,
     indent: {
       adjustMultilineComment: true,
       style: "  ",
       base: 0
     }
-  }, opts);
-
-  return opts;
+  }, opts.format || {});
 };
 
 CodeGenerator.generators = {
-  arrayComprehensions: require("./generators/array-comprehensions"),
-  templateLiterals:    require("./generators/template-literals"),
-  expressions:         require("./generators/expressions"),
-  statements:          require("./generators/statements"),
-  classes:             require("./generators/classes"),
-  methods:             require("./generators/methods"),
-  modules:             require("./generators/modules"),
-  types:               require("./generators/types"),
-  base:                require("./generators/base"),
-  jsx:                 require("./generators/jsx")
+  templateLiterals: require("./generators/template-literals"),
+  comprehensions:   require("./generators/comprehensions"),
+  expressions:      require("./generators/expressions"),
+  statements:       require("./generators/statements"),
+  classes:          require("./generators/classes"),
+  methods:          require("./generators/methods"),
+  modules:          require("./generators/modules"),
+  types:            require("./generators/types"),
+  base:             require("./generators/base"),
+  jsx:              require("./generators/jsx")
 };
 
 _.each(CodeGenerator.generators, function (generator) {
@@ -76,7 +72,6 @@ CodeGenerator.prototype.generate = function () {
 
   return {
     map:  this.map.get(),
-    ast:  ast,
     code: this.buffer.get()
   };
 };
@@ -116,8 +111,6 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
   opts = opts || {};
 
   var newline = function (leading) {
-    var ignoreDuplicates = false;
-
     if (!opts.statement && !n.isUserWhitespacable(node, parent)) {
       return;
     }
@@ -140,7 +133,7 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
       lines += needs(node, parent);
     }
 
-    self.newline(lines, ignoreDuplicates);
+    self.newline(lines);
   };
 
   if (this[node.type]) {

lib/6to5/generation/generators/classes.js

@@ -30,3 +30,11 @@ exports.ClassBody = function (node, print) {
     this.rightBrace();
   }
 };
+
+exports.MethodDefinition = function (node, print) {
+  if (node.static) {
+    this.push("static ");
+  }
+
+  this._method(node, print);
+};

lib/6to5/generation/generators/comprehensions.js

@@ -8,7 +8,8 @@ exports.ComprehensionBlock = function (node, print) {
 };
 
 exports.ComprehensionExpression = function (node, print) {
-  this.push("[");
+  this.push(node.generator ? "(" : "[");
+
   print.join(node.blocks, { separator: " " });
   this.space();
 
@@ -21,5 +22,6 @@ exports.ComprehensionExpression = function (node, print) {
   }
 
   print(node.body);
-  this.push("]");
+
+  this.push(node.generator ? ")" : "]");
 };

lib/6to5/generation/generators/expressions.js

@@ -1,4 +1,5 @@
-var t = require("../../types");
+var util = require("../../util");
+var t    = require("../../types");
 
 exports.UnaryExpression = function (node, print) {
   var hasSpace = /[a-z]$/.test(node.operator);
@@ -105,6 +106,11 @@ exports.MemberExpression = function (node, print) {
     print(node.property);
     this.push("]");
   } else {
+    // 5..toFixed(2);
+    if (t.isLiteral(node.object) && util.isInteger(node.object.value)) {
+      this.push(".");
+    }
+
     this.push(".");
     print(node.property);
   }

lib/6to5/generation/generators/jsx.js

@@ -74,5 +74,5 @@ exports.XJSClosingElement = function (node, print) {
 };
 
 exports.XJSEmptyExpression = function () {
-  this.push("null");
+
 };

lib/6to5/generation/generators/methods.js

@@ -41,6 +41,8 @@ exports._method = function (node, print) {
     this.push(kind + " ");
   }
 
+  if (value.async) this.push("async ");
+
   if (node.computed) {
     this.push("[");
     print(key);
@@ -54,16 +56,9 @@ exports._method = function (node, print) {
   print(value.body);
 };
 
-exports.MethodDefinition = function (node, print) {
-  if (node.static) {
-    this.push("static ");
-  }
-
-  this._method(node, print);
-};
-
 exports.FunctionDeclaration =
 exports.FunctionExpression = function (node, print) {
+  if (node.async) this.push("async ");
   this.push("function");
   if (node.generator) this.push("*");
   this.space();
@@ -74,6 +69,8 @@ exports.FunctionExpression = function (node, print) {
 };
 
 exports.ArrowFunctionExpression = function (node, print) {
+  if (node.async) this.push("async ");
+
   if (node.params.length === 1 && !node.defaults.length && !node.rest && t.isIdentifier(node.params[0])) {
     print(node.params[0]);
   } else {

lib/6to5/generation/generators/modules.js

@@ -25,9 +25,10 @@ exports.ExportDeclaration = function (node, print) {
 
   if (node.declaration) {
     print(node.declaration);
+    if (t.isStatement(node.declaration)) return;
   } else {
     if (specifiers.length === 1 && t.isExportBatchSpecifier(specifiers[0])) {
-      this.push("*");
+      print(specifiers[0]);
     } else {
       this.push("{");
       if (specifiers.length) {

lib/6to5/generation/generators/statements.js

@@ -4,6 +4,7 @@ exports.WithStatement = function (node, print) {
   this.keyword("with");
   this.push("(");
   print(node.object);
+  this.push(")");
   print.block(node.body);
 };
 
@@ -134,15 +135,6 @@ exports.SwitchStatement = function (node, print) {
   this.push(") {");
   print.sequence(node.cases, { indent: true });
   this.push("}");
-
-  //if (node.cases.length) {
-  //  this.newline();
-  //  print.sequence(node.cases, { indent: true });
-  //  this.newline();
-  //  this.rightBrace();
-  //} else {
-  //  this.push("}");
-  //}
 };
 
 exports.SwitchCase = function (node, print) {
@@ -154,13 +146,8 @@ exports.SwitchCase = function (node, print) {
     this.push("default:");
   }
 
-  if (node.consequent.length === 1) {
-    this.space();
-    print(node.consequent[0]);
-  } else if (node.consequent.length > 1) {
-    this.newline();
-    print.sequence(node.consequent, { indent: true });
-  }
+  this.space();
+  print.sequence(node.consequent, { indent: true });
 };
 
 exports.DebuggerStatement = function () {

lib/6to5/generation/generators/types.js

@@ -74,13 +74,20 @@ exports.Literal = function (node) {
   var val  = node.value;
   var type = typeof val;
 
-  if (type === "boolean" || type === "number" || type === "string") {
+  if (type === "string") {
+    val = JSON.stringify(val);
+
+    // escape unicode characters
+    val = val.replace(/[\u007f-\uffff]/g, function(c) {
+      return "\\u" + ("0000" + c.charCodeAt(0).toString(16)).slice(-4);
+    });
+
+    this.push(val);
+  } else if (type === "boolean" || type === "number") {
     this.push(JSON.stringify(val));
   } else if (node.regex) {
     this.push("/" + node.regex.pattern + "/" + node.regex.flags);
   } else if (val === null) {
     this.push("null");
-  } else if (node.raw) {
-    this.push(node.raw);
   }
 };

lib/6to5/generation/node/index.js

@@ -2,8 +2,8 @@ module.exports = Node;
 
 var whitespace = require("./whitespace");
 var parens     = require("./parentheses");
-var t           = require("../../types");
-var _           = require("lodash");
+var t          = require("../../types");
+var _          = require("lodash");
 
 var find = function (obj, node, parent) {
   var result;
@@ -24,17 +24,14 @@ function Node(node, parent) {
 }
 
 Node.prototype.isUserWhitespacable = function () {
-  //var parent = this.parent;
+  var parent = this.parent;
   var node = this.node;
 
-  if (t.isUserWhitespacable(node)) {
+  if (t.isUserWhitespacable(node) ||
+      t.isSequenceExpression(parent)) {
     return true;
   }
 
-  //if (t.isArrayExpression(parent)) {
-  //  return true;
-  //}
-
   return false;
 };
 

lib/6to5/generation/source-map.js

@@ -9,7 +9,8 @@ function SourceMap(position, opts, code) {
 
   if (opts.sourceMap) {
     this.map = new sourceMap.SourceMapGenerator({
-      file: opts.sourceMapName
+      file: opts.sourceMapName,
+      sourceRoot: opts.sourceRoot
     });
 
     this.map.setSourceContent(opts.sourceFileName, code);

lib/6to5/polyfill.js

@@ -3,4 +3,4 @@ if (typeof Symbol === "undefined") {
 }
 
 require("es6-shim");
-require("regenerator-6to5/runtime");
+require("./transformation/transformers/generators/runtime");

lib/6to5/register.js

@@ -36,6 +36,7 @@ var blacklistTest = function (transformer, code) {
 };
 
 blacklistTest("arrayComprehension", "var foo = [for (foo of bar) foo * foo];");
+//blacklistTest("generatorComprehension", "");
 blacklistTest("arrowFunctions", "var foo = x => x * x;");
 blacklistTest("classes", "class Foo {}");
 blacklistTest("computedPropertyNames", "var foo = { [foo]: bar };");

lib/6to5/runtime.js

@@ -5,7 +5,7 @@ var t         = require("./types");
 var _         = require("lodash");
 
 module.exports = function (namespace) {
-  namespace = t.identifier(namespace || "to5Runtime");
+  namespace = t.identifier(t.toIdentifier(namespace || "to5Runtime"));
 
   var body      = [];
   var container = t.functionExpression(null, [], t.blockStatement(body));

lib/6to5/templates/apply-constructor.js

@@ -0,0 +1,5 @@
+(function (Constructor, args) {
+  var bindArgs = [null].concat(args);
+  var Factory = Constructor.bind.apply(Constructor, bindArgs);
+  return new Factory;
+});

lib/6to5/templates/tagged-template-literal.js

@@ -0,0 +1,4 @@
+(function (strings, raw) {
+  return Object.defineProperties(strings, { raw: { value: raw } });
+});
+

lib/6to5/transformation/modules/amd.js

@@ -29,12 +29,41 @@ AMDFormatter.prototype.transform = function (ast) {
   var params = _.values(this.ids);
   params.unshift(t.identifier("exports"));
 
+  var moduleName = this.getModuleName();
+
   var container = t.functionExpression(null, params, t.blockStatement(body));
-  var call = t.callExpression(t.identifier("define"), [names, container]);
+  var call = t.callExpression(t.identifier("define"), [t.literal(moduleName), names, container]);
 
   program.body = [t.expressionStatement(call)];
 };
 
+AMDFormatter.prototype.getModuleName = function () {
+  var opts = this.file.opts;
+  var filenameRelative = opts.filenameRelative;
+  var moduleName = "";
+
+  if (opts.moduleRoot) {
+    moduleName = opts.moduleRoot + "/";
+  }
+
+  if (!opts.filenameRelative) {
+    return moduleName + opts.filename.replace(/^\//, "");
+  }
+
+  if (opts.sourceRoot) {
+    // remove sourceRoot from filename
+    var sourceRootRegEx = new RegExp("^" + opts.sourceRoot + "\/?");
+    filenameRelative = filenameRelative.replace(sourceRootRegEx, "");
+  }
+
+  // remove extension
+  filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
+
+  moduleName += filenameRelative;
+
+  return moduleName;
+};
+
 AMDFormatter.prototype._push = function (node) {
   var id  = node.source.value;
   var ids = this.ids;

lib/6to5/transformation/modules/umd.js

@@ -32,8 +32,10 @@ UMDFormatter.prototype.transform = function (ast) {
 
   // runner
 
+  var moduleName = this.getModuleName();
+
   var runner = util.template("umd-runner-body", {
-    AMD_ARGUMENTS: t.arrayExpression([t.literal("exports")].concat(names)),
+    AMD_ARGUMENTS: [t.literal(moduleName), t.arrayExpression([t.literal("exports")].concat(names))],
 
     COMMON_ARGUMENTS: names.map(function (name) {
       return t.callExpression(t.identifier("require"), [name]);

lib/6to5/transformation/transform.js

@@ -27,36 +27,39 @@ transform.moduleFormatters = {
 };
 
 _.each({
-  modules:                  require("./transformers/modules"),
-  propertyNameShorthand:    require("./transformers/property-name-shorthand"),
-  constants:                require("./transformers/constants"),
-  arrayComprehension:       require("./transformers/array-comprehension"),
-  arrowFunctions:           require("./transformers/arrow-functions"),
-  classes:                  require("./transformers/classes"),
+  modules:                   require("./transformers/modules"),
+  propertyNameShorthand:     require("./transformers/property-name-shorthand"),
+  arrayComprehension:        require("./transformers/array-comprehension"),
+  generatorComprehension:    require("./transformers/generator-comprehension"),
+  arrowFunctions:            require("./transformers/arrow-functions"),
+  classes:                   require("./transformers/classes"),
 
-  _propertyLiterals:        require("./transformers/_property-literals"),
-  computedPropertyNames:    require("./transformers/computed-property-names"),
+  _propertyLiterals:         require("./transformers/_property-literals"),
+  computedPropertyNames:     require("./transformers/computed-property-names"),
 
-  spread:                   require("./transformers/spread"),
-  templateLiterals:         require("./transformers/template-literals"),
-  propertyMethodAssignment: require("./transformers/property-method-assignment"),
-  defaultParameters:        require("./transformers/default-parameters"),
-  restParameters:           require("./transformers/rest-parameters"),
-  destructuring:            require("./transformers/destructuring"),
-  letScoping:               require("./transformers/let-scoping"),
-  forOf:                    require("./transformers/for-of"),
-  unicodeRegex:             require("./transformers/unicode-regex"),
+  spread:                    require("./transformers/spread"),
+  templateLiterals:          require("./transformers/template-literals"),
+  propertyMethodAssignment:  require("./transformers/property-method-assignment"),
+  defaultParameters:         require("./transformers/default-parameters"),
+  restParameters:            require("./transformers/rest-parameters"),
+  destructuring:             require("./transformers/destructuring"),
+  forOf:                     require("./transformers/for-of"),
+  unicodeRegex:              require("./transformers/unicode-regex"),
+  react:                     require("./transformers/react"),
 
-  react:                    require("./transformers/react"),
+  constants:                 require("./transformers/constants"),
+  letScoping:                require("./transformers/let-scoping"),
 
-  _aliasFunctions:          require("./transformers/_alias-functions"),
-  _blockHoist:              require("./transformers/_block-hoist"),
-  _declarations:            require("./transformers/_declarations"),
+  generators:                require("./transformers/generators"),
 
-  generators:               require("./transformers/generators"),
-  useStrict:                require("./transformers/use-strict"),
+  _blockHoist:               require("./transformers/_block-hoist"),
+  _declarations:             require("./transformers/_declarations"),
+  _aliasFunctions:           require("./transformers/_alias-functions"),
 
-  _moduleFormatter:         require("./transformers/_module-formatter")
+  useStrict:                 require("./transformers/use-strict"),
+
+  _memberExpressionKeywords: require("./transformers/_member-expression-keywords"),
+  _moduleFormatter:          require("./transformers/_module-formatter")
 }, function (transformer, key) {
   transform.transformers[key] = new Transformer(key, transformer);
 });

lib/6to5/transformation/transformer.js

@@ -15,6 +15,7 @@ Transformer.normalise = function (transformer) {
   }
 
   _.each(transformer, function (fns, type) {
+    if (type[0] === "_") return;
     if (_.isFunction(fns)) fns = { enter: fns };
     transformer[type] = fns;
   });

lib/6to5/transformation/transformers/_member-expression-keywords.js

@@ -0,0 +1,10 @@
+var esutils = require("esutils");
+var t = require("../../types");
+
+exports.MemberExpression = function (node) {
+  var prop = node.property;
+  if (t.isIdentifier(prop) && esutils.keyword.isKeywordES6(prop.name, true)) {
+    node.property = t.literal(prop.name);
+    node.computed = true;
+  }
+};

lib/6to5/transformation/transformers/array-comprehension.js

@@ -37,39 +37,42 @@ var multiple = function (node, file) {
 
   var returnStatement = body.pop();
 
-  var build = function () {
-    var self = node.blocks.shift();
-    if (!self) return;
-
-    var child = build();
-    if (!child) {
-      // last item
-
-      child = util.template("array-push", {
-        STATEMENT: node.body,
-        KEY:       uid
-      }, true);
-
-      // add a filter as this is our final stop
-      if (node.filter) {
-        child = t.ifStatement(node.filter, t.blockStatement([child]));
-      }
-    }
-
-    return t.forOfStatement(
-      t.variableDeclaration("var", [t.variableDeclarator(self.left)]),
-      self.right,
-      t.blockStatement([child])
-    );
-  };
-
-  body.push(build());
+  body.push(exports._build(node, function () {
+    return util.template("array-push", {
+      STATEMENT: node.body,
+      KEY:       uid
+    }, true);
+  }));
   body.push(returnStatement);
 
   return container;
 };
 
+exports._build = function (node, buildBody) {
+  var self = node.blocks.shift();
+  if (!self) return;
+
+  var child = exports._build(node, buildBody);
+  if (!child) {
+    // last item
+    child = buildBody();
+
+    // add a filter as this is our final stop
+    if (node.filter) {
+      child = t.ifStatement(node.filter, t.blockStatement([child]));
+    }
+  }
+
+  return t.forOfStatement(
+    t.variableDeclaration("var", [t.variableDeclarator(self.left)]),
+    self.right,
+    t.blockStatement([child])
+  );
+};
+
 exports.ComprehensionExpression = function (node, parent, file) {
+  if (node.generator) return;
+
   if (node.blocks.length === 1 && t.isArrayExpression(node.blocks[0].right)) {
     return singleArrayExpression(node);
   } else {

lib/6to5/transformation/transformers/classes.js

@@ -4,7 +4,7 @@ var t        = require("../../types");
 var _        = require("lodash");
 
 exports.ClassDeclaration = function (node, parent, file, scope) {
-  return t.variableDeclaration("var", [
+  return t.variableDeclaration("let", [
     t.variableDeclarator(node.id, new Class(node, file, scope).run())
   ]);
 };
@@ -254,6 +254,7 @@ Class.prototype.pushConstructor = function (method) {
 
   this.hasConstructor = true;
   t.inherits(construct, fn);
+  t.inheritsComments(construct, method);
 
   construct.defaults = fn.defaults;
   construct.params   = fn.params;

lib/6to5/transformation/transformers/constants.js

@@ -7,26 +7,30 @@ exports.BlockStatement =
 exports.ForInStatement =
 exports.ForOfStatement =
 exports.ForStatement = function (node, parent, file) {
-  var constants = [];
+  var constants = {};
 
-  var check = function (node, names) {
-    _.each(names, function (name) {
-      if (constants.indexOf(name) >= 0) {
-        throw file.errorWithNode(node, name + " is read-only");
-      }
+  var check = function (parent, names) {
+    _.each(names, function (nameNode, name) {
+      if (!_.has(constants, name)) return;
+      if (parent && t.isBlockStatement(parent) && parent !== constants[name]) return;
+
+      throw file.errorWithNode(nameNode, name + " is read-only");
     });
   };
 
   var getIds = function (node) {
-    return t.getIds(node, false, ["MemberExpression"]);
+    return t.getIds(node, true, ["MemberExpression"]);
   };
 
-  _.each(node.body, function (child) {
+  _.each(node.body, function (child, parent) {
     if (child && t.isVariableDeclaration(child, { kind: "const" })) {
       _.each(child.declarations, function (declar) {
-        _.each(getIds(declar), function (name) {
-          check(declar, [name]);
-          constants.push(name);
+        _.each(getIds(declar), function (nameNode, name) {
+          var names = {};
+          names[name] = nameNode;
+          check(parent, names);
+
+          constants[name] = parent;
         });
 
         declar._ignoreConstant = true;
@@ -37,13 +41,14 @@ exports.ForStatement = function (node, parent, file) {
     }
   });
 
-  if (!constants.length) return;
+  if (_.isEmpty(constants)) return;
 
-  traverse(node, function (child) {
+  traverse(node, function (child, parent) {
     if (child._ignoreConstant) return;
+    if (t.isVariableDeclaration(child)) return;
 
     if (t.isVariableDeclarator(child) || t.isDeclaration(child) || t.isAssignmentExpression(child)) {
-      check(child, getIds(child));
+      check(parent, getIds(child));
     }
   });
 };

lib/6to5/transformation/transformers/default-parameters.js

@@ -1,21 +1,70 @@
-var util = require("../../util");
-var t    = require("../../types");
-var _    = require("lodash");
+var traverse = require("../../traverse");
+var util     = require("../../util");
+var t        = require("../../types");
+var _        = require("lodash");
 
-exports.Function = function (node) {
-  if (!node.defaults.length) return;
+exports.Function = function (node, parent, file, scope) {
+  if (!node.defaults || !node.defaults.length) return;
   t.ensureBlock(node);
 
+  var ids = node.params.map(function (param) {
+    return t.getIds(param);
+  });
+
+  var closure = false;
+
   _.each(node.defaults, function (def, i) {
     if (!def) return;
 
     var param = node.params[i];
 
-    node.body.body.unshift(util.template("if-undefined-set-to", {
-      VARIABLE: param,
-      DEFAULT: def
+    // temporal dead zone check - here we prevent accessing of params that
+    // are to the right - ie. uninitialized parameters
+    _.each(ids.slice(i), function (ids) {
+      var check = function (node, parent) {
+        if (!t.isIdentifier(node) || !t.isReferenced(node, parent)) return;
+
+        if (_.contains(ids, node.name)) {
+          throw file.errorWithNode(node, "Temporal dead zone - accessing a variable before it's initialized");
+        }
+
+        if (scope.has(node.name)) {
+          closure = true;
+        }
+      };
+
+      check(def, node);
+      traverse(def, check);
+    });
+
+    // we're accessing a variable that's already defined within this function
+    var has = scope.get(param.name);
+    if (has && !_.contains(node.params, has)) {
+      closure = true;
+    }
+  });
+
+  var body = [];
+
+  _.each(node.defaults, function (def, i) {
+    if (!def) return;
+
+    body.push(util.template("if-undefined-set-to", {
+      VARIABLE: node.params[i],
+      DEFAULT:  def
     }, true));
   });
 
+  if (closure) {
+    var container = t.functionExpression(null, [], node.body, node.generator);
+    container._aliasFunction = true;
+
+    body.push(t.returnStatement(t.callExpression(container, [])));
+
+    node.body = t.blockStatement(body);
+  } else {
+    node.body.body = body.concat(node.body.body);
+  }
+
   node.defaults = [];
 };

lib/6to5/transformation/transformers/destructuring.js

@@ -146,6 +146,12 @@ exports.ExpressionStatement = function (node, parent, file, scope) {
   return nodes;
 };
 
+exports.AssignmentExpression = function (node, parent, file) {
+  if (parent.type === "ExpressionStatement") return;
+  if (!t.isPattern(node.left)) return;
+  throw file.errorWithNode(node, "AssignmentExpression destructuring outside of a ExpressionStatement is forbidden due to current 6to5 limitations");
+};
+
 exports.VariableDeclaration = function (node, parent, file, scope) {
   if (t.isForInStatement(parent) || t.isForOfStatement(parent)) return;
 

lib/6to5/transformation/transformers/for-of.js

@@ -5,17 +5,17 @@ exports.ForOfStatement = function (node, parent, file, scope) {
   var left = node.left;
   var declar;
 
-  var stepKey = t.identifier(file.generateUid("step", scope));
-  var stepValueId = t.memberExpression(stepKey, t.identifier("value"));
+  var stepKey   = t.identifier(file.generateUid("step", scope));
+  var stepValue = t.memberExpression(stepKey, t.identifier("value"));
 
   if (t.isIdentifier(left)) {
-    declar = t.expressionStatement(t.assignmentExpression("=", left, stepValueId));
+    declar = t.expressionStatement(t.assignmentExpression("=", left, stepValue));
   } else if (t.isVariableDeclaration(left)) {
     declar = t.variableDeclaration(left.kind, [
-      t.variableDeclarator(left.declarations[0].id, stepValueId)
+      t.variableDeclarator(left.declarations[0].id, stepValue)
     ]);
   } else {
-    return;
+    throw file.errorWithNode(left, "Unknown node type " + left.type + " in ForOfStatement");
   }
 
   var node2 = util.template("for-of", {

lib/6to5/transformation/transformers/generator-comprehension.js

@@ -0,0 +1,15 @@
+var arrayComprehension = require("./array-comprehension");
+var t                  = require("../../types");
+
+exports.ComprehensionExpression = function (node) {
+  if (!node.generator) return;
+
+  var body = [];
+  var container = t.functionExpression(null, [], t.blockStatement(body), true);
+
+  body.push(arrayComprehension._build(node, function () {
+    return t.expressionStatement(t.yieldExpression(node.body));
+  }));
+
+  return t.callExpression(container, []);
+};

lib/6to5/transformation/transformers/generators.js

@@ -1,3 +0,0 @@
-var regenerator = require("regenerator-6to5");
-
-module.exports = regenerator.transform;

lib/6to5/transformation/transformers/generators/hoist.js

@@ -0,0 +1,152 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+ * additional grant of patent rights can be found in the PATENTS file in
+ * the same directory.
+ */
+
+var assert = require("assert");
+var types = require("ast-types");
+var n = types.namedTypes;
+var b = types.builders;
+var hasOwn = Object.prototype.hasOwnProperty;
+
+// The hoist function takes a FunctionExpression or FunctionDeclaration
+// and replaces any Declaration nodes in its body with assignments, then
+// returns a VariableDeclaration containing just the names of the removed
+// declarations.
+exports.hoist = function(funPath) {
+  assert.ok(funPath instanceof types.NodePath);
+  n.Function.assert(funPath.value);
+
+  var vars = {};
+
+  function varDeclToExpr(vdec, includeIdentifiers) {
+    n.VariableDeclaration.assert(vdec);
+    var exprs = [];
+
+    vdec.declarations.forEach(function(dec) {
+      vars[dec.id.name] = dec.id;
+
+      if (dec.init) {
+        exprs.push(b.assignmentExpression(
+          "=", dec.id, dec.init
+        ));
+      } else if (includeIdentifiers) {
+        exprs.push(dec.id);
+      }
+    });
+
+    if (exprs.length === 0)
+      return null;
+
+    if (exprs.length === 1)
+      return exprs[0];
+
+    return b.sequenceExpression(exprs);
+  }
+
+  types.visit(funPath.get("body"), {
+    visitVariableDeclaration: function(path) {
+      var expr = varDeclToExpr(path.value, false);
+      if (expr === null) {
+        path.replace();
+      } else {
+        // We don't need to traverse this expression any further because
+        // there can't be any new declarations inside an expression.
+        return b.expressionStatement(expr);
+      }
+
+      // Since the original node has been either removed or replaced,
+      // avoid traversing it any further.
+      return false;
+    },
+
+    visitForStatement: function(path) {
+      var init = path.value.init;
+      if (n.VariableDeclaration.check(init)) {
+        path.get("init").replace(varDeclToExpr(init, false));
+      }
+      this.traverse(path);
+    },
+
+    visitForInStatement: function(path) {
+      var left = path.value.left;
+      if (n.VariableDeclaration.check(left)) {
+        path.get("left").replace(varDeclToExpr(left, true));
+      }
+      this.traverse(path);
+    },
+
+    visitFunctionDeclaration: function(path) {
+      var node = path.value;
+      vars[node.id.name] = node.id;
+
+      var assignment = b.expressionStatement(
+        b.assignmentExpression(
+          "=",
+          node.id,
+          b.functionExpression(
+            node.id,
+            node.params,
+            node.body,
+            node.generator,
+            node.expression
+          )
+        )
+      );
+
+      if (n.BlockStatement.check(path.parent.node)) {
+        // Insert the assignment form before the first statement in the
+        // enclosing block.
+        path.parent.get("body").unshift(assignment);
+
+        // Remove the function declaration now that we've inserted the
+        // equivalent assignment form at the beginning of the block.
+        path.replace();
+
+      } else {
+        // If the parent node is not a block statement, then we can just
+        // replace the declaration with the equivalent assignment form
+        // without worrying about hoisting it.
+        path.replace(assignment);
+      }
+
+      // Don't hoist variables out of inner functions.
+      return false;
+    },
+
+    visitFunctionExpression: function() {
+      // Don't descend into nested function expressions.
+      return false;
+    }
+  });
+
+  var paramNames = {};
+  funPath.get("params").each(function(paramPath) {
+    var param = paramPath.value;
+    if (n.Identifier.check(param)) {
+      paramNames[param.name] = param;
+    } else {
+      // Variables declared by destructuring parameter patterns will be
+      // harmlessly re-declared.
+    }
+  });
+
+  var declarations = [];
+
+  Object.keys(vars).forEach(function(name) {
+    if (!hasOwn.call(paramNames, name)) {
+      declarations.push(b.variableDeclarator(vars[name], null));
+    }
+  });
+
+  if (declarations.length === 0) {
+    return null; // Be sure to handle this case!
+  }
+
+  return b.variableDeclaration("var", declarations);
+};

lib/6to5/transformation/transformers/generators/index.js

@@ -0,0 +1 @@
+module.exports = require("./visit").transform;

lib/6to5/transformation/transformers/generators/leap.js

@@ -0,0 +1,179 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+ * additional grant of patent rights can be found in the PATENTS file in
+ * the same directory.
+ */
+
+var assert = require("assert");
+var types = require("ast-types");
+var n = types.namedTypes;
+var inherits = require("util").inherits;
+
+function Entry() {
+  assert.ok(this instanceof Entry);
+}
+
+function FunctionEntry(returnLoc) {
+  Entry.call(this);
+
+  n.Literal.assert(returnLoc);
+
+  Object.defineProperties(this, {
+    returnLoc: { value: returnLoc }
+  });
+}
+
+inherits(FunctionEntry, Entry);
+exports.FunctionEntry = FunctionEntry;
+
+function LoopEntry(breakLoc, continueLoc, label) {
+  Entry.call(this);
+
+  n.Literal.assert(breakLoc);
+  n.Literal.assert(continueLoc);
+
+  if (label) {
+    n.Identifier.assert(label);
+  } else {
+    label = null;
+  }
+
+  Object.defineProperties(this, {
+    breakLoc: { value: breakLoc },
+    continueLoc: { value: continueLoc },
+    label: { value: label }
+  });
+}
+
+inherits(LoopEntry, Entry);
+exports.LoopEntry = LoopEntry;
+
+function SwitchEntry(breakLoc) {
+  Entry.call(this);
+
+  n.Literal.assert(breakLoc);
+
+  Object.defineProperties(this, {
+    breakLoc: { value: breakLoc }
+  });
+}
+
+inherits(SwitchEntry, Entry);
+exports.SwitchEntry = SwitchEntry;
+
+function TryEntry(firstLoc, catchEntry, finallyEntry) {
+  Entry.call(this);
+
+  n.Literal.assert(firstLoc);
+
+  if (catchEntry) {
+    assert.ok(catchEntry instanceof CatchEntry);
+  } else {
+    catchEntry = null;
+  }
+
+  if (finallyEntry) {
+    assert.ok(finallyEntry instanceof FinallyEntry);
+  } else {
+    finallyEntry = null;
+  }
+
+  // Have to have one or the other (or both).
+  assert.ok(catchEntry || finallyEntry);
+
+  Object.defineProperties(this, {
+    firstLoc: { value: firstLoc },
+    catchEntry: { value: catchEntry },
+    finallyEntry: { value: finallyEntry }
+  });
+}
+
+inherits(TryEntry, Entry);
+exports.TryEntry = TryEntry;
+
+function CatchEntry(firstLoc, paramId) {
+  Entry.call(this);
+
+  n.Literal.assert(firstLoc);
+  n.Identifier.assert(paramId);
+
+  Object.defineProperties(this, {
+    firstLoc: { value: firstLoc },
+    paramId: { value: paramId }
+  });
+}
+
+inherits(CatchEntry, Entry);
+exports.CatchEntry = CatchEntry;
+
+function FinallyEntry(firstLoc) {
+  Entry.call(this);
+
+  n.Literal.assert(firstLoc);
+
+  Object.defineProperties(this, {
+    firstLoc: { value: firstLoc }
+  });
+}
+
+inherits(FinallyEntry, Entry);
+exports.FinallyEntry = FinallyEntry;
+
+function LeapManager(emitter) {
+  assert.ok(this instanceof LeapManager);
+
+  var Emitter = require("./emit").Emitter;
+  assert.ok(emitter instanceof Emitter);
+
+  Object.defineProperties(this, {
+    emitter: { value: emitter },
+    entryStack: {
+      value: [new FunctionEntry(emitter.finalLoc)]
+    }
+  });
+}
+
+var LMp = LeapManager.prototype;
+exports.LeapManager = LeapManager;
+
+LMp.withEntry = function(entry, callback) {
+  assert.ok(entry instanceof Entry);
+  this.entryStack.push(entry);
+  try {
+    callback.call(this.emitter);
+  } finally {
+    var popped = this.entryStack.pop();
+    assert.strictEqual(popped, entry);
+  }
+};
+
+LMp._findLeapLocation = function(property, label) {
+  for (var i = this.entryStack.length - 1; i >= 0; --i) {
+    var entry = this.entryStack[i];
+    var loc = entry[property];
+    if (loc) {
+      if (label) {
+        if (entry.label &&
+            entry.label.name === label.name) {
+          return loc;
+        }
+      } else {
+        return loc;
+      }
+    }
+  }
+
+  return null;
+};
+
+LMp.getBreakLoc = function(label) {
+  return this._findLeapLocation("breakLoc", label);
+};
+
+LMp.getContinueLoc = function(label) {
+  return this._findLeapLocation("continueLoc", label);
+};

lib/6to5/transformation/transformers/generators/meta.js

@@ -0,0 +1,100 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+ * additional grant of patent rights can be found in the PATENTS file in
+ * the same directory.
+ */
+
+var assert = require("assert");
+var types = require("ast-types");
+var m = require("private").makeAccessor();
+var isArray = types.builtInTypes.array;
+var n = types.namedTypes;
+var hasOwn = Object.prototype.hasOwnProperty;
+
+function makePredicate(propertyName, knownTypes) {
+  function onlyChildren(node) {
+    n.Node.assert(node);
+
+    // Assume no side effects until we find out otherwise.
+    var result = false;
+
+    function check(child) {
+      if (result) {
+        // Do nothing.
+      } else if (isArray.check(child)) {
+        child.some(check);
+      } else if (n.Node.check(child)) {
+        assert.strictEqual(result, false);
+        result = predicate(child);
+      }
+      return result;
+    }
+
+    types.eachField(node, function(name, child) {
+      check(child);
+    });
+
+    return result;
+  }
+
+  function predicate(node) {
+    n.Node.assert(node);
+
+    var meta = m(node);
+    if (hasOwn.call(meta, propertyName))
+      return meta[propertyName];
+
+    // Certain types are "opaque," which means they have no side
+    // effects or leaps and we don't care about their subexpressions.
+    if (hasOwn.call(opaqueTypes, node.type))
+      return meta[propertyName] = false;
+
+    if (hasOwn.call(knownTypes, node.type))
+      return meta[propertyName] = true;
+
+    return meta[propertyName] = onlyChildren(node);
+  }
+
+  predicate.onlyChildren = onlyChildren;
+
+  return predicate;
+}
+
+var opaqueTypes = {
+  FunctionExpression: true
+};
+
+// These types potentially have side effects regardless of what side
+// effects their subexpressions have.
+var sideEffectTypes = {
+  CallExpression: true, // Anything could happen!
+  ForInStatement: true, // Modifies the key variable.
+  UnaryExpression: true, // Think delete.
+  BinaryExpression: true, // Might invoke .toString() or .valueOf().
+  AssignmentExpression: true, // Side-effecting by definition.
+  UpdateExpression: true, // Updates are essentially assignments.
+  NewExpression: true // Similar to CallExpression.
+};
+
+// These types are the direct cause of all leaps in control flow.
+var leapTypes = {
+  YieldExpression: true,
+  BreakStatement: true,
+  ContinueStatement: true,
+  ReturnStatement: true,
+  ThrowStatement: true
+};
+
+// All leap types are also side effect types.
+for (var type in leapTypes) {
+  if (hasOwn.call(leapTypes, type)) {
+    sideEffectTypes[type] = leapTypes[type];
+  }
+}
+
+exports.hasSideEffects = makePredicate("hasSideEffects", sideEffectTypes);
+exports.containsLeap = makePredicate("containsLeap", leapTypes);

lib/6to5/transformation/transformers/generators/runtime.js

@@ -0,0 +1,459 @@
+/**
+* Copyright (c) 2014, Facebook, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the BSD-style license found in the
+* https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+* additional grant of patent rights can be found in the PATENTS file in
+* the same directory.
+*/
+
+if (typeof global.regeneratorRuntime === "object") {
+  return;
+}
+
+var hasOwn = Object.prototype.hasOwnProperty;
+var iteratorSymbol = typeof Symbol === "function" && Symbol.iterator || "@@iterator";
+var runtime = global.regeneratorRuntime = exports;
+
+var wrap = runtime.wrap = function wrap(innerFn, outerFn, self, tryList) {
+  return new Generator(innerFn, outerFn, self || null, tryList || []);
+};
+
+var GenStateSuspendedStart = "suspendedStart";
+var GenStateSuspendedYield = "suspendedYield";
+var GenStateExecuting = "executing";
+var GenStateCompleted = "completed";
+
+// Returning this object from the innerFn has the same effect as
+// breaking out of the dispatch switch statement.
+var ContinueSentinel = {};
+
+// Dummy constructor that we use as the .constructor property for
+// functions that return Generator objects.
+var GF = function GeneratorFunction() {};
+var GFp = function GeneratorFunctionPrototype() {};
+var Gp = GFp.prototype = Generator.prototype;
+(GFp.constructor = GF).prototype =
+  Gp.constructor = GFp;
+
+// Ensure isGeneratorFunction works when Function#name not supported.
+var GFName = "GeneratorFunction";
+if (GF.name !== GFName) GF.name = GFName;
+if (GF.name !== GFName) throw new Error(GFName + " renamed?");
+
+runtime.isGeneratorFunction = function(genFun) {
+  var ctor = genFun && genFun.constructor;
+  return ctor ? GF.name === ctor.name : false;
+};
+
+runtime.mark = function(genFun) {
+  genFun.__proto__ = GFp;
+  genFun.prototype = Object.create(Gp);
+  return genFun;
+};
+
+runtime.async = function(innerFn, outerFn, self, tryList) {
+  return new Promise(function(resolve, reject) {
+    var generator = wrap(innerFn, outerFn, self, tryList);
+    var callNext = step.bind(generator.next);
+    var callThrow = step.bind(generator["throw"]);
+
+    function step(arg) {
+      var info;
+      var value;
+
+      try {
+        info = this(arg);
+        value = info.value;
+      } catch (error) {
+        return reject(error);
+      }
+
+      if (info.done) {
+        resolve(value);
+      } else {
+        Promise.resolve(value).then(callNext, callThrow);
+      }
+    }
+
+    callNext();
+  });
+};
+
+function Generator(innerFn, outerFn, self, tryList) {
+  var generator = outerFn ? Object.create(outerFn.prototype) : this;
+  var context = new Context(tryList);
+  var state = GenStateSuspendedStart;
+
+  function invoke(method, arg) {
+    if (state === GenStateExecuting) {
+      throw new Error("Generator is already running");
+    }
+
+    if (state === GenStateCompleted) {
+      throw new Error("Generator has already finished");
+    }
+
+    while (true) {
+      var delegate = context.delegate;
+      var info;
+
+      if (delegate) {
+        try {
+          info = delegate.iterator[method](arg);
+
+          // Delegate generator ran and handled its own exceptions so
+          // regardless of what the method was, we continue as if it is
+          // "next" with an undefined arg.
+          method = "next";
+          arg = undefined;
+
+        } catch (uncaught) {
+          context.delegate = null;
+
+          // Like returning generator.throw(uncaught), but without the
+          // overhead of an extra function call.
+          method = "throw";
+          arg = uncaught;
+
+          continue;
+        }
+
+        if (info.done) {
+          context[delegate.resultName] = info.value;
+          context.next = delegate.nextLoc;
+        } else {
+          state = GenStateSuspendedYield;
+          return info;
+        }
+
+        context.delegate = null;
+      }
+
+      if (method === "next") {
+        if (state === GenStateSuspendedStart &&
+            typeof arg !== "undefined") {
+          // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-generatorresume
+          throw new TypeError(
+            "attempt to send " + JSON.stringify(arg) + " to newborn generator"
+          );
+        }
+
+        if (state === GenStateSuspendedYield) {
+          context.sent = arg;
+        } else {
+          delete context.sent;
+        }
+
+      } else if (method === "throw") {
+        if (state === GenStateSuspendedStart) {
+          state = GenStateCompleted;
+          throw arg;
+        }
+
+        if (context.dispatchException(arg)) {
+          // If the dispatched exception was caught by a catch block,
+          // then let that catch block handle the exception normally.
+          method = "next";
+          arg = undefined;
+        }
+
+      } else if (method === "return") {
+        context.abrupt("return", arg);
+      }
+
+      state = GenStateExecuting;
+
+      try {
+        var value = innerFn.call(self, context);
+
+        // If an exception is thrown from innerFn, we leave state ===
+        // GenStateExecuting and loop back for another invocation.
+        state = context.done ? GenStateCompleted : GenStateSuspendedYield;
+
+        info = {
+          value: value,
+          done: context.done
+        };
+
+        if (value === ContinueSentinel) {
+          if (context.delegate && method === "next") {
+            // Deliberately forget the last sent value so that we don't
+            // accidentally pass it on to the delegate.
+            arg = undefined;
+          }
+        } else {
+          return info;
+        }
+
+      } catch (thrown) {
+        state = GenStateCompleted;
+
+        if (method === "next") {
+          context.dispatchException(thrown);
+        } else {
+          arg = thrown;
+        }
+      }
+    }
+  }
+
+  generator.next = invoke.bind(generator, "next");
+  generator["throw"] = invoke.bind(generator, "throw");
+  generator["return"] = invoke.bind(generator, "return");
+
+  return generator;
+}
+
+Gp[iteratorSymbol] = function() {
+  return this;
+};
+
+Gp.toString = function() {
+  return "[object Generator]";
+};
+
+function pushTryEntry(triple) {
+  var entry = { tryLoc: triple[0] };
+
+  if (1 in triple) {
+    entry.catchLoc = triple[1];
+  }
+
+  if (2 in triple) {
+    entry.finallyLoc = triple[2];
+  }
+
+  this.tryEntries.push(entry);
+}
+
+function resetTryEntry(entry, i) {
+  var record = entry.completion || {};
+  record.type = i === 0 ? "normal" : "return";
+  delete record.arg;
+  entry.completion = record;
+}
+
+function Context(tryList) {
+  // The root entry object (effectively a try statement without a catch
+  // or a finally block) gives us a place to store values thrown from
+  // locations where there is no enclosing try statement.
+  this.tryEntries = [{ tryLoc: "root" }];
+  tryList.forEach(pushTryEntry, this);
+  this.reset();
+}
+
+runtime.keys = function(object) {
+  var keys = [];
+  for (var key in object) {
+    keys.push(key);
+  }
+  keys.reverse();
+
+  // Rather than returning an object with a next method, we keep
+  // things simple and return the next function itself.
+  return function next() {
+    while (keys.length) {
+      var key = keys.pop();
+      if (key in object) {
+        next.value = key;
+        next.done = false;
+        return next;
+      }
+    }
+
+    // To avoid creating an additional object, we just hang the .value
+    // and .done properties off the next function object itself. This
+    // also ensures that the minifier will not anonymize the function.
+    next.done = true;
+    return next;
+  };
+};
+
+function values(iterable) {
+  var iterator = iterable;
+  if (iteratorSymbol in iterable) {
+    iterator = iterable[iteratorSymbol]();
+  } else if (!isNaN(iterable.length)) {
+    var i = -1;
+    iterator = function next() {
+      while (++i < iterable.length) {
+        if (i in iterable) {
+          next.value = iterable[i];
+          next.done = false;
+          return next;
+        }
+      }
+      next.done = true;
+      return next;
+    };
+    iterator.next = iterator;
+  }
+  return iterator;
+}
+runtime.values = values;
+
+Context.prototype = {
+  constructor: Context,
+
+  reset: function() {
+    this.prev = 0;
+    this.next = 0;
+    this.sent = undefined;
+    this.done = false;
+    this.delegate = null;
+
+    this.tryEntries.forEach(resetTryEntry);
+
+    // Pre-initialize at least 20 temporary variables to enable hidden
+    // class optimizations for simple generators.
+    for (var tempIndex = 0, tempName;
+         hasOwn.call(this, tempName = "t" + tempIndex) || tempIndex < 20;
+         ++tempIndex) {
+      this[tempName] = null;
+    }
+  },
+
+  stop: function() {
+    this.done = true;
+
+    var rootEntry = this.tryEntries[0];
+    var rootRecord = rootEntry.completion;
+    if (rootRecord.type === "throw") {
+      throw rootRecord.arg;
+    }
+
+    return this.rval;
+  },
+
+  dispatchException: function(exception) {
+    if (this.done) {
+      throw exception;
+    }
+
+    var context = this;
+    function handle(loc, caught) {
+      record.type = "throw";
+      record.arg = exception;
+      context.next = loc;
+      return !!caught;
+    }
+
+    for (var i = this.tryEntries.length - 1; i >= 0; --i) {
+      var entry = this.tryEntries[i];
+      var record = entry.completion;
+
+      if (entry.tryLoc === "root") {
+        // Exception thrown outside of any try block that could handle
+        // it, so set the completion value of the entire function to
+        // throw the exception.
+        return handle("end");
+      }
+
+      if (entry.tryLoc <= this.prev) {
+        var hasCatch = hasOwn.call(entry, "catchLoc");
+        var hasFinally = hasOwn.call(entry, "finallyLoc");
+
+        if (hasCatch && hasFinally) {
+          if (this.prev < entry.catchLoc) {
+            return handle(entry.catchLoc, true);
+          } else if (this.prev < entry.finallyLoc) {
+            return handle(entry.finallyLoc);
+          }
+
+        } else if (hasCatch) {
+          if (this.prev < entry.catchLoc) {
+            return handle(entry.catchLoc, true);
+          }
+
+        } else if (hasFinally) {
+          if (this.prev < entry.finallyLoc) {
+            return handle(entry.finallyLoc);
+          }
+
+        } else {
+          throw new Error("try statement without catch or finally");
+        }
+      }
+    }
+  },
+
+  _findFinallyEntry: function(finallyLoc) {
+    for (var i = this.tryEntries.length - 1; i >= 0; --i) {
+      var entry = this.tryEntries[i];
+      if (entry.tryLoc <= this.prev &&
+          hasOwn.call(entry, "finallyLoc") && (
+            entry.finallyLoc === finallyLoc ||
+            this.prev < entry.finallyLoc)) {
+        return entry;
+      }
+    }
+  },
+
+  abrupt: function(type, arg) {
+    var entry = this._findFinallyEntry();
+    var record = entry ? entry.completion : {};
+
+    record.type = type;
+    record.arg = arg;
+
+    if (entry) {
+      this.next = entry.finallyLoc;
+    } else {
+      this.complete(record);
+    }
+
+    return ContinueSentinel;
+  },
+
+  complete: function(record) {
+    if (record.type === "throw") {
+      throw record.arg;
+    }
+
+    if (record.type === "break" ||
+        record.type === "continue") {
+      this.next = record.arg;
+    } else if (record.type === "return") {
+      this.rval = record.arg;
+      this.next = "end";
+    }
+
+    return ContinueSentinel;
+  },
+
+  finish: function(finallyLoc) {
+    var entry = this._findFinallyEntry(finallyLoc);
+    return this.complete(entry.completion);
+  },
+
+  "catch": function(tryLoc) {
+    for (var i = this.tryEntries.length - 1; i >= 0; --i) {
+      var entry = this.tryEntries[i];
+      if (entry.tryLoc === tryLoc) {
+        var record = entry.completion;
+        var thrown;
+        if (record.type === "throw") {
+          thrown = record.arg;
+          resetTryEntry(entry, i);
+        }
+        return thrown;
+      }
+    }
+
+    // The context.catch method must only be called with a location
+    // argument that corresponds to a known catch block.
+    throw new Error("illegal catch attempt");
+  },
+
+  delegateYield: function(iterable, resultName, nextLoc) {
+    this.delegate = {
+      iterator: values(iterable),
+      resultName: resultName,
+      nextLoc: nextLoc
+    };
+
+    return ContinueSentinel;
+  }
+};

lib/6to5/transformation/transformers/generators/util.js

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+ * additional grant of patent rights can be found in the PATENTS file in
+ * the same directory.
+ */
+
+var b = require("ast-types").builders;
+var hasOwn = Object.prototype.hasOwnProperty;
+
+exports.defaults = function(obj) {
+  var len = arguments.length;
+  var extension;
+
+  for (var i = 1; i < len; ++i) {
+    if ((extension = arguments[i])) {
+      for (var key in extension) {
+        if (hasOwn.call(extension, key) && !hasOwn.call(obj, key)) {
+          obj[key] = extension[key];
+        }
+      }
+    }
+  }
+
+  return obj;
+};
+
+exports.runtimeProperty = function(name) {
+  return b.memberExpression(
+    b.identifier("regeneratorRuntime"),
+    b.identifier(name),
+    false
+  );
+};

lib/6to5/transformation/transformers/generators/visit.js

@@ -0,0 +1,222 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * https://raw.github.com/facebook/regenerator/master/LICENSE file. An
+ * additional grant of patent rights can be found in the PATENTS file in
+ * the same directory.
+ */
+
+var types = require("ast-types");
+var n = types.namedTypes;
+var b = types.builders;
+var hoist = require("./hoist").hoist;
+var Emitter = require("./emit").Emitter;
+var runtimeProperty = require("./util").runtimeProperty;
+var runtimeWrapMethod = runtimeProperty("wrap");
+var runtimeMarkMethod = runtimeProperty("mark");
+var runtimeAsyncMethod = runtimeProperty("async");
+
+exports.transform = function transform(node) {
+  return types.visit(node, visitor);
+};
+
+var visitor = types.PathVisitor.fromMethodsObject({
+  visitFunction: function(path) {
+    // Calling this.traverse(path) first makes for a post-order traversal.
+    this.traverse(path);
+
+    var node = path.value;
+
+    if (!node.generator && !node.async) {
+      return;
+    }
+
+    node.generator = false;
+
+    if (node.expression) {
+      // Transform expression lambdas into normal functions.
+      node.expression = false;
+      node.body = b.blockStatement([
+        b.returnStatement(node.body)
+      ]);
+    }
+
+    if (node.async) {
+      awaitVisitor.visit(path.get("body"));
+    }
+
+    var outerFnId = node.id || (
+      node.id = path.scope.parent.declareTemporary("callee$")
+    );
+
+    var innerFnId = b.identifier(node.id.name + "$");
+    var contextId = path.scope.declareTemporary("context$");
+    var vars = hoist(path);
+
+    var emitter = new Emitter(contextId);
+    emitter.explode(path.get("body"));
+
+    var outerBody = [];
+
+    if (vars && vars.declarations.length > 0) {
+      outerBody.push(vars);
+    }
+
+    var wrapArgs = [
+      emitter.getContextFunction(innerFnId),
+      // Async functions don't care about the outer function because they
+      // don't need it to be marked and don't inherit from its .prototype.
+      node.async ? b.literal(null) : outerFnId,
+      b.thisExpression()
+    ];
+
+    var tryEntryList = emitter.getTryEntryList();
+    if (tryEntryList) {
+      wrapArgs.push(tryEntryList);
+    }
+
+    var wrapCall = b.callExpression(
+      node.async ? runtimeAsyncMethod : runtimeWrapMethod,
+      wrapArgs
+    );
+
+    outerBody.push(b.returnStatement(wrapCall));
+    node.body = b.blockStatement(outerBody);
+
+    if (node.async) {
+      node.async = false;
+      return;
+    }
+
+    if (n.FunctionDeclaration.check(node)) {
+      var pp = path.parent;
+
+      while (pp && !(n.BlockStatement.check(pp.value) ||
+                     n.Program.check(pp.value))) {
+        pp = pp.parent;
+      }
+
+      if (!pp) {
+        return;
+      }
+
+      // Here we turn the FunctionDeclaration into a named
+      // FunctionExpression that will be assigned to a variable of the
+      // same name at the top of the enclosing block. This is important
+      // for a very subtle reason: named function expressions can refer to
+      // themselves by name without fear that the binding may change due
+      // to code executing outside the function, whereas function
+      // declarations are vulnerable to the following rebinding:
+      //
+      //   function f() { return f }
+      //   var g = f;
+      //   f = "asdf";
+      //   g(); // "asdf"
+      //
+      // One way to prevent the problem illustrated above is to transform
+      // the function declaration thus:
+      //
+      //   var f = function f() { return f };
+      //   var g = f;
+      //   f = "asdf";
+      //   g(); // f
+      //   g()()()()(); // f
+      //
+      // In the code below, we transform generator function declarations
+      // in the following way:
+      //
+      //   gen().next(); // { value: gen, done: true }
+      //   function *gen() {
+      //     return gen;
+      //   }
+      //
+      // becomes something like
+      //
+      //   var gen = runtime.mark(function *gen() {
+      //     return gen;
+      //   });
+      //   gen().next(); // { value: gen, done: true }
+      //
+      // which ensures that the generator body can always reliably refer
+      // to gen by name.
+
+      // Remove the FunctionDeclaration so that we can add it back as a
+      // FunctionExpression passed to runtime.mark.
+      path.replace();
+
+      // Change the type of the function to be an expression instead of a
+      // declaration. Note that all the other fields are the same.
+      node.type = "FunctionExpression";
+
+      var varDecl = b.variableDeclaration("var", [
+        b.variableDeclarator(
+          node.id,
+          b.callExpression(runtimeMarkMethod, [node])
+        )
+      ]);
+
+      if (node.comments) {
+        // Copy any comments preceding the function declaration to the
+        // variable declaration, to avoid weird formatting consequences.
+        varDecl.comments = node.comments;
+        node.comments = null;
+      }
+
+      var bodyPath = pp.get("body");
+      var bodyLen = bodyPath.value.length;
+
+      for (var i = 0; i < bodyLen; ++i) {
+        var firstStmtPath = bodyPath.get(i);
+        if (!shouldNotHoistAbove(firstStmtPath)) {
+          firstStmtPath.insertBefore(varDecl);
+          return;
+        }
+      }
+
+      bodyPath.push(varDecl);
+
+    } else {
+      n.FunctionExpression.assert(node);
+      return b.callExpression(runtimeMarkMethod, [node]);
+    }
+  }
+});
+
+function shouldNotHoistAbove(stmtPath) {
+  var value = stmtPath.value;
+  n.Statement.assert(value);
+
+  // If the first statement is a "use strict" declaration, make sure to
+  // insert hoisted declarations afterwards.
+  if (n.ExpressionStatement.check(value) &&
+      n.Literal.check(value.expression) &&
+      value.expression.value === "use strict") {
+    return true;
+  }
+
+  if (n.VariableDeclaration.check(value)) {
+    for (var i = 0; i < value.declarations.length; ++i) {
+      var decl = value.declarations[i];
+      if (n.CallExpression.check(decl.init) &&
+          types.astNodesAreEquivalent(decl.init.callee,
+                                      runtimeMarkMethod)) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+var awaitVisitor = types.PathVisitor.fromMethodsObject({
+  visitFunction: function() {
+    return false; // Don't descend into nested function scopes.
+  },
+
+  visitAwaitExpression: function(path) {
+    // Convert await expressions to yield expressions.
+    return b.yieldExpression(path.value.argument, false);
+  }
+});

lib/6to5/transformation/transformers/let-scoping.js

@@ -74,7 +74,6 @@ function LetScoping(forParent, block, parent, file, scope) {
 
   this.letReferences = {};
   this.body          = [];
-  this.info          = this.getInfo();
 }
 
 /**
@@ -87,8 +86,10 @@ LetScoping.prototype.run = function () {
   if (block._letDone) return;
   block._letDone = true;
 
+  this.info = this.getInfo();
+
   // this is a block within a `Function` so we can safely leave it be
-  if (t.isFunction(this.parent)) return;
+  if (t.isFunction(this.parent)) return this.noClosure();
 
   // this block has no let references so let's clean up
   if (!this.info.keys.length) return this.noClosure();
@@ -127,12 +128,18 @@ LetScoping.prototype.run = function () {
   var call = t.callExpression(fn, params);
   var ret  = t.identifier(this.file.generateUid("ret", this.scope));
 
+  var hasYield = traverse.hasType(fn.body, "YieldExpression", t.FUNCTION_TYPES);
+  if (hasYield) {
+    fn.generator = true;
+    call = t.yieldExpression(call, true);
+  }
+
   this.build(ret, call);
 };
 
 /**
  * There are no let references accessed within a closure so we can just traverse
- * through this block and replace all references that exist in a high scope to
+ * through this block and replace all references that exist in a higher scope to
  * their uids.
  */
 
@@ -145,11 +152,25 @@ LetScoping.prototype.noClosure = function () {
 
   if (_.isEmpty(replacements)) return;
 
-  traverse(block, function (node, parent) {
+  var replace = function (node, parent) {
     if (!t.isIdentifier(node)) return;
     if (!t.isReferenced(node, parent)) return;
     node.name = replacements[node.name] || node.name;
-  });
+  };
+
+  var traverseReplace = function (node, parent) {
+    replace(node, parent);
+    traverse(node, replace);
+  };
+
+  var forParent = this.forParent;
+  if (forParent) {
+    traverseReplace(forParent.right, forParent);
+    traverseReplace(forParent.test, forParent);
+    traverseReplace(forParent.update, forParent);
+  }
+
+  traverse(block, replace);
 };
 
 /**
@@ -181,10 +202,23 @@ LetScoping.prototype.getInfo = function () {
     keys:        []
   };
 
+  var duplicates = function (id, key) {
+    var has = scope.parentGet(key);
+
+    if (has && has !== id) {
+      // there's a variable with this exact name in an upper scope so we need
+      // to generate a new name
+      opts.duplicates[key] = id.name = file.generateUid(key, scope);
+    }
+  };
+
   _.each(opts.declarators, function (declar) {
     opts.declarators.push(declar);
 
-    var keys = t.getIds(declar);
+    var keys = t.getIds(declar, true);
+    _.each(keys, duplicates);
+    keys = _.keys(keys);
+
     opts.outsideKeys = opts.outsideKeys.concat(keys);
     opts.keys = opts.keys.concat(keys);
   });
@@ -193,14 +227,7 @@ LetScoping.prototype.getInfo = function () {
     if (!isLet(declar)) return;
 
     _.each(t.getIds(declar, true), function (id, key) {
-      var has = scope.parentGet(key);
-
-      if (has && has !== id) {
-        // there's a variable with this exact name in an upper scope so we need
-        // to generate a new name
-        opts.duplicates[key] = id.name = file.generateUid(key, scope);
-      }
-
+      duplicates(id, key);
       opts.keys.push(key);
     });
   });
@@ -211,7 +238,8 @@ LetScoping.prototype.getInfo = function () {
 /**
  * If we're inside of a `For*Statement` then traverse it and check if it has one
  * of the following node types `ReturnStatement`, `BreakStatement`,
- * `ContinueStatement` and replace it with a return value we can track later on.
+ * `ContinueStatement` and replace it with a return value that we can track
+ * later on.
  *
  * @returns {Object}
  */
@@ -223,35 +251,41 @@ LetScoping.prototype.checkFor = function () {
     hasBreak:    false,
   };
 
-  if (this.forParent) {
-    traverse(this.block, function (node) {
-      var replace;
+  var forParent = this.forParent;
 
-      if (t.isFunction(node) || t.isFor(node)) {
-        return false;
-      } else if (t.isBreakStatement(node) && !node.label) {
+  traverse(this.block, function (node) {
+    var replace;
+
+    if (t.isFunction(node) || t.isFor(node)) {
+      return false;
+    }
+
+    if (forParent && !node.label) {
+      if (t.isBreakStatement(node)) {
         has.hasBreak = true;
         replace = t.returnStatement(t.literal("break"));
-      } else if (t.isContinueStatement(node) && !node.label) {
+      } else if (t.isContinueStatement(node)) {
         has.hasContinue = true;
         replace = t.returnStatement(t.literal("continue"));
-      } else if (t.isReturnStatement(node)) {
-        has.hasReturn = true;
-        replace = t.returnStatement(t.objectExpression([
-          t.property("init", t.identifier("v"), node.argument || t.identifier("undefined"))
-        ]));
       }
+    }
 
-      if (replace) return t.inherits(replace, node);
-    });
-  }
+    if (t.isReturnStatement(node)) {
+      has.hasReturn = true;
+      replace = t.returnStatement(t.objectExpression([
+        t.property("init", t.identifier("v"), node.argument || t.identifier("undefined"))
+      ]));
+    }
+
+    if (replace) return t.inherits(replace, node);
+  });
 
   return has;
 };
 
 /**
  * Hoist all var declarations in this block to before it so they retain scope
- * once we wrap everything is in a closure.
+ * once we wrap everything in a closure.
  */
 
 LetScoping.prototype.hoistVarDeclarations = function () {
@@ -340,7 +374,7 @@ LetScoping.prototype.getLetReferences = function () {
  * @returns {Array}
  */
 
-LetScoping.prototype.buildPushDeclar = function (node) {
+LetScoping.prototype.pushDeclar = function (node) {
   this.body.push(t.variableDeclaration(node.kind, node.declarations.map(function (declar) {
     return t.variableDeclarator(declar.id);
   })));

lib/6to5/transformation/transformers/react.js

@@ -106,11 +106,35 @@ exports.XJSElement = {
   exit: function (node) {
     var callExpr = node.openingElement;
 
-    var childrenToRender = node.children.filter(function(child) {
-      return !(t.isLiteral(child) && _.isString(child.value) && child.value.match(/^[ \t]*[\r\n][ \t\r\n]*$/));
-    });
+    _.each(node.children, function (child) {
+      if (t.isLiteral(child)) {
+        var lines = child.value.split(/\r\n|\n|\r/);
+
+        _.each(lines, function (line, i) {
+          var isFirstLine = i === 0;
+          var isLastLine = i === lines.length - 1;
+
+          // replace rendered whitespace tabs with spaces
+          var trimmedLine = line.replace(/\t/g, ' ');
+
+          // trim whitespace touching a newline
+          if (!isFirstLine) {
+            trimmedLine = trimmedLine.replace(/^[ ]+/, '');
+          }
+
+          // trim whitespace touching an endline
+          if (!isLastLine) {
+            trimmedLine = trimmedLine.replace(/[ ]+$/, '');
+          }
+
+          if (trimmedLine) {
+            callExpr.arguments.push(t.literal(trimmedLine));
+          }
+        });
+
+        return;
+      }
 
-    _.each(childrenToRender, function (child) {
       callExpr.arguments.push(child);
     });
 

lib/6to5/transformation/transformers/spread.js

@@ -1,14 +1,13 @@
-var util = require("../../util");
-var t    = require("../../types");
-var _    = require("lodash");
+var t = require("../../types");
+var _ = require("lodash");
 
-var getSpreadLiteral = function (spread, file) {
+var getSpreadLiteral = function (spread) {
   var literal = spread.argument;
   if (!t.isArrayExpression(literal)) {
-    literal = util.template("call", {
-      OBJECT: file.addDeclaration("slice"),
-      CONTEXT: literal
-    });
+    literal = t.callExpression(
+      t.memberExpression(t.identifier("Array"), t.identifier("from")),
+      [literal]
+    );
   }
   return literal;
 };
@@ -24,7 +23,7 @@ var hasSpread = function (nodes) {
   return has;
 };
 
-var build = function (props, file) {
+var build = function (props) {
   var nodes = [];
 
   var _props = [];
@@ -38,7 +37,7 @@ var build = function (props, file) {
   _.each(props, function (prop) {
     if (t.isSpreadElement(prop)) {
       push();
-      nodes.push(getSpreadLiteral(prop, file));
+      nodes.push(getSpreadLiteral(prop));
     } else {
       _props.push(prop);
     }
@@ -49,11 +48,11 @@ var build = function (props, file) {
   return nodes;
 };
 
-exports.ArrayExpression = function (node, parent, file) {
+exports.ArrayExpression = function (node) {
   var elements = node.elements;
   if (!hasSpread(elements)) return;
 
-  var nodes = build(elements, file);
+  var nodes = build(elements);
   var first = nodes.shift();
 
   if (!nodes.length) return first;
@@ -61,7 +60,7 @@ exports.ArrayExpression = function (node, parent, file) {
   return t.callExpression(t.memberExpression(first, t.identifier("concat")), nodes);
 };
 
-exports.CallExpression = function (node, parent, file) {
+exports.CallExpression = function (node) {
   var args = node.arguments;
   if (!hasSpread(args)) return;
 
@@ -69,7 +68,7 @@ exports.CallExpression = function (node, parent, file) {
 
   node.arguments = [];
 
-  var nodes = build(args, file);
+  var nodes = build(args);
   var first = nodes.shift();
 
   if (nodes.length) {
@@ -96,3 +95,19 @@ exports.CallExpression = function (node, parent, file) {
 
   node.arguments.unshift(contextLiteral);
 };
+
+exports.NewExpression = function (node, parent, file) {
+  var args = node.arguments;
+  if (!hasSpread(args)) return;
+
+  var nodes = build(args);
+  var first = nodes.shift();
+
+  if (nodes.length) {
+    args = t.callExpression(t.memberExpression(first, t.identifier("concat")), nodes);
+  } else {
+    args = first;
+  }
+
+  return t.callExpression(file.addDeclaration("apply-constructor"), [node.callee, args]);
+};

lib/6to5/transformation/transformers/template-literals.js

@@ -5,14 +5,22 @@ var buildBinaryExpression = function (left, right) {
   return t.binaryExpression("+", left, right);
 };
 
-exports.TaggedTemplateExpression = function (node) {
+exports.TaggedTemplateExpression = function (node, parent, file) {
   var args = [];
   var quasi = node.quasi;
 
-  var strings = quasi.quasis.map(function (elem) {
-    return t.literal(elem.value.raw);
+  var strings = [];
+  var raw = [];
+
+  _.each(quasi.quasis, function (elem) {
+    strings.push(t.literal(elem.value.cooked));
+    raw.push(t.literal(elem.value.raw));
   });
-  args.push(t.arrayExpression(strings));
+
+  args.push(t.callExpression(file.addDeclaration("tagged-template-literal"), [
+    t.arrayExpression(strings),
+    t.arrayExpression(raw)
+  ]));
 
   _.each(quasi.expressions, function (expr) {
     args.push(expr);

lib/6to5/traverse/index.js

@@ -29,25 +29,32 @@ function traverse(parent, callbacks, opts) {
   // normalise callbacks
   if (_.isFunction(callbacks)) callbacks = { enter: callbacks };
 
-  _.each(keys, function (key) {
+  for (var i in keys) {
+    var key = keys[i];
     var nodes = parent[key];
-    if (!nodes) return;
+    if (!nodes) continue;
+
+    var updated = false;
 
     var handle = function (obj, key) {
       var node = obj[key];
       if (!node) return;
 
       // type is blacklisted
-      if (_.contains(blacklistTypes, node.type)) return;
+      if (blacklistTypes.indexOf(node.type) > -1) return;
 
       // replace node
       var maybeReplace = function (result) {
         if (result === false) return;
-        if (result != null) node = obj[key] = result;
+
+        if (result != null) {
+          updated = true;
+          node = obj[key] = result;
+        }
       };
 
       //
-      var opts2 = _.clone(opts);
+      var opts2 = { scope: opts.scope, blacklist: opts.blacklist };
       if (t.isScope(node)) opts2.scope = new Scope(opts.scope, node);
 
       // enter
@@ -69,15 +76,15 @@ function traverse(parent, callbacks, opts) {
     };
 
     if (_.isArray(nodes)) {
-      _.each(nodes, function (node, i) {
+      for (i in nodes) {
         handle(nodes, i);
-      });
+      }
 
-      parent[key] = _.flatten(parent[key]);
+      if (updated) parent[key] = _.flatten(parent[key]);
     } else {
       handle(parent, key);
     }
-  });
+  }
 }
 
 traverse.removeProperties = function (tree) {

lib/6to5/traverse/scope.js

@@ -4,54 +4,93 @@ var traverse = require("./index");
 var t        = require("../types");
 var _        = require("lodash");
 
+var FOR_KEYS = ["left", "init"];
+
 function Scope(parent, block) {
   this.parent = parent;
   this.block  = block;
-  this.ids    = this.getIds();
 
-  this.getIds();
+  this.info         = this.getInfo();
+  this.declarations = this.info.declarations;
 }
 
-Scope.prototype.getIds = function () {
+Scope.prototype.getInfo = function () {
   var block = this.block;
-  if (block._scopeIds) return block._scopeIds;
+  if (block._scope) return block._scope;
 
   var self = this;
-  var ids  = block._scopeIds = {};
+  var info = block._scope = {
+    declarations: {}
+  };
 
-  if (t.isBlockStatement(block)) {
-    _.each(block.body, function (node) {
-      if (t.isVariableDeclaration(node) && node.kind !== "var") {
-        self.add(node, ids);
-      }
-    });
-  } else if (t.isProgram(block) || t.isFunction(block)) {
-    traverse(block, function (node, parent) {
-      if (parent !== block && t.isVariableDeclaration(node) && node.kind !== "var") {
-        return;
-      }
+  var add = function (node) {
+    self.addDeclaration(node, info.declarations);
+  };
 
-      if (t.isDeclaration(node)) {
-        self.add(node, ids);
-      } else if (t.isFunction(node)) {
-        return false;
-      }
+  // ForStatement - left, init
+
+  if (t.isFor(block)) {
+    _.each(FOR_KEYS, function (key) {
+      var node = block[key];
+      if (t.isLet(node)) add(node);
     });
-  } else if (t.isCatchClause(block)) {
-    self.add(block.param, ids);
+
+    block = block.body;
   }
 
+  // Program, BlockStatement - let variables
+
+  if (t.isBlockStatement(block) || t.isProgram(block)) {
+    _.each(block.body, function (node) {
+      // check for non-var `VariableDeclaration`s
+      if (t.isLet(node)) add(node);
+    });
+  }
+
+  // CatchClause - param
+
+  if (t.isCatchClause(block)) {
+    add(block.param);
+  }
+
+  // Program, Function - var variables
+
+  if (t.isProgram(block) || t.isFunction(block)) {
+    traverse(block, function (node) {
+      if (t.isFor(node)) {
+        _.each(FOR_KEYS, function (key) {
+          var declar = node[key];
+          if (t.isVar(declar)) add(declar);
+        });
+      }
+
+      // this block is a function so we'll stop since none of the variables
+      // declared within are accessible
+      if (t.isFunction(node)) return false;
+
+      // we've ran into a declaration!
+      // we'll let the BlockStatement scope deal with `let` declarations
+      if (t.isDeclaration(node) && !t.isLet(node)) {
+        add(node);
+      }
+    });
+  }
+
+  // Function - params, rest
+
   if (t.isFunction(block)) {
+    add(block.rest);
     _.each(block.params, function (param) {
-      self.add(param, ids);
+      add(param);
     });
   }
 
-  return ids;
+  return info;
 };
 
-Scope.prototype.add = function (node, ids) {
-  _.merge(ids || this.ids, t.getIds(node, true));
+Scope.prototype.addDeclaration = function (node, declarations) {
+  if (!node) return;
+  _.merge(declarations || this.declarations, t.getIds(node, true));
 };
 
 Scope.prototype.get = function (id) {
@@ -59,7 +98,7 @@ Scope.prototype.get = function (id) {
 };
 
 Scope.prototype.getOwn = function (id) {
-  return _.has(this.ids, id) && this.ids[id];
+  return _.has(this.declarations, id) && this.declarations[id];
 };
 
 Scope.prototype.parentGet = function (id) {

lib/6to5/types/alias-keys.json

@@ -35,12 +35,13 @@
   "ClassDeclaration": ["Statement", "Declaration", "Class"],
   "ClassExpression":  ["Class"],
 
-  "ForOfStatement": ["Statement", "For"],
-  "ForInStatement": ["Statement", "For"],
-  "ForStatement":   ["Statement", "For"],
+  "ForOfStatement": ["Statement", "For", "Scope"],
+  "ForInStatement": ["Statement", "For", "Scope"],
+  "ForStatement":   ["Statement", "For", "Scope"],
 
   "ObjectPattern": ["Pattern"],
   "ArrayPattern":  ["Pattern"],
 
-  "Property": ["UserWhitespacable"]
+  "Property": ["UserWhitespacable"],
+  "XJSElement": ["UserWhitespacable"]
 }

lib/6to5/types/builder-keys.json

@@ -7,11 +7,12 @@
   "ConditionalExpression":   ["test", "consequent", "alternate"],
   "ExpressionStatement":     ["expression"],
   "File":                    ["program", "comments", "tokens"],
-  "FunctionExpression":      ["id", "params", "body"],
+  "FunctionExpression":      ["id", "params", "body", "generator"],
   "Identifier":              ["name"],
   "IfStatement":             ["test", "consequent", "alternate"],
   "Literal":                 ["value"],
   "MemberExpression":        ["object", "property", "computed"],
+  "NewExpression":           ["callee", "arguments"],
   "ObjectExpression":        ["properties"],
   "ParenthesizedExpression": ["expression"],
   "Program":                 ["body"],
@@ -20,5 +21,6 @@
   "SequenceExpression":      ["expressions"],
   "UnaryExpression":         ["operator", "argument", "prefix"],
   "VariableDeclaration":     ["kind", "declarations"],
-  "VariableDeclarator":      ["id", "init"]
+  "VariableDeclarator":      ["id", "init"],
+  "YieldExpression":         ["argument", "delegate"]
 }

lib/6to5/types/index.js

@@ -70,6 +70,9 @@ t.isReferenced = function (node, parent) {
   // we're a property key so we aren't referenced
   if (t.isProperty(parent) && parent.key === node) return false;
 
+  // we're a variable declarator id so we aren't referenced
+  if (t.isVariableDeclarator(parent) && parent.id === node) return false;
+
   var isMemberExpression = t.isMemberExpression(parent);
 
   // we're in a member expression and we're the computed property so we're referenced
@@ -106,6 +109,10 @@ t.ensureBlock = function (node) {
 };
 
 t.toStatement = function (node, ignore) {
+  if (t.isStatement(node)) {
+    return node;
+  }
+
   var mustHaveId = false;
   var newType;
 
@@ -115,8 +122,6 @@ t.toStatement = function (node, ignore) {
   } else if (t.isFunction(node)) {
     mustHaveId = true;
     newType = "FunctionDeclaration";
-  } else if (t.isStatement(node)) {
-    newType = node.type;
   }
 
   if (mustHaveId && !node.id) {
@@ -159,7 +164,7 @@ t.toBlock = function (node, parent) {
 t.getIds = function (node, map, ignoreTypes) {
   ignoreTypes = ignoreTypes || [];
 
-  var search = [node];
+  var search = [].concat(node);
   var ids    = {};
 
   while (search.length) {
@@ -204,13 +209,32 @@ t.getIds.arrays = {
   ObjectPattern: "properties"
 };
 
+t.isLet = function (node) {
+  return t.isVariableDeclaration(node) && (node.kind !== "var" || node._let);
+};
+
+t.isVar = function (node) {
+  return t.isVariableDeclaration(node, { kind: "var" }) && !node._let;
+};
+
+t.removeComments = function (child) {
+  delete child.leadingComments;
+  delete child.trailingComments;
+  return child;
+};
+
+t.inheritsComments = function (child, parent) {
+  child.leadingComments  = _.compact([].concat(child.leadingComments, parent.leadingComments));
+  child.trailingComments = _.compact([].concat(child.trailingComments, parent.trailingComments));
+  return child;
+};
+
 t.inherits = function (child, parent) {
-  child.loc              = parent.loc;
-  child.end              = parent.end;
-  child.range            = parent.range;
-  child.start            = parent.start;
-  child.leadingComments  = parent.leadingComments;
-  child.trailingComments = parent.trailingComments;
+  child.loc   = parent.loc;
+  child.end   = parent.end;
+  child.range = parent.range;
+  child.start = parent.start;
+  t.inheritsComments(child, parent);
   return child;
 };
 

lib/6to5/util.js

@@ -17,6 +17,10 @@ exports.canCompile = function (filename, altExts) {
   return _.contains(exts, ext);
 };
 
+exports.isInteger = function (i) {
+  return _.isNumber(i) && i % 1 === 0;
+};
+
 exports.resolve = function (loc) {
   try {
     return require.resolve(loc);
@@ -102,8 +106,13 @@ exports.buildDefineProperties = function (mutatorMap) {
       if (key[0] === "_") return;
 
       node = _.clone(node);
+      var inheritNode = node;
       if (t.isMethodDefinition(node)) node = node.value;
-      mapNode.properties.push(t.property("init", t.identifier(key), node));
+
+      var prop = t.property("init", t.identifier(key), node);
+      t.inheritsComments(prop, inheritNode);
+      t.removeComments(inheritNode);
+      mapNode.properties.push(prop);
     });
 
     objExpr.properties.push(propNode);
@@ -123,23 +132,17 @@ exports.template = function (name, nodes, keepExpression) {
 
   template = _.cloneDeep(template);
 
-  var inherits = false;
-  if (nodes) {
-    inherits = nodes.inherits;
-    delete nodes.inherits;
-
-    if (!_.isEmpty(nodes)) {
-      traverse(template, function (node) {
-        if (t.isIdentifier(node) && _.has(nodes, node.name)) {
-          var newNode = nodes[node.name];
-          if (_.isString(newNode)) {
-            node.name = newNode;
-          } else {
-            return newNode;
-          }
+  if (!_.isEmpty(nodes)) {
+    traverse(template, function (node) {
+      if (t.isIdentifier(node) && _.has(nodes, node.name)) {
+        var newNode = nodes[node.name];
+        if (_.isString(newNode)) {
+          node.name = newNode;
+        } else {
+          return newNode;
         }
-      });
-    }
+      }
+    });
   }
 
   var node = template.body[0];
@@ -150,10 +153,6 @@ exports.template = function (name, nodes, keepExpression) {
     if (t.isParenthesizedExpression(node)) node = node.expression;
   }
 
-  if (inherits) {
-    node = t.inherits(node, inherits);
-  }
-
   return node;
 };
 
@@ -244,7 +243,7 @@ exports.parse = function (opts, code, callback) {
   }
 };
 
-exports.parseNoProperties = function (loc, code) {
+exports.parseTemplate = function (loc, code) {
   var ast = exports.parse({ filename: loc }, code).program;
   return traverse.removeProperties(ast);
 };
@@ -266,7 +265,7 @@ var loadTemplates = function () {
     var loc  = templatesLoc + "/" + name;
     var code = fs.readFileSync(loc, "utf8");
 
-    templates[key] = exports.parseNoProperties(loc, code);
+    templates[key] = exports.parseTemplate(loc, code);
   });
 
   return templates;
@@ -277,9 +276,5 @@ try {
 } catch (err) {
   if (err.code !== "MODULE_NOT_FOUND") throw err;
 
-  Object.defineProperty(exports, "templates", {
-    get: function () {
-      return exports.templates = loadTemplates();
-    }
-  });
+  exports.templates = loadTemplates();
 }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "1.12.2",
+  "version": "1.12.20",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/6to5/6to5",
   "repository": {
@@ -44,12 +44,12 @@
     "es6-symbol": "0.1.1",
     "regexpu": "0.3.0",
     "source-map": "0.1.40",
-    "regenerator-6to5": "https://github.com/6to5/regenerator-6to5/archive/62d1bfcb331dcf0bbcdbbee8043da0c6408f09cf.tar.gz",
     "chokidar": "0.10.5",
     "source-map-support": "0.2.8",
     "esutils": "1.1.4",
-    "acorn-6to5": "https://github.com/6to5/acorn-6to5/archive/0384a0d51f630f66ed591769c1765581a17d2124.tar.gz",
-    "estraverse": "^1.7.0"
+    "acorn-6to5": "https://github.com/6to5/acorn-6to5/archive/74d8e9bed20ba302d3504f53d0b1c649968959e1.tar.gz",
+    "estraverse": "^1.7.0",
+    "private": "^0.1.6"
   },
   "devDependencies": {
     "istanbul": "0.3.2",

test/_generator-helpers.js

@@ -0,0 +1,33 @@
+var assert = require("assert");
+
+exports.check = function check(g, yields, returnValue) {
+  for (var i = 0; i < yields.length; ++i) {
+    var info = i > 0 ? g.next(i) : g.next();
+    assert.deepEqual(info.value, yields[i]);
+    assert.strictEqual(info.done, false);
+  }
+
+  assert.deepEqual(
+    i > 0 ? g.next(i) : g.next(),
+    { value: returnValue, done: true }
+  );
+};
+
+// A version of `throw` whose behavior can't be statically analyzed.
+// Useful for testing dynamic exception dispatching.
+exports.raise = function raise(argument) {
+  throw argument;
+};
+
+exports.assertAlreadyFinished = function assertAlreadyFinished(generator) {
+  try {
+    generator.next();
+    assert.ok(false, "should have thrown an exception");
+  } catch (err) {
+    assert.ok(err instanceof Error);
+    assert.strictEqual(
+      err.message,
+      "Generator has already finished"
+    );
+  }
+};

test/_helper.js

@@ -36,8 +36,6 @@ exports.get = function (entryName) {
     if (fs.existsSync(suiteOptsLoc)) suite.options = require(suiteOptsLoc);
 
     _.each(fs.readdirSync(suite.filename), function (taskName) {
-      if (taskName[0] === ".") return;
-
       var taskDir = suite.filename + "/" + taskName;
       if (fs.statSync(taskDir).isFile()) return;
 
@@ -50,8 +48,9 @@ exports.get = function (entryName) {
       var execLoc   = taskDir + "/exec.js";
 
       var taskOpts = _.merge({
-        filename: actualLocAlias,
-        sourceMapName: expectLocAlias
+        filenameRelative: expectLocAlias,
+        sourceFileName:   actualLocAlias,
+        sourceMapName:    expectLocAlias
       }, _.cloneDeep(suite.options));
 
       var taskOptsLoc = taskDir + "/options.json";
@@ -59,8 +58,10 @@ exports.get = function (entryName) {
 
       var test = {
         title: humanise(taskName),
+        disabled: taskName[0] === ".",
         options: taskOpts,
         exec: {
+          loc: execLoc,
           code: readFile(execLoc),
           filename: execLocAlias,
         },

test/api.js

@@ -0,0 +1,17 @@
+var transform = require("../lib/6to5/transformation/transform");
+var assert    = require("assert");
+var File      = require("../lib/6to5/file");
+
+suite("api", function () {
+  test("{ code: false }", function () {
+    var result = transform("foo('bar');", { code: false });
+    assert.ok(!result.code);
+  });
+
+  test("addDeclaration unknown", function () {
+    var file = new File;
+    assert.throws(function () {
+      file.addDeclaration("foob");
+    }, /unknown declaration foob/);
+  });
+});

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/bar/bar.js

@@ -1,3 +1,4 @@
 "use strict";
 
 var Test = function Test() {};
+//# sourceMappingURL=bar.js.map

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/foo.js

@@ -3,3 +3,4 @@
 arr.map(function (x) {
   return x * MULTIPLIER;
 });
+//# sourceMappingURL=foo.js.map

test/fixtures/bin/6to5/filenames --out-file --source-maps/out-files/script3.js

@@ -6,3 +6,5 @@ var Test = function Test() {};
 arr.map(function (x) {
   return x * MULTIPLIER;
 });
+
+//# sourceMappingURL=script3.js.map

test/fixtures/bin/6to5/stdin --out-file --source-maps/out-files/test.js

@@ -3,3 +3,5 @@
 arr.map(function (x) {
   return x * x;
 });
+
+//# sourceMappingURL=test.js.map

test/fixtures/generation/basic/array-comprehensions/actual.js

@@ -1,3 +0,0 @@
-var multiples = [for (num of nums) num * num];
-var multiples = [for (num of nums) for (num2 of nums) num * num];
-var multiples = [for (num of nums) if (num > 5) num * num];

test/fixtures/generation/basic/array-comprehensions/expected.js

@@ -1,3 +0,0 @@
-var multiples = [for (num of nums) num * num];
-var multiples = [for (num of nums) for (num2 of nums) num * num];
-var multiples = [for (num of nums) if (num > 5) num * num];

test/fixtures/generation/basic/arrays/actual.js

@@ -1 +0,0 @@
-var foo = [1, 2, 3];

test/fixtures/generation/basic/arrays/expected.js

@@ -1 +0,0 @@
-var foo = [1, 2, 3];

test/fixtures/generation/basic/template-literals/actual.js

@@ -1,17 +0,0 @@
-var foo = `i
-am a multiline string`;
-
-var foo = `i am also
-   a multiline string
-foobar`;
-
-var foo = `im a single line string`;
-
-var foo = tagit`i
-am a multiline string`;
-
-var foo = tagit`i am also
-   a multiline string
-foobar`;
-
-var foo = tagit`im a single line string`;

test/fixtures/generation/basic/template-literals/expected.js

@@ -1,17 +0,0 @@
-var foo = `i
-am a multiline string`;
-
-var foo = `i am also
-   a multiline string
-foobar`;
-
-var foo = `im a single line string`;
-
-var foo = tagit`i
-am a multiline string`;
-
-var foo = tagit`i am also
-   a multiline string
-foobar`;
-
-var foo = tagit`im a single line string`;

test/fixtures/generation/comments/.comment-only/actual.js

@@ -2,3 +2,5 @@
 /**/
 /*
 */
+
+test

test/fixtures/generation/comments/simple-a-lot-of-line-comment/expected.js

@@ -20,8 +20,11 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+
 function test() {}
 
+
+
 // Copyright (C) 2012 Yusuke Suzuki <utatane.tea@gmail.com>
 //
 // Redistribution and use in source and binary forms, with or without

test/fixtures/generation/harmony-edgecase/exports/expected.js

@@ -4,6 +4,6 @@ export { a as b, c as d } from "hello";
 export { a as b, c as d };
 export {};
 export default i = 20;
-export function test() {};
+export function test() {}
 export var i = 20;
 export let i = 42;