v5.2.3

This reverts commit c3c4cf17e3.

.babelrc

@@ -1,6 +1,6 @@
 {
-  "experimental": true,
+  "stage": 0,
-  "playground": true,
+  "loose": ["all"],
-  "loose": true,
+  "blacklist": ["es6.tailCall"],
-  "blacklist": ["es6.tailCall"]
+  "optional": ["optimisation.flow.forOf"]
 }

.gitignore

@@ -11,6 +11,7 @@ test/core/tmp
 coverage
 dist
 .package.json
+packages/babel-runtime/core-js
 packages/babel-runtime/helpers/*.js
 packages/babel-runtime/regenerator/*.js
 lib

.gitmodules

@@ -1,12 +1,6 @@
 [submodule "vendor/traceur"]
 	path = vendor/traceur
 	url = https://github.com/google/traceur-compiler
-[submodule "vendor/regenerator"]
-	path = vendor/regenerator
-	url = https://github.com/babel/regenerator-babel
-[submodule "vendor/test262"]
-	path = vendor/test262
-	url = https://github.com/tc39/test262
 [submodule "vendor/compat-table"]
 	path = vendor/compat-table
 	url = https://github.com/kangax/compat-table

.travis.yml

@@ -1,5 +1,8 @@
-sudo: false
+#sudo: false
 language: node_js
+cache:
+  directories:
+    - node_modules
 node_js:
   - "0.12"
   - "iojs"

CHANGELOG.md

@@ -13,6 +13,236 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
 
+## 5.2.3
+
+ * **Bug Fix**
+  * Fix plugin containers being called with an undefined import. Thanks [@timbur](https://github.com/timbur)!
+  * Allow Flow object separators to be commas. Thanks [@monsanto](https://github.com/monsanto)!
+  * Add missing `Statement` and `Declaration` node aliases to flow types.
+
+## 5.2.2
+
+ * **Internal**
+  * Allow `util.arrayify` to take arbitrary types and coerce it into an array.
+
+## 5.2.1
+
+ * **Bug Fix**
+  * Fix regression in `node/register` that caused `node_modules` to not be ignored.
+
+## 5.2.0
+
+ * **Bug Fix**
+  * Fix plugin strings splitting arbitrarily on `:` which caused full paths on Windows to fail as they include `:` after the drive letter.
+  * Call class property `initializer`s with their target instead of their descriptor.
+  * Fix `ignore` and `only` not properly working on Windows path separators. Thanks [@stagas](https://github.com/stagas)!
+  * Fix `resolveRc` running on files twice causing issues. Thanks [@lukescott](https://github.com/lukescott)!
+  * Fix shorthand properties not correctly being target for `isReferenced` checks. Thanks [@monsanto](https://github.com/monsanto)!
+ * **Polish**
+  * Allow passing an array of globs to `babel/register` `only` and `ignore` options. Thanks [@Mark-Simulacrum](https://github.com/Mark-Simulacrum)!
+  * When inferring function names that collide with upper bindings, instead of doing the wrapper, instead rename them.
+  * Consider constant-like variable declaration functions to always refer to themselves so TOC can be performed.
+  * Process globs manually when using `$ babel` as some shells such as Windows don't explode them. Thanks [@jden](https://github.com/jden)!
+  * Add alternative way to execute plugins via a closure that's called with the current Babel instance.
+ * **Internal**
+  * Remove multiple internal transformers in favor of directly doing things when we need to. Previously, declarations such as `_ref` that we needed to create in specific scopes were done at the very end via the `_declarations` transformer. Now, they're done and added to the scope **right** when they're needed. This gets rid of the crappy `_declarations` property on scope nodes and fixes the crappy regenerator bug where it was creating a new `BlockStatement` so the declarations were being lost.
+  * Rework transformer traversal optimisation. Turns out that calling a `check` function for **every single node** in the AST is ridiculously expensive. 300,000 nodes timesed by ~30 transformers meant that it took tens of seconds to perform while it's quicker to just do the unnecessary traversal. Seems obvious in hindsight.
+ * **New Feature**
+  * Add `jscript` transformer that turns named function expressions into function declarations to get around [JScript's horribly broken function expression semantics](https://kangax.github.io/nfe/#jscript-bugs). Thanks [@kondi](https://github.com/kondi)!
+  * Add `@@hasInstance` support to objects when using the `es6.spec.symbols` transformer.
+  * Add `retainLines` option that retains the line (but not the columns!) of the input code.
+
+## 5.1.13
+
+ * **Polish**
+  * Remove symbol check from `defineProperty` helper.
+
+## 5.1.12
+
+ * **Bug Fix**
+  * Fix `resolveModuleSource` not being ran on `ExportAllDeclaration`s.
+  * Fix `.babelrc` being resolved multiple times when using the require hook.
+  * Fix parse error on spread properties in assignment position.
+  * Fix `externalHelpers` option being incorrectly listed as type `string`.
+ * **Internal**
+  * Upgrade `core-js` to `0.9.0`.
+ * **Spec Compliancy**
+  * Fix object decorators not using the `initializer` pattern.
+  * Remove property initializer descriptor reflection.
+
+## 5.1.11
+
+ * **Bug Fix**
+  * Memoise and bind member expression decorators.
+  * Move JSX children cleaning to opening element visitor. Fixes elements not being cleaned in certain scenarios.
+  * Consider `SwitchStatement`s to be `Scopable`.
+  * Fix `bluebirdCoroutines` calling `interopRequireWildcard` before it's defined.
+  * Add space to `do...while` code generation.
+  * Validate `super` use before `this` on `super` exit rather than entrance.
+ * **Polish**
+  * Add Babel name to logger.
+
+## 5.1.10
+
+ * **Bug Fix**
+  * Remove `makePredicate` from acorn in favor of an `indexOf`.
+  * Remove statements to expression explosion when inserting a block statement.
+ * **Internal**
+  * Remove runtime compatibility check.
+
+## 5.1.9
+
+ * **Bug Fix**
+  * Fix class property initializers with `undefined` values not being correctly writable.
+  * Fix self inferring generators incorrectly causing a stack error.
+  * Fix default export specifiers not triggering AMD `module` argument inclusion.
+  * Fix assignments not having their module references properly remapped.
+ * **Internal**
+  * Upgrade to latest `acorn`.
+ * **Polish**
+  * Make invalid LHS pattern error messages nicer.
+
+## 5.1.8
+
+ * **Bug Fix**
+  * Only make parenthesized object pattern LHS illegal.
+
+## 5.1.7
+
+ * **Internal**
+  * Add `parse` node API.
+
+## 5.1.6
+
+ * **Bug Fix**
+  * Fix `runtime` built-in catchall not properly checking for local variables.
+
+## 5.1.5
+
+ * **Internal**
+  * Bump `core-js` version.
+
+## 5.1.4
+
+ * **Polish**
+  * Add missing `Reflect` methods to runtime transformer.
+
+## 5.1.3
+
+ * **Internal**
+  * Switch entirely to vanilla regenerator.
+  * Clean up and make the parsing of decorators stateless.
+ * **Bug Fix**
+  * Don't do TCO on generators and async functions.
+  * Add missing `core-js` runtime definitions.
+
+## 5.1.2
+
+ * **Bug Fix**
+  * Add `getIterator` and `isIterable` to `babel-runtime` build script.
+
+## 5.1.1
+
+ * **Bug Fix**
+  * Add missing runtime symbol definitions.
+
+## 5.1.0
+
+ * **Bug Fix**
+  * Fix super reference when using decorators.
+  * Don't do array unpack optimisation when member expressions are present.
+  * Add missing descriptors for undecorated class properties.
+  * Don't consider `arguments` and `eval` valid function names when doing function name inferrence.
+  * Fix scope tracking of constants in loop heads.
+  * Parse `AwaitExpression` as a unary instead of an assignment.
+  * Fix regex evaluation when attempting static evaluation.
+  * Don't emit tokens when doing a lookahead.
+  * Add missing `test` declaration to `utility.deadCodeElimination` transformer.
+ * **Internal**
+  * Upgrade `regenerator` to the latest and use my branch with the hope of eventually switching to vanilla regenerator.
+  * Add support for the replacement of for loop `init`s with statements.
+  * Upgrade dependencies.
+ * **Polish**
+  * When adding the scope IIFE when using default parameters, don't shadow the function expression, just `apply` `this` and `arguments` if necessary.
+  * Use path basename as non-default import fallback.
+ * **New Feature**
+  * Add [trailing function comma proposal](https://github.com/jeffmo/es-trailing-function-commas). Thanks [@AluisioASG](https://github.com/AluisioASG)!
+  * Add support for object literal decorators.
+  * Make core-js modular when using the `runtime` transformer.
+
+## 5.0.12
+
+ * **Bug Fix**
+  * Fix incorrect remapping of module references inside of a function id redirection container.
+
+## 5.0.11
+
+ * **Bug Fix**
+  * Fix new `for...of` loops not properly inheriting their original loop.
+ * **Internal**
+  * Disable scope instance cache.
+ * **Polish**
+  * Allow comments in `.babelrc` JSON.
+
+## 5.0.9
+
+ * **Polish**
+  * Use `moduleId` for UMD global name if available.
+ * **Bug Fix**
+  * Fix UMD global `module` variable shadowing the `amd`/`common` `module` variable.
+  * Fix Flow param type annotation regression.
+  * Fix function name collision `toString` wrapper. Thanks [@alawatthe](https://github.com/alawatthe)!
+
+## 5.0.8
+
+ * **Bug Fix**
+  * Fix falsy static class properties not being writable.
+  * Fix block scoping collisions not properly detecting modules and function clashes.
+  * Skip `this` before `super` for derived constructors on functions.
+
+## 5.0.7
+
+ * **New Feature**
+  * Add `--ignore` and `--only` support to the CLI.
+ * **Bug Fix**
+  * Remove `HOMEPATH` environment variable from home resolution in `babel/register` cache.
+ * **Internal**
+  * Disable WIP path resolution introducing infinite recursion in some code examples.
+ * **Polish**
+  * Add live binding to CommonJS default imports.
+
+## 5.0.6
+
+ * **Bug Fix**
+  * Fix mangling of import references that collide with properties on `Object.prototype`.
+  * Fix duplicate declarations incorrectly being reported for `var`.
+
+## 5.0.5
+
+ * **Internal**
+  * Upgrade `core-js`.
+ * **Bug Fix**
+  * Fix arrays not being supported in `util.list`.
+
+## 5.0.4
+
+ * **Polish**
+  * Check for top level `breakConfig` in `resolveRc`.
+
+## 5.0.3
+
+ * **Bug Fix**
+  * Make relative location absolute before calling `resolveRc`.
+ * **Internal**
+  * Switch to global UID registry.
+  * Add `breakConfig` option to prevent Babel from erroring when hitting that option.
+
+## 5.0.1
+
+ * **Bug Fix**
+  * Fix duplicate declaration regression.
+  * Fix not being able to call non-writable methods.
+
 ## 5.0.0
 
  * **New Feature**

CONTRIBUTING.md

@@ -1,9 +1,24 @@
+<p align="center">
+   <strong><a href="#setup">Setup</a></strong>
+   |
+   <strong><a href="#running-tests">Running tests</a></strong>
+   |
+   <strong><a href="#workflow">Workflow</a></strong>
+   |
+   <strong><a href="#dependencies">Dependencies</a></strong>
+   |
+   <strong><a href="#code-standards">Code Standards</a></strong>
+</p>
+
+----
+
 # Contributing
 
 Contributions are always welcome, no matter how large or small. Before
 contributing, please read the
 [code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
 
+
 ## Developing
 
 #### Setup
@@ -14,14 +29,19 @@ $ cd babel
 $ make bootstrap
 ```
 
-Then you need to run:
+Then you can either run:
+
+```sh
+$ make build-core
+```
+
+to build Babel **once** or:
 
 ```sh
 $ make watch-core
 ```
 
-This will compile Babel and then sit in the background and on file modification
+to have Babel build itself then incrementally build files on change.
-recompile the necessary files.
 
 #### Running tests
 
@@ -35,15 +55,20 @@ This is mostly overkill and you can limit the tests to a select few by directly
 running them with `mocha`:
 
 ```sh
-$ mocha test/transformation.js
+$ mocha test/core/transformation.js
 ```
 
 Use mocha's `--grep` option to run a subset of tests by name:
 
 ```sh
-$ mocha test/transformation.js --grep es7
+$ mocha test/core/transformation.js --grep es7
 ```
 
+If you don't have `mocha` installed globally, you can still use it from Babel's
+dependencies in `node_modules`, but make sure `node_modules/.bin` is added to
+your [`$PATH`](http://unix.stackexchange.com/questions/26047/how-to-correctly-add-a-path-to-path) environment variable.
+
+
 #### Workflow
 
 * Fork the repository
@@ -54,24 +79,91 @@ $ mocha test/transformation.js --grep es7
 * Ensure the test are passing (`make test`)
 * Create new pull request explaining your proposed change or reference an issue in your commit message
 
+
+#### Dependencies
+
++ [ast-types](http://ghub.io/ast-types) This is required to monkeypatch regenerators AST definitions. Could be improved in the future.
+
++ [chalk](http://ghub.io/chalk) This is used for terminal color highlighting for syntax errors.
+
++ [convert-source-map](http://ghub.io/convert-source-map) Turns a source map object into a comment etc.
+
++ [core-js](http://ghub.io/core-js) Used for the polyfill.
+
++ [debug](http://ghub.io/debug) Used to output debugging information when NODE_DEBUG is set to babel.
+
++ [detect-indent](http://ghub.io/detect-indent) This is used in the code generator so it can infer indentation.
+
++ [estraverse](http://ghub.io/estraverse) The only method on this is attachComments. I'd like to implement our own comment attachment algorithm eventually though.
+
++ [esutils](http://ghub.io/esutils) Various ES related utilities. Check whether something is a keyword etc.
+
++ [fs-readdir-recursive](http://ghub.io/fs-readdir-recursive) Recursively search a directory for.
+
++ [globals](http://ghub.io/globals) A list of JavaScript global variables. This is used by the scope tracking to check for colliding variables.
+
++ [is-integer](http://ghub.io/is-integer) Checks if something is an integer.
+
++ [js-tokens](http://ghub.io/js-tokens) This is used to get tokens for syntax error highlighting.
+
++ [leven](http://ghub.io/leven) A levenstein algorithm to determine how close a word is to another. This is used to offer suggestions when using the utility.undeclaredVariableCheck transformer.
+
++ [line-numbers](http://ghub.io/line-numbers) Used to produce the code frames in syntax errors.
+
++ [lodash](http://ghub.io/lodash) Used for various utilities.
+
++ [minimatch](http://ghub.io/minimatch) This is used to match glob-style ignore/only filters.
+
++ [output-file-sync](http://ghub.io/output-file-sync) Synchronously writes a file and create its ancestor directories if needed.
+
++ [path-is-absolute](http://ghub.io/path-is-absolute) Checks if a path is absolute. C:\foo and \foo are considered absolute.
+
++ [regenerator](http://ghub.io/regenerator) This is used to transform generators/async functions.
+
++ [regexpu](http://ghub.io/regexpu) Used to transform unicode regex patterns.
+
++ [repeating](http://ghub.io/repeating) Repeats a string.
+
++ [shebang-regex](http://ghub.io/shebang-regex) Literally just a regex that matches shebangs.
+
++ [slash](http://ghub.io/slash) Normalises path separators.
+
++ [source-map](http://ghub.io/source-map) Generates sourcemaps.
+
++ [source-map-support](http://ghub.io/source-map-support) Adds source map support to babel-node/babel/register.
+
++ [strip-json-comments](http://ghub.io/strip-json-comments) Remove comments from a JSON string. This is used for .babelrc files.
+
++ [to-fast-properties](http://ghub.io/to-fast-properties) A V8 trick to put an object into fast properties mode.
+
++ [trim-right](http://ghub.io/trim-right) Trims the rightside whitespace.
+
++ [user-home](http://ghub.io/user-home) Gets the users home directory. This is used to resolve the babel-node/babel/register cache.
+
+
 #### Code Standards
 
  * **General**
    * 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**
    * 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

Makefile

@@ -9,17 +9,20 @@ BABEL_CMD = node_modules/babel/bin/babel
 
 export NODE_ENV = test
 
-.PHONY: clean test test-cov test-clean test-travis test-simple test-all test-browser test-parser publish build bootstrap publish-core publish-runtime build-core watch-core build-core-test
+.PHONY: clean test test-cov test-clean test-travis test-simple test-all test-browser test-parser publish build bootstrap publish-core publish-runtime build-core watch-core build-core-test clean-core
 
-build-core:
+build-core: clean-core
 	node $(BABEL_CMD) src --out-dir lib --copy-files
 
-build-core-test:
+build-core-test: clean-core
 	node $(BABEL_CMD) src --out-dir lib --copy-files --auxiliary-comment "istanbul ignore next"
 
-watch-core:
+watch-core: clean-core
 	node $(BABEL_CMD) src --out-dir lib --watch --copy-files
 
+clean-core:
+	rm -rf lib
+
 build:
 	mkdir -p dist
 	make build-core
@@ -109,9 +112,10 @@ publish-cli:
 	npm publish
 
 bootstrap:
+	npm list --global --depth 1 babel >/dev/null 2>&1 && npm uninstall -g babel || true
 	npm install
 	npm link
-	cd packages/babel-cli && npm install && npm link
+	cd packages/babel-cli && npm install && npm link && npm link babel-core
 	git submodule update --init
-	cd vendor/regenerator && npm install
 	cd vendor/compat-table && npm install object-assign
+	make build

README.md

@@ -9,7 +9,7 @@
 </p>
 
 <p align="center">
-  For questions and support please visit the <a href="https://gitter.im/babel/babel">gitter room</a> or <a href="stackoverflow.com">StackOverflow</a>. The Babel issue tracker is <strong>exclusively</strong> for bug reports and future requests.
+  For questions and support please visit the <a href="https://gitter.im/babel/babel">gitter room</a> or <a href="http://stackoverflow.com/questions/tagged/babeljs">StackOverflow</a>. The Babel issue tracker is <strong>exclusively</strong> for bug reports and feature requests.
 </p>
 
 <p align="center">

package.json

@@ -1,7 +1,7 @@
 {
   "name": "babel-core",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "5.0.0",
+  "version": "5.2.3",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
   "repository": "babel/babel",
@@ -28,45 +28,49 @@
   },
   "dependencies": {
     "ast-types": "~0.7.0",
+    "bluebird": "^2.9.25",
     "chalk": "^1.0.0",
-    "convert-source-map": "^0.5.0",
+    "convert-source-map": "^1.1.0",
-    "core-js": "^0.8.0",
+    "core-js": "^0.9.0",
     "debug": "^2.1.1",
     "detect-indent": "^3.0.0",
-    "estraverse": "^1.9.1",
+    "estraverse": "^3.0.0",
-    "esutils": "^1.1.6",
+    "esutils": "^2.0.0",
     "fs-readdir-recursive": "^0.1.0",
-    "globals": "^6.2.0",
+    "globals": "^6.4.0",
     "is-integer": "^1.0.4",
     "js-tokens": "1.0.0",
     "leven": "^1.0.1",
     "line-numbers": "0.2.0",
-    "lodash": "^3.2.0",
+    "lodash": "^3.6.0",
     "minimatch": "^2.0.3",
     "output-file-sync": "^1.1.0",
     "path-is-absolute": "^1.0.0",
     "private": "^0.1.6",
-    "regenerator-babel": "0.8.13-2",
+    "regenerator": "^0.8.20",
     "regexpu": "^1.1.2",
     "repeating": "^1.1.2",
+    "resolve": "^1.1.6",
     "shebang-regex": "^1.0.0",
     "slash": "^1.0.0",
     "source-map": "^0.4.0",
-    "source-map-support": "^0.2.9",
+    "source-map-support": "^0.2.10",
+    "strip-json-comments": "^1.0.2",
     "to-fast-properties": "^1.0.0",
-    "trim-right": "^1.0.0"
+    "trim-right": "^1.0.0",
+    "user-home": "^1.1.1"
   },
   "devDependencies": {
-    "babel": "4.7.13",
+    "babel": "5.1.13",
-    "browserify": "^9.0.3",
+    "browserify": "^9.0.8",
-    "chai": "^2.0.0",
+    "chai": "^2.2.0",
-    "eslint": "^0.15.1",
+    "eslint": "^0.18.0",
-    "babel-eslint": "^1.0.1",
+    "babel-eslint": "^2.0.0",
     "esvalid": "^1.1.0",
     "istanbul": "^0.3.5",
     "matcha": "^0.6.0",
-    "mocha": "^2.1.0",
+    "mocha": "2.2.0",
-    "rimraf": "^2.2.8",
+    "rimraf": "^2.3.2",
     "uglify-js": "^2.4.16"
   }
 }

packages/babel-cli/README.md

@@ -0,0 +1,5 @@
+# babel-cli
+
+Babel CLI
+
+For more information please look at [babel](https://github.com/babel/babel).

packages/babel-cli/bin/_babel-node

@@ -4,6 +4,7 @@ var pathIsAbsolute = require("path-is-absolute");
 var commander      = require("commander");
 var Module         = require("module");
 var babel          = require("babel-core");
+var inspect        = require("util").inspect;
 var path           = require("path");
 var repl           = require("repl");
 var util           = require("babel-core").util;
@@ -71,7 +72,10 @@ if (program.eval || program.print) {
   global.require = module.require.bind(module);
 
   var result = _eval(code, global.__filename);
-  if (program.print) console.log(result);
+  if (program.print) {
+    var output = _.isString(result) ? result : inspect(result);
+    process.stdout.write(output + "\n");
+  }
 } else {
   if (program.args.length) {
     // slice all arguments up to the first filename since they're babel args that we handle

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

@@ -28,6 +28,8 @@ module.exports = function (commander, filenames, opts) {
   };
 
   var handleFile = function (src, filename) {
+    if (util.shouldIgnore(src)) return;
+
     if (util.canCompile(filename)) {
       write(src, filename);
     } else if (commander.copyFiles) {

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

@@ -107,6 +107,8 @@ module.exports = function (commander, filenames, opts) {
     });
 
     _.each(_filenames, function (filename) {
+      if (util.shouldIgnore(filename)) return;
+
       results.push(util.compile(filename));
     });
 

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

@@ -8,6 +8,7 @@ var util      = require("babel-core").util;
 var each      = require("lodash/collection/each");
 var keys      = require("lodash/object/keys");
 var fs        = require("fs");
+var glob      = require("glob");
 
 each(options, function (option, key) {
   if (option.hidden) return;
@@ -69,7 +70,9 @@ commander.parse(process.argv);
 
 var errors = [];
 
-var filenames = commander.args;
+var filenames = commander.args.reduce(function (globbed, input) {
+  return globbed.concat(glob.sync(input));
+}, []);
 
 each(filenames, function (filename) {
   if (!fs.existsSync(filename)) {
@@ -102,12 +105,15 @@ if (errors.length) {
 
 //
 
-exports.opts = {};
+var opts = exports.opts = {};
 
 each(options, function (opt, key) {
-  exports.opts[key] = commander[key];
+  opts[key] = commander[key];
 });
 
+opts.ignore = util.arrayify(opts.ignore, util.regexify);
+opts.only   = util.arrayify(opts.only, util.regexify);
+
 var fn;
 
 if (commander.outDir) {

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

@@ -16,6 +16,10 @@ exports.readdir = readdir;
 
 exports.canCompile = util.canCompile;
 
+exports.shouldIgnore = function (loc) {
+  return util.shouldIgnore(loc, index.opts.ignore, index.opts.only);
+};
+
 exports.addSourceMappingUrl = function (code, loc) {
   return code + "\n//# sourceMappingURL=" + path.basename(loc);
 };
@@ -23,6 +27,8 @@ exports.addSourceMappingUrl = function (code, loc) {
 exports.transform = function (filename, code, opts) {
   opts = _.defaults(opts || {}, index.opts);
   opts.filename = filename;
+  opts.ignore = null;
+  opts.only = null;
 
   var result = babel.transform(code, opts);
   result.filename = filename;

packages/babel-cli/package.json

@@ -1,19 +1,21 @@
 {
   "name": "babel",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "5.0.0-beta4",
+  "version": "5.2.2",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
   "repository": "babel/babel",
   "preferGlobal": true,
   "dependencies": {
-    "chokidar": "^0.12.6",
+    "babel-core": "^5.2.2",
-    "babel-core": "5.0.0-beta4",
+    "chokidar": "^1.0.0",
     "commander": "^2.6.0",
+    "convert-source-map": "^1.1.0",
     "fs-readdir-recursive": "^0.1.0",
-    "output-file-sync": "^1.1.0",
+    "glob": "^5.0.5",
     "lodash": "^3.2.0",
-    "convert-source-map": "^0.5.0",
+    "output-file-sync": "^1.1.0",
+    "path-is-absolute": "^1.0.0",
     "source-map": "^0.4.0"
   },
   "bin": {
@@ -21,4 +23,4 @@
     "babel-node": "./bin/babel-node",
     "babel-external-helpers": "./bin/babel-external-helpers"
   }
-}
+}

packages/babel-cli/register-without-polyfill.js

@@ -0,0 +1 @@
+module.exports = require("babel-core/register-without-polyfill");

packages/babel-runtime/package.json

@@ -1,10 +1,10 @@
 {
   "name": "babel-runtime",
   "description": "babel selfContained runtime",
-  "version": "5.0.0-beta4",
+  "version": "5.2.2",
   "repository": "babel/babel",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "dependencies": {
-    "core-js": "^0.8.0"
+    "core-js": "^0.9.0"
   }
-}
+}

packages/build-cli.js

@@ -6,6 +6,6 @@ var pkg    = require(pkgLoc);
 var mainPkg = require("../package.json");
 
 pkg.version = mainPkg.version;
-pkg.dependencies["babel-core"] = mainPkg.version;
+pkg.dependencies["babel-core"] = "^" + mainPkg.version;
 
 outputFile(pkgLoc, JSON.stringify(pkg, null, 2));

packages/build-runtime.js

@@ -13,16 +13,20 @@ function relative(filename) {
   return __dirname + "/babel-runtime/" + filename;
 }
 
-function readFile(filename, defaultify) {
+function readFile(filename, shouldDefaultify) {
   var file = fs.readFileSync(require.resolve(filename), "utf8");
 
-  if (defaultify) {
+  if (shouldDefaultify) {
-    file += '\nmodule.exports = { "default": module.exports, __esModule: true };\n';
+    file += "\n" + defaultify("module.exports") + "\n";
   }
 
   return file;
 }
 
+function defaultify(name) {
+  return 'module.exports = { "default": ' + name + ', __esModule: true };';
+}
+
 function updatePackage() {
   var pkgLoc = relative("package.json");
   var pkg    = require(pkgLoc);
@@ -66,7 +70,29 @@ each(File.helpers, function (helperName) {
   writeFile("helpers/" + helperName + ".js", buildHelper(helperName));
 });
 
-writeFile("regenerator/index.js", readFile("regenerator-babel/runtime-module", true));
+writeFile("regenerator/index.js", readFile("regenerator/runtime-module", true));
-writeFile("regenerator/runtime.js", selfContainify(readFile("regenerator-babel/runtime")));
+writeFile("regenerator/runtime.js", selfContainify(readFile("regenerator/runtime")));
+
+//
+
+var coreDefinitions = require("../lib/babel/transformation/transformers/other/runtime/definitions");
+
+var paths = ["is-iterable", "get-iterator"];
+
+each(coreDefinitions.builtins, function (path) {
+  paths.push(path);
+});
+
+each(coreDefinitions.methods, function (props) {
+  each(props, function (path) {
+    paths.push(path);
+  });
+});
+
+each(paths, function (path) {
+  writeFile("core-js/" + path + ".js", defaultify('require("core-js/library/fn/' + path + '")'));
+});
+
+//
 
 updatePackage();

register-without-polyfill.js

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

register.js

@@ -1 +1 @@
-module.exports = require("./lib/babel/api/register/node");
+module.exports = require("./lib/babel/api/register/node-polyfill");

src/acorn/index.js

@@ -0,0 +1,3 @@
+export * from "./src/index";
+import "./plugins/flow";
+import "./plugins/jsx";

src/acorn/package.json

@@ -2,7 +2,7 @@
   "name": "acorn",
   "description": "ECMAScript parser",
   "homepage": "https://github.com/marijnh/acorn",
-  "main": "src/index.js",
+  "main": "index.js",
   "version": "1.0.0",
   "engines": {
     "node": ">=0.4.0"

src/acorn/plugins/flow.js

@@ -1,4 +1,4 @@
-var acorn = require("..")
+var acorn = require("../src/index")
 
 var pp = acorn.Parser.prototype
 var tt = acorn.tokTypes
@@ -322,7 +322,7 @@ pp.flow_parseObjectType = function (allowStatic) {
 }
 
 pp.flow_objectTypeSemicolon = function () {
-  if (!this.eat(tt.semi) && this.type !== tt.braceR) {
+  if (!this.eat(tt.semi) && !this.eat(tt.comma) && this.type !== tt.braceR) {
     this.unexpected()
   }
 }

src/acorn/plugins/jsx.js

@@ -1,4 +1,4 @@
-var acorn = require("..")
+var acorn = require("../src/index")
 
 var tt = acorn.tokTypes;
 var tc = acorn.tokContexts;

src/acorn/src/expression.js

@@ -93,19 +93,25 @@ pp.parseMaybeAssign = function(noIn, refShorthandDefaultPos, afterLeftParse) {
     failOnShorthandAssign = false
   }
   let start = this.markPosition()
+  if (this.type == tt.parenL || this.type == tt.name)
+    this.potentialArrowAt = this.start
   let left = this.parseMaybeConditional(noIn, refShorthandDefaultPos)
   if (afterLeftParse) left = afterLeftParse.call(this, left, start)
   if (this.type.isAssign) {
     let node = this.startNodeAt(start)
     node.operator = this.value
     node.left = this.type === tt.eq ? this.toAssignable(left) : left
-    refShorthandDefaultPos.start = 0; // reset because shorthand default was used correctly
+    refShorthandDefaultPos.start = 0 // reset because shorthand default was used correctly
     this.checkLVal(left)
     if (left.parenthesizedExpression) {
+      let errorMsg
       if (left.type === "ObjectPattern") {
-        this.raise(left.start, "You're trying to assign to a parenthesized expression, instead of `({ foo }) = {}` use `({ foo } = {})`");
+        errorMsg = "`({a}) = 0` use `({a} = 0)`"
-      } else {
+      } else if (left.type === "ArrayPattern") {
-        this.raise(left.start, "Parenthesized left hand expressions are illegal");
+        errorMsg = "`([a]) = 0` use `([a] = 0)`"
+      }
+      if (errorMsg) {
+        this.raise(left.start, `You're trying to assign to a parenthesized expression, eg. instead of ${errorMsg}`)
       }
     }
     this.next()
@@ -224,7 +230,7 @@ pp.parseSubscripts = function(base, start, noCalls) {
   } else if (!noCalls && this.eat(tt.parenL)) {
     let node = this.startNodeAt(start)
     node.callee = base
-    node.arguments = this.parseExprList(tt.parenR, false)
+    node.arguments = this.parseExprList(tt.parenR, this.options.features["es7.trailingFunctionCommas"])
     return this.parseSubscripts(this.finishNode(node, "CallExpression"), start, noCalls)
   } else if (this.type === tt.backQuote) {
     let node = this.startNodeAt(start)
@@ -240,7 +246,7 @@ pp.parseSubscripts = function(base, start, noCalls) {
 // or `{}`.
 
 pp.parseExprAtom = function(refShorthandDefaultPos) {
-  let node
+  let node, canBeArrow = this.potentialArrowAt == this.start
   switch (this.type) {
   case tt._this:
   case tt._super:
@@ -250,7 +256,7 @@ pp.parseExprAtom = function(refShorthandDefaultPos) {
     return this.finishNode(node, type)
 
   case tt._yield:
-    if (this.inGenerator) unexpected()
+    if (this.inGenerator) this.unexpected()
 
   case tt._do:
     if (this.options.features["es7.doExpressions"]) {
@@ -271,7 +277,7 @@ pp.parseExprAtom = function(refShorthandDefaultPos) {
       if (id.name === "async") {
         // arrow functions
         if (this.type === tt.parenL) {
-          let expr = this.parseParenAndDistinguishExpression(start, true)
+          let expr = this.parseParenAndDistinguishExpression(start, true, true)
           if (expr && expr.type === "ArrowFunctionExpression") {
             return expr
           } else {
@@ -302,9 +308,8 @@ pp.parseExprAtom = function(refShorthandDefaultPos) {
     }
     //
 
-    if (!this.canInsertSemicolon() && this.eat(tt.arrow)) {
+    if (canBeArrow && !this.canInsertSemicolon() && this.eat(tt.arrow))
       return this.parseArrowExpression(this.startNodeAt(start), [id])
-    }
     return id
 
   case tt.regexp:
@@ -324,7 +329,7 @@ pp.parseExprAtom = function(refShorthandDefaultPos) {
     return this.finishNode(node, "Literal")
 
   case tt.parenL:
-    return this.parseParenAndDistinguishExpression()
+    return this.parseParenAndDistinguishExpression(null, null, canBeArrow)
 
   case tt.bracketL:
     node = this.startNode()
@@ -378,7 +383,7 @@ pp.parseParenExpression = function() {
   return val
 }
 
-pp.parseParenAndDistinguishExpression = function(start, isAsync) {
+pp.parseParenAndDistinguishExpression = function(start, isAsync, canBeArrow) {
   start = start || this.markPosition()
   let val
   if (this.options.ecmaVersion >= 6) {
@@ -407,7 +412,7 @@ pp.parseParenAndDistinguishExpression = function(start, isAsync) {
     let innerEnd = this.markPosition()
     this.expect(tt.parenR)
 
-    if (!this.canInsertSemicolon() && this.eat(tt.arrow)) {
+    if (canBeArrow && !this.canInsertSemicolon() && this.eat(tt.arrow)) {
       if (innerParenStart) this.unexpected(innerParenStart)
       return this.parseParenArrowList(start, exprList, isAsync)
     }
@@ -508,14 +513,21 @@ pp.parseTemplate = function() {
 pp.parseObj = function(isPattern, refShorthandDefaultPos) {
   let node = this.startNode(), first = true, propHash = {}
   node.properties = []
+  let decorators = []
   this.next()
   while (!this.eat(tt.braceR)) {
     if (!first) {
       this.expect(tt.comma)
       if (this.afterTrailingComma(tt.braceR)) break
     } else first = false
-
+    while (this.type === tt.at) {
+      decorators.push(this.parseDecorator())
+    }
     let prop = this.startNode(), isGenerator = false, isAsync = false, start
+    if (decorators.length) {
+      prop.decorators = decorators
+      decorators = []
+    }
     if (this.options.features["es7.objectRestSpread"] && this.type === tt.ellipsis) {
       prop = this.parseSpread()
       prop.type = "SpreadProperty"
@@ -546,6 +558,9 @@ pp.parseObj = function(isPattern, refShorthandDefaultPos) {
     this.checkPropClash(prop, propHash)
     node.properties.push(this.finishNode(prop, "Property"))
   }
+  if (decorators.length) {
+    this.raise(this.start, "You have trailing decorators with no property");
+  }
   return this.finishNode(node, isPattern ? "ObjectPattern" : "ObjectExpression")
 }
 
@@ -726,7 +741,7 @@ pp.parseAwait = function (node) {
     this.unexpected()
   }
   node.all = this.eat(tt.star)
-  node.argument = this.parseMaybeAssign(true)
+  node.argument = this.parseMaybeUnary()
   return this.finishNode(node, "AwaitExpression")
 };
 

src/acorn/src/identifier.js

@@ -9,41 +9,9 @@
 
 function makePredicate(words) {
   words = words.split(" ")
-  let f = "", cats = []
+  return function(str) {
-  out: for (let i = 0; i < words.length; ++i) {
+    return words.indexOf(str) >= 0
-    for (let j = 0; j < cats.length; ++j)
-      if (cats[j][0].length == words[i].length) {
-        cats[j].push(words[i])
-        continue out
-      }
-    cats.push([words[i]])
   }
-  function compareTo(arr) {
-    if (arr.length == 1) return f += "return str === " + JSON.stringify(arr[0]) + ";"
-    f += "switch(str){"
-    for (let i = 0; i < arr.length; ++i) f += "case " + JSON.stringify(arr[i]) + ":"
-    f += "return true}return false;"
-  }
-
-  // When there are more than three length categories, an outer
-  // switch first dispatches on the lengths, to save on comparisons.
-
-  if (cats.length > 3) {
-    cats.sort((a, b) => b.length - a.length)
-    f += "switch(str.length){"
-    for (let i = 0; i < cats.length; ++i) {
-      let cat = cats[i]
-      f += "case " + cat[0].length + ":"
-      compareTo(cat)
-    }
-    f += "}"
-
-    // Otherwise, simply generate a flat `switch` statement.
-
-  } else {
-    compareTo(words)
-  }
-  return new Function("str", f)
 }
 
 // Reserved word lists for various dialects of the language

src/acorn/src/index.js

@@ -38,9 +38,6 @@ export {isIdentifierChar, isIdentifierStart} from "./identifier"
 export {Token} from "./tokenize"
 export {isNewLine, lineBreak, lineBreakG} from "./whitespace"
 
-import "../plugins/flow";
-import "../plugins/jsx";
-
 export const version = "1.0.0"
 
 // The main exported interface (under `self.acorn` when in the

src/acorn/src/lookahead.js

@@ -18,17 +18,19 @@ var STATE_KEYS = [
 ];
 
 pp.getState = function () {
-  var state = {};
+  var state = {}
   for (var i = 0; i < STATE_KEYS.length; i++) {
-    var key = STATE_KEYS[i];
+    var key = STATE_KEYS[i]
-    state[key] = this[key];
+    state[key] = this[key]
   }
-  return state;
+  return state
 };
 
 pp.lookahead = function() {
   var old = this.getState();
-  this.next();
+  this.isLookahead = true
+  this.next()
+  this.isLookahead = false
   var curr = this.getState();
   for (var key in old) this[key] = old[key];
   return curr;

src/acorn/src/lval.js

@@ -21,6 +21,7 @@ pp.toAssignable = function(node, isBinding) {
       node.type = "ObjectPattern"
       for (let i = 0; i < node.properties.length; i++) {
         let prop = node.properties[i]
+        if (prop.type === "SpreadProperty") continue;
         if (prop.kind !== "init") this.raise(prop.key.start, "Object pattern can't contain getter or setter")
         this.toAssignable(prop.value, isBinding)
       }
@@ -125,7 +126,9 @@ pp.parseBindingList = function(close, allowEmpty, allowTrailingComma) {
       this.expect(close)
       break
     } else {
-      elts.push(this.parseAssignableListItemTypes(this.parseMaybeDefault()))
+      var left = this.parseMaybeDefault()
+      this.parseAssignableListItemTypes(left)
+      elts.push(this.parseMaybeDefault(null, left))
     }
   }
   return elts

src/acorn/src/state.js

@@ -46,6 +46,9 @@ export function Parser(options, input, startPos) {
   this.inModule = this.options.sourceType === "module"
   this.strict = this.options.strictMode === false ? false : this.inModule
 
+  // Used to signify the start of a potential arrow function
+  this.potentialArrowAt = -1
+
   // Flags to track whether we are in a function, a generator.
   this.inFunction = this.inGenerator = false
   // Labels in scope.

src/acorn/src/statement.js

@@ -458,7 +458,7 @@ pp.parseFunction = function(node, isStatement, allowExpressionBody, isAsync) {
 
 pp.parseFunctionParams = function(node) {
   this.expect(tt.parenL)
-  node.params = this.parseBindingList(tt.parenR, false, false)
+  node.params = this.parseBindingList(tt.parenR, false, this.options.features["es7.trailingFunctionCommas"])
 }
 
 // Parse a class declaration or literal (depending on the
@@ -471,14 +471,18 @@ pp.parseClass = function(node, isStatement) {
   var classBody = this.startNode()
   classBody.body = []
   this.expect(tt.braceL)
+  let decorators = []
   while (!this.eat(tt.braceR)) {
     if (this.eat(tt.semi)) continue
     if (this.type === tt.at) {
-      this.decorators.push(this.parseDecorator())
+      decorators.push(this.parseDecorator())
-      continue;
+      continue
     }
     var method = this.startNode()
-    this.takeDecorators(method)
+    if (decorators.length) {
+      method.decorators = decorators
+      decorators = []
+    }
     var isGenerator = this.eat(tt.star), isAsync = false
     this.parsePropertyName(method)
     if (this.type !== tt.parenL && !method.computed && method.key.type === "Identifier" &&
@@ -517,7 +521,7 @@ pp.parseClass = function(node, isStatement) {
     }
     this.parseClassMethod(classBody, method, isGenerator, isAsync)
   }
-  if (this.decorators.length) {
+  if (decorators.length) {
     this.raise(this.start, "You have trailing decorators with no method");
   }
   node.body = this.finishNode(classBody, "ClassBody")
@@ -687,7 +691,6 @@ pp.parseImport = function(node) {
   if (this.type === tt.string) {
     node.specifiers = empty
     node.source = this.parseExprAtom()
-    node.kind = ""
   } else {
     node.specifiers = []
     this.parseImportSpecifiers(node)

src/acorn/src/tokenize.js

@@ -28,7 +28,7 @@ const pp = Parser.prototype
 // Move to the next token
 
 pp.next = function() {
-  if (this.options.onToken)
+  if (this.options.onToken && !this.isLookahead)
     this.options.onToken(new Token(this))
 
   this.lastTokEnd = this.end

src/acorn/src/tokentype.js

@@ -116,7 +116,7 @@ kw("do", {isLoop: true})
 kw("else", beforeExpr)
 kw("finally")
 kw("for", {isLoop: true})
-kw("function")
+kw("function", startsExpr)
 kw("if")
 kw("return", beforeExpr)
 kw("switch")

src/babel/api/browser.js

@@ -11,7 +11,7 @@ transform.run = function (code, opts = {}) {
 };
 
 transform.load = function (url, callback, opts = {}, hold) {
-  opts.filename ||= url;
+  opts.filename = opts.filename || url;
 
   var xhr = global.ActiveXObject ? new global.ActiveXObject("Microsoft.XMLHTTP") : new global.XMLHttpRequest();
   xhr.open("GET", url, true);

src/babel/api/node.js

@@ -4,12 +4,12 @@ import * as acorn from "../../acorn";
 import * as util from "../util";
 import fs from "fs";
 
-export { util, acorn };
+export { util, acorn, transform };
 export { canCompile } from "../util";
 
 export { default as options } from "../transformation/file/options";
 export { default as Transformer } from "../transformation/transformer";
-export { default as transform } from "../transformation";
+export { default as Pipeline } from "../transformation/transformer-pipeline";
 export { default as traverse } from "../traversal";
 export { default as buildExternalHelpers } from "../tools/build-external-helpers";
 export { version } from "../../../package";
@@ -18,7 +18,7 @@ import * as t from "../types";
 export { t as types };
 
 export function register(opts?: Object) {
-  var callback = require("./register/node");
+  var callback = require("./register/node-polyfill");
   if (opts != null) callback(opts);
   return callback;
 }
@@ -54,3 +54,19 @@ export function transformFileSync(filename: string, opts?: Object = {}) {
   opts.filename = filename;
   return transform(fs.readFileSync(filename), opts);
 }
+
+export function parse(code, opts = {}) {
+  opts.sourceType = "module";
+  opts.ecmaVersion = Infinity;
+  opts.plugins = {
+    flow: true,
+    jsx:  true
+  };
+  opts.features = {};
+
+  for (var key in transform.transformers) {
+    opts.features[key] = true;
+  }
+
+  return acorn.parse(code, opts);
+}

src/babel/api/register/cache.js

@@ -1,12 +1,9 @@
 import path from "path";
 import os from "os";
 import fs from "fs";
+import userHome from "user-home";
 
-function getUserHome() {
+const FILENAME = process.env.BABEL_CACHE_PATH || path.join(userHome || os.tmpdir(), ".babel.json");
-  return process.env.HOME || process.env.HOMEPATH || process.env.USERPROFILE;
-}
-
-const FILENAME = process.env.BABEL_CACHE_PATH || path.join(getUserHome() || os.tmpdir(), ".babel.json");
 var data = {};
 
 export function save() {

src/babel/api/register/node-polyfill.js

@@ -0,0 +1,2 @@
+import "../../polyfill";
+export { default } from "./node";

src/babel/api/register/node.js

@@ -1,4 +1,3 @@
-import "../../polyfill";
 import sourceMapSupport from "source-map-support";
 import * as registerCache from "./cache";
 import resolveRc from "../../tools/resolve-rc";
@@ -7,6 +6,7 @@ import * as babel from "../node";
 import each from "lodash/collection/each";
 import * as util from  "../../util";
 import fs from "fs";
+import slash from "slash";
 
 sourceMapSupport.install({
   handleUncaughtExceptions: false,
@@ -31,8 +31,10 @@ var cache = registerCache.get();
 //
 
 var transformOpts = {};
-var ignoreRegex   = /node_modules/;
+
-var onlyRegex;
+var ignore;
+var only;
+
 var oldHandlers   = {};
 var maps          = {};
 
@@ -76,7 +78,11 @@ var compile = function (filename) {
 };
 
 var shouldIgnore = function (filename) {
-  return (ignoreRegex && ignoreRegex.test(filename)) || (onlyRegex && !onlyRegex.test(filename));
+  if (!ignore && !only) {
+    return /node_modules/.test(filename);
+  } else {
+    return util.shouldIgnore(filename, ignore || [], only || []);
+  }
 };
 
 var istanbulMonkey = {};
@@ -142,8 +148,8 @@ var hookExtensions = function (_exts) {
 hookExtensions(util.canCompile.EXTENSIONS);
 
 export default function (opts = {}) {
-  if (opts.only != null) onlyRegex = util.regexify(opts.only);
+  if (opts.only != null) only = util.arrayify(opts.only, util.regexify);
-  if (opts.ignore != null) ignoreRegex = util.regexify(opts.ignore);
+  if (opts.ignore != null) ignore = util.arrayify(opts.ignore, util.regexify);
 
   if (opts.extensions) hookExtensions(util.arrayify(opts.extensions));
 
@@ -156,16 +162,3 @@ export default function (opts = {}) {
 
   extend(transformOpts, opts);
 };
-
-//
-
-try {
-  var runtimePackage = require("babel-runtime/package");
-  var version = require("../../../../package").version;
-  if (runtimePackage.version !== version) {
-    throw new ReferenceError(`The verison of babel-runtime of ${runtimePackage.runtime} that you have installed does not match the babel verison of ${version}`);
-  }
-} catch (err) {
-  if (err.code !== "MODULE_NOT_FOUND") throw err;
-}
-

src/babel/generation/buffer.js

@@ -70,14 +70,14 @@ export default class Buffer {
   }
 
   newline(i, removeLast) {
-    if (this.format.compact) return;
+    if (this.format.compact || this.format.retainLines) return;
 
     if (this.format.concise) {
       this.space();
       return;
     }
 
-    removeLast ||= false;
+    removeLast = removeLast || false;
 
     if (isNumber(i)) {
       i = Math.min(2, i);

src/babel/generation/generators/base.js

@@ -13,7 +13,7 @@ export function BlockStatement(node, print) {
     this.push("{");
     this.newline();
     print.sequence(node.body, { indent: true });
-    this.removeLast("\n");
+    if (!this.format.retainLines) this.removeLast("\n");
     this.rightBrace();
   }
 }

src/babel/generation/generators/expressions.js

@@ -169,4 +169,8 @@ export function MemberExpression(node, print) {
   }
 }
 
-export { MemberExpression as MetaProperty };
+export function MetaProperty(node, print) {
+  print(node.meta);
+  this.push(".");
+  print(node.property);
+}

src/babel/generation/generators/jsx.js

@@ -45,7 +45,7 @@ export function JSXElement(node, print) {
   this.indent();
   each(node.children, (child) => {
     if (t.isLiteral(child)) {
-      this.push(child.value);
+      this.push(child.value, true);
     } else {
       print(child);
     }

src/babel/generation/generators/methods.js

@@ -75,5 +75,16 @@ export function ArrowFunctionExpression(node, print) {
   }
 
   this.push(" => ");
+
+  const bodyNeedsParens = t.isObjectExpression(node.body);
+
+  if (bodyNeedsParens) {
+    this.push("(");
+  }
+
   print(node.body);
+
+  if (bodyNeedsParens) {
+    this.push(")");
+  }
 }

src/babel/generation/generators/statements.js

@@ -71,7 +71,7 @@ export var ForInStatement = buildForXStatement("in");
 export var ForOfStatement = buildForXStatement("of");
 
 export function DoWhileStatement(node, print) {
-  this.keyword("do");
+  this.push("do ");
   print(node.body);
   this.space();
   this.keyword("while");

src/babel/generation/index.js

@@ -12,7 +12,7 @@ import * as t from "../types";
 
 class CodeGenerator {
   constructor(ast, opts, code) {
-    opts ||= {};
+    opts = opts || {};
 
     this.comments = ast.comments || [];
     this.tokens   = ast.tokens || [];
@@ -34,9 +34,10 @@ class CodeGenerator {
     }
 
     var format = {
+      retainLines: opts.retainLines,
       comments: opts.comments == null || opts.comments,
       compact: opts.compact,
-      quotes: CodeGenerator.findCommonStringDelimeter(code, tokens),
+      quotes: CodeGenerator.findCommonStringDelimiter(code, tokens),
       indent: {
         adjustMultilineComment: true,
         style: style,
@@ -48,14 +49,14 @@ class CodeGenerator {
       format.compact = code.length > 100000; // 100KB
 
       if (format.compact) {
-        console.error(messages.get("codeGeneratorDeopt", opts.filename, "100KB"));
+        console.error("[BABEL] " + messages.get("codeGeneratorDeopt", opts.filename, "100KB"));
       }
     }
 
     return format;
   }
 
-  static findCommonStringDelimeter(code, tokens) {
+  static findCommonStringDelimiter(code, tokens) {
     var occurences = {
       single: 0,
       double: 0
@@ -146,6 +147,22 @@ class CodeGenerator {
     return print;
   }
 
+  catchUp(node, parent) {
+    // catch up to this nodes newline if we're behind
+    if (node.loc && this.format.retainLines && this.buffer.buf) {
+      var needsParens = false;
+      if (parent && this.position.line < node.loc.start.line && t.isTerminatorless(parent)) {
+        needsParens = true;
+        this._push("(");
+      }
+      while (this.position.line < node.loc.start.line) {
+        this._push("\n");
+      }
+      return needsParens;
+    }
+    return false;
+  }
+
   print(node, parent, opts = {}) {
     if (!node) return;
 
@@ -197,6 +214,8 @@ class CodeGenerator {
 
       this.printLeadingComments(node, parent);
 
+      var needsParensFromCatchup = this.catchUp(node, parent);
+
       newline(true);
 
       if (opts.before) opts.before();
@@ -208,7 +227,7 @@ class CodeGenerator {
         this.newline();
         this.dedent();
       }
-      if (needsParens) this.push(")");
+      if (needsParens || needsParensFromCatchup) this.push(")");
 
       this.map.mark(node, "end");
       if (opts.after) opts.after();
@@ -328,6 +347,8 @@ class CodeGenerator {
 
       if (skip) return;
 
+      this.catchUp(comment);
+
       // whitespace before
       this.newline(this.whitespace.getNewlinesBefore(comment));
 
@@ -340,7 +361,6 @@ class CodeGenerator {
       }
 
       //
-
       if (comment.type === "Block" && this.format.indent.adjustMultilineComment) {
         var offset = comment.loc.start.column;
         if (offset) {
@@ -356,8 +376,13 @@ class CodeGenerator {
         val = this.getIndent() + val;
       }
 
-      //
+      // force a newline for line comments when retainLines is set in case the next printed node
+      // doesn't catch up
+      if (this.format.retainLines && comment.type === "Line") {
+        val += "\n";
+      }
 
+      //
       this._push(val);
 
       // whitespace after

src/babel/generation/node/index.js

@@ -85,16 +85,7 @@ export default class Node {
       return false;
     }
 
-    if (t.isYieldExpression(parent) || t.isAwaitExpression(parent)) {
+    return t.isTerminatorless(parent);
-      return true;
-    }
-
-    if (t.isContinueStatement(parent) || t.isBreakStatement(parent) ||
-        t.isReturnStatement(parent) || t.isThrowStatement(parent)) {
-      return true;
-    }
-
-    return false;
   }
 }
 

src/babel/generation/node/parentheses.js

@@ -171,4 +171,10 @@ export function ConditionalExpression(node, parent) {
   return false;
 }
 
-export { ConditionalExpression as AssignmentExpression };
+export function AssignmentExpression(node) {
+  if (t.isObjectPattern(node.left)) {
+    return true;
+  } else {
+    return ConditionalExpression(...arguments);
+  }
+}

src/babel/generation/node/whitespace.js

@@ -16,7 +16,7 @@ function crawl(node, state = {}) {
   } else if (t.isFunction(node)) {
     state.hasFunction = true;
   } else if (t.isIdentifier(node)) {
-    state.hasHelper ||= isHelper(node.callee);
+    state.hasHelper = state.hasHelper || isHelper(node.callee);
   }
 
   return state;

src/babel/messages.js

@@ -22,7 +22,19 @@ export const MESSAGES = {
   codeGeneratorDeopt: "Note: The code generator has deoptimised the styling of $1 as it exceeds the max of $2.",
   missingTemplatesDirectory: "no templates directory - this is most likely the result of a broken `npm publish`. Please report to https://github.com/babel/babel/issues",
   unsupportedOutputType: "Unsupported output type $1",
-  illegalMethodName: "Illegal method name $1"
+  illegalMethodName: "Illegal method name $1",
+  traverseNeedsParent: "Must pass a scope and parentPath unless traversing a Program/File got a $1 node",
+  traverseVerifyRootFunction: "You passed `traverse()` a function when it expected a visitor object, are you sure you didn't mean `{ enter: Function }`?",
+  traverseVerifyVisitorFunction: "Hey! You passed \`traverse()\` a visitor object with the key $1 that's a straight up `Function` instead of `{ enter: Function }`. You need to normalise it with `traverse.explode(visitor)`.",
+  traverseVerifyVisitorProperty: "You passed `traverse()` a visitor object with the property $1 that has the invalid property $2",
+
+  pluginIllegalKind: "Illegal kind $1 for plugin $2",
+  pluginIllegalPosition: "Illegal position $1 for plugin $2",
+  pluginKeyCollision: "The plugin $1 collides with another of the same name",
+  pluginNotTransformer: "The plugin $1 didn't export a Transformer instance",
+  pluginUnknown: "Unknown plugin $1",
+
+  transformerNotFile: "Transformer $1 is resolving to a different Babel version to what is doing the actual transformation..."
 };
 
 export function get(key: String, ...args) {

src/babel/patch.js

@@ -7,15 +7,15 @@ import * as t from "./types";
 
 extend(estraverse.VisitorKeys, t.VISITOR_KEYS);
 
-// regenerator-babel/ast-types
+// regenerator/ast-types
 
 var def = types.Type.def;
 var or  = types.Type.or;
 
-def("File")
+//def("File")
-  .bases("Node")
+//  .bases("Node")
-  .build("program")
+//  .build("program")
-  .field("program", def("Program"));
+//  .field("program", def("Program"));
 
 def("AssignmentPattern")
   .bases("Pattern")
@@ -55,4 +55,18 @@ def("ExportNamedDeclaration")
   )])
   .field("source", or(def("ModuleSpecifier"), null));
 
+def("ExportNamespaceSpecifier")
+  .bases("Specifier")
+  .field("exported", def("Identifier"));
+
+def("ExportDefaultSpecifier")
+  .bases("Specifier")
+  .field("exported", def("Identifier"));
+
+def("ExportAllDeclaration")
+  .bases("Declaration")
+  .build("exported", "source")
+  .field("exported", def("Identifier"))
+  .field("source", def("Literal"));
+
 types.finalize();

src/babel/polyfill.js

@@ -4,4 +4,4 @@ if (global._babelPolyfill) {
 global._babelPolyfill = true;
 
 import "core-js/shim";
-import "regenerator-babel/runtime";
+import "regenerator/runtime";

src/babel/tools/resolve-rc.js

@@ -1,3 +1,4 @@
+import stripJsonComments from "strip-json-comments";
 import merge from "lodash/object/merge";
 import path from "path";
 import fs from "fs";
@@ -16,24 +17,40 @@ function exists(filename) {
 export default function (loc, opts = {}) {
   var rel = ".babelrc";
 
+  if (!opts.babelrc) {
+    opts.babelrc = [];
+  }
+
   function find(start, rel) {
     var file = path.join(start, rel);
 
+    if (opts.babelrc.indexOf(file) >= 0) {
+      return;
+    }
+
     if (exists(file)) {
       var content = fs.readFileSync(file, "utf8");
       var json;
 
       try {
-        json = jsons[content] ||= JSON.parse(content);
+        json = jsons[content] = jsons[content] || JSON.parse(stripJsonComments(content));
       } catch (err) {
         err.message = `${file}: ${err.message}`;
         throw err;
       }
 
+      opts.babelrc.push(file);
+
       if (json.breakConfig) return;
       merge(opts, json, function(a, b) {
         if (Array.isArray(a)) {
-          return a.concat(b);
+          var c = a.slice(0);
+          for (var v of b) {
+            if (a.indexOf(v) < 0) {
+              c.push(v);
+            }
+          }
+          return c;
         }
       });
     }
@@ -44,7 +61,9 @@ export default function (loc, opts = {}) {
     }
   }
 
-  find(loc, rel);
+  if (opts.babelrc.indexOf(loc) < 0 && opts.breakConfig !== true) {
+    find(loc, rel);
+  }
 
   return opts;
 };

src/babel/transformation/file/index.js

@@ -1,5 +1,7 @@
 import convertSourceMap from "convert-source-map";
 import * as optionParsers from "./option-parsers";
+import moduleFormatters from "../modules";
+import PluginManager from "./plugin-manager";
 import shebangRegex from "shebang-regex";
 import TraversalPath from "../../traversal/path";
 import isFunction from "lodash/lang/isFunction";
@@ -16,39 +18,42 @@ import Logger from "./logger";
 import parse from "../../helpers/parse";
 import Scope from "../../traversal/scope";
 import slash from "slash";
+import clone from "lodash/lang/clone";
 import * as util from  "../../util";
+import * as api from  "../../api/node";
 import path from "path";
 import each from "lodash/collection/each";
 import * as t from "../../types";
 
 var checkTransformerVisitor = {
-  enter(node, parent, scope, state) {
+  exit(node, parent, scope, state) {
-    checkNode(state.stack, node, scope);
+    checkPath(state.stack, this);
   }
 };
 
-function checkNode(stack, node, scope) {
+function checkPath(stack, path) {
   each(stack, function (pass) {
     if (pass.shouldRun || pass.ran) return;
-    pass.checkNode(node, scope);
+    pass.checkPath(path);
   });
 }
 
 export default class File {
-  constructor(opts = {}) {
+  constructor(opts = {}, pipeline) {
-    this.dynamicImportedNoDefault = [];
+    this.dynamicImportTypes = {};
-    this.dynamicImportIds         = {};
+    this.dynamicImportIds   = {};
-    this.dynamicImported          = [];
+    this.dynamicImports     = [];
-    this.dynamicImports           = [];
 
-    this.usedHelpers = {};
+    this.declarations = {};
-    this.dynamicData = {};
+    this.usedHelpers  = {};
-    this.data        = {};
+    this.dynamicData  = {};
+    this.data         = {};
+    this.uids         = {};
 
-    this.lastStatements = [];
+    this.pipeline = pipeline;
-    this.log            = new Logger(this, opts.filename || "unknown");
+    this.log      = new Logger(this, opts.filename || "unknown");
-    this.opts           = this.normalizeOptions(opts);
+    this.opts     = this.normalizeOptions(opts);
-    this.ast            = {};
+    this.ast      = {};
 
     this.buildTransformers();
   }
@@ -58,9 +63,10 @@ export default class File {
     "defaults",
     "create-class",
     "create-decorated-class",
+    "create-decorated-object",
+    "define-decorated-property-descriptor",
     "tagged-template-literal",
     "tagged-template-literal-loose",
-    "interop-require",
     "to-array",
     "to-consumable-array",
     "sliced-to-array",
@@ -72,6 +78,7 @@ export default class File {
     "define-property",
     "async-to-generator",
     "interop-require-wildcard",
+    "interop-require-default",
     "typeof",
     "extends",
     "get",
@@ -81,7 +88,16 @@ export default class File {
     "temporal-undefined",
     "temporal-assert-defined",
     "self-global",
-    "default-props"
+    "default-props",
+    "instanceof",
+
+    // legacy
+    "interop-require",
+  ];
+
+  static soloHelpers = [
+    "ludicrous-proxy-create",
+    "ludicrous-proxy-directory"
   ];
 
   static options = require("./options");
@@ -89,8 +105,10 @@ export default class File {
   normalizeOptions(opts: Object) {
     opts = assign({}, opts);
 
-    if (opts.filename && isAbsolute(opts.filename)) {
+    if (opts.filename) {
-      opts = resolveRc(opts.filename, opts);
+      var rcFilename = opts.filename;
+      if (!isAbsolute(rcFilename)) rcFilename = path.join(process.cwd(), rcFilename);
+      opts = resolveRc(rcFilename, opts);
     }
 
     //
@@ -112,13 +130,15 @@ export default class File {
         throw new Error("Deprecated option " + key + ": " + option.deprecated);
       }
 
-      if (val == null) val = option.default || val;
+      if (val == null) {
+        val = clone(option.default);
+      }
 
       var optionParser = optionParsers[option.type];
-      if (optionParser) val = optionParser(key, val);
+      if (optionParser) val = optionParser(key, val, this.pipeline);
 
       if (option.alias) {
-        opts[option.alias] ||= val;
+        opts[option.alias] = opts[option.alias] || val;
       } else {
         opts[key] = val;
       }
@@ -182,7 +202,7 @@ export default class File {
     var stack = [];
 
     // build internal transformers
-    each(transform.transformers, function (transformer, key) {
+    each(this.pipeline.transformers, function (transformer, key) {
       var pass = transformers[key] = transformer.buildPass(file);
 
       if (pass.canTransform()) {
@@ -201,8 +221,14 @@ export default class File {
     // init plugins!
     var beforePlugins = [];
     var afterPlugins = [];
+    var pluginManager = new PluginManager({
+      file: this,
+      transformers: this.transformers,
+      before: beforePlugins,
+      after: afterPlugins
+    });
     for (var i = 0; i < file.opts.plugins.length; i++) {
-      this.addPlugin(file.opts.plugins[i], beforePlugins, afterPlugins);
+      pluginManager.add(file.opts.plugins[i]);
     }
     stack = beforePlugins.concat(stack, afterPlugins);
 
@@ -211,7 +237,7 @@ export default class File {
   }
 
   getModuleFormatter(type: string) {
-    var ModuleFormatter = isFunction(type) ? type : transform.moduleFormatters[type];
+    var ModuleFormatter = isFunction(type) ? type : moduleFormatters[type];
 
     if (!ModuleFormatter) {
       var loc = util.resolveRelative(type);
@@ -225,57 +251,6 @@ export default class File {
     return new ModuleFormatter(this);
   }
 
-  addPlugin(name, before, after) {
-    var position = "before";
-    var plugin;
-
-    if (name) {
-      if (typeof name === "string") {
-        // this is a plugin in the form of "foobar" or "foobar:after"
-        // where the optional colon is the delimiter for plugin position in the transformer stack
-
-        [name, position = "before"] = name.split(":");
-
-        var loc = util.resolveRelative(name) || util.resolveRelative(`babel-plugin-${name}`);
-        if (loc) {
-          plugin = require(loc)
-        } else {
-          throw new ReferenceError(`Unknown plugin ${JSON.stringify(name)}`);
-        }
-      } else {
-        // not a string so we'll just assume that it's a direct Transformer instance, if not then
-        // the checks later on will complain
-        plugin = name;
-      }
-    } else {
-      throw new TypeError(`Ilegal kind ${typeof name} for plugin name ${JSON.stringify(name)}`);
-    }
-
-    // validate position
-    if (position !== "before" && position !== "after") {
-      throw new TypeError(`Plugin ${JSON.stringify(name)} has an illegal position of ${JSON.stringify(position)}`);
-    }
-
-    // validate transformer key
-    var key = plugin.key;
-    if (this.transformers[key]) {
-      throw new ReferenceError(`The key for plugin ${JSON.stringify(name)} of ${key} collides with an existing plugin`);
-    }
-
-    // validate Transformer instance
-    if (!plugin.buildPass || plugin.constructor.name !== "Transformer") {
-      throw new TypeError(`Plugin ${JSON.stringify(name)} didn't export default a Transformer instance`);
-    }
-
-    // build!
-    var pass = this.transformers[key] = plugin.buildPass(this);
-    if (pass.canTransform()) {
-      var stack = before;
-      if (position === "after") stack = after;
-      stack.push(pass);
-    }
-  }
-
   parseInputSourceMap(code: string) {
     var opts = this.opts;
 
@@ -329,8 +304,8 @@ export default class File {
     return source;
   }
 
-  addImport(source: string, name?: string, noDefault?: boolean): Object {
+  addImport(source: string, name?: string, type?: string): Object {
-    name ||= source;
+    name = name || source;
     var id = this.dynamicImportIds[name];
 
     if (!id) {
@@ -341,8 +316,10 @@ export default class File {
       var declar = t.importDeclaration(specifiers, t.literal(source));
       declar._blockHoist = 3;
 
-      this.dynamicImported.push(declar);
+      if (type) {
-      if (noDefault) this.dynamicImportedNoDefault.push(declar);
+        var modules = this.dynamicImportTypes[type] = this.dynamicImportTypes[type] || [];
+        modules.push(declar);
+      }
 
       if (this.transformers["es6.modules"].canTransform()) {
         this.moduleFormatter.importSpecifier(specifiers[0], declar, this.dynamicImports);
@@ -355,14 +332,10 @@ export default class File {
     return id;
   }
 
-  isConsequenceExpressionStatement(node: Object): boolean {
-    return t.isExpressionStatement(node) && this.lastStatements.indexOf(node) >= 0;
-  }
-
   attachAuxiliaryComment(node: Object): Object {
     var comment = this.opts.auxiliaryComment;
     if (comment) {
-      node.leadingComments ||= [];
+      node.leadingComments = node.leadingComments || [];
       node.leadingComments.push({
         type: "Line",
         value: " " + comment
@@ -372,35 +345,39 @@ export default class File {
   }
 
   addHelper(name: string): Object {
-    if (!includes(File.helpers, name)) {
+    var isSolo = includes(File.soloHelpers, name);
+
+    if (!isSolo && !includes(File.helpers, name)) {
       throw new ReferenceError(`Unknown helper ${name}`);
     }
 
     var program = this.ast.program;
 
-    var declar = program._declarations && program._declarations[name];
+    var declar = this.declarations[name];
-    if (declar) return declar.id;
+    if (declar) return declar;
 
     this.usedHelpers[name] = true;
 
-    var generator = this.get("helperGenerator");
+    if (!isSolo) {
-    var runtime   = this.get("helpersNamespace");
+      var generator = this.get("helperGenerator");
-    if (generator) {
+      var runtime   = this.get("helpersNamespace");
-      return generator(name);
+      if (generator) {
-    } else if (runtime) {
+        return generator(name);
-      var id = t.identifier(t.toIdentifier(name));
+      } else if (runtime) {
-      return t.memberExpression(runtime, id);
+        var id = t.identifier(t.toIdentifier(name));
-    } else {
+        return t.memberExpression(runtime, id);
-      var ref = util.template("helper-" + name);
+      }
-      ref._compact = true;
-      var uid = this.scope.generateUidIdentifier(name);
-      this.scope.push({
-        key: name,
-        id: uid,
-        init: ref
-      });
-      return uid;
     }
+
+    var ref = util.template("helper-" + name);
+    ref._compact = true;
+    var uid = this.declarations[name] = this.scope.generateUidIdentifier(name);
+    this.scope.push({
+      id: uid,
+      init: ref,
+      unique: true
+    });
+    return uid;
   }
 
   errorWithNode(node, msg, Error = SyntaxError) {
@@ -419,23 +396,7 @@ export default class File {
 
   shouldIgnore() {
     var opts = this.opts;
-
+    return util.shouldIgnore(opts.filename, opts.ignore, opts.only);
-    var filename = opts.filename;
-    var ignore   = opts.ignore;
-    var only     = opts.only;
-
-    if (only.length) {
-      for (var i = 0; i < only.length; i++) {
-        if (only[i].test(filename)) return false;
-      }
-      return true;
-    } else if (ignore.length) {
-      for (var i = 0; i < ignore.length; i++) {
-        if (ignore[i].test(filename)) return true;
-      }
-    }
-
-    return false;
   }
 
   parse(code: string) {
@@ -471,9 +432,12 @@ export default class File {
     parseOpts.strictMode = features.strict;
     parseOpts.sourceType = "module";
 
+    this.log.debug("Parse start");
+
     //
 
     return parse(parseOpts, code, (tree) => {
+      this.log.debug("Parse stop");
       this.transform(tree);
       return this.generate();
     });
@@ -496,25 +460,25 @@ export default class File {
   }
 
   transform(ast) {
-    this.log.debug();
+    this.log.debug("Start set AST");
-
     this.setAst(ast);
+    this.log.debug("End set AST");
 
-    this.lastStatements = t.getLastStatements(ast.program);
+    this.log.debug("Start prepass");
+    this.checkPath(this.path);
+    this.log.debug("End prepass");
 
+    this.log.debug("Start module formatter init");
     var modFormatter = this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
     if (modFormatter.init && this.transformers["es6.modules"].canTransform()) {
       modFormatter.init();
     }
-
+    this.log.debug("End module formatter init");
-    this.checkNode(ast);
 
     this.call("pre");
-
     each(this.transformerStack, function (pass) {
       pass.transform();
     });
-
     this.call("post");
   }
 
@@ -527,20 +491,19 @@ export default class File {
     }
   }
 
-  checkNode(node, scope) {
+  checkPath(path) {
-    if (Array.isArray(node)) {
+    if (Array.isArray(path)) {
-      for (var i = 0; i < node.length; i++) {
+      for (var i = 0; i < path.length; i++) {
-        this.checkNode(node[i], scope);
+        this.checkPath(path[i]);
       }
       return;
     }
 
     var stack = this.transformerStack;
-    scope ||= this.scope;
 
-    checkNode(stack, node, scope);
+    checkPath(stack, path);
 
-    scope.traverse(node, checkTransformerVisitor, {
+    path.traverse(checkTransformerVisitor, {
       stack: stack
     });
   }
@@ -590,10 +553,14 @@ export default class File {
     if (opts.ast) result.ast = ast;
     if (!opts.code) return result;
 
+    this.log.debug("Generation start");
+
     var _result = generate(ast, opts, this.code);
     result.code = _result.code;
     result.map  = _result.map;
 
+    this.log.debug("Generation end");
+
     if (this.shebang) {
       // add back shebang
       result.code = `${this.shebang}\n${result.code}`;

src/babel/transformation/file/logger.js

@@ -7,7 +7,7 @@ export default class Logger {
   }
 
   _buildMessage(msg: string): string {
-    var parts = this.filename;
+    var parts = `[BABEL] ${this.filename}`;
     if (msg) parts += `: ${msg}`;
     return parts;
   }
@@ -18,7 +18,7 @@ export default class Logger {
 
   deprecate(msg) {
     if (!this.file.opts.suppressDeprecationMessages) {
-      console.error(msg);
+      console.error(this._buildMessage(msg));
     }
   }
 

src/babel/transformation/file/option-parsers.js

@@ -1,14 +1,13 @@
-import transform from "./../index";
 import * as util from  "../../util";
 
-export function transformerList(key, val) {
+export function transformerList(key, val, pipeline) {
   val = util.arrayify(val);
 
   if (val.indexOf("all") >= 0 || val.indexOf(true) >= 0) {
-    val = Object.keys(transform.transformers);
+    val = Object.keys(pipeline.transformers);
   }
 
-  return transform._ensureTransformerNames(key, val);
+  return pipeline._ensureTransformerNames(key, val);
 }
 
 export function number(key, val) {

src/babel/transformation/file/options.json

@@ -15,11 +15,23 @@
     "hidden": true
   },
 
+  "extra": {
+    "hidden": true,
+    "default": {}
+  },
+
   "moduleId": {
     "description": "specify a custom name for module ids",
     "type": "string"
   },
 
+  "retainLines": {
+    "hidden": true,
+    "type": "boolean",
+    "default": false,
+    "description": "retain line numbers - will result in really ugly code"
+  },
+
   "nonStandard": {
     "type": "boolean",
     "default": true,
@@ -152,7 +164,7 @@
   },
 
   "externalHelpers": {
-    "type": "string",
+    "type": "boolean",
     "default": false,
     "shorthand": "r",
     "description": "uses a reference to `babelHelpers` instead of placing helpers at the top of your code."
@@ -194,5 +206,17 @@
   "moduleRoot": {
     "type": "string",
     "description": "optional prefix for the AMD module formatter that will be prepend to the filename on module definitions"
+  },
+
+  "breakConfig": {
+    "type": "boolean",
+    "default": false,
+    "hidden": true,
+    "description": "stop trying to load .babelrc files"
+  },
+
+  "babelrc": {
+    "hidden": true,
+    "description": "do not load the same .babelrc file twice"
   }
 }

src/babel/transformation/file/plugin-manager.js

@@ -0,0 +1,105 @@
+import * as node from  "../../api/node";
+import * as messages from "../../messages";
+import * as util from  "../../util";
+
+export default class PluginManager {
+  static memoisedPlugins = [];
+
+  static memoisePluginContainer(fn) {
+    for (var i = 0; i < PluginManager.memoisedPlugins.length; i++) {
+      var plugin = PluginManager.memoisedPlugins[i];
+      if (plugin.container === fn) return plugin.transformer;
+    }
+
+    var transformer = fn(node);
+    PluginManager.memoisedPlugins.push({
+      container: fn,
+      transformer: transformer
+    });
+    return transformer;
+  }
+
+  static positions = ["before", "after"];
+
+  constructor({ file, transformers, before, after } = { transformers: {}, before: [], after: [] }) {
+    this.transformers = transformers;
+    this.file         = file;
+    this.before       = before;
+    this.after        = after;
+  }
+
+  subnormaliseString(name, position) {
+    // this is a plugin in the form of "foobar" or "foobar:after"
+    // where the optional colon is the delimiter for plugin position in the transformer stack
+
+    var match = name.match(/^(.*?):(after|before)$/);
+    if (match) [, name, position] = match;
+
+    var loc = util.resolveRelative(name) || util.resolveRelative(`babel-plugin-${name}`);
+    if (loc) {
+      return {
+        position: position,
+        plugin:   require(loc)
+      };
+    } else {
+      throw new ReferenceError(messages.get("pluginUnknown", name));
+    }
+  }
+
+  validate(name, plugin) {
+    // validate transformer key
+    var key = plugin.key;
+    if (this.transformers[key]) {
+      throw new ReferenceError(messages.get("pluginKeyCollision", key));
+    }
+
+    // validate Transformer instance
+    if (!plugin.buildPass || plugin.constructor.name !== "Transformer") {
+      throw new TypeError(messages.get("pluginNotTransformer", name));
+    }
+  }
+
+  add(name) {
+    var position;
+    var plugin;
+
+    if (name) {
+      if (typeof name === "object" && name.transformer) {
+        ({ plugin: name, position } = name);
+      } else if (typeof name !== "string") {
+        // not a string so we'll just assume that it's a direct Transformer instance, if not then
+        // the checks later on will complain
+        plugin = name;
+      }
+
+      if (typeof name === "string") {
+        ({ plugin, position } = this.subnormaliseString(name, position));
+      }
+    } else {
+      throw new TypeError(messages.get("pluginIllegalKind", typeof name, name));
+    }
+
+    // default position
+    position = position || "before";
+
+    // validate position
+    if (PluginManager.positions.indexOf(position) < 0) {
+      throw new TypeError(messages.get("pluginIllegalPosition", position, name));
+    }
+
+    // allow plugin containers to be specified so they don't have to manually require
+    if (typeof plugin === "function") {
+      plugin = PluginManager.memoisePluginContainer(plugin);
+    }
+
+    //
+    this.validate(name, plugin);
+
+    // build!
+    var pass = this.transformers[plugin.key] = plugin.buildPass(this.file);
+    if (pass.canTransform()) {
+      var stack = position === "before" ? this.before : this.after;
+      stack.push(pass);
+    }
+  }
+}

src/babel/transformation/helpers/build-binary-assignment-operator-transformer.js

@@ -10,9 +10,13 @@ export default function (exports, opts) {
     return t.assignmentExpression("=", left, right);
   };
 
+  exports.shouldVisit = function (node) {
+    return node.operator && (node.operator === opts.operator || node.operator === opts.operator + "=");
+  };
+
   exports.ExpressionStatement = function (node, parent, scope, file) {
     // hit the `AssignmentExpression` one below
-    if (file.isConsequenceExpressionStatement(node)) return;
+    if (this.isCompletionRecord()) return;
 
     var expr = node.expression;
     if (!isAssignment(expr)) return;

src/babel/transformation/helpers/build-conditional-assignment-operator-transformer.js

@@ -8,7 +8,7 @@ export default function (exports, opts) {
 
   exports.ExpressionStatement = function (node, parent, scope, file) {
     // hit the `AssignmentExpression` one below
-    if (file.isConsequenceExpressionStatement(node)) return;
+    if (this.isCompletionRecord()) return;
 
     var expr = node.expression;
     if (!opts.is(expr, file)) return;

src/babel/transformation/helpers/build-react-transformer.js

@@ -19,7 +19,7 @@ export default function (exports, opts) {
   exports.JSXIdentifier = function (node, parent) {
     if (node.name === "this" && t.isReferenced(node, parent)) {
       return t.thisExpression();
-    } else if (esutils.keyword.isIdentifierName(node.name)) {
+    } else if (esutils.keyword.isIdentifierNameES6(node.name)) {
       node.type = "Identifier";
     } else {
       return t.literal(node.name);
@@ -57,6 +57,8 @@ export default function (exports, opts) {
 
   exports.JSXOpeningElement = {
     exit(node, parent, scope, file) {
+      parent.children = react.buildChildren(parent);
+
       var tagExpr = node.name;
       var args = [];
 
@@ -144,10 +146,6 @@ export default function (exports, opts) {
   };
 
   exports.JSXElement = {
-    enter(node) {
-      node.children = react.buildChildren(node);
-    },
-
     exit(node) {
       var callExpr = node.openingElement;
 

src/babel/transformation/helpers/call-delegate.js

@@ -1,10 +1,33 @@
+import traverse from "../../traversal";
 import * as t from "../../types";
 
-export default function (node) {
+var visitor = {
-  var container = t.functionExpression(null, [], node.body, node.generator, node.async);
+  enter(node, parent, scope, state) {
-  container.shadow = true;
+    if (this.isThisExpression() || this.isReferencedIdentifier({ name: "arguments" })) {
+      state.found = true;
+      this.stop();
+    }
 
-  var call = t.callExpression(container, []);
+    if (this.isFunction()) {
+      this.skip();
+    }
+  }
+};
+
+export default function (node, scope) {
+  var container = t.functionExpression(null, [], node.body, node.generator, node.async);
+
+  var callee = container;
+  var args   = [];
+
+  var state = { found: false };
+  scope.traverse(node, visitor, state);
+  if (state.found) {
+    callee = t.memberExpression(container, t.identifier("apply"));
+    args = [t.thisExpression(), t.identifier("arguments")];
+  }
+
+  var call = t.callExpression(callee, args);
   if (node.generator) call = t.yieldExpression(call, true);
 
   return t.returnStatement(call);

src/babel/transformation/helpers/define-map.js

@@ -4,17 +4,45 @@ import each from "lodash/collection/each";
 import has from "lodash/object/has";
 import * as t from "../../types";
 
-export function push(mutatorMap, key, kind, computed, value) {
+export function push(mutatorMap, node, kind, file) {
-  var alias = t.toKeyAlias({ computed }, key);
+  var alias = t.toKeyAlias(node);
+
+  //
 
   var map = {};
   if (has(mutatorMap, alias)) map = mutatorMap[alias];
   mutatorMap[alias] = map;
 
-  map._key = key;
+  //
-  if (computed) map._computed = true;
 
-  map[kind] = value;
+  map._inherits = map._inherits || [];
+  map._inherits.push(node);
+
+  map._key = node.key;
+
+  if (node.computed) {
+    map._computed = true;
+  }
+
+  if (node.decorators) {
+    var decorators = map.decorators = map.decorators || t.arrayExpression([]);
+    decorators.elements = decorators.elements.concat(node.decorators.map(dec => dec.expression));
+  }
+
+  if (map.value || map.initializer) {
+    throw file.errorWithNode(node, "Key conflict with sibling node");
+  }
+
+  if (node.value) {
+    if (node.kind === "init") kind = "value";
+    if (node.kind === "get") kind = "get";
+    if (node.kind === "set") kind = "set";
+
+    t.inheritsComments(node.value, node);
+    map[kind] = node.value;
+  }
+
+  return map;
 }
 
 export function hasComputed(mutatorMap) {

src/babel/transformation/helpers/memoise-decorators.js

@@ -0,0 +1,37 @@
+import * as t from "../../types";
+
+export default function (decorators, scope) {
+  for (var i = 0; i < decorators.length; i++) {
+    var decorator = decorators[i];
+    var expression = decorator.expression;
+    if (!t.isMemberExpression(expression)) continue;
+
+    var temp = scope.generateMemoisedReference(expression.object);
+    var ref;
+
+    var nodes = [];
+
+    if (temp) {
+      ref = temp;
+      nodes.push(t.assignmentExpression("=", temp, expression.object));
+    } else {
+      ref = expression.object;
+    }
+
+    nodes.push(t.callExpression(
+      t.memberExpression(
+        t.memberExpression(ref, expression.property, expression.computed),
+        t.identifier("bind")
+      ),
+      [ref]
+    ));
+
+    if (nodes.length === 1) {
+      decorator.expression = nodes[0];
+    } else {
+      decorator.expression = t.sequenceExpression(nodes);
+    }
+  }
+
+  return decorators;
+}

src/babel/transformation/helpers/name-method.js

@@ -20,26 +20,32 @@ var visitor = {
 
 var wrap = function (state, method, id, scope) {
   if (state.selfReference) {
-    var templateName = "property-method-assignment-wrapper";
+    if (scope.hasBinding(id.name)) {
-    if (method.generator) templateName += "-generator";
+      // we can just munge the local binding
-    var template = util.template(templateName, {
+      scope.rename(id.name);
-      FUNCTION: method,
+    } else {
-      FUNCTION_ID: id,
+      // need to add a wrapper since we can't change the references
-      FUNCTION_KEY: scope.generateUidIdentifier(id.name)
+      var templateName = "property-method-assignment-wrapper";
-    });
+      if (method.generator) templateName += "-generator";
+      var template = util.template(templateName, {
+        FUNCTION: method,
+        FUNCTION_ID: id,
+        FUNCTION_KEY: scope.generateUidIdentifier(id.name)
+      });
+      template.callee._skipModulesRemap = true;
 
-    // shim in dummy params to retain function arity, if you try to read the
+      // shim in dummy params to retain function arity, if you try to read the
-    // source then you'll get the original since it's proxied so it's all good
+      // source then you'll get the original since it's proxied so it's all good
-    var params = template.callee.body.body[0].params;
+      var params = template.callee.body.body[0].params;
-    for (var i = 0, len = getFunctionArity(method); i < len; i++) {
+      for (var i = 0, len = getFunctionArity(method); i < len; i++) {
-      params.push(scope.generateUidIdentifier("x"));
+        params.push(scope.generateUidIdentifier("x"));
+      }
+
+      return template;
     }
-
-    return template;
-  } else {
-    method.id = id;
-    return method;
   }
+
+  method.id = id;
 };
 
 var visit = function (node, name, scope) {
@@ -81,7 +87,7 @@ var visit = function (node, name, scope) {
       // so we can safely just set the id and move along as it shadows the
       // bound function id
     }
-  } else {
+  } else if (state.outerDeclar || scope.hasGlobal(name)) {
     scope.traverse(node, visitor, state);
   }
 
@@ -95,19 +101,20 @@ export function custom(node, id, scope) {
 
 export function property(node, file, scope) {
   var key = t.toComputedKey(node, node.key);
-  if (!t.isLiteral(key)) return node; // we can't set a function id with this
+  if (!t.isLiteral(key)) return; // we can't set a function id with this
 
   var name = t.toIdentifier(key.value);
+  if (name === "eval" || name === "arguments") name = "_" + name;
   var id = t.identifier(name);
 
   var method = node.value;
   var state  = visit(method, name, scope);
-  node.value = wrap(state, method, id, scope);
+  node.value = wrap(state, method, id, scope) || method;
 }
 
 export function bare(node, parent, scope) {
   // has an `id` so we don't need to infer one
-  if (node.id) return node;
+  if (node.id) return;
 
   var id;
   if (t.isProperty(parent) && parent.kind === "init" && (!parent.computed || t.isLiteral(parent.key))) {
@@ -116,8 +123,17 @@ export function bare(node, parent, scope) {
   } else if (t.isVariableDeclarator(parent)) {
     // var foo = function () {};
     id = parent.id;
+
+    if (t.isIdentifier(id)) {
+      var bindingInfo = scope.parent.getBinding(id.name);
+      if (bindingInfo && bindingInfo.constant && scope.getBinding(id.name) === bindingInfo) {
+        // always going to reference this method
+        node.id = id;
+        return;
+      }
+    }
   } else {
-    return node;
+    return;
   }
 
   var name;

src/babel/transformation/helpers/react.js

@@ -34,9 +34,8 @@ function cleanJSXElementLiteralChild(child, args) {
   var lines = child.value.split(/\r\n|\n|\r/);
 
   var lastNonEmptyLine = 0;
-  var i;
 
-  for (i = 0; i < lines.length; i++) {
+  for (let i = 0; i < lines.length; i++) {
     if (lines[i].match(/[^ \t]/)) {
       lastNonEmptyLine = i;
     }
@@ -44,7 +43,7 @@ function cleanJSXElementLiteralChild(child, args) {
 
   var str = "";
 
-  for (i = 0; i < lines.length; i++) {
+  for (let i = 0; i < lines.length; i++) {
     var line = lines[i];
 
     var isFirstLine = i === 0;

src/babel/transformation/helpers/remap-async-to-generator.js

@@ -20,7 +20,7 @@ var referenceVisitor = {
   enter(node, parent, scope, state) {
     var name = state.id.name;
     if (t.isReferencedIdentifier(node, parent, { name: name }) && scope.bindingIdentifierEquals(name, state.id)) {
-      return state.ref ||= scope.generateUidIdentifier(name);
+      return state.ref = state.ref || scope.generateUidIdentifier(name);
     }
   }
 };

src/babel/transformation/helpers/replace-supers.js

@@ -218,7 +218,7 @@ export default class ReplaceSupers {
       return this.setSuperProperty(node.left.property, node.right, node.left.computed, getThisReference());
     } else {
       // super.age += 2; -> var _ref = super.age; super.age = _ref + 2;
-      ref ||= path.scope.generateUidIdentifier("ref");
+      ref = ref || path.scope.generateUidIdentifier("ref");
       return [
         t.variableDeclaration("var", [
           t.variableDeclarator(ref, node.left)

src/babel/transformation/index.js

@@ -1,68 +1,34 @@
-import normalizeAst from "../helpers/normalize-ast";
+import Pipeline from "./transformer-pipeline";
-import Transformer from "./transformer";
-import object from "../helpers/object";
-import File from "./file";
-import each from "lodash/collection/each";
 
-export default function transform(code: string, opts?: Object) {
+var pipeline = new Pipeline;
-  var file = new File(opts);
-  return file.parse(code);
-}
 
-transform.fromAst = function (ast, code, opts) {
+//
-  ast = normalizeAst(ast);
 
-  var file = new File(opts);
+import transformers from "./transformers";
-  file.addCode(code);
+pipeline.addTransformers(transformers);
-  file.transform(ast);
-  return file.generate();
-};
 
-transform._ensureTransformerNames = function (type: string, rawKeys: Array<string>) {
+//
-  var keys = [];
 
-  for (var i = 0; i < rawKeys.length; i++) {
+import deprecated from "./transformers/deprecated";
-    var key = rawKeys[i];
+pipeline.addDeprecated(deprecated);
 
-    var deprecatedKey = transform.deprecatedTransformerMap[key];
+//
-    var aliasKey = transform.aliasTransformerMap[key];
-    if (aliasKey) {
-      keys.push(aliasKey);
-    } else if (deprecatedKey) {
-      // deprecated key, remap it to the new one
-      console.error(`The transformer ${key} has been renamed to ${deprecatedKey}`);
-      rawKeys.push(deprecatedKey);
-    } else if (transform.transformers[key]) {
-      // valid key
-      keys.push(key);
-    } else if (transform.namespaces[key]) {
-      // namespace, append all transformers within this namespace
-      keys = keys.concat(transform.namespaces[key]);
-    } else {
-      // invalid key
-      throw new ReferenceError(`Unknown transformer ${key} specified in ${type}`);
-    }
-  }
 
-  return keys;
+import aliases from "./transformers/aliases";
-};
+pipeline.addDeprecated(aliases);
 
-transform.transformerNamespaces = object();
+//
-transform.transformers          = object();
-transform.namespaces            = object();
 
-transform.deprecatedTransformerMap = require("./transformers/deprecated");
+import * as filters from "./transformers/filters";
-transform.aliasTransformerMap = require("./transformers/aliases");
+pipeline.addFilter(filters.internal);
-transform.moduleFormatters = require("./modules");
+pipeline.addFilter(filters.blacklist);
+pipeline.addFilter(filters.whitelist);
+pipeline.addFilter(filters.stage);
+pipeline.addFilter(filters.optional);
 
-import rawTransformers from "./transformers";
+//
 
-each(rawTransformers, function (transformer, key) {
+var transform = pipeline.transform.bind(pipeline);
-  var namespace = key.split(".")[0];
+transform.fromAst = pipeline.transformFromAst.bind(pipeline);
-
+transform.pipeline = pipeline;
-  transform.namespaces[namespace] ||= [];
+export default transform;
-  transform.namespaces[namespace].push(key);
-  transform.transformerNamespaces[key] = namespace;
-
-  transform.transformers[key] = new Transformer(key, transformer);
-});

src/babel/transformation/modules/_default.js

@@ -46,10 +46,15 @@ var remapVisitor = {
       }
     }
 
-    if (t.isAssignmentExpression(node)) {
+    if (node._skipModulesRemap) {
+      return this.skip();
+    }
+  },
+
+  exit(node, parent, scope, formatter) {
+    if (t.isAssignmentExpression(node) && !node._ignoreModulesRemap) {
       var exported = formatter.getExport(node.left, scope);
       if (exported) {
-        this.skip();
         return formatter.remapExportAssignment(node, exported);
       }
     }
@@ -61,7 +66,6 @@ var importsVisitor = {
     enter(node, parent, scope, formatter) {
       formatter.hasLocalImports = true;
       extend(formatter.localImports, this.getBindingIdentifiers());
-      formatter.bumpImportOccurences(node);
     }
   }
 };
@@ -69,7 +73,7 @@ var importsVisitor = {
 var exportsVisitor = traverse.explode({
   ExportDeclaration: {
     enter(node, parent, scope, formatter) {
-      formatter.hasLocalImports = true;
+      formatter.hasLocalExports = true;
 
       var declar = this.get("declaration");
       if (declar.isStatement()) {
@@ -96,29 +100,23 @@ var exportsVisitor = traverse.explode({
           formatter.hasNonDefaultExports = true;
         }
       }
-
-      if (node.source) {
-        formatter.bumpImportOccurences(node);
-      }
     }
   }
 });
 
 export default class DefaultFormatter {
   constructor(file) {
-    this.internalRemap = {};
+    this.internalRemap = object();
-
+    this.defaultIds    = object();
-    this.defaultIds = object();
+    this.scope         = file.scope;
-    this.scope      = file.scope;
+    this.file          = file;
-    this.file       = file;
+    this.ids           = object();
-    this.ids        = object();
 
     this.hasNonDefaultExports = false;
 
     this.hasLocalExports = false;
     this.hasLocalImports = false;
 
-    this.localImportOccurences = object();
     this.localExports = object();
     this.localImports = object();
 
@@ -126,6 +124,11 @@ export default class DefaultFormatter {
     this.getLocalImports();
   }
 
+  isModuleType(node, type) {
+    var modules = this.file.dynamicImportTypes[type];
+    return modules && modules.indexOf(node) >= 0;
+  }
+
   transform() {
     this.remapAssignments();
   }
@@ -134,15 +137,6 @@ export default class DefaultFormatter {
     return (t.isExportDefaultDeclaration(node) || t.isSpecifierDefault(node)) && !this.noInteropRequireExport && !this.hasNonDefaultExports;
   }
 
-  bumpImportOccurences(node) {
-    var source = node.source.value;
-    var occurs = this.localImportOccurences;
-    occurs[source] ||= 0;
-    if (node.specifiers) {
-      occurs[source] += node.specifiers.length;
-    }
-  }
-
   getLocalExports() {
     this.file.path.traverse(exportsVisitor, this);
   }
@@ -152,7 +146,7 @@ export default class DefaultFormatter {
   }
 
   remapAssignments() {
-    if (this.hasLocalImports) {
+    if (this.hasLocalExports || this.hasLocalImports) {
       this.file.path.traverse(remapVisitor, this);
     }
   }
@@ -172,7 +166,7 @@ export default class DefaultFormatter {
   }
 
   _addExport(name, exported) {
-    var info = this.localExports[name] ||= {
+    var info = this.localExports[name] = this.localExports[name] || {
       binding: this.scope.getBindingIdentifier(name),
       exported: []
     };

src/babel/transformation/modules/amd.js

@@ -6,7 +6,9 @@ import * as util from  "../../util";
 import * as t from "../../types";
 
 export default class AMDFormatter extends DefaultFormatter {
-  init = CommonFormatter.prototype.init;
+  init() {
+    CommonFormatter.prototype._init.call(this, this.hasNonDefaultExports);
+  }
 
   buildDependencyLiterals() {
     var names = [];
@@ -78,9 +80,12 @@ export default class AMDFormatter extends DefaultFormatter {
       this.defaultIds[key] = specifier.local;
     }
 
-    if (includes(this.file.dynamicImportedNoDefault, node)) {
+    if (this.isModuleType(node, "absolute")) {
-      // Prevent unnecessary renaming of dynamic imports.
+      // absolute module reference
+    } else if (this.isModuleType(node, "absoluteDefault")) {
+      // prevent unnecessary renaming of dynamic imports
       this.ids[node.source.value] = ref;
+      ref = t.memberExpression(ref, t.identifier("default"));
     } else if (t.isImportNamespaceSpecifier(specifier)) {
       // import * as bar from "foo";
     } else if (!includes(this.file.dynamicImported, node) && t.isSpecifierDefault(specifier) && !this.noInteropRequireImport) {
@@ -100,15 +105,35 @@ export default class AMDFormatter extends DefaultFormatter {
     this.internalRemap[specifier.local.name] = ref;
   }
 
-  exportSpecifier() {
+  exportSpecifier(specifier, node, nodes) {
-    CommonFormatter.prototype.exportSpecifier.apply(this, arguments);
+    if (this.doDefaultExportInterop(specifier)) {
+      this.passModuleArg = true;
+      nodes.push(util.template("exports-default-assign", {
+        VALUE: specifier.local
+      }, true));
+    } else {
+      CommonFormatter.prototype.exportSpecifier.apply(this, arguments);
+    }
   }
 
-  exportDeclaration(node) {
+  exportDeclaration(node, nodes) {
     if (this.doDefaultExportInterop(node)) {
       this.passModuleArg = true;
+
+      var declar = node.declaration;
+      var assign = util.template("exports-default-assign", {
+        VALUE: this._pushStatement(declar, nodes)
+      }, true);
+
+      if (t.isFunctionDeclaration(declar)) {
+        // we can hoist this assignment to the top of the file
+        assign._blockHoist = 3;
+      }
+
+      nodes.push(assign);
+      return;
     }
 
-    CommonFormatter.prototype.exportDeclaration.apply(this, arguments);
+    DefaultFormatter.prototype.exportDeclaration.apply(this, arguments);
   }
 }

src/babel/transformation/modules/common.js

@@ -5,18 +5,36 @@ import * as t from "../../types";
 
 export default class CommonJSFormatter extends DefaultFormatter {
   init() {
+    this._init(this.hasLocalExports);
+  }
+
+  _init(conditional) {
     var file  = this.file;
     var scope = file.scope;
 
     scope.rename("module");
     scope.rename("exports");
 
-    if (!this.noInteropRequireImport && this.hasNonDefaultExports) {
+    if (!this.noInteropRequireImport && conditional) {
       var templateName = "exports-module-declaration";
       if (this.file.isLoose("es6.modules")) templateName += "-loose";
       var declar = util.template(templateName, true);
       declar._blockHoist = 3;
-      file.ast.program.body.unshift(declar);
+      file.path.unshiftContainer("body", [declar]);
+    }
+  }
+
+  transform(program) {
+    DefaultFormatter.prototype.transform.apply(this, arguments);
+
+    if (this.hasDefaultOnlyExport) {
+      program.body.push(
+        t.expressionStatement(t.assignmentExpression(
+          "=",
+          t.memberExpression(t.identifier("module"), t.identifier("exports")),
+          t.memberExpression(t.identifier("exports"), t.identifier("default"))
+        ))
+      );
     }
   }
 
@@ -27,16 +45,20 @@ export default class CommonJSFormatter extends DefaultFormatter {
 
     // import foo from "foo";
     if (t.isSpecifierDefault(specifier)) {
-      if (includes(this.file.dynamicImportedNoDefault, node)) {
+      if (this.isModuleType(node, "absolute")) {
+        // absolute module reference
+      } else if (this.isModuleType(node, "absoluteDefault")) {
         this.internalRemap[variableName.name] = ref;
+      } else if (this.noInteropRequireImport) {
+        this.internalRemap[variableName.name] = t.memberExpression(ref, t.identifier("default"));
       } else {
-        if (this.noInteropRequireImport) {
+        var uid = this.scope.generateUidBasedOnNode(node, "import");
-          this.internalRemap[variableName.name] = t.memberExpression(ref, t.identifier("default"))
+
-        } else if (!includes(this.file.dynamicImported, node)) {
+        nodes.push(t.variableDeclaration("var", [
-          nodes.push(t.variableDeclaration("var", [
+          t.variableDeclarator(uid, t.callExpression(this.file.addHelper("interop-require-default"), [ref]))
-            t.variableDeclarator(variableName, t.callExpression(this.file.addHelper("interop-require"), [ref]))
+        ]));
-          ]));
+
-        }
+        this.internalRemap[variableName.name] = t.memberExpression(uid, t.identifier("default"));
       }
     } else {
       if (t.isImportNamespaceSpecifier(specifier)) {
@@ -64,29 +86,15 @@ export default class CommonJSFormatter extends DefaultFormatter {
 
   exportSpecifier(specifier, node, nodes) {
     if (this.doDefaultExportInterop(specifier)) {
-      nodes.push(util.template("exports-default-assign", {
+      this.hasDefaultOnlyExport = true;
-        VALUE: specifier.local
-      }, true));
-      return;
-    } else {
-      DefaultFormatter.prototype.exportSpecifier.apply(this, arguments);
     }
+
+    DefaultFormatter.prototype.exportSpecifier.apply(this, arguments);
   }
 
   exportDeclaration(node, nodes) {
     if (this.doDefaultExportInterop(node)) {
-      var declar = node.declaration;
+      this.hasDefaultOnlyExport = true;
-      var assign = util.template("exports-default-assign", {
-        VALUE: this._pushStatement(declar, nodes)
-      }, true);
-
-      if (t.isFunctionDeclaration(declar)) {
-        // we can hoist this assignment to the top of the file
-        assign._blockHoist = 3;
-      }
-
-      nodes.push(assign);
-      return;
     }
 
     DefaultFormatter.prototype.exportDeclaration.apply(this, arguments);
@@ -98,13 +106,16 @@ export default class CommonJSFormatter extends DefaultFormatter {
     var call = t.callExpression(t.identifier("require"), [node.source]);
     var uid;
 
-    if (includes(this.file.dynamicImported, node) && !includes(this.file.dynamicImportedNoDefault, node)) {
+    if (this.isModuleType(node, "absolute")) {
+      // absolute module reference
+    } else if (this.isModuleType(node, "absoluteDefault")) {
       call = t.memberExpression(call, t.identifier("default"));
-      uid = node.specifiers[0].local;
     } else {
       uid = this.scope.generateUidBasedOnNode(node, "import");
     }
 
+    uid = uid || node.specifiers[0].local;
+
     var declar = t.variableDeclaration("var", [
       t.variableDeclarator(uid, call)
     ]);

src/babel/transformation/modules/system.js

@@ -6,12 +6,8 @@ import each from "lodash/collection/each";
 import map from "lodash/collection/map";
 import * as t from "../../types";
 
-var canHoist = function (node, file) {
-  return node._blockHoist && !file.transformers.runtime.canTransform();
-}
-
 var hoistVariablesVisitor = {
-  enter(node, parent, scope, hoistDeclarators) {
+  enter(node, parent, scope, state) {
     if (t.isFunction(node)) {
       // nothing inside is accessible
       return this.skip();
@@ -24,13 +20,13 @@ var hoistVariablesVisitor = {
       }
 
       // ignore block hoisted nodes as these can be left in
-      if (canHoist(node, scope.file)) return;
+      if (state.formatter.canHoist(node)) return;
 
       var nodes = [];
 
       for (var i = 0; i < node.declarations.length; i++) {
         var declar = node.declarations[i];
-        hoistDeclarators.push(t.variableDeclarator(declar.id));
+        state.hoistDeclarators.push(t.variableDeclarator(declar.id));
         if (declar.init) {
           // no initializer so we can just hoist it as-is
           var assign = t.expressionStatement(t.assignmentExpression("=", declar.id, declar.init));
@@ -40,14 +36,8 @@ var hoistVariablesVisitor = {
 
       // for (var i in test)
       // for (var i = 0;;)
-      if (t.isFor(parent)) {
+      if (t.isFor(parent) && parent.left === node) {
-        if (parent.left === node) {
+        return node.declarations[0].id;
-          return node.declarations[0].id;
-        }
-
-        if (parent.init === node) {
-          return nodes;
-        }
       }
 
       return nodes;
@@ -56,11 +46,11 @@ var hoistVariablesVisitor = {
 };
 
 var hoistFunctionsVisitor = {
-  enter(node, parent, scope, handlerBody) {
+  enter(node, parent, scope, state) {
     if (t.isFunction(node)) this.skip();
 
-    if (t.isFunctionDeclaration(node) || canHoist(node, scope.file)) {
+    if (t.isFunctionDeclaration(node) || state.formatter.canHoist(node)) {
-      handlerBody.push(node);
+      state.handlerBody.push(node);
       this.remove();
     }
   }
@@ -87,11 +77,11 @@ var runnerSettersVisitor = {
 
 export default class SystemFormatter extends AMDFormatter {
   constructor(file) {
+    super(file);
+
     this.exportIdentifier = file.scope.generateUidIdentifier("export");
     this.noInteropRequireExport = true;
     this.noInteropRequireImport = true;
-
-    DefaultFormatter.apply(this, arguments);
   }
 
   _addImportSource(node, exportNode) {
@@ -174,6 +164,10 @@ export default class SystemFormatter extends AMDFormatter {
     }));
   }
 
+  canHoist(node) {
+    return node._blockHoist && !this.file.dynamicImports.length;
+  }
+
   transform(program) {
     DefaultFormatter.prototype.transform.apply(this, arguments);
 
@@ -197,7 +191,10 @@ export default class SystemFormatter extends AMDFormatter {
     var returnStatement = handlerBody.pop();
 
     // hoist up all variable declarations
-    this.file.scope.traverse(block, hoistVariablesVisitor, hoistDeclarators);
+    this.file.scope.traverse(block, hoistVariablesVisitor, {
+      formatter: this,
+      hoistDeclarators: hoistDeclarators
+    });
 
     if (hoistDeclarators.length) {
       var hoistDeclar = t.variableDeclaration("var", hoistDeclarators);
@@ -206,7 +203,10 @@ export default class SystemFormatter extends AMDFormatter {
     }
 
     // hoist up function declarations for circular references
-    this.file.scope.traverse(block, hoistFunctionsVisitor, handlerBody);
+    this.file.scope.traverse(block, hoistFunctionsVisitor, {
+      formatter: this,
+      handlerBody: handlerBody
+    });
 
     handlerBody.push(returnStatement);
 

src/babel/transformation/modules/umd.js

@@ -1,6 +1,7 @@
 import DefaultFormatter from "./_default";
 import AMDFormatter from "./amd";
 import values from "lodash/object/values";
+import path from "path";
 import * as util from  "../../util";
 import * as t from "../../types";
 
@@ -47,11 +48,11 @@ export default class UMDFormatter extends AMDFormatter {
 
     // globals
 
-    var browserArgs = [t.memberExpression(t.identifier("module"), t.identifier("exports"))];
+    var browserArgs = [];
-    if (this.passModuleArg) browserArgs.push(t.identifier("module"));
+    if (this.passModuleArg) browserArgs.push(t.identifier("mod"));
 
     for (let name in this.ids) {
-      var id = this.defaultIds[name] || t.identifier(t.toIdentifier(name));
+      var id = this.defaultIds[name] || t.identifier(t.toIdentifier(path.basename(name, path.extname(name))));
       browserArgs.push(t.memberExpression(t.identifier("global"), id));
     }
 
@@ -60,12 +61,17 @@ export default class UMDFormatter extends AMDFormatter {
     var moduleName = this.getModuleName();
     if (moduleName) defineArgs.unshift(t.literal(moduleName));
 
+    //
+    var globalArg = this.file.opts.basename;
+    if (moduleName) globalArg = moduleName;
+    globalArg = t.identifier(t.toIdentifier(globalArg));
+
     var runner = util.template("umd-runner-body", {
       AMD_ARGUMENTS: defineArgs,
       COMMON_TEST: commonTests,
       COMMON_ARGUMENTS: commonArgs,
       BROWSER_ARGUMENTS: browserArgs,
-      GLOBAL_ARG: t.identifier(t.toIdentifier(this.file.opts.basename))
+      GLOBAL_ARG: globalArg
     });
 
     //

src/babel/transformation/templates/.babelrc

@@ -1,4 +1,4 @@
 {
-  "blacklist": ["useStrict", "es6.blockScoping", "regenerator"],
+  "blacklist": ["useStrict", "es6.blockScoping", "regenerator", "es6.spread"],
   "loose": ["es6.modules"]
 }

src/babel/transformation/templates/call-instance-decorator.js

@@ -1 +0,0 @@
-this.KEY = INITIALIZERS.KEY.call(this);

src/babel/transformation/templates/call-static-decorator.js

@@ -1 +0,0 @@
-CONSTRUCTOR.KEY = INITIALIZERS.KEY.call(CONSTRUCTOR);

src/babel/transformation/templates/class-super-native-constructor-call.js

@@ -0,0 +1,5 @@
+if (SUPER_NAME != null) {
+  var NATIVE_REF = new SUPER_NAME(...arguments);
+  NATIVE_REF.__proto__ = CLASS_NAME.prototype;
+  return NATIVE_REF;
+}

src/babel/transformation/templates/corejs-is-iterator.js

@@ -1 +0,0 @@
-CORE_ID.isIterable(VALUE);

src/babel/transformation/templates/corejs-iterator.js

@@ -1 +0,0 @@
-CORE_ID.getIterator(VALUE);

src/babel/transformation/templates/helper-create-class.js

@@ -4,7 +4,7 @@
       var descriptor = props[i];
       descriptor.enumerable = descriptor.enumerable || false;
       descriptor.configurable = true;
-      if (descriptor.value) descriptor.writable = true;
+      if ("value" in descriptor) descriptor.writable = true;
       Object.defineProperty(target, descriptor.key, descriptor);
     }
   }

src/babel/transformation/templates/helper-create-decorated-class.js

@@ -23,7 +23,11 @@
             throw new TypeError("The decorator for method " + descriptor.key + " is of the invalid type " + typeof decorator);
           }
         }
-        if (initializers) initializers[key] = descriptor.initializer;
+
+        if (descriptor.initializer !== undefined) {
+          initializers[key] = descriptor;
+          continue;
+        }
       }
 
       Object.defineProperty(target, key, descriptor);

src/babel/transformation/templates/helper-create-decorated-object.js

@@ -0,0 +1,36 @@
+(function (descriptors) {
+  var target = {};
+
+  for (var i = 0; i < descriptors.length; i ++) {
+    var descriptor = descriptors[i];
+    var decorators = descriptor.decorators;
+    var key        = descriptor.key;
+
+    // don't want to expose these to userland since i know people will rely on them
+    // and think it's spec behaviour
+    delete descriptor.key;
+    delete descriptor.decorators;
+
+    descriptor.enumerable = true;
+    descriptor.configurable = true;
+    descriptor.writable = true;
+
+    if (decorators) {
+      for (var f = 0; f < decorators.length; f++) {
+        var decorator = decorators[f];
+        if (typeof decorator === "function") {
+          descriptor = decorator(target, key, descriptor) || descriptor;
+        } else {
+          throw new TypeError("The decorator for method " + descriptor.key + " is of the invalid type " + typeof decorator);
+        }
+      }
+    }
+
+    if (descriptor.initializer) {
+      descriptor.value = descriptor.initializer.call(target);
+      Object.defineProperty(target, key, descriptor);
+    }
+  }
+
+  return target;
+})

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

@@ -0,0 +1,13 @@
+(function (target, key, descriptors) {
+  var _descriptor = descriptors[key];
+
+  // clone it
+  var descriptor = {};
+  for (var _key in _descriptor) descriptor[_key] = _descriptor[_key];
+
+  // initialize it
+  if (!descriptor.initializer) return;
+  descriptor.value = descriptor.initializer.call(target);
+
+  Object.defineProperty(target, key, descriptor);
+})

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

@@ -1,7 +1,7 @@
 (function (obj, key, value) {
   return Object.defineProperty(obj, key, {
     value: value,
-    enumerable: key == null || typeof Symbol == "undefined" || key.constructor !== Symbol,
+    enumerable: true,
     configurable: true,
     writable: true
   });

src/babel/transformation/templates/helper-get.js

@@ -9,7 +9,7 @@
     } else {
       return get(parent, property, receiver);
     }
-  } else if ("value" in desc && desc.writable) {
+  } else if ("value" in desc) {
     return desc.value;
   } else {
     var getter = desc.get;

src/babel/transformation/templates/helper-instanceof.js

@@ -0,0 +1,7 @@
+(function (left, right) {
+  if (right != null && right[Symbol.hasInstance]) {
+    return right[Symbol.hasInstance](left);
+  } else {
+    return left instanceof right;
+  }
+});

src/babel/transformation/templates/helper-interop-require-default.js

@@ -0,0 +1,3 @@
+(function (obj) {
+  return obj && obj.__esModule ? obj : { default: obj };
+})

src/babel/transformation/templates/helper-interop-require-wildcard.js

@@ -1,3 +1,14 @@
 (function (obj) {
-  return obj && obj.__esModule ? obj : { default: obj };
+  if (obj && obj.__esModule) {
+    return obj;
+  } else {
+    var newObj = {};
+    if (obj != null) {
+      for (var key in obj) {
+        if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key];
+      }
+    }
+    newObj.default = obj;
+    return newObj;
+  }
 })

src/babel/transformation/templates/helper-ludicrous-proxy-create.js

@@ -0,0 +1,4 @@
+(function (proxy, directory) {
+  directory.push(proxy);
+  return proxy;
+})

src/babel/transformation/templates/helper-ludicrous-proxy-directory.js

@@ -0,0 +1 @@
+[];

src/babel/transformation/templates/property-method-assignment-wrapper-generator.js

@@ -1,10 +1,10 @@
 (function (FUNCTION_KEY) {
   function* FUNCTION_ID() {
-    return yield* FUNCTION_ID.apply(this, arguments);
+    return yield* FUNCTION_KEY.apply(this, arguments);
   }
 
   FUNCTION_ID.toString = function () {
-    return FUNCTION_ID.toString();
+    return FUNCTION_KEY.toString();
   };
 
   return FUNCTION_ID;

src/babel/transformation/templates/property-method-assignment-wrapper.js

@@ -4,7 +4,7 @@
   }
 
   FUNCTION_ID.toString = function () {
-    return FUNCTION_ID.toString();
+    return FUNCTION_KEY.toString();
   }
 
   return FUNCTION_ID;

src/babel/transformation/templates/umd-runner-body.js

@@ -4,8 +4,8 @@
   } else if (COMMON_TEST) {
     factory(COMMON_ARGUMENTS);
   } else {
-    var module = { exports: {} };
+    var mod = { exports: {} };
-    factory(BROWSER_ARGUMENTS);
+    factory(mod.exports, BROWSER_ARGUMENTS);
-    global.GLOBAL_ARG = module.exports;
+    global.GLOBAL_ARG = mod.exports;
   }
 });

src/babel/transformation/transformer-pass.js

@@ -8,58 +8,35 @@ import traverse from "../traversal";
 
 export default class TransformerPass {
   constructor(file: File, transformer: Transformer) {
-    this.transformer = transformer;
+    this.shouldTransform = !transformer.shouldVisit;
-    this.shouldRun   = !transformer.check;
+    this.transformer     = transformer;
-    this.handlers    = transformer.handlers;
+    this.handlers        = transformer.handlers;
-    this.file        = file;
+    this.skipKey         = transformer.skipKey;
-    this.ran         = false;
+    this.file            = file;
+    this.ran             = false;
   }
 
   canTransform(): boolean {
-    var transformer = this.transformer;
+    return this.file.pipeline.canTransform(this.transformer, this.file.opts);
-
-    var opts = this.file.opts;
-    var key  = transformer.key;
-
-    // internal
-    if (key[0] === "_") return true;
-
-    // blacklist
-    var blacklist = opts.blacklist;
-    if (blacklist.length && includes(blacklist, key)) return false;
-
-    // whitelist
-    var whitelist = opts.whitelist;
-    if (whitelist) return includes(whitelist, key);
-
-    // stage
-    var stage = transformer.metadata.stage;
-    if (stage != null && stage >= opts.stage) return true;
-
-    // optional
-    if (transformer.metadata.optional && !includes(opts.optional, key)) return false;
-
-    return true;
   }
 
-  checkNode(node: Object): boolean {
+  checkPath(path: TraversalPath): boolean {
-    var check = this.transformer.check;
+    if (this.shouldTransform || this.ran) return;
-    if (check) {
+
-      return this.shouldRun = check(node);
+    this.shouldTransform = this.transformer.shouldVisit(path.node);
-    } else {
-      return true;
-    }
   }
 
   transform() {
-    if (!this.shouldRun) return;
+    if (!this.shouldTransform) return;
 
     var file = this.file;
 
-    file.log.debug(`Running transformer ${this.transformer.key}`);
+    file.log.debug(`Start transformer ${this.transformer.key}`);
 
     traverse(file.ast, this.handlers, file.scope, file);
 
+    file.log.debug(`Finish transformer ${this.transformer.key}`);
+
     this.ran = true;
   }
 }

src/babel/transformation/transformer-pipeline.js

@@ -0,0 +1,100 @@
+import Transformer from "./transformer";
+import normalizeAst from "../helpers/normalize-ast";
+import assign from "lodash/object/assign";
+import object from "../helpers/object";
+import File from "./file";
+
+export default class TransformerPipeline {
+  constructor() {
+    this.transformers = object();
+    this.namespaces   = object();
+    this.deprecated   = object();
+    this.aliases      = object();
+    this.filters      = [];
+  }
+
+  addTransformers(transformers) {
+    for (var key in transformers) {
+      this.addTransformer(key, transformers[key]);
+    }
+    return this;
+  }
+
+  addTransformer(key, transformer) {
+    if (this.transformers[key]) throw new Error(); // todo: error
+
+    var namespace = key.split(".")[0];
+    this.namespaces[namespace] = this.namespaces[namespace] || [];
+    this.namespaces[namespace].push(key);
+    this.namespaces[key] = namespace;
+
+    this.transformers[key] = new Transformer(key, transformer);
+  }
+
+  addAliases(names) {
+    assign(this.aliases, names);
+    return this;
+  }
+
+  addDeprecated(names) {
+    assign(this.deprecated, names);
+    return this;
+  }
+
+  addFilter(filter: Function) {
+    this.filters.push(filter);
+    return this;
+  }
+
+  canTransform(transformer, fileOpts) {
+    for (var filter of (this.filters: Array)) {
+      var result = filter(transformer, fileOpts);
+      if (result != null) return result;
+    }
+
+    return true;
+  }
+
+  transform(code: string, opts?: Object) {
+    var file = new File(opts, this);
+    return file.parse(code);
+  }
+
+  transformFromAst(ast, code, opts) {
+    ast = normalizeAst(ast);
+
+    var file = new File(opts, this);
+    file.addCode(code);
+    file.transform(ast);
+    return file.generate();
+  }
+
+  _ensureTransformerNames(type: string, rawKeys: Array<string>) {
+    var keys = [];
+
+    for (var i = 0; i < rawKeys.length; i++) {
+      var key = rawKeys[i];
+
+      var deprecatedKey = this.deprecated[key];
+      var aliasKey = this.aliases[key];
+      if (aliasKey) {
+        keys.push(aliasKey);
+      } else if (deprecatedKey) {
+        // deprecated key, remap it to the new one
+        console.error(`The transformer ${key} has been renamed to ${deprecatedKey}`);
+        rawKeys.push(deprecatedKey);
+      } else if (this.transformers[key]) {
+        // valid key
+        keys.push(key);
+      } else if (this.namespaces[key]) {
+        // namespace, append all transformers within this namespace
+        keys = keys.concat(this.namespaces[key]);
+      } else {
+        // invalid key
+        throw new ReferenceError(`Unknown transformer ${key} specified in ${type}`);
+      }
+    }
+
+    return keys;
+  }
+}

src/babel/transformation/transformer.js

@@ -1,4 +1,5 @@
 import TransformerPass from "./transformer-pass";
+import * as messages from "../messages";
 import isFunction from "lodash/lang/isFunction";
 import traverse from "../traversal";
 import isObject from "lodash/lang/isObject";
@@ -14,7 +15,7 @@ import each from "lodash/collection/each";
  */
 
 export default class Transformer {
-  constructor(transformerKey: key, transformer: Object, opts: Object) {
+  constructor(transformerKey: string, transformer: Object) {
     transformer = assign({}, transformer);
 
     var take = function (key) {
@@ -24,19 +25,34 @@ export default class Transformer {
     };
 
     this.manipulateOptions = take("manipulateOptions");
+    this.shouldVisit       = take("shouldVisit");
     this.metadata          = take("metadata") || {};
     this.parser            = take("parser");
-    this.check             = take("check");
     this.post              = take("post");
     this.pre               = take("pre");
 
+    //
+
     if (this.metadata.stage != null) {
       this.metadata.optional = true;
     }
 
+    //
+
     this.handlers = this.normalize(transformer);
-    this.opts     ||= {};
     this.key      = transformerKey;
+
+    //
+
+    if (!this.shouldVisit) {
+      var types = Object.keys(this.handlers);
+      this.shouldVisit = function (node) {
+        for (var i = 0; i < types.length; i++) {
+          if (node.type === types[i]) return true;
+        }
+        return false;
+      };
+    }
   }
 
   normalize(transformer: Object): Object {
@@ -71,7 +87,7 @@ export default class Transformer {
   buildPass(file: File): TransformerPass {
     // validate Transformer instance
     if (!(file instanceof File)) {
-      throw new TypeError(`Transformer ${this.key} is resolving to a different Babel version to what is doing the actual transformation...`);
+      throw new TypeError(messages.get("transformerNotFile", this.key));
     }
 
     return new TransformerPass(file, this);

src/babel/transformation/transformers/es5/properties.mutators.js

@@ -1,18 +1,18 @@
 import * as defineMap from "../../helpers/define-map";
 import * as t from "../../../types";
 
-export function check(node) {
+export function shouldVisit(node) {
   return t.isProperty(node) && (node.kind === "get" || node.kind === "set");
 }
 
-export function ObjectExpression(node) {
+export function ObjectExpression(node, parent, scope, file) {
   var mutatorMap = {};
   var hasAny = false;
 
   node.properties = node.properties.filter(function (prop) {
     if (prop.kind === "get" || prop.kind === "set") {
       hasAny = true;
-      defineMap.push(mutatorMap, prop.key, prop.kind, prop.computed, prop.value);
+      defineMap.push(mutatorMap, prop, prop.kind, file);
       return false;
     } else {
       return true;