v7.0.0-beta.3

Don't insert duplicated nodes when transforming function bind

.babelignore

@@ -0,0 +1,4 @@
+# Ensure babel-register won't compile fixtures, or try to recompile compiled code.
+packages/*/test/fixtures
+packages/*/lib
+packages/babel-standalone/babel.js

.babelrc.js

@@ -0,0 +1,57 @@
+"use strict";
+
+// Blame Logan for this.
+// This works around https://github.com/istanbuljs/istanbuljs/issues/92 until
+// we have a version of Istanbul that actually works with 7.x.
+function istanbulHacks() {
+  return {
+    inherits: require("babel-plugin-istanbul").default,
+    visitor: {
+      Program: {
+        exit: function(path) {
+          if (!this.__dv__) return
+
+          const node = path.node.body[0];
+          if (
+            node.type !== "VariableDeclaration" ||
+            node.declarations[0].id.type !== "Identifier" ||
+            !node.declarations[0].id.name.match(/cov_/) ||
+            node._blockHoist !== 3
+          ) {
+            throw new Error("Something has gone wrong in Logan's hacks.");
+          }
+
+          // Gross hacks to put the code coverage block above all compiled
+          // import statement output.
+          node._blockHoist = 5;
+        },
+      },
+    },
+  };
+}
+
+let envOpts = {
+  loose: true
+};
+
+module.exports = {
+  comments: false,
+  presets: [
+    ["env", envOpts],
+    "stage-0",
+    "flow"
+  ],
+  env: {
+    cov: {
+      auxiliaryCommentBefore: "istanbul ignore next",
+      plugins: [istanbulHacks]
+    }
+  }
+};
+
+if (process.env.BABEL_ENV === "development") {
+  envOpts.targets = {
+    node: "current"
+  };
+  envOpts.debug = true;
+}

.editorconfig

@@ -4,8 +4,8 @@ root = true
 insert_final_newline = true
 charset = utf-8
 trim_trailing_whitespace = true
-insert_final_newline = true
+end_of_line = lf
 
-[*.js]
+[*.{js,json}]
 indent_style = space
 indent_size = 2

.eslintignore

@@ -0,0 +1,26 @@
+/lib
+packages/babel-runtime
+!packages/babel-runtime/scripts
+!packages/babel-runtime/core-js.js
+packages/*/node_modules
+packages/*/lib
+packages/*/dist
+packages/*/test/fixtures
+packages/*/test/tmp
+codemods/*/node_modules
+codemods/*/lib
+codemods/*/dist
+codemods/*/test/fixtures
+codemods/*/test/tmp
+experimental/*/lib
+experimental/*/node_modules
+experimental/*/test/fixtures
+experimental/*/test/tmp
+experimental/babel-preset-env/data
+experimental/babel-preset-env/test/debug-fixtures
+packages/babel-standalone/babel.js
+packages/babel-standalone/babel.min.js
+
+# Prettier tries to insert trailing commas in function calls, which Node.js
+# doesn't natively support. This causes an error when loading the Gulp tasks.
+packages/babel-standalone/src/gulpTasks.js

.eslintrc

@@ -0,0 +1,14 @@
+{
+  "extends": "babel",
+  "plugins": [
+    "prettier"
+  ],
+  "rules": {
+    "curly": ["error", "multi-line"],
+    "prettier/prettier": ["error", { "trailingComma": "es5" }]
+  },
+  "env": {
+    "node": true,
+    "mocha": true
+  }
+}

.flowconfig

@@ -0,0 +1,24 @@
+[ignore]
+.*/packages/.*/lib
+.*/packages/.*/test
+.*/codemods/.*/lib
+.*/codemods/.*/test
+.*/experimental/.*/lib
+.*/experimental/.*/test
+.*/node_modules/conventional-changelog-core/
+
+[include]
+packages/*/src
+codemods/*/src
+experimental/*/src
+
+[libs]
+lib/file.js
+lib/parser.js
+lib/types.js
+lib/third-party-libs.js.flow
+
+[options]
+suppress_comment= \\(.\\|\n\\)*\\$FlowFixMe
+suppress_comment= \\(.\\|\n\\)*\\$FlowIssue
+esproposal.export_star_as=enable

.gitattributes

@@ -0,0 +1 @@
+* text eol=lf

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,62 @@
+<!---
+Thanks for filing an issue 😄 ! Before you submit, please read the following:
+
+Search open/closed issues before submitting since someone might have asked the same thing before!
+
+If you have a support request or question please submit them to one of this resources:
+
+* Slack Community: https://slack.babeljs.io/
+* StackOverflow: http://stackoverflow.com/questions/tagged/babeljs using the tag `babeljs`
+* Also have a look at the readme for more information on how to get support:
+  https://github.com/babel/babel/blob/master/README.md
+
+Issues on GitHub are only related to problems of Babel itself and we cannot answer 
+support questions here.
+-->
+
+Choose one: is this a bug report or feature request?
+
+<!--- Provide a general summary of the issue in the title above -->
+
+### Input Code
+<!--- If you're describing a bug, please let us know which sample code reproduces your problem -->
+<!--- If you have link to our REPL or a standalone repo please link that! -->
+
+```js
+var your => (code) => here;
+```
+
+### Babel Configuration (.babelrc, package.json, cli command)
+<!--- If describing a bug, tell us what your babel configuration looks like -->
+
+```js
+{
+  "your": { "config": "here" }
+}
+```
+
+### Expected Behavior
+<!--- If you're describing a bug, tell us what should happen -->
+<!--- If you're suggesting a change/improvement, tell us how it should work -->
+
+### Current Behavior
+<!--- If describing a bug, tell us what happens instead of the expected behavior -->
+<!--- If suggesting a change/improvement, explain the difference from current behavior -->
+
+### Possible Solution
+<!--- Not obligatory, but suggest a fix/reason for the bug, -->
+<!--- or ideas how to implement the addition or change -->
+
+### Context
+<!--- How has this issue affected you? What are you trying to accomplish? -->
+<!--- Providing context helps us come up with a solution that is most useful in the real world -->
+
+### Your Environment
+<!--- Include as many relevant details about the environment you experienced the bug in -->
+
+| software         | version(s)
+| ---------------- | -------
+| Babel            |  
+| node             | 
+| npm              | 
+| Operating System | 

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,18 @@
+<!-- 
+Before making a PR please make sure to read our contributing guidelines 
+https://github.com/babel/babel/blob/master/CONTRIBUTING.md
+
+For issue references: Add a comma-separated list of a [closing word](https://help.github.com/articles/closing-issues-via-commit-messages/) followed by the ticket number fixed by the PR. It should be underlined in the preview if done correctly.
+-->
+
+| Q                        | A <!--(Can use an emoji 👍) -->
+| ------------------------ | ---
+| Fixed Issues?            | `Fixes #1, Fixes #2` <!-- remove the (`) quotes to link the issues -->
+| Patch: Bug Fix?          | 
+| Major: Breaking Change?  | 
+| Minor: New Feature?      | 
+| Tests Added + Pass?      | Yes
+| Documentation PR         | <!-- If so, add `[skip ci]` to your commit message to skip CI -->
+| Any Dependency Changes?  | 
+
+<!-- Describe your changes below in as much detail as possible -->

.gitignore

@@ -1,13 +1,33 @@
 .DS_Store
-node_modules
-test/tmp
+/node_modules
+/packages/*/node_modules
 *.log
 *.cache
-/templates.json
-/tests.json
+/.eslintcache
 /browser.js
 /browser-polyfill.js
 /runtime.js
-coverage
+/coverage
 dist
-.package.json
+/.package.json
+package-lock.json
+/packages/babel-runtime/core-js/**/*.js
+!/packages/babel-runtime/core-js/map.js
+/packages/babel-runtime/helpers/*.js
+!/packages/babel-runtime/helpers/toArray.js
+/packages/babel-runtime/helpers/builtin/*.js
+!/packages/babel-runtime/helpers/builtin/toArray.js
+/packages/babel-runtime/helpers/builtin/es6/*.js
+!/packages/babel-runtime/helpers/builtin/es6/toArray.js
+/packages/babel-runtime/helpers/es6/*.js
+!/packages/babel-runtime/helpers/es6/toArray.js
+/packages/babel-register/test/.babel
+/packages/babel-cli/test/tmp
+/packages/babel-node/test/tmp
+/packages/*/lib
+.nyc_output
+/babel.sublime-workspace
+packages/babel-standalone/babel.js
+packages/babel-standalone/babel.min.js
+/codemods/*/lib
+/codemods/*/node_modules

.gitmodules

@@ -1,9 +0,0 @@
-[submodule "vendor/traceur"]
-	path = vendor/traceur
-	url = https://github.com/google/traceur-compiler
-[submodule "vendor/regenerator"]
-	path = vendor/regenerator
-	url = https://github.com/facebook/regenerator
-[submodule "vendor/test262"]
-	path = vendor/test262
-	url = https://github.com/tc39/test262

.jshintignore

@@ -1,3 +0,0 @@
-node_modules
-test
-lib/6to5/transformation/templates

.jshintrc

@@ -1,29 +0,0 @@
-{
-  "esnext": true,
-  "indent": 2,
-  "freeze": true,
-  "camelcase": true,
-  "unused": true,
-  "eqnull": true,
-  "proto": true,
-  "newcap": true,
-  "supernew": true,
-  "noyield": true,
-  "evil": true,
-  "node": true,
-  "boss": true,
-  "expr": true,
-  "undef": true,
-  "loopfunc": true,
-  "white": true,
-  "maxparams": 5,
-  "maxdepth": 4,
-
-  "globals": {
-    "window": true,
-    "suite": true,
-    "set": true,
-    "before": true,
-    "bench": true
-  }
-}

.npmignore

@@ -1,12 +0,0 @@
-node_modules
-*.log
-*.cache
-lib/6to5/transformation/templates
-test
-benchmark
-Makefile
-.*
-dist
-tests.json
-CHANGELOG.md
-.package.json

.travis.yml

@@ -1,19 +1,44 @@
+git:
+  depth: 10
+sudo: false
 language: node_js
+cache:
+  yarn: true
+  directories:
+  - node_modules
 node_js:
-  - "0.10"
-  - "0.11"
+  - '8'
+  - '6'
+  - '4'
+
+env:
+  global:
+    - PATH=$HOME/.yarn/bin:$PATH
+    - JOB=test
+
+before_install:
+  - curl -o- -L https://yarnpkg.com/install.sh | bash
+
+script:
+  - 'if [ "$JOB" = "test" ]; then make test-ci; fi'
+  - 'if [ "$JOB" = "lint" ]; then make lint && make flow; fi'
+
+matrix:
+  fast_finish: true
+  include:
+    - node_js: "node"
+      env: JOB=lint
+
+notifications:
+  slack:
+    on_success: change
+    on_failure: always
+    rooms:
+      # Generate with
+      #     travis encrypt "babeljs:<token>#activity" --add notifications.slack.rooms
+      # where <token> is from the Slack integration settings.
+      secure: SrwPKRe2AiNAKRo/+2yW/x4zxbWf2FBXuBuuPkdTJVTpWe++Jin1lXYJWTKP1a1i/IbmhffBO9YZcUFbeuXJpRM083vO8VYpyuBMQRqWD+Z3o+ttPlHGOJgnj0nkIcGRk6k7PpyHNnIkixfEJDvbbg9lN1Jswb3xkL8iYIHpuFE=
 
 branches:
   except:
-   - experimental
-
-before_script: "npm install -g codeclimate-test-reporter"
-script: "make test-travis"
-
-notifications:
-  webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/acf1870e9d223c65e8d5
-    on_success: always
-    on_failure: always
-    on_start: false
+    - /^v\d+\.\d+\.\d+$/

CODE_OF_CONDUCT.md

@@ -1,13 +1,74 @@
-# Contributor Code of Conduct
+# Contributor Covenant Code of Conduct
 
-As contributors and maintainers of this project, we pledge to respect all people who contribute through reporting issues, posting feature requests, updating documentation, submitting pull requests or patches, and other activities.
+## Our Pledge
 
-We are committed to making participation in this project a harassment-free experience for everyone, regardless of level of experience, gender, gender identity and expression, sexual orientation, disability, personal appearance, body size, race, age, or religion.
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
 
-Examples of unacceptable behavior by participants include the use of sexual language or imagery, derogatory comments or personal attacks, trolling, public or private harassment, insults, or other unprofessional conduct.
+## Our Standards
 
-Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct. Project maintainers who do not follow the Code of Conduct may be removed from the project team.
+Examples of behavior that contributes to creating a positive environment
+include:
 
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by opening an issue or contacting one or more of the project maintainers.
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
 
-This Code of Conduct is adapted from the [Contributor Covenant](http://contributor-covenant.org), version 1.0.0, available at [http://contributor-covenant.org/version/1/0/0/](http://contributor-covenant.org/version/1/0/0/)
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting hzoo, thejameskyle, sebastian, or loganfsmyth on [Slack](https://slack.babeljs.io/). All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/

CONTRIBUTING.md

@@ -1,32 +1,283 @@
+# NOTE: DO NOT OPEN ISSUES FOR QUESTIONS AND SUPPORT. SEE THE README FOR MORE INFO.
+
+----
+
+<p align="center" class="toc">
+   <strong><a href="#setup">Setup</a></strong>
+   |
+   <strong><a href="#running-lintingtests">Running linting/tests</a></strong>
+   |
+   <strong><a href="#writing-tests">Writing tests</a></strong>
+   |
+   <strong><a href="#debugging-code">Debugging code</a></strong>
+   |
+   <strong><a href="#internals">Internals</a></strong>
+</p>
+
+----
+
+
 # Contributing
 
-Before contributing, please read the [code of conduct](https://github.com/6to5/6to5/blob/master/CODE_OF_CONDUCT.md).
+> Before contributing, please read our [code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
 
- * **General**
-   * No ES6 syntax features or methods, exclusively ES5.
-   * Max of five arguments for functions
-   * Max depth of four nested blocks
-   * 2-spaced soft tabs
- * **Naming**
-   * CamelCase all class names
-   * camelBack all variable names
- * **Spacing**
-   * 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
+Contributions are always welcome, no matter how large or small.
 
-## Testing
+## Not sure where to start?
 
-    $ make test
+- If you aren't just making a documentation change, you'll probably want to learn a bit about a few topics.
+ - [ASTs](https://en.wikipedia.org/wiki/Abstract_syntax_tree) (Abstract Syntax Tree): The Babel AST [spec](https://github.com/babel/babylon/blob/master/ast/spec.md) is a bit different from [ESTree](https://github.com/estree/estree). The differences are listed [here](https://github.com/babel/babylon#output).
+ - Check out [`/doc`](https://github.com/babel/babel/tree/master/doc) for information about Babel's internals
+ - Check out [the Babel Plugin Handbook](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#babel-plugin-handbook) - core plugins are written the same way as any other plugin!
+ - Check out [AST Explorer](http://astexplorer.net/#/scUfOmVOG5) to learn more about ASTs or make your own plugin in the browser
+- When you feel ready to jump into the Babel source code, a good place to start is to look for issues tagged with [help wanted](https://github.com/babel/babel/labels/help%20wanted) and/or [good first issue](https://github.com/babel/babel/labels/good%20first%20issue).
+- Follow along with what we are working on by joining our Slack, following our announcements on [Twitter](https://twitter.com/babeljs), and reading (or participating!) in our [meeting notes](https://github.com/babel/notes).
+- Check out our [website](http://babeljs.io/) and the [repo](https://github.com/babel/website)
 
-## Linting
+## Chat
 
-    $ make lint
+Feel free to check out the `#discussion`/`#development` channels on our [Slack](https://slack.babeljs.io). Some of us are always online to chat!
+
+## Developing
+
+**Note:** Versions `< 5.1.10` can't be built.
+
+Babel is built for Node 4 and up but we develop using Node 8 and yarn. You can check this with `node -v`.
+
+Make sure that Yarn is installed with version >= `0.28.0`.
+Installation instructions can be found here: https://yarnpkg.com/en/docs/install.
+
+### Setup
+
+```sh
+$ git clone https://github.com/babel/babel
+$ cd babel
+$ make bootstrap
+```
+
+Then you can either run:
+
+```sh
+$ make build
+```
+
+to build Babel **once** or:
+
+```sh
+$ make watch
+```
+
+to have Babel build itself and incrementally build files on change.
+
+You can access the built files for individual packages from `packages/<package-name>/lib`.
+
+If you wish to build a copy of Babel for distribution, then run:
+
+```sh
+$ make build-dist
+```
+
+### Running linting/tests
+
+You can run lint via:
+
+```sh
+# ~6 sec on a MacBook Pro (Mid 2015)
+$ make lint
+```
+
+You can run eslint's autofix via:
+
+```sh
+$ make fix
+```
+
+You can run tests + lint for all packages (slow) via:
+
+```sh
+# ~46 sec on a MacBook Pro (Mid 2015)
+$ make test
+```
+
+If you just want to run all tests:
+
+```sh
+# ~40 sec on a MacBook Pro (Mid 2015)
+$ make test-only
+```
+
+Most likely you'll want to focus in on a specific issue.
+
+To run tests for a specific package in [packages](https://github.com/babel/babel/tree/master/packages), you can use the `TEST_ONLY` environment variable:
+
+```sh
+$ TEST_ONLY=babel-cli make test
+```
+
+`TEST_ONLY` will also match substrings of the package name:
+
+```sh
+# Run tests for the babel-plugin-transform-es2015-classes package.
+$ TEST_ONLY=es2015-class make test
+```
+
+Use the `TEST_GREP` variable to run a subset of tests by name:
+
+```sh
+$ TEST_GREP=transformation make test
+```
+
+Substitute spaces for hyphens and forward slashes when targeting specific test names:
+
+```sh
+$ TEST_GREP="arrow functions destructuring parameters" make test
+```
+
+To enable the Node.js debugger added in v6.3.0, set the `TEST_DEBUG` environment variable:
+
+```sh
+$ TEST_DEBUG=true make test
+```
+
+You can combine `TEST_DEBUG` with `TEST_GREP` or `TEST_ONLY` to debug a subset of tests. If you plan to stay long in the debugger (which you'll likely do!), you may increase the test timeout by editing [test/mocha.opts](https://github.com/babel/babel/blob/master/test/mocha.opts).
+
+To test the code coverage, use:
+
+```sh
+$ BABEL_ENV=cov make build
+$ ./scripts/test-cov.sh
+```
+
+
+#### Troubleshooting Tests
+
+In case you're not able to reproduce an error on CI locally, it may be due to
+
+ - Node Version: Travis CI runs the tests against all major node versions. If your tests use JavaScript features unsupported by lower versions of node, then use [minNodeVersion option](#writing-tests) in options.json.
+ - Timeout: Check the CI log and if the only errors are timeout errors and you are sure that it's not related to the changes you made, ask someone in the slack channel to trigger rebuild on the CI build and it might be resolved
+
+In case you're locally getting errors which are not on the CI, it may be due to
+
+ - Updates in Dependencies: Make sure you run `make bootstrap` before you run `make build` or `make watch` before you run the tests.
+
+### Writing tests
+
+Most packages in [`/packages`](https://github.com/babel/babel/tree/master/packages) have a `test` folder, however some tests might be in other packages or in [`/packages/babel-core`](https://github.com/babel/babel/tree/master/packages/babel-core/test/fixtures).
+
+#### `babel-plugin-x`
+
+All the Babel plugins (and other packages) that have a `/test/fixtures` are written in a similar way.
+
+For example, in [`babel-plugin-transform-exponentiation-operator/test`](https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-exponentiation-operator/test):
+
+- There is an `index.js` file. It imports our [test helper](https://github.com/babel/babel/tree/master/packages/babel-helper-plugin-test-runner). (You don't have to worry about this).
+- There can be multiple folders under [`/fixtures`](https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures)
+   - There is an [`options.json`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/options.json) file whose function is similar to a `.babelrc` file, allowing you to pass in the plugins and settings you need for your tests.
+   - For this test, we only need the relevant plugin, so it's just `{ "plugins": ["transform-exponentiation-operator"] }`.
+   - If necessary, you can have an `options.json` with different options in each subfolder.
+
+- In each subfolder, you can organize your directory structure by categories of tests. (Example: these folders can be named after the feature you are testing or can reference the issue number they fix)
+- Generally, there are two kinds of tests for plugins
+   - The first is a simple test of the input and output produced by running Babel on some code. We do this by creating an [`actual.js`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/binary/actual.js) file and an [`expected.js`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/binary/expected.js) file.
+   - If you need to expect an error, you can ignore creating the `expected.js` file and pass a new `throws` key to the `options.json` that contains the error string that is created.
+   - The second and preferred type is a test that actually evaluates the produced code and asserts that certain properties are true or false. We do this by creating an [`exec.js`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/comprehensive/exec.js) file.
+
+In an actual/expected test, you simply write out the code you want transformed in `actual.js`.
+
+```js
+// actual.js
+2 ** 2;
+```
+
+and the expected output after transforming it with your `options.json` in `expected.js`.
+
+```js
+// expected.js
+Math.pow(2, 2);
+```
+In an `exec.js` test, we run or check that the code actually does what it's supposed to do rather than just check the static output.
+
+```js
+// exec.js
+assert.equal(8, 2 ** 3);
+assert.equal(24, 3 * 2 ** 3);
+```
+
+If you need to check for an error that is thrown you can add to the `options.json`
+
+```js
+// options.json example
+{
+  "plugins": [["transform-object-rest-spread", { "useBuiltIns": "invalidOption" }]],
+  "throws": "transform-object-rest-spread currently only accepts a boolean option for useBuiltIns (defaults to false)"
+}
+```
+
+If the test requires a minimum Node version, you can add `minNodeVersion` (must be in semver format).
+
+```js
+// options.json example
+{
+  "minNodeVersion": "5.0.0"
+}
+```
+
+#### Bootstrapping expected output
+
+For both `babel-plugin-x` and `babylon`, you can easily generate an `expected.js`/`expected.json` automatically by just providing `actual.js` and running the tests as you usually would.
+
+```
+// Example
+- babylon
+  - test
+    - fixtures
+      - comments
+        - basic
+          - block-trailing-comment
+            - actual.js
+            - expected.json (will be generated if not created)
+```
+
+### Debugging code
+
+A common approach to debugging JavaScript code is to walk through the code using the [Chrome DevTools](https://developers.google.com/web/tools/chrome-devtools/) debugger.
+For illustration purposes, we are going to assume that we need to get a better understanding of [`Generator.generate()`](https://github.com/babel/babel/blob/b5246994b57f06af871be6a63dcc4c6fd41d94d6/packages/babel-generator/src/index.js#L32), which is responsible for generating code for a given AST.
+To get a better understanding of what is actually going on for this particular piece of code, we are going to make use of breakpoints.
+
+```diff
+generate() {
++ debugger; // breakpoint
+  return super.generate(this.ast);
+}
+```
+
+To include the changes, we have to make sure to build Babel:
+
+```bash
+$ make build
+```
+
+Next, we need to execute `Generator.generate()`, which can be achieved by running a test case in the `babel-generator` package.
+For example, we can run the test case that tests the generation of class declarations:
+
+```bash
+$ TEST_DEBUG=true TEST_GREP=ClassDeclaration make test-only
+
+./scripts/test.sh
+Debugger listening on port 9229.
+Warning: This is an experimental feature and could change at any time.
+To start debugging, open the following URL in Chrome:
+    chrome-devtools://devtools/remote/serve_file/@60cd6e859b9f557d2312f5bf532f6aec5f284980/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:9229/3cdaebd2-be88-4e7b-a94b-432950ab72d0
+```
+
+To start the debugging in Chrome DevTools, open the given URL.
+The debugger starts at the first executed line of code, which is Mocha's first line by default.
+Click _Resume script execution_ <img src="https://i.imgur.com/TmYBn9d.png" alt="Resume script execution button." width="16"> to jump to the set breakpoint.
+Note that the code shown in Chrome DevTools is compiled code and therefore differs.
+
+## Internals
+- AST spec ([babylon/ast/spec.md](https://github.com/babel/babylon/blob/master/ast/spec.md))
+- Versioning ([doc/design/versioning.md](https://github.com/babel/babel/blob/master/doc/design/versioning.md)
+- Monorepo ([doc/design/monorepo.md](https://github.com/babel/babel/blob/master/doc/design/monorepo.md))
+- Compiler environment support ([doc/design/compiler-environment-support.md](https://github.com/babel/babel/blob/master/doc/design/compiler-environment-support.md))
+- Compiler assumptions ([doc/design/compiler-assumptions.md](https://github.com/babel/babel/blob/master/doc/design/compiler-assumptions.md))

Gulpfile.js

@@ -0,0 +1,172 @@
+"use strict";
+
+const plumber = require("gulp-plumber");
+const through = require("through2");
+const chalk = require("chalk");
+const pump = require("pump");
+const uglify = require("gulp-uglify");
+const rename = require("gulp-rename");
+const newer = require("gulp-newer");
+const babel = require("gulp-babel");
+const watch = require("gulp-watch");
+const gutil = require("gulp-util");
+const gulp = require("gulp");
+const path = require("path");
+const merge = require("merge-stream");
+const RootMostResolvePlugin = require("webpack-dependency-suite")
+  .RootMostResolvePlugin;
+const webpack = require("webpack");
+const webpackStream = require("webpack-stream");
+
+const sources = ["codemods", "packages", "experimental"];
+
+function swapSrcWithLib(srcPath) {
+  const parts = srcPath.split(path.sep);
+  parts[1] = "lib";
+  return parts.join(path.sep);
+}
+
+function getGlobFromSource(source) {
+  return `./${source}/*/src/**/*.js`;
+}
+
+gulp.task("default", ["build"]);
+
+gulp.task("build", function() {
+  return merge(
+    sources.map(source => {
+      const base = path.join(__dirname, source);
+
+      return gulp
+        .src(getGlobFromSource(source), { base: base })
+        .pipe(
+          plumber({
+            errorHandler: function(err) {
+              gutil.log(err.stack);
+            },
+          })
+        )
+        .pipe(
+          newer({
+            dest: base,
+            map: swapSrcWithLib,
+          })
+        )
+        .pipe(
+          through.obj(function(file, enc, callback) {
+            gutil.log("Compiling", "'" + chalk.cyan(file.relative) + "'...");
+            callback(null, file);
+          })
+        )
+        .pipe(babel())
+        .pipe(
+          through.obj(function(file, enc, callback) {
+            // Passing 'file.relative' because newer() above uses a relative
+            // path and this keeps it consistent.
+            file.path = path.resolve(file.base, swapSrcWithLib(file.relative));
+            callback(null, file);
+          })
+        )
+        .pipe(gulp.dest(base));
+    })
+  );
+});
+
+gulp.task("watch", ["build"], function() {
+  watch(sources.map(getGlobFromSource), { debounceDelay: 200 }, function() {
+    gulp.start("build");
+  });
+});
+
+gulp.task("build-babel-standalone", cb => {
+  pump(
+    [
+      gulp.src(__dirname + "/packages/babel-standalone/src/index.js"),
+      webpackBuild(),
+      gulp.dest(__dirname + "/packages/babel-standalone"),
+      uglify(),
+      rename({ extname: ".min.js" }),
+      gulp.dest(__dirname + "/packages/babel-standalone"),
+    ],
+    cb
+  );
+});
+
+function webpackBuild() {
+  let version = require("./packages/babel-core/package.json").version;
+
+  // If this build is part of a pull request, include the pull request number in
+  // the version number.
+  if (process.env.CIRCLE_PR_NUMBER) {
+    version += "+pr." + process.env.CIRCLE_PR_NUMBER;
+  }
+
+  const config = {
+    module: {
+      rules: [
+        {
+          test: /\.js$/,
+          include: /node_modules/,
+          loader: "babel-loader",
+          options: {
+            // Some of the node_modules may have their own "babel" section in
+            // their project.json (or a ".babelrc" file). We need to ignore
+            // those as we're using our own Babel options.
+            babelrc: false,
+            presets: ["env"],
+          },
+        },
+        {
+          test: /\.js$/,
+          exclude: /node_modules/,
+          loader: "babel-loader",
+          options: {
+            // Some of the node_modules may have their own "babel" section in
+            // their project.json (or a ".babelrc" file). We need to ignore
+            // those as we're using our own Babel options.
+            babelrc: false,
+            presets: ["env", "stage-0"],
+          },
+        },
+      ],
+    },
+    node: {
+      // Mock Node.js modules that Babel require()s but that we don't
+      // particularly care about.
+      fs: "empty",
+      module: "empty",
+      net: "empty",
+    },
+    output: {
+      filename: "babel.js",
+      library: "Babel",
+      libraryTarget: "umd",
+    },
+    plugins: [
+      new webpack.DefinePlugin({
+        "process.env.NODE_ENV": '"production"',
+        BABEL_VERSION: JSON.stringify(version),
+        VERSION: JSON.stringify(version),
+      }),
+      /*new webpack.NormalModuleReplacementPlugin(
+        /..\/..\/package/,
+        "../../../../src/babel-package-shim"
+      ),*/
+      new webpack.optimize.ModuleConcatenationPlugin(),
+    ],
+    resolve: {
+      plugins: [
+        // Dedupe packages that are used across multiple plugins.
+        // This replaces DedupePlugin from Webpack 1.x
+        new RootMostResolvePlugin(__dirname, true),
+      ],
+    },
+  };
+
+  return webpackStream(config, webpack);
+  // To write JSON for debugging:
+  /*return webpackStream(config, webpack, (err, stats) => {
+    require('gulp-util').log(stats.toString({colors: true}));
+    require('fs').writeFileSync('webpack-debug.json', JSON.stringify(stats.toJson()));
+  });*/
+}

LICENSE

@@ -1,7 +1,7 @@
-Copyright (c) 2014-2015 Sebastian McKenzie
-
 MIT License
 
+Copyright (c) 2014-2017 Sebastian McKenzie <sebmck@gmail.com>
+
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including

Makefile

@@ -1,105 +1,117 @@
-BROWSERIFY_CMD = node_modules/browserify/bin/cmd.js
-ISTANBUL_CMD = node_modules/istanbul/lib/cli.js cover
-UGLIFY_CMD = node_modules/uglify-js/bin/uglifyjs
-JSHINT_CMD = node_modules/jshint/bin/jshint
-MOCHA_CMD = node_modules/mocha/bin/_mocha
+MAKEFLAGS = -j1
 
 export NODE_ENV = test
 
-.PHONY: clean test test-cov test-clean lint test-travis test-simple test-all test-browser publish build bootstrap publish-core
+# Fix color output until TravisCI fixes https://github.com/travis-ci/travis-ci/issues/7967
+export FORCE_COLOR = true
 
-build:
-	mkdir -p dist
+SOURCES = packages codemods experimental
 
-	node bin/cache-templates
+.PHONY: build build-dist watch lint fix clean test-clean test-only test test-ci publish bootstrap
 
-	node $(BROWSERIFY_CMD) -e lib/6to5/polyfill.js >dist/polyfill.js
-	node $(UGLIFY_CMD) dist/polyfill.js >dist/polyfill.min.js
+build: clean
+	make clean-lib
+	./node_modules/.bin/gulp build
+ifneq ("$(BABEL_ENV)", "cov")
+	make build-standalone
+endif
 
-	node $(BROWSERIFY_CMD) lib/6to5/browser.js -s to5 >dist/6to5.js
-	node $(UGLIFY_CMD) dist/6to5.js >dist/6to5.min.js
+build-standalone:
+	./node_modules/.bin/gulp build-babel-standalone
 
-	node bin/6to5-runtime >dist/runtime.js
-	node $(UGLIFY_CMD) dist/runtime.js >dist/runtime.min.js
+build-dist: build
+	cd packages/babel-polyfill; \
+	scripts/build-dist.sh
+	cd packages/babel-runtime; \
+	node scripts/build-dist.js
+	node scripts/generate-babel-types-docs.js
 
-	rm -rf templates.json
+watch: clean
+	make clean-lib
+	BABEL_ENV=development ./node_modules/.bin/gulp watch
 
-clean:
-	rm -rf coverage templates.json test/tmp dist
+flow:
+	./node_modules/.bin/flow check --strip-root
 
 lint:
-	$(JSHINT_CMD) --reporter node_modules/jshint-stylish/stylish.js lib bin
+	./node_modules/.bin/eslint scripts $(SOURCES) *.js --format=codeframe --rulesdir="./scripts/eslint_rules"
+
+fix:
+	./node_modules/.bin/eslint scripts $(SOURCES) *.js --format=codeframe --fix --rulesdir="./scripts/eslint_rules"
+
+clean: test-clean
+	rm -rf packages/babel-polyfill/browser*
+	rm -rf packages/babel-polyfill/dist
+	# rm -rf packages/babel-runtime/helpers
+	# rm -rf packages/babel-runtime/core-js
+	rm -rf coverage
+	rm -rf packages/*/npm-debug*
 
 test-clean:
-	rm -rf test/tmp
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-test, $(source)))
 
-test: lint
-	$(MOCHA_CMD)
+test-only:
+	./scripts/test.sh
 	make test-clean
 
-test-simple:
-	# excludes test262
-	export SIMPLE_6TO5_TESTS=1
-	make test
+test: lint test-only
 
-test-all:
-	# includes traceur, esnext, regenerator
-	export ALL_6TO5_TESTS=1
-	make test
+test-ci:
+	make bootstrap
+	make test-only
 
-test-cov:
-	export SIMPLE_6TO5_TESTS=1
-	rm -rf coverage
-	node $(ISTANBUL_CMD) $(MOCHA_CMD) --
-
-test-travis: bootstrap
-	node $(ISTANBUL_CMD) $(MOCHA_CMD) --
-	if test -n "$$CODECLIMATE_REPO_TOKEN"; then codeclimate < coverage/lcov.info; fi
-
-test-browser:
-	mkdir -p dist
-
-	node bin/cache-templates
-	node bin/cache-tests
-	node $(BROWSERIFY_CMD) -e test/_browser.js >dist/6to5-test.js
-	rm -rf templates.json tests.json
-
-	test -n "`which open`" && open test/browser.html
+test-ci-coverage: SHELL:=/bin/bash
+test-ci-coverage:
+	BABEL_ENV=cov make bootstrap
+	./scripts/test-cov.sh
+	bash <(curl -s https://codecov.io/bash) -f coverage/coverage-final.json
 
 publish:
 	git pull --rebase
-
+	make clean-lib
+	BABEL_ENV=production make build-dist
 	make test
-
-	read -p "Version: "  version; \
-	npm version $$version --message "v%s"
-
-	make build
-	cp dist/6to5.min.js browser.js
-	cp dist/polyfill.min.js browser-polyfill.js
-	cp dist/runtime.min.js runtime.js
-
-	node bin/cache-templates
-	test -f templates.json
-
-	npm publish
-
-	git push --follow-tags
-
-	# generate
-	bin/generate-core-package-json >package2.json
-	mv package.json .package.json
-	mv package2.json package.json
-
-	npm publish
-
-	# restore
-	rm -rf package.json
-	mv .package.json package.json
-
-	rm -rf templates.json browser.js runtime.js browser-polyfill.js
+	# not using lerna independent mode atm, so only update packages that have changed since we use ^
+	# --only-explicit-updates
+	./node_modules/.bin/lerna publish --force-publish=* --npm-tag=next --exact --skip-temp-tag
+	make clean
 
 bootstrap:
-	npm install
-	git submodule update --init
-	cd vendor/regenerator; npm install
+	make clean-all
+	yarn
+	./node_modules/.bin/lerna bootstrap
+	make build
+	cd packages/babel-runtime; \
+	node scripts/build-dist.js
+
+clean-lib:
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-lib, $(source)))
+
+clean-all:
+	rm -rf node_modules
+	rm -rf package-lock.json
+
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-all, $(source)))
+
+	make clean
+
+define clean-source-lib
+	rm -rf $(1)/*/lib
+
+endef
+
+define clean-source-test
+	rm -rf $(1)/*/test/tmp
+	rm -rf $(1)/*/test-fixtures.json
+
+endef
+
+define clean-source-all
+	rm -rf $(1)/*/lib
+	rm -rf $(1)/*/node_modules
+	rm -rf $(1)/*/package-lock.json
+
+endef

NOTES.md

@@ -1,13 +0,0 @@
-# Notes
-
- * Wildcard exports/imports wont normalise if `export default` is a non-object. See [#224](https://github.com/6to5/6to5/issues/224).
-
-## 3.0.0 breaking changes
-
- * Remove `allowImportExportEverywhere` option from acorn.
- * Remove this shorthand from playground.
- * Remove `super()` inside non-constructors - add descriptive error message.
- * Split up ES5 getter/setter transforming and ES6 property methods into separate transformers.
- * Add autoindentation.
- * Move `super` transformation from classes into a separate transformer that also supports object expressions.
- * Prefix all fast transformers with `fast`, make them declare that they're a fast transformer similar to optional transformers and add a `--fast` flag to enable them all.

README.md

@@ -1,34 +1,202 @@
 <p align="center">
-  <img alt="6to5" src="https://raw.githubusercontent.com/6to5/logo/master/logo.png" width="546">
-</p>
-
-<p align="center">
-  <a href="https://gratipay.com/sebmck">
-    <img alt="Gratipay" src="https://img.shields.io/gratipay/sebmck.svg?style=flat">
-  </a>
-
-  <a href="https://travis-ci.org/6to5/6to5">
-    <img alt="Travis Status" src="http://img.shields.io/travis/6to5/6to5/master.svg?style=flat&amp;label=travis">
-  </a>
-
-  <a href="https://codeclimate.com/github/6to5/6to5">
-    <img alt="Code Climate Score" src="http://img.shields.io/codeclimate/github/6to5/6to5.svg?style=flat">
-  </a>
-
-  <a href="https://codeclimate.com/github/6to5/6to5">
-    <img alt="Coverage" src="http://img.shields.io/codeclimate/coverage/github/6to5/6to5.svg?style=flat">
-  </a>
-
-  <a href="https://david-dm.org/6to5/6to5">
-    <img alt="Dependency Status" src="http://img.shields.io/david/6to5/6to5.svg?style=flat">
+  <a href="https://babeljs.io/">
+    <img alt="babel" src="https://raw.githubusercontent.com/babel/logo/master/babel.png" width="546">
   </a>
 </p>
 
 <p align="center">
-  <strong>6to5</strong> turns ES6+ code into vanilla ES5, so you can use next generation features <strong>today.</strong>
+  The compiler for writing next generation JavaScript.
 </p>
 
 <p align="center">
-  For more information view the <a href="https://6to5.github.io">documentation</a>. For
-  support visit the <a href="https://gitter.im/6to5/6to5">gitter room</a>.
+  <a href="https://travis-ci.org/babel/babel"><img alt="Travis Status" src="https://img.shields.io/travis/babel/babel/master.svg?label=travis&maxAge=43200"></a>
+  <a href="https://circleci.com/gh/babel/babel"><img alt="CircleCI Status" src="https://img.shields.io/circleci/project/github/babel/babel/master.svg?label=circle&maxAge=43200"></a>
+  <a href="https://codecov.io/github/babel/babel"><img alt="Coverage Status" src="https://img.shields.io/codecov/c/github/babel/babel/master.svg?maxAge=43200"></a>
+  <a href="https://slack.babeljs.io/"><img alt="Slack Status" src="https://slack.babeljs.io/badge.svg"></a>
+  <a href="https://www.npmjs.com/package/babel-core"><img alt="npm Downloads" src="https://img.shields.io/npm/dm/babel-core.svg?maxAge=43200"></a>
 </p>
+
+<h2 align="center">Supporting Babel</h2>
+
+<p align="center">
+  <a href="#backers"><img alt="Backers on Open Collective" src="https://opencollective.com/babel/backers/badge.svg" /></a>
+  <a href="#sponsors"><img alt="Sponsors on Open Collective" src="https://opencollective.com/babel/sponsors/badge.svg" /></a>
+  <a href="https://medium.com/friendship-dot-js/i-peeked-into-my-node-modules-directory-and-you-wont-believe-what-happened-next-b89f63d21558"><img alt="Business Strategy Status" src="https://img.shields.io/badge/business%20model-flavortown-green.svg"></a>
+</p>
+
+Babel is community-driven and thus mostly maintained by a group of volunteers. It has a lot of [companies and projects](http://babeljs.io/users) using it but almost no sponsors/people funded to work on it. If you'd like to help maintain the future of the project, please consider:
+
+- Giving developer time on the project. (Message us on [Twitter](https://twitter.com/babeljs) or [Slack](slack.babeljs.io))
+- [Giving funds by becoming a backer/sponsor on OpenCollective](https://opencollective.com/babel)
+
+## Intro
+
+Babel is a tool that helps you write code in the latest version of JavaScript. When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
+
+**In**
+
+```js
+// ES2015 arrow function
+[1, 2, 3].map((n) => n + 1);
+```
+
+**Out**
+
+```js
+[1, 2, 3].map(function(n) {
+  return n + 1;
+});
+```
+
+Try it out at our [REPL](https://babeljs.io/repl/build/master#?code_lz=NoRgNATGDMC6B0BbAhgBwBQDsAEBeAfNjgNTYgCUA3EA&lineWrap=true&presets=es2015%2Ces2016%2Ces2017&version=7.0.0-beta.2).
+
+- [FAQ](#faq)
+- [Team](#team)
+- [Backers](#backers)
+- [Sponsors](#sponsors)
+- [License](#license)
+
+## FAQ
+
+### Docs?
+
+Check out our website: [babeljs.io](http://babeljs.io/)
+
+### Looking for support?
+
+For questions and support please visit join our [Slack Community](https://slack.babeljs.io/), ask a question on [Stack Overflow](http://stackoverflow.com/questions/tagged/babeljs), or ping us on [Twitter](https://twitter.com/babeljs/).
+
+### Want to report a bug or request a feature?
+
+Please read through our [CONTRIBUTING.md](https://github.com/babel/babel/blob/master/CONTRIBUTING.md) and fill out the issue template at [babel/issues](https://github.com/babel/babel/issues)!
+
+### Want to report an issue with our website ([babeljs.io](https://babeljs.io))?
+
+For docs/website issues please visit the [babel/website](https://github.com/babel/website/issues).
+
+### Want to contribute to Babel?
+
+Check out our [CONTRIBUTING.md](https://github.com/babel/babel/blob/master/CONTRIBUTING.md) to get started with setting up the repo.
+
+- If you have already joined Slack, join our [#development](https://babeljs.slack.com/messages/development) channel and say hi!
+- Check out the issues with the [good first issue](https://github.com/babel/babel/labels/good%20first%20issue) and [help wanted](https://github.com/babel/babel/labels/help%20wanted) label.
+- Our discussions/notes/roadmap: [babel/notes](https://github.com/babel/notes)
+- Our progress on TC39 proposals: [babel/proposals](https://github.com/babel/proposals)
+
+### How is the repo structured?
+
+The Babel repo is managed as a [monorepo](https://github.com/babel/babel/blob/master/doc/design/monorepo.md) that is composed of many [npm packages](/packages#readme).
+
+## Team
+
+### Core members
+
+[![Babel](https://avatars.githubusercontent.com/u/9637642?s=64)](https://github.com/babel) | [![Daniel Tschinder](https://avatars.githubusercontent.com/u/231804?s=64)](https://github.com/danez) | [![Logan Smyth](https://avatars.githubusercontent.com/u/132260?s=64)](https://github.com/loganfsmyth) | [![Henry Zhu](https://avatars.githubusercontent.com/u/588473?s=64)](https://github.com/hzoo) |
+|---|---|---|---|
+Babel | Daniel Tschinder | Logan Smyth | Henry Zhu |
+:octocat: [@babel](https://github.com/babel) | [@danez](https://github.com/danez) | [@loganfsmyth](https://github.com/loganfsmyth) | [@hzoo](https://github.com/hzoo) |
+:bird: [@babeljs](https://twitter.com/babeljs) | [@TschinderDaniel](https://twitter.com/TschinderDaniel) | [@loganfsmyth](https://twitter.com/loganfsmyth) | [@left_pad](https://twitter.com/left_pad) |
+
+### Members
+
+[![Andrew Levine](https://avatars.githubusercontent.com/u/5233399?s=64)](https://github.com/drewml) | [![Boopathi Rajaa](https://avatars.githubusercontent.com/u/294474?s=64)](https://github.com/boopathi) | [![Brian Ng](https://avatars.githubusercontent.com/u/56288?s=64)](https://github.com/existentialism) | [![Dan Harper](https://avatars.githubusercontent.com/u/510740?s=64)](https://github.com/danharper) | [![diogo franco](https://avatars.githubusercontent.com/u/73085?s=64)](https://github.com/kovensky) | [![Aaron Ang](https://avatars1.githubusercontent.com/u/7579804?s=64)](https://github.com/aaronang) | [![Artem Yavorsky](https://avatars2.githubusercontent.com/u/1521229?s=64)](https://github.com/yavorsky) |
+|---|---|---|---|---|---|---|
+| Andrew Levine | Boopathi Rajaa | Brian Ng | Dan Harper | Diogo Franco | Aaron Ang | Artem Yavorsky |
+| [@drewml](https://github.com/drewml) | [@boopathi](https://github.com/boopathi) | [@existentialism](https://github.com/existentialism) | [@danharper](https://github.com/danharper) | [@kovensky](https://github.com/kovensky) | [@aaronang](https://github.com/aaronang) | [@yavorsky](https://github.com/yavorsky) |
+| [@drewml](https://twitter.com/drewml) | [@heisenbugger](https://twitter.com/heisenbugger) | [@existentialism](https://twitter.com/existentialism) | [@DanHarper7](https://twitter.com/DanHarper7) | [@kovnsk](https://twitter.com/kovnsk) | [@_aaronang](https://twitter.com/_aaronang) | [@yavorsky_](https://twitter.com/yavorsky_) |
+
+[![Juriy Zaytsev](https://avatars.githubusercontent.com/u/383?s=64)](https://github.com/kangax) | [![Kai Cataldo](https://avatars.githubusercontent.com/u/7041728?s=64)](https://github.com/kaicataldo) | [![Moti Zilberman](https://avatars.githubusercontent.com/u/2246565?s=64)](https://github.com/motiz88) | [![Sven Sauleau](https://avatars3.githubusercontent.com/u/1493671?s=64)](https://github.com/xtuc) | [![Samuel Reed](https://avatars3.githubusercontent.com/u/1197375?s=64)](https://github.com/STRML) | [![Sergey Rubanov](https://avatars1.githubusercontent.com/u/1507086?s=64)](https://github.com/chicoxyzzy) |
+|---|---|---|---|---|---|
+| Juriy Zaytsev | Kai Cataldo | Moti Zilberman | Sven Sauleau | Samuel Reed | Sergey Rubanov |
+| [@kangax](https://github.com/kangax) | [@kaicataldo](https://github.com/kaicataldo) | [@motiz88](https://github.com/motiz88) | [@xtuc](https://github.com/xtuc) | [@STRML](https://github.com/STRML) | [@chicoxyzzy](https://github.com/chicoxyzzy) |
+| [@kangax](https://twitter.com/kangax) | [@kai_cataldo](https://twitter.com/kai_cataldo) | [@motiz88](https://twitter.com/motiz88) | [@svensauleau](https://twitter.com/svensauleau) | [@STRML_](https://twitter.com/STRML_) | [@chicoxyzzy](https://twitter.com/chicoxyzzy) |
+
+### Non-Human Members
+
+[<img src="https://github.com/babel/babel-bot/raw/master/babel-bot.png" height="64">](https://github.com/babel-bot) |
+|---|
+| Babel Bot |
+| [@babel-bot](https://github.com/babel-bot) |
+| [@babeljs](https://twitter.com/babeljs) |
+
+### Inactive members
+
+[![Amjad Masad](https://avatars.githubusercontent.com/u/587518?s=64)](https://github.com/amasad) | [![James Kyle](https://avatars.githubusercontent.com/u/952783?s=64)](https://github.com/thejameskyle) | [![Jesse McCarthy](https://avatars.githubusercontent.com/u/129203?s=64)](https://github.com/jmm) | [![Sebastian McKenzie](https://avatars.githubusercontent.com/u/853712?s=64)](https://github.com/kittens) (Creator) |
+|---|---|---|---|
+Amjad Masad | James Kyle | Jesse McCarthy | Sebastian McKenzie |
+[@amasad](https://github.com/amasad) | [@thejameskyle](https://github.com/thejameskyle) | [@jmm](https://github.com/jmm) | [@sebmck](https://twitter.com/sebmck) |
+| [@amasad](https://twitter.com/amasad) | [@thejameskyle](https://twitter.com/thejameskyle) | [@mccjm](https://twitter.com/mccjm) | [@kittens](https://github.com/kittens)
+
+## Backers
+
+Support us with a monthly donation and help us continue our activities. [[Become a backer](https://opencollective.com/babel#backer)]
+
+<a href="https://opencollective.com/babel/backer/0/website" target="_blank"><img src="https://opencollective.com/babel/backer/0/avatar.svg"></a>
+<a href="https://opencollective.com/babel/backer/1/website" target="_blank"><img src="https://opencollective.com/babel/backer/1/avatar.svg"></a>
+<a href="https://opencollective.com/babel/backer/2/website" target="_blank"><img src="https://opencollective.com/babel/backer/2/avatar.svg"></a>
+<a href="https://opencollective.com/babel/backer/3/website" target="_blank"><img src="https://opencollective.com/babel/backer/3/avatar.svg"></a>
+<a href="https://opencollective.com/babel/backer/4/website" target="_blank"><img src="https://opencollective.com/babel/backer/4/avatar.svg"></a>
+<a href="https://opencollective.com/babel/backer/5/website" target="_blank"><img src="https://opencollective.com/babel/backer/5/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/6/website" target="_blank"><img src="https://opencollective.com/babel/backer/6/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/7/website" target="_blank"><img src="https://opencollective.com/babel/backer/7/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/8/website" target="_blank"><img src="https://opencollective.com/babel/backer/8/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/9/website" target="_blank"><img src="https://opencollective.com/babel/backer/9/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/10/website" target="_blank"><img src="https://opencollective.com/babel/backer/10/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/11/website" target="_blank"><img src="https://opencollective.com/babel/backer/11/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/12/website" target="_blank"><img src="https://opencollective.com/babel/backer/12/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/13/website" target="_blank"><img src="https://opencollective.com/babel/backer/13/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/14/website" target="_blank"><img src="https://opencollective.com/babel/backer/14/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/15/website" target="_blank"><img src="https://opencollective.com/babel/backer/15/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/16/website" target="_blank"><img src="https://opencollective.com/babel/backer/16/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/17/website" target="_blank"><img src="https://opencollective.com/babel/backer/17/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/18/website" target="_blank"><img src="https://opencollective.com/babel/backer/18/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/19/website" target="_blank"><img src="https://opencollective.com/babel/backer/19/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/20/website" target="_blank"><img src="https://opencollective.com/babel/backer/20/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/21/website" target="_blank"><img src="https://opencollective.com/babel/backer/21/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/22/website" target="_blank"><img src="https://opencollective.com/babel/backer/22/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/23/website" target="_blank"><img src="https://opencollective.com/babel/backer/23/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/24/website" target="_blank"><img src="https://opencollective.com/babel/backer/24/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/25/website" target="_blank"><img src="https://opencollective.com/babel/backer/25/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/26/website" target="_blank"><img src="https://opencollective.com/babel/backer/26/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/27/website" target="_blank"><img src="https://opencollective.com/babel/backer/27/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/28/website" target="_blank"><img src="https://opencollective.com/babel/backer/28/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/backer/29/website" target="_blank"><img src="https://opencollective.com/babel/backer/29/avatar.svg"></a>
+
+## Sponsors
+
+Become a sponsor and get your logo on our README on Github with a link to your site. [[Become a sponsor](https://opencollective.com/babel#sponsor)]
+
+<a href="https://opencollective.com/babel/sponsor/0/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/0/avatar.svg"></a>
+<a href="https://opencollective.com/babel/sponsor/1/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/1/avatar.svg"></a>
+<a href="https://opencollective.com/babel/sponsor/2/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/2/avatar.svg"></a>
+<a href="https://opencollective.com/babel/sponsor/3/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/3/avatar.svg"></a>
+<a href="https://opencollective.com/babel/sponsor/4/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/4/avatar.svg"></a>
+ <a href="https://opencollective.com/babel/sponsor/5/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/5/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/6/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/6/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/7/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/7/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/8/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/8/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/9/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/9/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/10/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/10/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/11/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/11/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/12/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/12/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/13/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/13/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/14/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/14/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/15/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/15/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/16/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/16/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/17/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/17/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/18/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/18/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/19/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/19/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/20/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/20/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/21/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/21/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/22/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/22/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/23/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/23/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/24/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/24/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/25/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/25/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/26/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/26/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/27/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/27/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/28/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/28/avatar.svg"></a>		
+  <a href="https://opencollective.com/babel/sponsor/29/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/29/avatar.svg"></a>
+
+## License
+
+[MIT](https://github.com/babel/babel/blob/master/LICENSE)

appveyor.yml

@@ -1,17 +0,0 @@
-environment:
-  matrix:
-    - nodejs_version: "0.10"
-    - nodejs_version: "0.11"
-
-install:
- - "npm install"
- - "cinst make"
-
-test_script:
- - "node --version"
- - "npm --version"
- - "make test-spec"
-
-build: "off"
-
-version: "{build}"

babel.sublime-project

@@ -0,0 +1,25 @@
+{
+    "settings": {
+        "rulers": [
+            80
+        ],
+
+        // Set to false to disable detection of tabs vs. spaces on load
+        "detect_indentation": false,
+
+        "translate_tabs_to_spaces": true,
+
+        "tab_size": 2
+    },
+
+    "folders": [{
+        "path": ".",
+        "folder_exclude_patterns": [
+            "packages/*/lib",
+            "node_modules"
+        ],
+        "file_exclude_patterns": [
+
+        ]
+    }]
+}

bin/6to5-node

@@ -1,68 +0,0 @@
-#!/usr/bin/env node
-
-/**
- * This tiny wrapper file checks for known node flags and appends them
- * when found, before invoking the "real" _6to5-node(1) executable.
- */
-
-var args  = ["--harmony", __dirname + "/_6to5-node"];
-
-process.argv.slice(2).forEach(function(arg){
-  var flag = arg.split("=")[0];
-
-  switch (flag) {
-    case "-d":
-      args.unshift("--debug");
-      break;
-
-    case "debug":
-    case "--debug":
-    case "--debug-brk":
-      args.unshift(arg);
-      break;
-
-    case "-gc":
-    case "--expose-gc":
-      args.unshift("--expose-gc");
-      break;
-
-    case "--gc-global":
-    case "--harmony":
-    case "--harmony-proxies":
-    case "--harmony-collections":
-    case "--harmony-generators":
-    case "--no-deprecation":
-    case "--prof":
-    case "--throw-deprecation":
-    case "--trace-deprecation":
-      args.unshift(arg);
-      break;
-
-    default:
-      if (arg.indexOf("--trace") === 0) {
-        args.unshift(arg);
-      } else {
-        args.push(arg);
-      }
-      break;
-  }
-});
-
-try {
-  var kexec = require("kexec");
-  kexec(process.argv[0], args);
-} catch (err) {
-  if (err.code !== "MODULE_NOT_FOUND") throw err;
-
-  var child_process = require("child_process");
-  var proc = child_process.spawn(process.argv[0], args, { stdio: "inherit" });
-  proc.on("exit", function (code, signal) {
-    process.on("exit", function () {
-      if (signal) {
-        process.kill(process.pid, signal);
-      } else {
-        process.exit(code);
-      }
-    })
-  });
-}

bin/6to5-runtime

@@ -1,4 +0,0 @@
-#!/usr/bin/env node
-
-var runtime = require("../lib/6to5/runtime-generator");
-console.log(runtime(process.argv[2]));

bin/6to5/dir.js

@@ -1,68 +0,0 @@
-var chokidar = require("chokidar");
-var mkdirp   = require("mkdirp");
-var path     = require("path");
-var util     = require("./util");
-var fs       = require("fs");
-var _        = require("lodash");
-
-module.exports = function (commander, filenames, opts) {
-  if (commander.sourceMapsInline) {
-    opts.sourceMap = "inline";
-  }
-
-  var write = function (src, relative) {
-    var dest = path.join(commander.outDir, relative);
-
-    var data = util.compile(src, { sourceMapName: dest });
-
-    var up = path.normalize(dest + "/..");
-    mkdirp.sync(up);
-
-    if (commander.sourceMaps) {
-      var mapLoc = dest + ".map";
-      data.code = util.addSourceMappingUrl(data.code, mapLoc);
-      fs.writeFileSync(mapLoc, JSON.stringify(data.map));
-    }
-
-    fs.writeFileSync(dest, data.code);
-
-    console.log(src + " -> " + dest);
-  };
-
-  var handle = function (filename) {
-    if (!fs.existsSync(filename)) return;
-
-    var stat = fs.statSync(filename);
-
-    if (stat.isDirectory(filename)) {
-      var dirname = filename;
-
-      _.each(util.readdirFilter(dirname), function (filename) {
-        write(path.join(dirname, filename), filename);
-      });
-    } else {
-      write(filename, filename);
-    }
-  };
-
-  _.each(filenames, handle);
-
-  if (commander.watch) {
-    _.each(filenames, function (dirname) {
-      var watcher = chokidar.watch(dirname, {
-        persistent: true,
-        ignoreInitial: true
-      });
-
-      _.each(["add", "change", "unlink"], function (type) {
-        watcher.on(type, function (filename) {
-          // chop off the dirname plus the path separator
-          var relative = filename.slice(dirname.length + 1);
-
-          console.log(type, filename);
-          write(filename, relative);
-        });
-      });
-    });
-  }
-};

bin/6to5/file.js

@@ -1,133 +0,0 @@
-var sourceMap = require("source-map");
-var chokidar  = require("chokidar");
-var util2     = require("../../lib/6to5/util");
-var path      = require("path");
-var util      = require("./util");
-var fs        = require("fs");
-var _         = require("lodash");
-
-module.exports = function (commander, filenames) {
-  var results = [];
-
-  var buildResult = function () {
-    var map = new sourceMap.SourceMapGenerator({
-      file: commander.outFile || "stdout"
-    });
-
-    var code = "";
-    var offset = 0;
-
-    _.each(results, function (result) {
-      var filename = result.filename;
-      code += result.code + "\n";
-
-      if (result.map) {
-        var consumer = new sourceMap.SourceMapConsumer(result.map);
-
-        map._sources.add(filename);
-        map.setSourceContent(filename, result.actual);
-
-        consumer.eachMapping(function (mapping) {
-          map._mappings.push({
-            generatedLine: mapping.generatedLine + offset,
-            generatedColumn: mapping.generatedColumn,
-            originalLine: mapping.originalLine,
-            originalColumn: mapping.originalColumn,
-            source: filename
-          });
-        });
-
-        offset = code.split("\n").length;
-      }
-    });
-
-    if (commander.sourceMapsInline || (!commander.outFile && commander.sourceMaps)) {
-      code += "\n" + util2.sourceMapToComment(map);
-    }
-
-    return {
-      map: map,
-      code: code
-    };
-  };
-
-  var output = function () {
-    var result = buildResult();
-
-    if (commander.outFile) {
-      if (commander.sourceMaps) {
-        var mapLoc = commander.outFile + ".map";
-        result.code = util.addSourceMappingUrl(result.code, mapLoc);
-        fs.writeFileSync(mapLoc, JSON.stringify(result.map));
-      }
-
-      fs.writeFileSync(commander.outFile, result.code);
-    } else {
-      console.log(result.code);
-    }
-  };
-
-  var stdin = function () {
-    var code = "";
-
-    process.stdin.setEncoding("utf8");
-
-    process.stdin.on("readable", function () {
-      var chunk = process.stdin.read();
-      if (chunk !== null) code += chunk;
-    });
-
-    process.stdin.on("end", function() {
-      results.push(util.transform(commander.filename, code));
-      output();
-    });
-  };
-
-  var walk = function () {
-    var _filenames = [];
-    results = [];
-
-    _.each(filenames, function (filename) {
-      if (!fs.existsSync(filename)) return;
-
-      var stat = fs.statSync(filename);
-      if (stat.isDirectory()) {
-        var dirname = filename;
-
-        _.each(util.readdirFilter(filename), function (filename) {
-          _filenames.push(path.join(dirname, filename));
-        });
-      } else {
-        _filenames.push(filename);
-      }
-    });
-
-    _.each(_filenames, function (filename) {
-      results.push(util.compile(filename));
-    });
-
-    output();
-  };
-
-  var files = function () {
-    walk();
-
-    if (commander.watch) {
-      chokidar.watch(filenames, {
-        persistent: true,
-        ignoreInitial: true
-      }).on("all", function (type, filename) {
-        if (type === "add" || type === "change" || type === "unlink" ) {
-          console.log(type, filename);
-          walk();
-        }
-      });
-    }
-  };
-
-  if (filenames.length) {
-    files();
-  } else {
-    stdin();
-  }
-};

bin/6to5/index.js

@@ -1,134 +0,0 @@
-#!/usr/bin/env node
-
-var commander = require("commander");
-var transform = require("../../lib/6to5/transformation/transform");
-var util      = require("../../lib/6to5/util");
-var fs        = require("fs");
-var _         = require("lodash");
-
-commander.option("-t, --source-maps-inline", "Append sourceMappingURL comment to bottom of code");
-commander.option("-s, --source-maps", "Save source map alongside the compiled code");
-commander.option("-f, --filename [filename]", "Filename to use when reading from stdin - this will be used in source-maps, errors etc [stdin]", "stdin");
-commander.option("-w, --watch", "Recompile files on changes");
-commander.option("-r, --runtime", "Replace 6to5 declarations with references to a runtime");
-commander.option("-e, --experimental", "Enable experimental support for proposed ES7 features");
-commander.option("-p, --playground", "Enable playground support");
-
-commander.option("-m, --modules [modules]", "Module formatter type to use [common]", "common");
-commander.option("-l, --whitelist [whitelist]", "Whitelist of transformers to ONLY use", util.list);
-commander.option("-b, --blacklist [blacklist]", "Blacklist of transformers to NOT use", util.list);
-commander.option("-i, --optional [list]", "List of optional transformers to enable", util.list);
-commander.option("-o, --out-file [out]", "Compile all input files into a single file");
-commander.option("-d, --out-dir [out]", "Compile an input directory of modules into an output directory");
-commander.option("-c, --remove-comments", "Remove comments from the compiled code", false);
-commander.option("-I, --indent [width]", "Indent width [2]", 2);
-commander.option("-a, --amd-module-ids", "Insert module id in AMD modules", false); // todo: remove in 3.0.0
-commander.option("-m, --module-ids", "Insert module id in modules", false);
-commander.option("-R, --react-compat", "Makes the react transformer produce pre-v0.12 code");
-commander.option("-E, --include-regenerator", "Include the regenerator runtime if necessary", false);
-commander.option("--keep-module-id-extensions", "Keep extensions when generating module ids", false);
-
-commander.on("--help", function(){
-  var outKeys = function (title, obj) {
-    console.log("  " + title + ":");
-    console.log();
-
-    var hasOptional = true;
-
-    _.each(_.keys(obj).sort(), function (key) {
-      if (key[0] === "_") return;
-
-      if (obj[key].optional) {
-        hasOptional = true;
-        key = "[" + key + "]";
-      }
-
-      console.log("    - " + key);
-    });
-
-    console.log();
-  };
-
-  outKeys("Transformers", transform.transformers);
-  outKeys("Module formatters", transform.moduleFormatters);
-});
-
-var pkg = require("../../package.json");
-commander.version(pkg.version);
-commander.usage("[options] <files ...>");
-commander.parse(process.argv);
-
-//
-
-var errors = [];
-
-var filenames = commander.args;
-
-_.each(filenames, function (filename) {
-  if (!fs.existsSync(filename)) {
-    errors.push(filename + " doesn't exist");
-  }
-});
-
-if (commander.outDir && !filenames.length) {
-  errors.push("filenames required for --out-dir");
-}
-
-if (commander.outFile && commander.outDir) {
-  errors.push("cannot have --out-file and --out-dir");
-}
-
-if (commander.watch) {
-  if (!commander.outFile && !commander.outDir) {
-    errors.push("--watch requires --out-file or --out-dir");
-  }
-
-  if (!filenames.length) {
-    errors.push("--watch requires filenames");
-  }
-}
-
-if (commander.sourceMaps) {
-  if (!commander.outFile && !commander.outDir) {
-    errors.push("--source-maps requires --out-file or --out-dir");
-  }
-}
-
-if (errors.length) {
-  console.error(errors.join(". "));
-  process.exit(2);
-}
-
-//
-
-exports.opts = {
-  keepModuleIdExtensions: commander.keepModuleIdExtensions,
-  includeRegenerator:     commander.includeRegenerator,
-  sourceMapName:          commander.outFile,
-  experimental:           commander.experimental,
-  reactCompat:            commander.reactCompat,
-  playground:             commander.playground,
-  moduleIds:              commander.amdModuleIds || commander.moduleIds,
-  blacklist:              commander.blacklist,
-  whitelist:              commander.whitelist,
-  sourceMap:              commander.sourceMaps || commander.sourceMapsInline,
-  optional:               commander.optional,
-  comments:               !commander.removeComments,
-  runtime:                commander.runtime,
-  modules:                commander.modules,
-  format: {
-    indent: {
-      style:     util.repeat(parseInt(commander.indent))
-    }
-  }
-};
-
-var fn;
-
-if (commander.outDir) {
-  fn = require("./dir");
-} else {
-  fn = require("./file");
-}
-
-fn(commander, filenames, exports.opts);

bin/6to5/util.js

@@ -1,42 +0,0 @@
-var readdir = require("fs-readdir-recursive");
-var index   = require("./index");
-var util    = require("../../lib/6to5/util");
-var path    = require("path");
-var to5     = require("../../lib/6to5");
-var fs      = require("fs");
-var _       = require("lodash");
-
-exports.readdirFilter = function (filename) {
-  return readdir(filename).filter(function (filename) {
-    return util.canCompile(filename);
-  });
-};
-
-exports.addSourceMappingUrl = function (code, loc) {
-  return code + "\n//# sourceMappingURL=" + path.basename(loc);
-};
-
-exports.transform = function (filename, code, opts) {
-  opts = _.extend(opts || {}, index.opts);
-  opts.filename = filename;
-
-  var result;
-  try {
-    result = to5.transform(code, opts);
-  } catch (e) {
-    if (e instanceof SyntaxError) {
-      console.error("SyntaxError:", e.message);
-      process.exit(1);
-    } else {
-      throw e;
-    }
-  }
-  result.filename = filename;
-  result.actual = code;
-  return result;
-};
-
-exports.compile = function (filename, opts) {
-  var code = fs.readFileSync(filename, "utf8");
-  return exports.transform(filename, code, opts);
-};

bin/_6to5-node

@@ -1,109 +0,0 @@
-#!/usr/bin/env node
-
-var roadrunner = require("roadrunner");
-var commander  = require("commander");
-var Module     = require("module");
-var path       = require("path");
-var repl       = require("repl");
-var to5        = require("../lib/6to5");
-var util       = require("../lib/6to5/util");
-var vm         = require("vm");
-var _          = require("lodash");
-
-var program = new commander.Command("6to5-node");
-
-program.option("-e, --eval [script]", "Evaluate script");
-program.option("-p, --print", "Evaluate script and print result");
-program.option("-i, --ignore [regex]", "Ignore all files that match this regex when using the require hook");
-program.option("-x, --extensions [extensions]", "List of extensions to hook into [.es6,.js]");
-program.option("-r, --experimental", "Enable experimental support for proposed ES7 features");
-program.option("-g, --playground", "Enable playground support");
-program.option("-c, --cache", "Cache compiled files and require paths");
-
-var pkg = require("../package.json");
-program.version(pkg.version);
-program.usage("[options] [ -e script | script.js ] [arguments]");
-program.parse(process.argv);
-
-if (program.cache) roadrunner.load();
-
-//
-
-to5.register({
-  experimental: program.experimental,
-  extensions:   program.extensions,
-  playground:   program.playground,
-  ignore:       program.ignore,
-  cache:        program.cache && roadrunner.get("6to5")
-});
-
-//
-
-var _eval = function (code, filename) {
-  code = to5.transform(code, {
-    filename: filename,
-    blacklist: ["useStrict"],
-    experimental: program.experimental,
-    playground: program.playground
-  }).code;
-  return vm.runInThisContext(code, filename);
-};
-
-if (program.eval) {
-  var result = _eval(program.eval, "eval");
-  if (program.print) console.log(result);
-} else {
-  if (program.args.length) {
-    // slice all arguments up to the first filename since they're 6to5 args that we handle
-    var args = process.argv.slice(2);
-
-    var i = 0;
-    _.each(args, function (arg, i2) {
-      if (arg[0] !== "-") {
-        i = i2;
-        return false;
-      }
-    });
-    args = args.slice(i);
-
-    // make the filename absolute
-    var filename = args[0]
-    if (!util.isAbsolute(filename)) args[0] = path.join(process.cwd(), filename);
-
-    // add back on node and concat the sliced args
-    process.argv = ["node"].concat(args);
-
-    Module.runMain();
-  } else {
-    replStart();
-  }
-}
-
-if (program.cache) roadrunner.save();
-
-function replStart() {
-  repl.start({
-    prompt: "> ",
-    input: process.stdin,
-    output: process.stdout,
-    eval: replEval,
-    useGlobal: true
-  });
-}
-
-function replEval(code, context, filename, callback) {
-  var err;
-  var result;
-
-  try {
-    if (/^\((.*?)\n\)$/.test(code)) {
-      code = code.slice(1, -2); // remove "(" and "\n)"
-    }
-
-    result = _eval(code, filename);
-  } catch (e) {
-    err = e;
-  }
-
-  callback(err, result);
-}

bin/cache-templates

@@ -1,5 +0,0 @@
-#!/usr/bin/env node
-
-var fs = require("fs");
-var templates = require("../lib/6to5/util").templates;
-fs.writeFileSync("templates.json", JSON.stringify(templates));

bin/cache-tests

@@ -1,5 +0,0 @@
-#!/usr/bin/env node
-
-var fs = require("fs");
-var cache = require("../test/_helper").cache;
-fs.writeFileSync("tests.json", JSON.stringify(cache));

bin/generate-core-package-json

@@ -1,11 +0,0 @@
-#!/usr/bin/env node
-
-var pkg = require("../package.json");
-pkg.name += "-core";
-delete pkg.dependencies.chokidar;
-delete pkg.optionalDependencies;
-delete pkg.devDependencies;
-delete pkg.preferGlobal;
-delete pkg.scripts;
-delete pkg.bin;
-console.log(JSON.stringify(pkg, null, "  "));

circle.yml

@@ -0,0 +1,27 @@
+general:
+  artifacts:
+    - "packages/babel-standalone/babel.js"
+    - "packages/babel-standalone/babel.min.js"
+
+machine:
+  node:
+    version:
+      8
+
+dependencies:
+  pre:
+    - curl -o- -L https://yarnpkg.com/install.sh | bash
+  cache_directories:
+    - ~/.yarn-cache
+  override:
+    - yarn
+
+test:
+  override:
+    - make test-ci-coverage
+    # Builds babel-standalone with the regular Babel config
+    - make build
+    # test-ci-coverage doesn't test babel-standalone, as trying to gather coverage
+    # data for a JS file that's several megabytes large is bound to fail. Here,
+    # we just run the babel-standalone test separately.
+    - ./node_modules/mocha/bin/_mocha packages/babel-standalone/test/ --opts test/mocha.opts

codecov.yml

@@ -0,0 +1,10 @@
+coverage:
+  parsers:
+    javascript:
+      enable_partials: yes
+  status:
+    project:
+      default:
+        target: "80%"
+    patch:
+      enabled: false

codemods/.eslintrc

@@ -0,0 +1,6 @@
+{
+  "rules": {
+    "prettier/prettier": ["error", { "trailingComma": "all" }],
+    "no-undefined-identifier": 2
+  }
+}

codemods/babel-plugin-codemod-optional-catch-binding/.npmignore

@@ -0,0 +1,3 @@
+src
+test
+*.log

codemods/babel-plugin-codemod-optional-catch-binding/README.md

@@ -0,0 +1,60 @@
+# babel-plugin-codemod-optional-catch-binding
+
+> If the argument bound to the catch block is not referenced in the catch block, that argument and the catch binding is removed.
+
+
+## Examples
+
+```js
+try {
+  throw 0;
+} catch (err) {
+  console.log("it failed, but this code executes");
+}
+```
+Is transformed to:
+
+```js
+try {
+  throw 0;
+} catch {
+  console.log("it failed, but this code executes");
+}
+```
+
+
+## Installation
+
+```sh
+npm install --save-dev babel-plugin-codemod-optional-catch-binding
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```json
+{
+  "plugins": ["codemod-optional-catch-binding"]
+}
+```
+
+### Via CLI
+
+```sh
+babel --plugins codemod-optional-catch-binding script.js
+```
+
+### Via Node API
+
+```javascript
+require("babel-core").transform("code", {
+  plugins: ["codemod-optional-catch-binding"]
+});
+```
+
+## References
+This codemod updates your source code in line with the following proposal:
+- [Proposal: Optional Catch Binding for ECMAScript](https://github.com/babel/proposals/issues/7)

codemods/babel-plugin-codemod-optional-catch-binding/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "babel-plugin-codemod-optional-catch-binding",
+  "version": "7.0.0-beta.3",
+  "description": "Remove unused catch bindings",
+  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-remove-unused-catch-binding",
+  "license": "MIT",
+  "main": "lib/index.js",
+  "keywords": [
+    "babel-plugin"
+  ],
+  "dependencies": {
+    "babel-plugin-syntax-optional-catch-binding": "7.0.0-beta.3"
+  },
+  "devDependencies": {
+    "babel-helper-plugin-test-runner": "7.0.0-beta.3"
+  }
+}

codemods/babel-plugin-codemod-optional-catch-binding/src/index.js

@@ -0,0 +1,24 @@
+import syntaxOptionalCatchBinding from "babel-plugin-syntax-optional-catch-binding";
+
+export default function(babel) {
+  const { types: t } = babel;
+  return {
+    inherits: syntaxOptionalCatchBinding,
+
+    visitor: {
+      CatchClause(path) {
+        if (path.node.param === null || !t.isIdentifier(path.node.param)) {
+          return;
+        }
+        const binding = path.scope.getOwnBinding(path.node.param.name);
+        if (binding.constantViolations.length > 0) {
+          return;
+        }
+        if (!binding.referenced) {
+          const paramPath = path.get("param");
+          paramPath.remove();
+        }
+      },
+    },
+  };
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-duplicate-variable-declaration/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (e) {
+  let e = new TypeError('Duplicate variable declaration; will throw an error.');
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-duplicate-variable-declaration/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["../../../../lib"],
+  "throws": "Duplicate declaration \"e\""
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-null-binding/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-null-binding/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-null-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-array-pattern-binding/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch ([message]) {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-array-pattern-binding/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch ([message]) {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-array-pattern-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-binding/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-binding/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-object-pattern-binding/actual.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch ({
+  message
+}) {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-object-pattern-binding/expected.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch ({
+  message
+}) {
+  console.log("it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-unused-object-pattern-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-array-pattern-binding/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch ([message]) {
+  console.log(message);
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-array-pattern-binding/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch ([message]) {
+  console.log(message);
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-array-pattern-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding-variable/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (e) {
+  e = new TypeError('A new variable is not being declared or initialized; the catch binding is being referenced and cannot be removed.');
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding-variable/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (e) {
+  e = new TypeError('A new variable is not being declared or initialized; the catch binding is being referenced and cannot be removed.');
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding-variable/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding/actual.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log(err, "it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding/expected.js

@@ -0,0 +1,5 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log(err, "it failed, but this code executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-object-pattern-binding/actual.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch ({
+  message
+}) {
+  console.log(message);
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-object-pattern-binding/expected.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch ({
+  message
+}) {
+  console.log(message);
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-block-used-object-pattern-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-unused-binding/actual.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log("it failed, but this code executes");
+} finally {
+  console.log("this code also executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-unused-binding/expected.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch {
+  console.log("it failed, but this code executes");
+} finally {
+  console.log("this code also executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-unused-binding/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-used-binding/actual.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log(err, "it failed, but this code executes");
+} finally {
+  console.log("this code also executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-used-binding/expected.js

@@ -0,0 +1,7 @@
+try {
+  throw 0;
+} catch (err) {
+  console.log(err, "it failed, but this code executes");
+} finally {
+  console.log("this code also executes");
+}

codemods/babel-plugin-codemod-optional-catch-binding/test/fixtures/codemod-optional-catch-binding/try-catch-finally-used-binding/options.json

@@ -0,0 +1,3 @@
+{
+    "plugins": ["../../../../lib"]
+  }

codemods/babel-plugin-codemod-optional-catch-binding/test/index.js

@@ -0,0 +1,3 @@
+import runner from "babel-helper-plugin-test-runner";
+
+runner(__dirname);

doc/ast/spec.md

@@ -0,0 +1 @@
+The [AST specification](https://github.com/babel/babylon/blob/master/ast/spec.md) has been moved to the Babylon repo, `babel/babylon`.

doc/design/compiler-assumptions.md

@@ -0,0 +1,9 @@
+# Compiler assumptions
+
+Babel and its associated official transforms make some assumptions about your code. These
+assumptions are only made as they're either **impossible** to take into consideration or
+are extremely exotic.
+
+ - `undefined`, `NaN` and `Infinity` have not been externally redefined.
+ - Built-in objects such as `Object`, `Array`, `String`, `Number`, `Boolean` etc have not been redefined.
+ - Standard methods on built-ins have not been redefined in a way that breaks the original contract.

doc/design/compiler-environment-support.md

@@ -0,0 +1,22 @@
+# Compiler environment support
+
+**NOTE:** Compiler support does not dictate the runtime requirements of compiled code.
+
+## Officially supported environments
+
+The Babel compiler is **only** supported in these environments:
+
+ - Modern browsers such as Chrome, Firefox, Safari, Edge etc.
+ - Node.js 4 and upper versions
+
+## Unsupported environments
+
+This means that any other environment is not supported, this includes but is not limited
+to:
+
+ - Rhino
+ - Nashorn
+ - Internet Explorer
+
+**NOTE:** If Babel works in any of the unsupported environments, it is purely
+coincidental and has no bearing on future compatibility. Use at your own risk.

doc/design/monorepo.md

@@ -0,0 +1,45 @@
+# Why is Babel a monorepo?
+
+> The tool for managing the monorepo in Babel has been extracted out as [Lerna](https://github.com/lerna/lerna)
+
+Juggling a multimodule project over multiple repos is like trying to teach a newborn baby how to
+ride a bike.
+
+Babel follows a monorepo approach, all officially maintained modules are in the same repo.
+
+This is quite taboo but let's look at the pros and cons:
+
+**Pros:**
+
+ * Single lint, build, test and release process.
+ * Easy to coordinate changes across modules.
+ * Single place to report issues.
+ * Easier to setup a development environment.
+ * Tests across modules are ran together which finds bugs that touch multiple modules easier.
+
+**Cons:**
+
+ * Codebase looks more intimidating.
+ * Repo is bigger in size.
+ * [Can't `npm install` modules directly from GitHub](https://github.com/npm/npm/issues/2974)
+ * ???
+
+## This is dumb! Nobody in open source does this!
+
+[React](https://github.com/facebook/react/tree/master/packages), [Meteor](https://github.com/meteor/meteor/tree/devel/packages), and [Ember](https://github.com/emberjs/ember.js/tree/master/packages), among others, do this.
+
+## Previous discussion
+
+- [Dan Luu](http://danluu.com/monorepo/)
+- [Gregory](http://gregoryszorc.com/blog/2014/09/09/on-monolithic-repositories/)
+- [Szorc](http://gregoryszorc.com/blog/2015/02/17/lost-productivity-due-to-non-unified-repositories/)
+- [Face](https://www.youtube.com/watch?v=X0VH78ye4yY)[book](https://code.facebook.com/posts/218678814984400/scaling-mercurial-at-facebook/)
+- [Benjamin Pollack](http://bitquabit.com/post/unorthodocs-abandon-your-dvcs-and-return-to-sanity/)
+- [Benjamin Eberlei](https://qafoo.com/resources/presentations/froscon_2015/monorepos.html)
+- [Simon Stewart](http://blog.rocketpoweredjetpants.com/2015/04/monorepo-one-source-code-repository-to.html)
+- [Digital Ocean](https://www.digitalocean.com/company/blog/taming-your-go-dependencies/)
+- [Google](http://www.infoq.com/presentations/Development-at-Google), [another](https://www.youtube.com/watch?v=W71BTkUbdqE)
+- [Twitter](https://www.youtube.com/watch?v=bjh4DHuOf4E)
+- [thedufer](http://www.reddit.com/r/programming/comments/1unehr/scaling_mercurial_at_facebook/cek9nkq)
+- [Paul Hammant](http://paulhammant.com/categories.html#Trunk_Based_Development)
+- [Exponent](https://blog.getexponent.com/universe-exponents-code-base-f12fa236b8e#.9dj8a82be)

doc/design/versioning.md

@@ -0,0 +1,5 @@
+# How does Babel versioning work?
+
+## Does Babel follow semver?
+
+Yes.

doc/index.md

@@ -1 +0,0 @@
-See [6to5.github.io/docs](https://github.com/6to5/6to5.github.io/tree/master/docs).

experimental/.eslintrc

@@ -0,0 +1,6 @@
+{
+  "rules": {
+    "prettier/prettier": ["error", { "trailingComma": "all" }],
+    "no-undefined-identifier": 2
+  }
+}

experimental/babel-preset-env/.eslintignore

@@ -0,0 +1,6 @@
+/lib
+debug-fixtures
+fixtures
+/data
+/flow-typed
+test/tmp

experimental/babel-preset-env/.gitignore

@@ -0,0 +1,10 @@
+node_modules
+coverage
+lib
+test/tmp
+.DS_Store
+*.log
+.vscode
+.nyc_output
+tmp
+babel-preset-env-*.tgz

experimental/babel-preset-env/.npmignore

@@ -0,0 +1,15 @@
+coverage
+src
+test
+lib/types.js
+node_modules
+scripts
+.eslintignore
+.travis.yml
+codecov.yml
+yarn.lock
+.nyc_output
+.vscode
+.eslintrc
+babel-preset-env-*.tgz
+flow-typed

experimental/babel-preset-env/CHANGELOG.md

@@ -0,0 +1,654 @@
+# Changelog
+
+## v1.6.0 (2017-07-04)
+
+### :rocket: New Feature
+
+- Bump compat-table for node8 support ([#363](https://github.com/babel/babel-preset-env/pull/363)) (@existentialism)
+
+We updated our mappings to support native trailing function commas and string paddings in Node.js 8+.
+
+### :bug: Bug Fix
+
+- Handle `chromeandroid` browserslist value ([#367](https://github.com/babel/babel-preset-env/pull/367)) (@yavorsky)
+
+We added support for using browserslist's `chromeandroid` in `targets`.
+
+### :memo: Documentation
+
+- Tweak uglify option docs ([#368](https://github.com/babel/babel-preset-env/pull/368)) (@existentialism)
+
+Thanks to @graingert and @pfiaux for pointing out some needed updates to the `uglify-js`-related docs.
+
+## v1.5.2 (2017-06-07)
+
+### :bug: Bug Fix
+
+- Ensure explicit targets always override browsers key targets ([#346](https://github.com/babel/babel-preset-env/pull/346)) (@existentialism)
+
+`browser` targets should be overridden by explicit targets, and we inadvertently broke this when we landed string version support.
+
+## v1.5.1 (2017-05-22)
+
+### :bug: Bug Fix
+
+- Compile with loose mode ([#322](https://github.com/babel/babel-preset-env/pull/332)) (@existentialism)
+
+## v1.5.0 (2017-05-19)
+
+### :rocket: New Feature
+
+- Support target versions as strings ([#321](https://github.com/babel/babel-preset-env/pull/321)) (@existentialism)
+
+We were originally waiting on 2.x for a breaking change, but since node v7.10
+and other targets are causing some pain, we decided to land a backwards
+compatible version.
+
+### :house: Internal
+
+- Backport: use preset-env and remove flow-strip-types ([#324](https://github.com/babel/babel-preset-env/pull/324)) (@yavorsky)
+- Bump electron-to-chromium ([#329](https://github.com/babel/babel-preset-env/pull/329)) (@existentialism)
+- Tweak version mappings to match compat-table updates ([#323](https://github.com/babel/babel-preset-env/pull/323)) (@existentialism)
+- Bump browserslist ([#319](https://github.com/babel/babel-preset-env/pull/319)) (@existentialism)
+- Bump compat-table ([#307](https://github.com/babel/babel-preset-env/pull/307)) (@existentialism)
+- Add debug-fixtures and test/tmp to .eslintignore ([#305](https://github.com/babel/babel-preset-env/pull/305)) (@yavorsky)
+
+## v1.4.0 (2017-04-14)
+
+### :rocket: New Feature
+
+- Support `spec` option ([#98](https://github.com/babel/babel-preset-env/pull/98)) (@Kovensky)
+
+Added an option to enable more spec compliant, but potentially slower, transformations for any plugins in this preset that support them.
+
+- Bump compat-table for Edge 15 support ([#273](https://github.com/babel/babel-preset-env/pull/273)) (@existentialism)
+
+We updated our mappings so that you can get native support for async/await and other goodies when targeting Edge 15!
+
+### :bug: Bug Fix
+
+- Add Android browser to name map ([#270](https://github.com/babel/babel-preset-env/pull/270)) (@existentialism)
+
+Fixed a bug that was ignoring Android targets in browserslist queries (for example: "Android >= 4").
+
+### :memo: Documentation
+
+- Clarify note about loading polyfills only once ([#282](https://github.com/babel/babel-preset-env/pull/282)) (@darahak)
+- Add a reminder about include/exclude options ([#275](https://github.com/babel/babel-preset-env/pull/275)) (@existentialism)
+
+### :house: Internal
+
+- Chore: reduce package size. ([#281](https://github.com/babel/babel-preset-env/pull/281)) (@evilebottnawi)
+- Remove deprecated comment ([#271](https://github.com/babel/babel-preset-env/pull/271)) (@yavorsky)
+
+## v1.3.3 (2017-04-07)
+
+### :bug: Bug Fix
+
+- Support electron version in a string format ([#252](https://github.com/babel/babel-preset-env/pull/252)) (@yavorsky)
+
+Adding electron as a target was an inadvertent breaking change as it no longer
+allowed string versions. We added an exception for now, even though it is
+inconsistent with other versions. Just as a note, the upcoming version 2.x will
+allow _both_ number and string versions.
+
+- Ensure const-check plugin order ([#257](https://github.com/babel/babel-preset-env/pull/257)) (@existentialism)
+
+We now force the `const-es2015-check` plugin to run first (so that it can
+correctly report issues before they get transpiled away).
+
+### :rocket: New Feature
+
+- Allow use `babel-plugin-` prefix for include and exclude ([#242](https://github.com/babel/babel-preset-env/pull/242)) (@yavorsky)
+
+The `include` and `exclude` options now allow both prefixed (`babel-plugin-transform-es2015-spread`) 
+and prefix-less (`transform-es2015-spread`) plugin names.
+
+### :memo: Documentation 
+
+- Note babel plugin prefix handling in include/exclude ([#245](https://github.com/babel/babel-preset-env/pull/245)) (@existentialism)
+- Fix README: debug option shows info in stdout. ([#236](https://github.com/babel/babel-preset-env/pull/236)) (@Gerhut)
+
+### :house: Internal
+
+- Add simple smoke-test ([#240](https://github.com/babel/babel-preset-env/pull/240)) (@existentialism)
+- Add prepublish script (@existentialism)
+
+## v1.3.2 (2017-03-30)
+
+- Fixed an issue with a broken publish
+
+## v1.3.1 (2017-03-30)
+
+- Fixed a regression with missing files due to `.npmignore`.
+
+## v1.3.0 (2017-03-30)
+
+### :bug: Bug Fix
+
+- Add check for ArrayBuffer[Symbol.species] ([#233](https://github.com/babel/babel-preset-env/pull/233)) (@existentialism)
+
+We now properly check for `Symbol.species` support in ArrayBuffer and include the
+polyfill if necessary. This should, as a side effect, fix ArrayBuffer-related 
+errors on IE9.
+
+### :nail_care: Polish
+
+- Fill data with electron as a target. ([#229](https://github.com/babel/babel-preset-env/pull/229)) (@yavorsky)
+
+We've simplified things by adding `electron` as a target instead of doing a bunch of 
+things at runtime. Electron targets should now also be displayed in the debug output.
+
+- separate default builtins for platforms ([#226](https://github.com/babel/babel-preset-env/pull/226)) (@restrry)
+
+If you are targeting the `node` environment exclusively, the always-included web polyfills
+(like `dom.iterable`, and a few others) will now no longer be included.
+
+### :memo: Documentation 
+
+ * remove deprecated projects ([#223](https://github.com/babel/babel-preset-env/pull/223)) [skip ci] (@stevemao)
+
+### :house: Internal
+
+ * npmignore: Add related to build data and codecov. ([#216](https://github.com/babel/babel-preset-env/pull/216)) (@yavorsky)
+
+## v1.2.2 (2017-03-14)
+
+### :bug: Bug Fix
+
+- Refactor browser data parsing to handle families ([#208](https://github.com/babel/babel-preset-env/pull/208)) (@existentialism)
+
+When parsing plugin data, we weren't properly handling browser families. This caused 
+`transform-es2015-block-scoping` and other plugins to be incorrectly added for Edge >= 12. 
+(s/o to @mgol for the the report and review!)
+
+- Add typed array methods to built-ins features. ([#198](https://github.com/babel/babel-preset-env/pull/198)) (@yavorsky)
+
+Fixes an issue where some TypedArray features were not being polyfilled properly. (s/o to @alippai for the report!)
+
+### :memo: Documentation
+
+- Fixed minor typo in readme ([#199](https://github.com/babel/babel-preset-env/pull/199)) (@bl4ckdu5t)
+- Add built-ins, better links, compat-table url, etc ([#195](https://github.com/babel/babel-preset-env/pull/195)) (@yavorsky)
+- Change CONTRIBUTING.md to use absolute paths ([#194](https://github.com/babel/babel-preset-env/pull/194)) (@aaronang)
+
+### :house: Internal
+
+- Bump plugins ([#201](https://github.com/babel/babel-preset-env/pull/201)) (@yavorsky)
+- Enable code coverage ([#200](https://github.com/babel/babel-preset-env/pull/200)) (@alxpy)
+- Increase mocha timeout to 10s ([#202](https://github.com/babel/babel-preset-env/pull/202)) (@yavorsky)
+
+## v1.2.1 (2017-03-06)
+
+### :bug: Bug Fix
+
+- Add transform-duplicate-keys mapping ([#192](https://github.com/babel/babel-preset-env/pull/192)) (@existentialism)
+
+Our plugin data was missing a mapping for the `transform-duplicate-keys` plugin which caused it to never be included. (s/o to @Timer for the report!)
+
+### :memo: Documentation
+
+- Clarify reasons for the uglify option in README.md ([#188](https://github.com/babel/babel-preset-env/pull/188)) (@mikegreiling)
+
+## v1.2.0 (2017-03-03)
+
+### :rocket: New Feature
+
+- Add uglify as a target ([#178](https://github.com/babel/babel-preset-env/pull/178)) (@yavorsky)
+
+Support for `uglify` as a target is now available! This will enable all plugins and, as a result, fully compiles your code to ES5. Note, that useBuiltIns will work as before, and only the polyfills that your other target(s) need will be included.
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": 55,
+        "uglify": true
+      },
+      "useBuiltIns": true,
+      "modules": false
+    }]
+  ]
+}
+```
+
+### :bug: Bug Fix
+
+- Respect older versions in invert equals map ([#180](https://github.com/babel/babel-preset-env/pull/180)) (@danez)
+
+Fixes a number of bugs that caused some incorrect and/or missing environment data when parsing `compat-table`.
+
+## v1.1.11 (2017-03-01)
+
+This release primarily upgrades `compat-table`, which adds support for async on Node 7.6!
+
+### :bug: Bug Fix
+
+- Fix hasBeenWarned condition. ([#175](https://github.com/babel/babel-preset-env/pull/175)) (@yavorsky)
+
+### :memo: Documentation
+
+- Add yarn example. ([#174](https://github.com/babel/babel-preset-env/pull/174)) (@yavorsky)
+
+### :house: Internal
+
+- Bump compat-table ([#177](https://github.com/babel/babel-preset-env/pull/177)) (@existentialism)
+- Add electron version exception test ([#176](https://github.com/babel/babel-preset-env/pull/176)) (@existentialism)
+
+## v1.1.10 (2017-02-24)
+
+### :bug: Bug Fix
+
+- Drop use of lodash/intersection from checkDuplicateIncludeExcludes ([#173](https://github.com/babel/babel-preset-env/pull/173)) (@existentialism)
+
+## v1.1.9 (2017-02-24)
+
+### :bug: Bug Fix
+
+- Add tests for debug output ([#156](https://github.com/babel/babel-preset-env/pull/156)) (@existentialism)
+
+Since we've (mostly @yavorsky) have fixed a number of bugs recently with the `debug` option output, we added the ability to assert stdout matches what we expect. Read the updated [CONTRIBUTING.md](https://github.com/babel/babel-preset-env/blob/master/CONTRIBUTING.md#testing-the-debug-option) for more info.
+
+- Fixes #143. Log correct targets. ([#155](https://github.com/babel/babel-preset-env/pull/155)) (@yavorsky)
+
+This fixes a bug in the `debug` output where incorrect target(s) were being displayed for why a particular plugin/preset was being included.
+
+Given targets:
+
+```txt
+{
+  "firefox": 52,
+  "node": 7.4 
+}
+```
+
+Before:
+
+```txt
+Using plugins:
+  transform-es2015-destructuring {"node":6.5}
+  transform-es2015-for-of {"node":6.5}
+  transform-es2015-function-name {"node":6.5}
+  transform-es2015-literals {"node":4}
+  transform-exponentiation-operator {"firefox":52}
+  syntax-trailing-function-commas {"firefox":52}
+```
+
+After:
+
+```txt
+Using plugins:
+  transform-es2015-destructuring {"firefox":52}
+  transform-es2015-for-of {"firefox":52}
+  transform-es2015-function-name {"firefox":52}
+  transform-es2015-literals {"firefox":52}
+  transform-exponentiation-operator {"node":7.4}
+  syntax-trailing-function-commas {"node":7.4}
+```
+
+### :memo: Documentation
+
+- Fix compat-table link in contributing.md (@existentialism)
+- Update README examples to fix website ([#151](https://github.com/babel/babel-preset-env/pull/)) (@existentialism)
+- Fix few typos ([#146](https://github.com/babel/babel-preset-env/pull/146)) (@existentialism)
+- Add configuration example to clarify `debug: true` ([#138](https://github.com/babel/babel-preset-env/pull/138)) (@yavorsky)
+- Fix CHANGELOG’s v1.1.8 updates typo. ([#136](https://github.com/babel/babel-preset-env/pull/136)) (@yavorsky)
+- README: Update `debug: true` example. ([#138](https://github.com/babel/babel-preset-env/pull/138)) (@yavorsky)
+
+### :house: Internal
+
+- update compat ([#169](https://github.com/babel/babel-preset-env/pull/169)) (@hzoo)
+- Use external Electron to Chromium library ([#144](https://github.com/babel/babel-preset-env/pull/144)) (@Kilian)
+- Update yarn lockfile ([#152](https://github.com/babel/babel-preset-env/pull/152)) (@existentialism)
+- Extract option normalization into independant file ([#125](https://github.com/babel/babel-preset-env/pull/125)) (@baer)
+- Update yarnfile ([#145](https://github.com/babel/babel-preset-env/pull/145)) (@baer)
+- devDeps: eslint-config-babel v5.0.0 ([#139](https://github.com/babel/babel-preset-env/pull/139)) (@kaicataldo)
+- Update compat-table, build data ([#135](https://github.com/babel/babel-preset-env/pull/135)) (@hzoo)
+ 
+## v1.1.8 (2017-01-10)
+
+### :bug: Bug Fix
+
+- Debug: Transformations before logs. ([#128](https://github.com/babel/babel-preset-env/pull/128)) (@yavorsky)
+
+Makes sure that all transformations on `targets` (such as `exclude`/`include`) are run before logging out with the `debug` option. Fixes ([#127](https://github.com/babel/babel-preset-env/issues/127)).
+
+### :house: Internal
+
+- Remove unnecessary extension. ([#131](https://github.com/babel/babel-preset-env/pull/131)) (@roman-yakobnyuk)
+- Include yarn.lock and update CI. ([#124](https://github.com/babel/babel-preset-env/pull/124)) (@existentialism)
+
+## v1.1.7 (2017-01-09)
+ 
+Had a publishing issue in the previous release.
+
+## v1.1.6 (2017-01-06)
+
+### :bug: Bug Fix
+
+- Explicitly resolve lowest browser version. ([#121](https://github.com/babel/babel-preset-env/pull/121)) (@brokenmass)
+
+```js
+{
+  "targets": {
+    "browsers": ["ios >= 6"] // was resolving to {ios: 10} rather than {ios: 6}
+  }
+}
+```
+
+## v1.1.5 (2017-01-04)
+
+### :bug: Bug Fix
+
+- Show error if target version is not a number. ([#107](https://github.com/babel/babel-preset-env/pull/107)) (@existentialism)
+
+```js
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": "52", // will error since it's not a number,
+        "chrome": 52 // correct!
+      }
+    }]
+  ]
+}
+```
+
+- Fix targets for the `debug` option. ([#109](https://github.com/babel/babel-preset-env/pull/109)) (@yavorsky)
+
+Now it prints the transformed targets/environments rather than the browsers query.
+
+```txt
+Using targets:
+{
+  "chrome": 53,
+  "ie": 10,
+  "node": 6
+}
+
+Modules transform: false
+
+Using plugins:
+  transform-es2015-arrow-functions {"chrome":47,"node":6}
+  transform-es2015-block-scoped-functions {"chrome":41,"ie":11,"node":4}
+
+Using polyfills:
+  es6.typed.uint8-clamped-array {"chrome":5,"node":0.12}
+  es6.map {"chrome":51,"node":6.5}
+```
+
+## v1.1.4 (2016-12-16)
+
+v1.1.2-v1.1.4
+
+### :bug: Bug Fix
+
+The new `exclude`/`include` options weren't working correctly for built-ins. ([#102](https://github.com/babel/babel-preset-env/pull/102)).
+
+Also fixes an issue with debug option.
+
+## v1.1.1 (2016-12-13)
+
+### :bug: Bug Fix
+
+Regression with the previous release due to using `Object.values` (ES2017). This wasn't caught because we are using babel-register to run tests and includes polyfills so it didn't fail on CI even though we have Node 0.10 as an env. Looking into fixing this to prevent future issues.
+
+## v1.1.0 (2016-12-13)
+
+### :rocket: New Feature
+
+- Add `exclude` option, rename `whitelist` to `include` ([#89](https://github.com/babel/babel-preset-env/pull/89)) (@hzoo)
+
+Example:
+
+```js
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "browsers": ["last 2 versions", "safari >= 7"]
+      },
+      "include": ["transform-es2015-arrow-functions"],
+      "exclude": [
+        "transform-regenerator",
+        "transform-async-to-generator",
+        "map"
+      ],
+      "useBuiltIns": true
+    }]
+  ]
+}
+```
+
+`"exclude": ["transform-regenerator"]` doesn't transform generators and removes `regeneratorRuntime` from being imported.
+
+`"exclude": ["transform-async-to-generator"]` doesn't use the built-in async-to-gen transform so you can use something like [fast-async](https://github.com/MatAtBread/fast-async).
+
+`"exclude": ["map"]` doesn't include the `Map` polyfill if you know you aren't using it in your code (w/ `useBuiltIns`). (We will figure out a way to automatically do this [#84](https://github.com/babel/babel-preset-env/issues/84)).
+
+If you pass a wrong plugin it will error: valid options for `include/exclude` are in [/data/plugin-features.js](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js) and [/data/built-in-features.js](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js) (without the `es6.`)
+
+### :house: Internal
+
+- Optimize result filtration. ([#77](https://github.com/babel/babel-preset-env/pull/77)) (@yavorsky)
+- Update eslint config to align with other babel projects ([#79](https://github.com/babel/babel-preset-env/pull/79)) (@baer)
+- Update pathnames to avoid uppercase ([#80](https://github.com/babel/babel-preset-env/pull/80)) (@baer)
+- Refactor build data for clarity/consistency ([#81](https://github.com/babel/babel-preset-env/pull/81)) (@baer)
+- Update linting rules to cover all js ([#82](https://github.com/babel/babel-preset-env/pull/82)) (@baer)
+- Cleanup lib before rebuilding ([#87](https://github.com/babel/babel-preset-env/pull/87)) (@baer)
+- Move linting dependency to be dev only ([#88](https://github.com/babel/babel-preset-env/pull/88)) (@baer)
+
+### :memo: Documentation
+
+- Fix typo ([#78](https://github.com/babel/babel-preset-env/pull/78)) (@rohmanhm)
+- Fix PR link in changelog. ([#75](https://github.com/babel/babel-preset-env/pull/75)) (@nhajidin)
+
+## v1.0.2 (2016-12-10)
+
+### :bug: Bug Fix
+
+* Fix issue with Object.getOwnPropertySymbols ([#71](https://github.com/babel/babel-preset-env/pull/71)) ([@existentialism](https://github.com/existentialism))
+
+Was requiring the wrong module kinda of like in v1.0.1:
+
+https://github.com/zloirock/core-js#ecmascript-6-symbol
+
+```diff
+-import "core-js/modules/es6.object.get-own-property-symbols";
+```
+
+The test is just a part of `Symbol`.
+
+## v1.0.1 (2016-12-10)
+
+### :bug: Bug Fix
+
+* Fix regenerator import ([#68](https://github.com/babel/babel-preset-env/pull/68)) ([@hzoo](https://github.com/hzoo))
+
+We were outputting an invalid path for `regenerator`!
+
+```diff
++import "regenerator-runtime/runtime";
+-import "core-js/modules/regenerator-runtime/runtime"-
+```
+
+## v1.0.0 (2016-12-09)
+
+### :rocket: New Feature
+
+* Add `useBuiltIns` option ([#56](https://github.com/babel/babel-preset-env/pull/56)) ([@hzoo](https://github.com/hzoo)), ([@yavorsky](https://github.com/yavorsky)), ([@existentialism](https://github.com/existentialism))
+
+A way to apply `babel-preset-env` for polyfills (via `"babel-polyfill"``).
+
+> This option will apply a new Babel plugin that replaces `require("babel-polyfill")` with the individual requires for `babel-polyfill` based on the target environments.
+
+Install
+
+```
+npm install babel-polyfill --save
+```
+
+In
+
+```js
+import "babel-polyfill"; // create an entry js file that contains this
+// or 
+import "core-js";
+```
+
+Out (different based on environment)
+
+```js
+// chrome 55
+import "core-js/modules/es7.string.pad-start"; // haha left_pad
+import "core-js/modules/es7.string.pad-end";
+import "core-js/modules/web.timers";
+import "core-js/modules/web.immediate";
+import "core-js/modules/web.dom.iterable";
+```
+
+`.babelrc` Usage
+
+```js
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "electron": 1.4
+      },
+      "modules": false, // webpack 2
+      "useBuiltIns": true // new option
+    }]
+  ]
+}
+```
+
+> Also looking to make an easier integration point via Webpack with this method. Please reach out if you have ideas!
+
+---
+
+* Support [Electron](http://electron.atom.io/) ([#55](https://github.com/babel/babel-preset-env/pull/55)) ([@paulcbetts](https://github.com/paulcbetts))
+
+Electron is also an environment, so [Paul went ahead](https://twitter.com/paulcbetts/status/804507070103851008) and added support for this!
+
+`.babelrc` Usage
+
+```js
+{
+  "presets": [ ["env", {"targets": { "electron": 1.4 }}]]
+}
+```
+
+> Currently we are manually updating the data in [/data/electron-to-chromium.js](https://github.com/babel/babel-preset-env/blob/master/data/electron-to-chromium.js), but [@kevinsawicki](https://github.com/kevinsawicki) says we could generate the data from [atom-shell/dist/index.json](https://gh-contractor-zcbenz.s3.amazonaws.com/atom-shell/dist/index.json) as well! (Someone should make a PR :smile:)
+
+
+
+## v0.0.9 (2016-11-24)
+
+### :rocket: New Feature
+
+* Support Opera ([#48](https://github.com/babel/babel-preset-env/pull/48)) (Henry Zhu)
+
+Was as simple as modifying the chrome version and subtracting 13! (so chrome 54 = opera 41)
+
+```js
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "opera": 41
+      }
+    }]
+  ]
+}
+```
+
+## v0.0.8 (2016-11-16)
+
+### :nail_care: Polish
+
+* Only print the debug info once ([#46](https://github.com/babel/babel-preset-env/pull/46) (Henry Zhu)
+
+When using the `debug` option it was printing the data for each file processed rather than once.
+
+```js
+{
+  "presets": [
+    ["env", {
+      "debug": true
+    }]
+  ]
+}
+```
+
+## v0.0.7 (2016-11-02)
+
+### :rocket: New Feature
+
+* hardcode a current node version option ([#35](https://github.com/babel/babel-preset-env/pull/35)) (Henry Zhu)
+
+```js
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "node": "current" // parseFloat(process.versions.node)
+      }
+    }]
+  ]
+}
+```
+
+* add 'whitelist' option ([#31](https://github.com/babel/babel-preset-env/pull/31)) (Henry Zhu)
+
+```js
+ {
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": 52
+      },
+      "whitelist": ["transform-es2015-arrow-functions"]
+    }]
+  ]
+}
+```
+
+* Add more aliases (Henry Zhu)
+* Update plugin data: firefox 52 supports async/await! ([#29](https://github.com/babel/babel-preset-env/pull/29)) (Henry Zhu)
+
+### :bug: Bug Fixes
+
+* Use compat-table equals option ([#36](https://github.com/babel/babel-preset-env/pull/36)) (Henry Zhu)
+
+Compute and use `compat-table` equivalents
+
+```js
+{
+  "safari6": "phantom",
+  "chrome44": "iojs",
+  "chrome50": "node64",
+  "chrome51": "node65",
+  "chrome54": "node7",
+  "chrome30": "android44",
+  "chrome37": "android50",
+  "chrome39": "android51",
+  "safari7": "ios7",
+  "safari71_8": "ios8",
+  "safari9": "ios9",
+  "safari10": "ios10",
+  "chrome50": "node6"
+}
+```
+
+* Change default behavior to act the same as babel-preset-latest ([#33](https://github.com/babel/babel-preset-env/pull/33)) (Henry Zhu)
+
+```js
+{ "presets": ["env"] } // should act the same as babel-preset-latest
+```
+
+## Internal
+
+* Add fixture helper for tests ([#28](https://github.com/babel/babel-preset-env/pull/28)) (Henry Zhu)

experimental/babel-preset-env/CONTRIBUTING.md

@@ -0,0 +1,93 @@
+# Contributing
+
+## Adding a new plugin to support (when approved in the next ECMAScript version)
+
+### Update [`plugin-features.js`](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js)
+
+*Example:*
+
+If you were going to add `**` which is in ES2016:
+
+Find the relevant entries on [compat-table](https://kangax.github.io/compat-table/es2016plus/#test-exponentiation_(**)_operator):
+
+`exponentiation (**) operator`
+
+Find the corresponding babel plugin:
+
+`transform-exponentiation-operator`
+
+And add them in this structure:
+
+```js
+// es2016
+"transform-exponentiation-operator": {
+  features: [
+    "exponentiation (**) operator",
+  ],
+},
+```
+
+### Update [`built-in-features.js`](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js)
+
+*Example:*
+
+In case you want to add `Object.values` which is in ES2017:
+
+Find the relevant feature and subfeature on [compat-table](https://kangax.github.io/compat-table/es2016plus/#test-Object_static_methods_Object.values)
+and split it with `/`:
+
+`Object static methods / Object.values`
+
+Find the corresponding module on [core-js](https://github.com/zloirock/core-js/tree/master/modules):
+
+`es7.object.values.js`
+
+Find required ES version in [`built-in-features.js`](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js) and add the new feature:
+
+```js
+const es2017 = {
+  //...
+  "es7.object.values": "Object static methods / Object.values"
+}
+```
+
+### Update [`plugins.json`](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json)
+
+Until `compat-table` is a standalone npm module for data we are using the git url
+
+`"compat-table": "kangax/compat-table#[latest-commit-hash]"`,
+
+So we update and then run `npm run build-data`. If there are no changes, then `plugins.json` will be the same.
+
+## Tests
+
+### Running tests locally
+
+```bash
+npm test
+```
+
+### Checking code coverage locally
+
+```bash
+npm run coverage
+```
+
+### Writing tests
+
+#### General
+
+All the tests for `babel-preset-env` exist in the `test/fixtures` folder. The
+test setup and conventions are exactly the same as testing a Babel plugin, so
+please read our [documentation on writing tests](https://github.com/babel/babel/blob/master/CONTRIBUTING.md#babel-plugin-x).
+
+#### Testing the `debug` option
+
+Testing debug output to `stdout` is similar. Under the `test/debug-fixtures`,
+create a folder with a descriptive name of your test, and add the following:
+
+* Add a `options.json` file (just as the other tests, this is essentially a
+`.babelrc`) with the desired test configuration (required)
+* Add a `stdout.txt` file with the expected debug output. For added
+convenience, if there is no `stdout.txt` present, the test runner will
+generate one for you.

experimental/babel-preset-env/README.md

@@ -0,0 +1,572 @@
+# babel-preset-env [![npm](https://img.shields.io/npm/v/babel-preset-env.svg)](https://www.npmjs.com/package/babel-preset-env) [![travis](https://img.shields.io/travis/babel/babel-preset-env/master.svg)](https://travis-ci.org/babel/babel-preset-env) [![npm-downloads](https://img.shields.io/npm/dm/babel-preset-env.svg)](https://www.npmjs.com/package/babel-preset-env) [![codecov](https://img.shields.io/codecov/c/github/babel/babel-preset-env/master.svg?maxAge=43200)](https://codecov.io/github/babel/babel-preset-env)
+
+> A Babel preset that compiles [ES2015+](https://github.com/tc39/proposals/blob/master/finished-proposals.md) down to ES5 by automatically determining the Babel plugins and polyfills you need based on your targeted browser or runtime environments.
+
+```sh
+npm install babel-preset-env --save-dev
+```
+
+Without any configuration options, babel-preset-env behaves exactly the same as babel-preset-latest (or babel-preset-es2015, babel-preset-es2016, and babel-preset-es2017 together).
+
+```json
+{
+  "presets": ["env"]
+}
+```
+
+You can also configure it to only include the polyfills and transforms needed for the browsers you support. Compiling only what's needed can make your bundles smaller and your life easier.
+
+This example only includes the polyfills and code transforms needed for the last two versions of each browser, and versions of Safari greater than or equal to 7. We use [browserslist](https://github.com/ai/browserslist) to parse this information, so you can use [any valid query format supported by browserslist](https://github.com/ai/browserslist#queries).
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "browsers": ["last 2 versions", "safari >= 7"]
+      }
+    }]
+  ]
+}
+```
+
+Similarly, if you're targeting Node.js instead of the browser, you can configure babel-preset-env to only include the polyfills and transforms necessary for a particular version:
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "node": "6.10"
+      }
+    }]
+  ]
+}
+```
+
+For convenience, you can use `"node": "current"` to only include the necessary polyfills and transforms for the Node.js version that you use to run Babel:
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "node": "current"
+      }
+    }]
+  ]
+}
+```
+
+- [How it Works](#how-it-works)
+- [Install](#install)
+- [Usage](#usage)
+- [Options](#options)
+- [Examples](#examples)
+- [Issues](#issues)
+
+## How it Works
+
+### Determine environment support for ECMAScript features
+
+Use external data such as [`compat-table`](https://github.com/kangax/compat-table) to determine browser support. (We should create PRs there when necessary)
+
+![](https://cloud.githubusercontent.com/assets/588473/19214029/58deebce-8d48-11e6-9004-ee3fbcb75d8b.png)
+
+We can periodically run [build-data.js](https://github.com/babel/babel-preset-env/blob/master/scripts/build-data.js) which generates [plugins.json](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json).
+
+Ref: [#7](https://github.com/babel/babel-preset-env/issues/7)
+
+### Maintain a mapping between JavaScript features and Babel plugins
+
+> Currently located at [plugin-features.js](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js).
+
+This should be straightforward to do in most cases. There might be cases where plugins should be split up more or certain plugins aren't standalone enough (or impossible to do).
+
+### Support all plugins in Babel that are considered `latest`
+
+> Default behavior without options is the same as `babel-preset-latest`.
+
+It won't include `stage-x` plugins. env will support all plugins in what we consider the latest version of JavaScript (by matching what we do in [`babel-preset-latest`](http://babeljs.io/docs/plugins/preset-latest/)).
+
+Ref: [#14](https://github.com/babel/babel-preset-env/issues/14)
+
+### Determine the lowest common denominator of plugins to be included in the preset
+
+If you are targeting IE 8 and Chrome 55 it will include all plugins required by IE 8 since you would need to support both still.
+
+### Support a target option `"node": "current"` to compile for the currently running node version.
+
+For example, if you are building on Node 6, arrow functions won't be converted, but they will if you build on Node 0.12.
+
+### Support a `browsers` option like autoprefixer.
+
+Use [browserslist](https://github.com/ai/browserslist) to declare supported environments by performing queries like `> 1%, last 2 versions`.
+
+Ref: [#19](https://github.com/babel/babel-preset-env/pull/19)
+
+### Browserslist support.
+
+[Browserslist](https://github.com/ai/browserslist) is a library used to share a supported list of browsers between different front-end tools like [autoprefixer](https://github.com/postcss/autoprefixer), [stylelint](https://stylelint.io/), [eslint-plugin-compat](https://github.com/amilajack/eslint-plugin-compat) and many others.
+
+By default, babel-preset-env will use [browserslist config sources](https://github.com/ai/browserslist#queries).
+
+For example, to enable only the polyfills and plugins needed for a project targeting *last 2 versions* and *IE10*:
+
+**.babelrc**
+```json
+{
+  "presets": [
+    ["env", {
+      "useBuiltIns": true
+    }]
+  ]
+}
+```
+
+**browserslist**
+```
+Last 2 versions
+IE 10
+```
+
+or
+
+**package.json**
+```
+"browserslist": "last 2 versions, ie 10"
+```
+
+Browserslist config will be ignored if: 1) `targets.browsers` was specified 2) or with `ignoreBrowserslistConfig: true` option ([see more](#ignoreBrowserslistConfig)):
+
+#### Targets merging.
+
+1. If [targets.browsers](#targetsbrowsers) is defined - the browserslist config will be ignored. The browsers specified in `targets` will be merged with [any other explicitly defined targets](#targets). If merged, targets defined explicitly will override the same targets received from `targets.browsers`.
+
+2. If [targets.browsers](#targetsbrowsers) is _not_ defined - the program will search browserslist file or `package.json` with `browserslist` field. The search will start from the working directory of the process or from the path specified by the `configPath` option, and go up to the system root. If both a browserslist file and configuration inside a `package.json` are found, an exception will be thrown.
+
+3. If a browserslist config was found and other targets are defined (but not [targets.browsers](#targetsbrowsers)), the targets will be merged in the same way as `targets` defined explicitly with `targets.browsers`.
+
+## Install
+
+With [npm](https://www.npmjs.com):
+
+```sh
+npm install --save-dev babel-preset-env
+```
+
+Or [yarn](https://yarnpkg.com):
+
+```sh
+yarn add babel-preset-env --dev
+```
+
+## Usage
+
+The default behavior without options runs all transforms (behaves the same as [babel-preset-latest](https://babeljs.io/docs/plugins/preset-latest/)).
+
+```json
+{
+  "presets": ["env"]
+}
+```
+
+## Options
+
+For more information on setting options for a preset, refer to the [plugin/preset options](http://babeljs.io/docs/plugins/#plugin-preset-options) documentation.
+
+### `targets`
+
+`{ [string]: number | string }`, defaults to `{}`.
+
+Takes an object of environment versions to support.
+
+Each target environment takes a number or a string (we recommend using a string when specifying minor versions like `node: "6.10"`).
+
+Example environments: `chrome`, `opera`, `edge`, `firefox`, `safari`, `ie`, `ios`, `android`, `node`, `electron`.
+
+The [data](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json) for this is generated by running the [build-data script](https://github.com/babel/babel-preset-env/blob/master/scripts/build-data.js) which pulls in data from [compat-table](https://kangax.github.io/compat-table).
+
+### `targets.node`
+
+`number | string | "current" | true`
+
+If you want to compile against the current node version, you can specify `"node": true` or `"node": "current"`, which would be the same as `"node": process.versions.node`.
+
+### `targets.browsers`
+
+`Array<string> | string`
+
+A query to select browsers (ex: last 2 versions, > 5%) using [browserslist](https://github.com/ai/browserslist).
+
+Note, browsers' results are overridden by explicit items from `targets`.
+
+### `spec`
+
+`boolean`, defaults to `false`.
+
+Enable more spec compliant, but potentially slower, transformations for any plugins in this preset that support them.
+
+### `loose`
+
+`boolean`, defaults to `false`.
+
+Enable "loose" transformations for any plugins in this preset that allow them.
+
+### `modules`
+
+`"amd" | "umd" | "systemjs" | "commonjs" | false`, defaults to `"commonjs"`.
+
+Enable transformation of ES6 module syntax to another module type.
+
+Setting this to `false` will not transform modules.
+
+### `debug`
+
+`boolean`, defaults to `false`.
+
+Outputs the targets/plugins used and the version specified in [plugin data version](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json) to `console.log`.
+
+### `include`
+
+`Array<string>`, defaults to `[]`.
+
+An array of plugins to always include.
+
+Valid options include any:
+
+- [Babel plugins](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js) - both with (`babel-plugin-transform-es2015-spread`) and without prefix (`transform-es2015-spread`) are supported.
+
+- [Built-ins](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js), such as `map`, `set`, or `object.assign`.
+
+This option is useful if there is a bug in a native implementation, or a combination of a non-supported feature + a supported one doesn't work.
+
+For example, Node 4 supports native classes but not spread. If `super` is used with a spread argument, then the `transform-es2015-classes` transform needs to be `include`d, as it is not possible to transpile a spread with `super` otherwise.
+
+> NOTE: The `include` and `exclude` options _only_ work with the [plugins included with this preset](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js); so, for example, including `transform-do-expressions` or excluding `transform-function-bind` will throw errors. To use a plugin _not_ included with this preset, add them to your [config](https://babeljs.io/docs/usage/babelrc/) directly.
+
+### `exclude`
+
+`Array<string>`, defaults to `[]`.
+
+An array of plugins to always exclude/remove.
+
+The possible options are the same as the `include` option.
+
+This option is useful for "blacklisting" a transform like `transform-regenerator` if you don't use generators and don't want to include `regeneratorRuntime` (when using `useBuiltIns`) or for using another plugin like [fast-async](https://github.com/MatAtBread/fast-async) instead of [Babel's async-to-gen](http://babeljs.io/docs/plugins/transform-async-generator-functions/).
+
+### `useBuiltIns`
+
+`"usage"` | `"entry"` | `false`, defaults to `false`.
+
+A way to apply `babel-preset-env` for polyfills (via `babel-polyfill`).
+
+```sh
+npm install babel-polyfill --save
+```
+
+#### `useBuiltIns: 'usage'`
+
+Adds specific imports for polyfills when they are used in each file. We take advantage of the fact that a bundler will load the same polyfill only once.
+
+**In**
+
+a.js
+
+```js
+var a = new Promise();
+```
+
+b.js
+
+```js
+var b = new Map();
+```
+
+**Out (if environment doesn't support it)**
+
+```js
+import "babel-polyfill/core-js/modules/es6.promise";
+var a = new Promise();
+```
+
+```js
+import "babel-polyfill/core-js/modules/es6.map";
+var b = new Map();
+```
+
+**Out (if environment supports it)**
+
+```js
+var a = new Promise();
+```
+
+```js
+var b = new Map();
+```
+
+#### `useBuiltIns: 'entry'`
+
+> NOTE: Only use `require("babel-polyfill");` once in your whole app.
+> Multiple imports or requires of `babel-polyfill` will throw an error since it can cause global collisions and other issues that are hard to trace.
+> We recommend creating a single entry file that only contains the `require` statement.
+
+This option enables a new plugin that replaces the statement `import "babel-polyfill"` or `require("babel-polyfill")` with individual requires for `babel-polyfill` based on environment.
+
+**In**
+
+```js
+import "babel-polyfill";
+```
+
+**Out (different based on environment)**
+
+```js
+import "babel-polyfill/core-js/modules/es7.string.pad-start";
+import "babel-polyfill/core-js/modules/es7.string.pad-end";
+```
+
+#### `useBuiltIns: false`
+
+Don't add polyfills automatically per file, or transform `import "babel-polyfill"` to individual polyfills.
+
+### `forceAllTransforms`
+
+`boolean`, defaults to `false`.
+
+<p><details>
+  <summary><b>Example</b></summary>
+
+  With Babel 7's .babelrc.js support, you can force all transforms to be run if env is set to `production`.
+
+  ```js
+  module.exports = {
+    presets: [
+      ["env", {
+        targets: {
+          chrome: 59,
+          edge: 13,
+          firefox: 50,
+        },
+        // for uglifyjs...
+        forceAllTransforms: process.env === "production"
+      }],
+    ],
+  };
+  ```
+</details></p>
+
+
+> NOTE: `targets.uglify` is deprecated and will be removed in the next major in
+favor of this.
+
+By default, this preset will run all the transforms needed for the targeted
+environment(s). Enable this option if you want to force running _all_
+transforms, which is useful if the output will be run through UglifyJS or an
+environment that only supports ES5.
+
+> NOTE: Uglify has a work-in-progress "Harmony" branch to address the lack of
+ES6 support, but it is not yet stable.  You can follow its progress in
+[UglifyJS2 issue #448](https://github.com/mishoo/UglifyJS2/issues/448).  If you
+require an alternative minifier which _does_ support ES6 syntax, we recommend
+using [babel-minify](https://github.com/babel/minify).
+
+### `configPath`
+
+`string`, defaults to `process.cwd()`
+
+The starting point where the config search for browserslist will start, and ascend to the system root until found.
+
+### `ignoreBrowserslistConfig`
+
+`boolean`, defaults to `false`
+
+Toggles whether or not [browserslist config sources](https://github.com/ai/browserslist#queries) are used, which includes searching for any browserslist files or referencing the browserslist key inside package.json. This is useful for projects that use a browserslist config for files that won't be compiled with Babel.
+
+### `shippedProposals`
+
+`boolean`, defaults to `false`
+
+Toggles enabling support for builtin/feature proposals that have shipped in browsers. If your target environments have native support for a feature proposal, its matching parser syntax plugin is enabled instead of performing any transform. Note that this _does not_ enable the same transformations as [`babel-preset-stage3`](https://babeljs.io/docs/plugins/preset-stage-3/), since proposals can continue to change before landing in browsers.
+
+The following are currently supported:
+
+**Builtins**
+
+- [Promise.prototype.finally](https://github.com/tc39/proposal-promise-finally)
+
+**Features**
+
+- [Asynchronous Iterators](https://github.com/tc39/proposal-async-iteration)
+- [Object rest/spread properties](https://github.com/tc39/proposal-object-rest-spread)
+- [Optional catch binding](https://github.com/tc39/proposal-optional-catch-binding)
+- [Unicode property escapes in regular expressions](https://github.com/tc39/proposal-regexp-unicode-property-escapes)
+
+---
+
+## Examples
+
+### Export with various targets
+
+```js
+export class A {}
+```
+
+#### Target only Chrome 52
+
+**.babelrc**
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": 52
+      }
+    }]
+  ]
+}
+```
+
+**Out**
+
+```js
+class A {}
+exports.A = A;
+```
+
+#### Target Chrome 52 with webpack 2/rollup and loose mode
+
+**.babelrc**
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": 52
+      },
+      "modules": false,
+      "loose": true
+    }]
+  ]
+}
+```
+
+**Out**
+
+```js
+export class A {}
+```
+
+#### Target specific browsers via browserslist
+
+**.babelrc**
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "chrome": 52,
+        "browsers": ["last 2 versions", "safari 7"]
+      }
+    }]
+  ]
+}
+```
+
+**Out**
+
+```js
+export var A = function A() {
+  _classCallCheck(this, A);
+};
+```
+
+#### Target latest node via `node: true` or `node: "current"`
+
+**.babelrc**
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "node": "current"
+      }
+    }]
+  ]
+}
+```
+
+**Out**
+
+```js
+class A {}
+exports.A = A;
+```
+
+### Show debug output
+
+**.babelrc**
+
+```json
+{
+  "presets": [
+    [ "env", {
+      "targets": {
+        "safari": 10
+      },
+      "modules": false,
+      "useBuiltIns": true,
+      "debug": true
+    }]
+  ]
+}
+```
+
+**stdout**
+
+```sh
+Using targets:
+{
+  "safari": 10
+}
+
+Modules transform: false
+
+Using plugins:
+  transform-exponentiation-operator {}
+  transform-async-to-generator {}
+
+Using polyfills:
+  es7.object.values {}
+  es7.object.entries {}
+  es7.object.get-own-property-descriptors {}
+  web.timers {}
+  web.immediate {}
+  web.dom.iterable {}
+```
+
+### Include and exclude specific plugins/built-ins
+
+> always include arrow functions, explicitly exclude generators
+
+```json
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "browsers": ["last 2 versions", "safari >= 7"]
+      },
+      "include": ["transform-es2015-arrow-functions", "es6.map"],
+      "exclude": ["transform-regenerator", "es6.set"]
+    }]
+  ]
+}
+```
+
+## Issues
+
+If you get a `SyntaxError: Unexpected token ...` error when using the [object-rest-spread](https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-object-rest-spread) transform then make sure the plugin has been updated to, at least, `v6.19.0`.

experimental/babel-preset-env/data/built-in-features.js

@@ -0,0 +1,194 @@
+const typedArrayMethods = [
+  "typed arrays / %TypedArray%.from",
+  "typed arrays / %TypedArray%.of",
+  "typed arrays / %TypedArray%.prototype.subarray",
+  "typed arrays / %TypedArray%.prototype.join",
+  "typed arrays / %TypedArray%.prototype.indexOf",
+  "typed arrays / %TypedArray%.prototype.lastIndexOf",
+  "typed arrays / %TypedArray%.prototype.slice",
+  "typed arrays / %TypedArray%.prototype.every",
+  "typed arrays / %TypedArray%.prototype.filter",
+  "typed arrays / %TypedArray%.prototype.forEach",
+  "typed arrays / %TypedArray%.prototype.map",
+  "typed arrays / %TypedArray%.prototype.reduce",
+  "typed arrays / %TypedArray%.prototype.reduceRight",
+  "typed arrays / %TypedArray%.prototype.reverse",
+  "typed arrays / %TypedArray%.prototype.some",
+  "typed arrays / %TypedArray%.prototype.sort",
+  "typed arrays / %TypedArray%.prototype.copyWithin",
+  "typed arrays / %TypedArray%.prototype.find",
+  "typed arrays / %TypedArray%.prototype.findIndex",
+  "typed arrays / %TypedArray%.prototype.fill",
+  "typed arrays / %TypedArray%.prototype.keys",
+  "typed arrays / %TypedArray%.prototype.values",
+  "typed arrays / %TypedArray%.prototype.entries",
+  "typed arrays / %TypedArray%.prototype[Symbol.iterator]",
+  "typed arrays / %TypedArray%[Symbol.species]",
+];
+
+const es2015 = {
+  "es6.typed.array-buffer": "typed arrays / ArrayBuffer[Symbol.species]",
+  "es6.typed.data-view": "typed arrays / DataView",
+  "es6.typed.int8-array": {
+    features: ["typed arrays / Int8Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.uint8-array": {
+    features: ["typed arrays / Uint8Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.uint8-clamped-array": {
+    features: ["typed arrays / Uint8ClampedArray"].concat(typedArrayMethods)
+  },
+  "es6.typed.int16-array": {
+    features: ["typed arrays / Int16Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.uint16-array": {
+    features: ["typed arrays / Uint16Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.int32-array": {
+    features: ["typed arrays / Int32Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.uint32-array": {
+    features: ["typed arrays / Uint32Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.float32-array": {
+    features: ["typed arrays / Float32Array"].concat(typedArrayMethods)
+  },
+  "es6.typed.float64-array": {
+    features: ["typed arrays / Float64Array"].concat(typedArrayMethods)
+  },
+
+  "es6.map": "Map",
+  "es6.set": "Set",
+  "es6.weak-map": "WeakMap",
+  "es6.weak-set": "WeakSet",
+
+  // Proxy not implementable
+
+  "es6.reflect.apply": "Reflect / Reflect.apply",
+  "es6.reflect.construct": "Reflect / Reflect.construct",
+  "es6.reflect.define-property": "Reflect / Reflect.defineProperty",
+  "es6.reflect.delete-property": "Reflect / Reflect.deleteProperty",
+  "es6.reflect.get": "Reflect / Reflect.get",
+  "es6.reflect.get-own-property-descriptor": "Reflect / Reflect.getOwnPropertyDescriptor",
+  "es6.reflect.get-prototype-of": "Reflect / Reflect.getPrototypeOf",
+  "es6.reflect.has": "Reflect / Reflect.has",
+  "es6.reflect.is-extensible": "Reflect / Reflect.isExtensible",
+  "es6.reflect.own-keys": "Reflect / Reflect.ownKeys",
+  "es6.reflect.prevent-extensions": "Reflect / Reflect.preventExtensions",
+  "es6.reflect.set": "Reflect / Reflect.set",
+  "es6.reflect.set-prototype-of": "Reflect / Reflect.setPrototypeOf",
+
+  "es6.promise": {
+    features: [
+      "Promise / basic functionality",
+      "Promise / constructor requires new",
+      "Promise / Promise.prototype isn\'t an instance",
+      "Promise / Promise.all",
+      "Promise / Promise.all, generic iterables",
+      "Promise / Promise.race",
+      "Promise / Promise.race, generic iterables",
+      "Promise / Promise[Symbol.species]"
+    ]
+  },
+
+  "es6.symbol": {
+    features: [
+      "Symbol",
+      "Object static methods / Object.getOwnPropertySymbols",
+      "well-known symbols / Symbol.hasInstance",
+      "well-known symbols / Symbol.isConcatSpreadable",
+      "well-known symbols / Symbol.iterator",
+      "well-known symbols / Symbol.match",
+      "well-known symbols / Symbol.replace",
+      "well-known symbols / Symbol.search",
+      "well-known symbols / Symbol.species",
+      "well-known symbols / Symbol.split",
+      "well-known symbols / Symbol.toPrimitive",
+      "well-known symbols / Symbol.toStringTag",
+      "well-known symbols / Symbol.unscopables",
+    ]
+  },
+
+  "es6.object.assign": "Object static methods / Object.assign",
+  "es6.object.is": "Object static methods / Object.is",
+  "es6.object.set-prototype-of": "Object static methods / Object.setPrototypeOf",
+
+  "es6.function.name": "function \"name\" property",
+
+  "es6.string.raw": "String static methods / String.raw",
+  "es6.string.from-code-point": "String static methods / String.fromCodePoint",
+
+  "es6.string.code-point-at": "String.prototype methods / String.prototype.codePointAt",
+  // "String.prototype methods / String.prototype.normalize" not implemented
+  "es6.string.repeat": "String.prototype methods / String.prototype.repeat",
+  "es6.string.starts-with": "String.prototype methods / String.prototype.startsWith",
+  "es6.string.ends-with": "String.prototype methods / String.prototype.endsWith",
+  "es6.string.includes": "String.prototype methods / String.prototype.includes",
+
+  "es6.regexp.flags": "RegExp.prototype properties / RegExp.prototype.flags",
+  "es6.regexp.match": "RegExp.prototype properties / RegExp.prototype[Symbol.match]",
+  "es6.regexp.replace": "RegExp.prototype properties / RegExp.prototype[Symbol.replace]",
+  "es6.regexp.split": "RegExp.prototype properties / RegExp.prototype[Symbol.split]",
+  "es6.regexp.search": "RegExp.prototype properties / RegExp.prototype[Symbol.search]",
+
+  "es6.array.from": "Array static methods / Array.from",
+  "es6.array.of": "Array static methods / Array.of",
+
+  "es6.array.copy-within": "Array.prototype methods / Array.prototype.copyWithin",
+  "es6.array.find": "Array.prototype methods / Array.prototype.find",
+  "es6.array.find-index": "Array.prototype methods / Array.prototype.findIndex",
+  "es6.array.fill": "Array.prototype methods / Array.prototype.fill",
+
+  "es6.array.iterator": {
+    features: [
+      "Array.prototype methods / Array.prototype.keys",
+     // can use Symbol.iterator, not implemented in many environments
+     // "Array.prototype methods / Array.prototype.values",
+      "Array.prototype methods / Array.prototype.entries",
+    ]
+  },
+
+  "es6.number.is-finite": "Number properties / Number.isFinite",
+  "es6.number.is-integer": "Number properties / Number.isInteger",
+  "es6.number.is-safe-integer": "Number properties / Number.isSafeInteger",
+  "es6.number.is-nan": "Number properties / Number.isNaN",
+  "es6.number.epsilon": "Number properties / Number.EPSILON",
+  "es6.number.min-safe-integer": "Number properties / Number.MIN_SAFE_INTEGER",
+  "es6.number.max-safe-integer": "Number properties / Number.MAX_SAFE_INTEGER",
+  "es6.number.parse-float": "Number properties / Number.parseFloat",
+  "es6.number.parse-int": "Number properties / Number.parseInt",
+
+  "es6.math.acosh": "Math methods / Math.acosh",
+  "es6.math.asinh": "Math methods / Math.asinh",
+  "es6.math.atanh": "Math methods / Math.atanh",
+  "es6.math.cbrt": "Math methods / Math.cbrt",
+  "es6.math.clz32": "Math methods / Math.clz32",
+  "es6.math.cosh": "Math methods / Math.cosh",
+  "es6.math.expm1": "Math methods / Math.expm1",
+  "es6.math.fround": "Math methods / Math.fround",
+  "es6.math.hypot": "Math methods / Math.hypot",
+  "es6.math.imul": "Math methods / Math.imul",
+  "es6.math.log1p": "Math methods / Math.log1p",
+  "es6.math.log10": "Math methods / Math.log10",
+  "es6.math.log2": "Math methods / Math.log2",
+  "es6.math.sign": "Math methods / Math.sign",
+  "es6.math.sinh": "Math methods / Math.sinh",
+  "es6.math.tanh": "Math methods / Math.tanh",
+  "es6.math.trunc": "Math methods / Math.trunc",
+};
+
+const es2016 = {
+  "es7.array.includes": "Array.prototype.includes",
+};
+
+const es2017 = {
+  "es7.object.values": "Object static methods / Object.values",
+  "es7.object.entries": "Object static methods / Object.entries",
+  "es7.object.get-own-property-descriptors": "Object static methods / Object.getOwnPropertyDescriptors",
+  "es7.string.pad-start": "String padding / String.prototype.padStart",
+  "es7.string.pad-end": "String padding / String.prototype.padEnd",
+};
+
+const proposals = require("./shipped-proposals").builtIns;
+
+module.exports = Object.assign({}, es2015, es2016, es2017, proposals);

experimental/babel-preset-env/data/built-ins.json

@@ -0,0 +1,853 @@
+{
+  "es6.typed.array-buffer": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.data-view": {
+    "chrome": "5",
+    "opera": "12",
+    "edge": "12",
+    "firefox": "15",
+    "safari": "5.1",
+    "node": "0.12",
+    "ie": "10",
+    "android": "4",
+    "ios": "6",
+    "electron": "1.1"
+  },
+  "es6.typed.int8-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.uint8-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.uint8-clamped-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.int16-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.uint16-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.int32-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.uint32-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.float32-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.typed.float64-array": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "48",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.map": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.set": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.weak-map": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "53",
+    "safari": "9",
+    "node": "6.5",
+    "ios": "9",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.weak-set": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "53",
+    "safari": "9",
+    "node": "6.5",
+    "ios": "9",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.reflect.apply": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.construct": {
+    "chrome": "49",
+    "edge": "13",
+    "firefox": "44",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.define-property": {
+    "chrome": "49",
+    "edge": "13",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.delete-property": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.get": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.get-own-property-descriptor": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.get-prototype-of": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.has": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.is-extensible": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.own-keys": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.prevent-extensions": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.set": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.reflect.set-prototype-of": {
+    "chrome": "49",
+    "edge": "12",
+    "firefox": "42",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.promise": {
+    "chrome": "51",
+    "edge": "13",
+    "firefox": "45",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.symbol": {
+    "chrome": "51",
+    "firefox": "51",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.object.assign": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "34",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.object.is": {
+    "chrome": "19",
+    "edge": "12",
+    "firefox": "22",
+    "safari": "9",
+    "node": "0.12",
+    "android": "4.1",
+    "ios": "9",
+    "electron": "0.2"
+  },
+  "es6.object.set-prototype-of": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "31",
+    "safari": "9",
+    "node": "0.12",
+    "ie": "11",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.function.name": {
+    "chrome": "51",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.string.raw": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "34",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.from-code-point": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "29",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.code-point-at": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "29",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.repeat": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "24",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.starts-with": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "29",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.ends-with": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "29",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.string.includes": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "40",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "es6.regexp.flags": {
+    "chrome": "49",
+    "firefox": "37",
+    "safari": "9",
+    "node": "6",
+    "ios": "9",
+    "opera": "36",
+    "electron": "1"
+  },
+  "es6.regexp.match": {
+    "chrome": "50",
+    "firefox": "49",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "es6.regexp.replace": {
+    "chrome": "50",
+    "firefox": "49",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "es6.regexp.split": {
+    "chrome": "50",
+    "firefox": "49",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "es6.regexp.search": {
+    "chrome": "50",
+    "firefox": "49",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "es6.array.from": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "36",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "es6.array.of": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.array.copy-within": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "32",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.array.find": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "4",
+    "ios": "8",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.array.find-index": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "4",
+    "ios": "8",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.array.fill": {
+    "chrome": "45",
+    "edge": "12",
+    "firefox": "31",
+    "safari": "7.1",
+    "node": "4",
+    "ios": "8",
+    "opera": "32",
+    "electron": "0.35"
+  },
+  "es6.array.iterator": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "28",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.number.is-finite": {
+    "chrome": "19",
+    "edge": "12",
+    "firefox": "16",
+    "safari": "9",
+    "node": "0.12",
+    "android": "4.1",
+    "ios": "9",
+    "electron": "0.2"
+  },
+  "es6.number.is-integer": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "16",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.is-safe-integer": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "32",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.is-nan": {
+    "chrome": "19",
+    "edge": "12",
+    "firefox": "15",
+    "safari": "9",
+    "node": "0.12",
+    "android": "4.1",
+    "ios": "9",
+    "electron": "0.2"
+  },
+  "es6.number.epsilon": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.min-safe-integer": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "31",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.max-safe-integer": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "31",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.parse-float": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.number.parse-int": {
+    "chrome": "34",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "21",
+    "electron": "0.2"
+  },
+  "es6.math.acosh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.asinh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.atanh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.cbrt": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.clz32": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "31",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.cosh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.expm1": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.fround": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "26",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.hypot": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "27",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.imul": {
+    "chrome": "30",
+    "edge": "12",
+    "firefox": "23",
+    "safari": "7",
+    "node": "0.12",
+    "android": "4.4",
+    "ios": "7",
+    "opera": "17",
+    "electron": "0.2"
+  },
+  "es6.math.log1p": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.log10": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.log2": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.sign": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.sinh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.tanh": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es6.math.trunc": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "25",
+    "safari": "7.1",
+    "node": "0.12",
+    "ios": "8",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "es7.array.includes": {
+    "chrome": "47",
+    "edge": "14",
+    "firefox": "43",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "34",
+    "electron": "0.36"
+  },
+  "es7.object.values": {
+    "chrome": "54",
+    "edge": "14",
+    "firefox": "47",
+    "safari": "10.1",
+    "node": "7",
+    "ios": "10.3",
+    "opera": "41",
+    "electron": "1.5"
+  },
+  "es7.object.entries": {
+    "chrome": "54",
+    "edge": "14",
+    "firefox": "47",
+    "safari": "10.1",
+    "node": "7",
+    "ios": "10.3",
+    "opera": "41",
+    "electron": "1.5"
+  },
+  "es7.object.get-own-property-descriptors": {
+    "chrome": "54",
+    "edge": "15",
+    "firefox": "50",
+    "safari": "10.1",
+    "node": "7",
+    "ios": "10.3",
+    "opera": "41",
+    "electron": "1.5"
+  },
+  "es7.string.pad-start": {
+    "chrome": "57",
+    "edge": "15",
+    "firefox": "48",
+    "safari": "10",
+    "node": "8",
+    "ios": "10",
+    "opera": "44",
+    "electron": "1.7"
+  },
+  "es7.string.pad-end": {
+    "chrome": "57",
+    "edge": "15",
+    "firefox": "48",
+    "safari": "10",
+    "node": "8",
+    "ios": "10",
+    "opera": "44",
+    "electron": "1.7"
+  },
+  "es7.promise.finally": {
+    "chrome": "63",
+    "opera": "50"
+  }
+}

experimental/babel-preset-env/data/plugin-features.js

@@ -0,0 +1,140 @@
+const es2015 = {
+  "check-es2015-constants": {
+    features: [
+      "const",
+    ],
+  },
+  "transform-es2015-arrow-functions": {
+    features: [
+      "arrow functions",
+    ],
+  },
+  "transform-es2015-block-scoped-functions": {
+    features: [
+      "block-level function declaration"
+    ],
+  },
+  "transform-es2015-block-scoping": {
+    features: [
+      "const",
+      "let",
+    ],
+  },
+  "transform-es2015-classes": {
+    features: [
+      "class",
+      "super",
+    ],
+  },
+  "transform-es2015-computed-properties": {
+    features: [
+      "object literal extensions / computed properties",
+    ],
+  },
+  "transform-es2015-destructuring": {
+    features: [
+      "destructuring, assignment",
+      "destructuring, declarations",
+      "destructuring, parameters",
+    ],
+  },
+  "transform-es2015-duplicate-keys": {
+    features: [
+      "miscellaneous / duplicate property names in strict mode",
+    ],
+  },
+  "transform-es2015-for-of": {
+    features: [
+      "for..of loops",
+    ],
+  },
+  "transform-es2015-function-name": {
+    features: [
+      "function \"name\" property",
+    ]
+  },
+  "transform-es2015-literals": {
+    features: [
+      "Unicode code point escapes",
+    ],
+  },
+  "transform-es2015-object-super": {
+    features: [
+      "super",
+    ],
+  },
+  "transform-es2015-parameters": {
+    features: [
+      "default function parameters",
+      "rest parameters",
+    ],
+  },
+  "transform-es2015-shorthand-properties": {
+    features: [
+      "object literal extensions / shorthand properties",
+    ],
+  },
+  "transform-es2015-spread": {
+    features: [
+      "spread (...) operator",
+    ],
+  },
+  "transform-es2015-sticky-regex": {
+    features: [
+      "RegExp \"y\" and \"u\" flags / \"y\" flag, lastIndex",
+      "RegExp \"y\" and \"u\" flags / \"y\" flag",
+    ],
+  },
+  "transform-es2015-template-literals": {
+    features: [
+      "template literals",
+    ],
+  },
+  "transform-es2015-typeof-symbol": {
+    features: [
+      "Symbol / typeof support"
+    ],
+  },
+  "transform-es2015-unicode-regex": {
+    features: [
+      "RegExp \"y\" and \"u\" flags / \"u\" flag, case folding",
+      "RegExp \"y\" and \"u\" flags / \"u\" flag, Unicode code point escapes",
+      "RegExp \"y\" and \"u\" flags / \"u\" flag",
+    ],
+  },
+  "transform-new-target": {
+    features: [
+      "new.target",
+    ],
+  },
+  "transform-regenerator": {
+    features: [
+      "generators",
+    ],
+  }
+};
+
+const es2016 = {
+  "transform-exponentiation-operator": {
+    features: [
+      "exponentiation (**) operator",
+    ],
+  }
+};
+
+const es2017 = {
+  "transform-async-to-generator": {
+    features: [
+      "async functions",
+    ],
+  },
+  "syntax-trailing-function-commas": {
+    features: [
+      "trailing commas in function syntax",
+    ],
+  }
+};
+
+const proposals = require("./shipped-proposals").features;
+
+module.exports = Object.assign({}, es2015, es2016, es2017, proposals);

experimental/babel-preset-env/data/plugins.json

@@ -0,0 +1,253 @@
+{
+  "check-es2015-constants": {
+    "chrome": "49",
+    "edge": "14",
+    "firefox": "51",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "transform-es2015-arrow-functions": {
+    "chrome": "47",
+    "edge": "13",
+    "firefox": "45",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "34",
+    "electron": "0.36"
+  },
+  "transform-es2015-block-scoped-functions": {
+    "chrome": "41",
+    "edge": "12",
+    "firefox": "46",
+    "safari": "10",
+    "node": "4",
+    "ie": "11",
+    "ios": "10",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "transform-es2015-block-scoping": {
+    "chrome": "49",
+    "edge": "14",
+    "firefox": "51",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "transform-es2015-classes": {
+    "chrome": "46",
+    "edge": "13",
+    "firefox": "45",
+    "safari": "10",
+    "node": "5",
+    "ios": "10",
+    "opera": "33",
+    "electron": "0.36"
+  },
+  "transform-es2015-computed-properties": {
+    "chrome": "44",
+    "edge": "12",
+    "firefox": "34",
+    "safari": "7.1",
+    "node": "4",
+    "ios": "8",
+    "opera": "31",
+    "electron": "0.31"
+  },
+  "transform-es2015-destructuring": {
+    "chrome": "51",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "transform-es2015-duplicate-keys": {
+    "chrome": "42",
+    "edge": "12",
+    "firefox": "34",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "29",
+    "electron": "0.27"
+  },
+  "transform-es2015-for-of": {
+    "chrome": "51",
+    "edge": "15",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "transform-es2015-function-name": {
+    "chrome": "51",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6.5",
+    "ios": "10",
+    "opera": "38",
+    "electron": "1.2"
+  },
+  "transform-es2015-literals": {
+    "chrome": "44",
+    "edge": "12",
+    "firefox": "53",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "31",
+    "electron": "0.31"
+  },
+  "transform-es2015-object-super": {
+    "chrome": "46",
+    "edge": "13",
+    "firefox": "45",
+    "safari": "10",
+    "node": "5",
+    "ios": "10",
+    "opera": "33",
+    "electron": "0.36"
+  },
+  "transform-es2015-parameters": {
+    "chrome": "49",
+    "edge": "14",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "transform-es2015-shorthand-properties": {
+    "chrome": "43",
+    "edge": "12",
+    "firefox": "33",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "30",
+    "electron": "0.29"
+  },
+  "transform-es2015-spread": {
+    "chrome": "46",
+    "edge": "13",
+    "firefox": "36",
+    "safari": "10",
+    "node": "5",
+    "ios": "10",
+    "opera": "33",
+    "electron": "0.36"
+  },
+  "transform-es2015-sticky-regex": {
+    "chrome": "49",
+    "edge": "13",
+    "firefox": "3",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "36",
+    "electron": "1"
+  },
+  "transform-es2015-template-literals": {
+    "chrome": "41",
+    "edge": "13",
+    "firefox": "34",
+    "safari": "9",
+    "node": "4",
+    "ios": "9",
+    "opera": "28",
+    "electron": "0.24"
+  },
+  "transform-es2015-typeof-symbol": {
+    "chrome": "38",
+    "edge": "12",
+    "firefox": "36",
+    "safari": "9",
+    "node": "0.12",
+    "ios": "9",
+    "opera": "25",
+    "electron": "0.2"
+  },
+  "transform-es2015-unicode-regex": {
+    "chrome": "50",
+    "edge": "13",
+    "firefox": "46",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "transform-new-target": {
+    "chrome": "46",
+    "edge": "14",
+    "firefox": "41",
+    "safari": "10",
+    "node": "5",
+    "ios": "10",
+    "opera": "33",
+    "electron": "0.36"
+  },
+  "transform-regenerator": {
+    "chrome": "50",
+    "edge": "13",
+    "firefox": "53",
+    "safari": "10",
+    "node": "6",
+    "ios": "10",
+    "opera": "37",
+    "electron": "1.1"
+  },
+  "transform-exponentiation-operator": {
+    "chrome": "52",
+    "edge": "14",
+    "firefox": "52",
+    "safari": "10.1",
+    "node": "7",
+    "ios": "10.3",
+    "opera": "39",
+    "electron": "1.3"
+  },
+  "transform-async-to-generator": {
+    "chrome": "55",
+    "edge": "15",
+    "firefox": "52",
+    "safari": "10.1",
+    "node": "7.6",
+    "ios": "10.3",
+    "opera": "42",
+    "electron": "1.6"
+  },
+  "syntax-trailing-function-commas": {
+    "chrome": "58",
+    "edge": "14",
+    "firefox": "52",
+    "safari": "10",
+    "node": "8",
+    "ios": "10",
+    "opera": "45",
+    "electron": "1.7"
+  },
+  "transform-async-generator-functions": {
+    "chrome": "63",
+    "opera": "50"
+  },
+  "transform-object-rest-spread": {
+    "chrome": "60",
+    "firefox": "55",
+    "node": "8.3",
+    "opera": "47"
+  },
+  "transform-optional-catch-binding": {},
+  "transform-unicode-property-regex": {}
+}

experimental/babel-preset-env/data/shipped-proposals.js

@@ -0,0 +1,22 @@
+// These mappings represent the builtin/feature proposals that have been
+// shipped by browsers, and are enabled by the `shippedProposals` option.
+
+const builtIns = {
+  "es7.promise.finally": "Promise.prototype.finally"
+};
+
+const features = {
+  "transform-async-generator-functions": "Asynchronous Iterators",
+  "transform-object-rest-spread": "object rest/spread properties",
+  "transform-optional-catch-binding": "optional catch binding",
+  "transform-unicode-property-regex": "RegExp Unicode Property Escapes",
+};
+
+const pluginSyntaxMap = new Map([
+  ["transform-async-generator-functions", "syntax-async-generators"],
+  ["transform-object-rest-spread", "syntax-object-rest-spread"],
+  ["transform-optional-catch-binding", "syntax-optional-catch-binding"],
+  ["transform-unicode-property-regex", null],
+]);
+
+module.exports = { builtIns, features, pluginSyntaxMap };

experimental/babel-preset-env/package.json

@@ -0,0 +1,59 @@
+{
+  "name": "babel-preset-env",
+  "version": "7.0.0-beta.3",
+  "description": "A Babel preset for each environment.",
+  "author": "Henry Zhu <hi@henryzoo.com>",
+  "homepage": "https://babeljs.io/",
+  "license": "MIT",
+  "repository": "https://github.com/babel/babel/tree/master/experimental/babel-preset-env",
+  "main": "lib/index.js",
+  "scripts": {
+    "build-data": "node ./scripts/build-data.js"
+  },
+  "dependencies": {
+    "babel-plugin-check-es2015-constants": "7.0.0-beta.3",
+    "babel-plugin-syntax-async-generators": "7.0.0-beta.3",
+    "babel-plugin-syntax-object-rest-spread": "7.0.0-beta.3",
+    "babel-plugin-syntax-optional-catch-binding": "7.0.0-beta.3",
+    "babel-plugin-syntax-trailing-function-commas": "7.0.0-beta.0",
+    "babel-plugin-transform-async-generator-functions": "7.0.0-beta.3",
+    "babel-plugin-transform-async-to-generator": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-arrow-functions": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-block-scoped-functions": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-block-scoping": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-classes": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-computed-properties": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-destructuring": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-duplicate-keys": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-for-of": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-function-name": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-literals": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-modules-amd": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-modules-commonjs": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-modules-systemjs": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-modules-umd": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-object-super": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-parameters": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-shorthand-properties": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-spread": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-sticky-regex": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-template-literals": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-typeof-symbol": "7.0.0-beta.3",
+    "babel-plugin-transform-es2015-unicode-regex": "7.0.0-beta.3",
+    "babel-plugin-transform-exponentiation-operator": "7.0.0-beta.3",
+    "babel-plugin-transform-new-target": "7.0.0-beta.3",
+    "babel-plugin-transform-object-rest-spread": "7.0.0-beta.3",
+    "babel-plugin-transform-optional-catch-binding": "7.0.0-beta.3",
+    "babel-plugin-transform-regenerator": "7.0.0-beta.3",
+    "babel-plugin-transform-unicode-property-regex": "^2.0.5",
+    "browserslist": "^2.4.0",
+    "invariant": "^2.2.2",
+    "semver": "^5.3.0"
+  },
+  "devDependencies": {
+    "babel-cli": "7.0.0-beta.3",
+    "babel-helper-fixtures": "7.0.0-beta.3",
+    "babel-helper-plugin-test-runner": "7.0.0-beta.3",
+    "compat-table": "kangax/compat-table#07dce174cc63f2b15b5f86b99cdfc89358dd072a"
+  }
+}

experimental/babel-preset-env/scripts/.eslintrc

@@ -0,0 +1,5 @@
+{
+    "rules": {
+      "prettier/prettier": ["error", { "trailingComma": "es5" }]
+    }
+  }

experimental/babel-preset-env/scripts/build-data.js

@@ -0,0 +1,287 @@
+"use strict";
+
+const fs = require("fs");
+const path = require("path");
+
+const flattenDeep = require("lodash/flattenDeep");
+const isEqual = require("lodash/isEqual");
+const mapValues = require("lodash/mapValues");
+const pickBy = require("lodash/pickBy");
+const electronToChromiumVersions = require("electron-to-chromium").versions;
+
+const electronToChromiumKeys = Object.keys(
+  electronToChromiumVersions
+).reverse();
+
+const chromiumToElectronMap = electronToChromiumKeys.reduce((all, electron) => {
+  all[electronToChromiumVersions[electron]] = +electron;
+  return all;
+}, {});
+const chromiumToElectronVersions = Object.keys(chromiumToElectronMap);
+
+const findClosestElectronVersion = targetVersion => {
+  const chromiumVersionsLength = chromiumToElectronVersions.length;
+  const maxChromium = +chromiumToElectronVersions[chromiumVersionsLength - 1];
+  if (targetVersion > maxChromium) return null;
+
+  const closestChrome = chromiumToElectronVersions.find(
+    version => targetVersion <= version
+  );
+  return chromiumToElectronMap[closestChrome];
+};
+
+const chromiumToElectron = chromium =>
+  chromiumToElectronMap[chromium] || findClosestElectronVersion(chromium);
+
+const renameTests = (tests, getName, category) =>
+  tests.map(test =>
+    Object.assign({}, test, { name: getName(test.name), category })
+  );
+
+// The following is adapted from compat-table:
+// https://github.com/kangax/compat-table/blob/gh-pages/build.js
+//
+// It parses and interpolates data so environments that "equal" other
+// environments (node4 and chrome45), as well as familial relationships (edge
+// and ie11) can be handled properly.
+
+const envs = require("compat-table/environments");
+
+const byTestSuite = suite => browser => {
+  return Array.isArray(browser.test_suites)
+    ? browser.test_suites.indexOf(suite) > -1
+    : true;
+};
+
+const compatSources = [
+  "es6",
+  "es2016plus",
+  "esnext",
+].reduce((result, source) => {
+  const data = require(`compat-table/data-${source}`);
+  data.browsers = pickBy(envs, byTestSuite(source));
+  result.push(data);
+  return result;
+}, []);
+
+const interpolateAllResults = (rawBrowsers, tests) => {
+  const interpolateResults = res => {
+    let browser;
+    let prevBrowser;
+    let result;
+    let prevResult;
+    let prevBid;
+
+    for (const bid in rawBrowsers) {
+      // For browsers that are essentially equal to other browsers,
+      // copy over the results.
+      browser = rawBrowsers[bid];
+      if (browser.equals && res[bid] === undefined) {
+        result = res[browser.equals];
+        res[bid] =
+          browser.ignore_flagged && result === "flagged" ? false : result;
+        // For each browser, check if the previous browser has the same
+        // browser full name (e.g. Firefox) or family name (e.g. Chakra) as this one.
+      } else if (
+        prevBrowser &&
+        (prevBrowser.full.replace(/,.+$/, "") ===
+          browser.full.replace(/,.+$/, "") ||
+          (browser.family !== undefined &&
+            prevBrowser.family === browser.family))
+      ) {
+        // For each test, check if the previous browser has a result
+        // that this browser lacks.
+        result = res[bid];
+        prevResult = res[prevBid];
+        if (prevResult !== undefined && result === undefined) {
+          res[bid] = prevResult;
+        }
+      }
+      prevBrowser = browser;
+      prevBid = bid;
+    }
+  };
+
+  // Now print the results.
+  tests.forEach(function(t) {
+    // Calculate the result totals for tests which consist solely of subtests.
+    if ("subtests" in t) {
+      t.subtests.forEach(function(e) {
+        interpolateResults(e.res);
+      });
+    } else {
+      interpolateResults(t.res);
+    }
+  });
+};
+
+compatSources.forEach(({ browsers, tests }) =>
+  interpolateAllResults(browsers, tests)
+);
+
+// End of compat-table code adaptation
+
+const environments = [
+  "chrome",
+  "opera",
+  "edge",
+  "firefox",
+  "safari",
+  "node",
+  "ie",
+  "android",
+  "ios",
+  "phantom",
+];
+
+const compatibilityTests = flattenDeep(
+  compatSources.map(data =>
+    data.tests.map(test => {
+      return test.subtests
+        ? [
+            test,
+            renameTests(
+              test.subtests,
+              name => test.name + " / " + name,
+              test.category
+            ),
+          ]
+        : test;
+    })
+  )
+);
+
+const getLowestImplementedVersion = ({ features }, env) => {
+  const tests = compatibilityTests
+    .filter(test => {
+      return (
+        features.indexOf(test.name) >= 0 ||
+        // for features === ["DataView"]
+        // it covers "DataView (Int8)" and "DataView (UInt8)"
+        (features.length === 1 && test.name.indexOf(features[0]) === 0)
+      );
+    })
+    .reduce((result, test) => {
+      const isBuiltIn =
+        test.category === "built-ins" ||
+        test.category === "built-in extensions";
+
+      if (!test.subtests) {
+        result.push({
+          name: test.name,
+          res: test.res,
+          isBuiltIn,
+        });
+      } else {
+        test.subtests.forEach(subtest =>
+          result.push({
+            name: `${test.name}/${subtest.name}`,
+            res: subtest.res,
+            isBuiltIn,
+          })
+        );
+      }
+
+      return result;
+    }, []);
+
+  const envTests = tests.map(({ res: test, isBuiltIn }, i) => {
+    // Babel itself doesn't implement the feature correctly,
+    // don't count against it
+    // only doing this for built-ins atm
+    if (!test.babel && isBuiltIn) {
+      return "-1";
+    }
+
+    return (
+      Object.keys(test)
+        .filter(t => t.startsWith(env))
+        // Babel assumes strict mode
+        .filter(
+          test => tests[i].res[test] === true || tests[i].res[test] === "strict"
+        )
+        // normalize some keys
+        .map(test => test.replace("_", "."))
+        .filter(test => !isNaN(parseFloat(test.replace(env, ""))))
+        .shift()
+    );
+  });
+
+  const envFiltered = envTests.filter(t => t);
+  if (envTests.length > envFiltered.length || envTests.length === 0) {
+    // envTests.forEach((test, i) => {
+    //   if (!test) {
+    //     // print unsupported features
+    //     if (env === 'node') {
+    //       console.log(`ENV(${env}): ${tests[i].name}`);
+    //     }
+    //   }
+    // });
+    return null;
+  }
+
+  return envTests.map(str => Number(str.replace(env, ""))).reduce((a, b) => {
+    return a < b ? b : a;
+  });
+};
+
+const generateData = (environments, features) => {
+  return mapValues(features, options => {
+    if (!options.features) {
+      options = {
+        features: [options],
+      };
+    }
+
+    const plugin = {};
+
+    environments.forEach(env => {
+      const version = getLowestImplementedVersion(options, env);
+
+      if (version !== null) {
+        plugin[env] = version.toString();
+      }
+    });
+
+    if (plugin.chrome) {
+      // add opera
+      if (plugin.chrome >= 28) {
+        plugin.opera = (plugin.chrome - 13).toString();
+      } else if (plugin.chrome === 5) {
+        plugin.opera = "12";
+      }
+
+      // add electron
+      const electronVersion = chromiumToElectron(plugin.chrome);
+      if (electronVersion) {
+        plugin.electron = electronVersion.toString();
+      }
+    }
+
+    return plugin;
+  });
+};
+
+["plugin", "built-in"].forEach(target => {
+  const newData = generateData(
+    environments,
+    require(`../data/${target}-features`)
+  );
+  const dataPath = path.join(__dirname, `../data/${target}s.json`);
+
+  if (process.argv[2] === "--check") {
+    const currentData = require(dataPath);
+
+    if (!isEqual(currentData, newData)) {
+      console.error(
+        "The newly generated plugin/built-in data does not match the current " +
+          "files. Re-run `npm run build-data`."
+      );
+      process.exit(1);
+    }
+
+    process.exit(0);
+  }
+
+  fs.writeFileSync(dataPath, `${JSON.stringify(newData, null, 2)}\n`);
+});

experimental/babel-preset-env/scripts/smoke-test.js

@@ -0,0 +1,111 @@
+const fs = require("fs-extra");
+const execSync = require("child_process").execSync;
+const path = require("path");
+const pkg = require("../package.json");
+
+let errorOccurred = false;
+
+const tempFolderPath = path.join(__dirname, "../tmp");
+const packPath = path.join(__dirname, `../babel-preset-env-${pkg.version}.tgz`);
+
+try {
+  console.log("Creating package");
+  execSync("npm pack");
+
+  console.log("Setting up smoke test dependencies");
+
+  fs.ensureDirSync(tempFolderPath);
+  process.chdir(tempFolderPath);
+
+  const babelCliVersion = pkg.devDependencies["babel-cli"];
+
+  if (!babelCliVersion) {
+    throw new Error("Could not read version of babel-cli from package.json");
+  }
+
+  fs.writeFileSync(
+    path.join(tempFolderPath, "package.json"),
+    `
+{
+  "name": "babel-preset-env-smoke-test",
+  "private": true,
+  "version": "1.0.0",
+  "scripts": {
+    "build": "babel index.js --out-file index.es6"
+  },
+  "dependencies": {
+    "babel-cli": "${babelCliVersion}",
+    "babel-preset-env": "${packPath}"
+  }
+}
+`
+  );
+
+  execSync("npm install");
+
+  console.log("Setting up 'usage' smoke test");
+
+  fs.writeFileSync(
+    path.join(tempFolderPath, ".babelrc"),
+    `
+{
+  "presets": [
+    ["env", {
+      modules: false,
+      useBuiltIns: "usage"
+    }]
+  ]
+}
+`
+  );
+
+  fs.writeFileSync(
+    path.join(tempFolderPath, "index.js"),
+    `
+const foo = new Promise((resolve) => {
+  resolve(new Map());
+});
+`
+  );
+
+  console.log("Running 'usage' smoke test");
+
+  execSync("npm run build");
+
+  console.log("Setting up 'entry' smoke test");
+
+  fs.writeFileSync(
+    path.join(tempFolderPath, ".babelrc"),
+    `
+{
+  "presets": [
+    ["env", {
+      modules: false,
+      useBuiltIns: "entry"
+    }]
+  ]
+}
+`
+  );
+
+  fs.writeFileSync(
+    path.join(tempFolderPath, "index.js"),
+    `
+import "babel-polyfill";
+1 ** 2;
+`
+  );
+
+  console.log("Running 'entry' smoke test");
+
+  execSync("npm run build");
+} catch (e) {
+  console.log(e);
+  errorOccurred = true;
+}
+
+console.log("Cleaning up");
+fs.removeSync(tempFolderPath);
+fs.removeSync(packPath);
+
+process.exit(errorOccurred ? 1 : 0);

experimental/babel-preset-env/src/available-plugins.js

@@ -0,0 +1,37 @@
+export default {
+  "check-es2015-constants": require("babel-plugin-check-es2015-constants"),
+  "syntax-async-generators": require("babel-plugin-syntax-async-generators"),
+  "syntax-object-rest-spread": require("babel-plugin-syntax-object-rest-spread"),
+  "syntax-optional-catch-binding": require("babel-plugin-syntax-optional-catch-binding"),
+  "syntax-trailing-function-commas": require("babel-plugin-syntax-trailing-function-commas"),
+  "transform-async-to-generator": require("babel-plugin-transform-async-to-generator"),
+  "transform-async-generator-functions": require("babel-plugin-transform-async-generator-functions"),
+  "transform-es2015-arrow-functions": require("babel-plugin-transform-es2015-arrow-functions"),
+  "transform-es2015-block-scoped-functions": require("babel-plugin-transform-es2015-block-scoped-functions"),
+  "transform-es2015-block-scoping": require("babel-plugin-transform-es2015-block-scoping"),
+  "transform-es2015-classes": require("babel-plugin-transform-es2015-classes"),
+  "transform-es2015-computed-properties": require("babel-plugin-transform-es2015-computed-properties"),
+  "transform-es2015-destructuring": require("babel-plugin-transform-es2015-destructuring"),
+  "transform-es2015-duplicate-keys": require("babel-plugin-transform-es2015-duplicate-keys"),
+  "transform-es2015-for-of": require("babel-plugin-transform-es2015-for-of"),
+  "transform-es2015-function-name": require("babel-plugin-transform-es2015-function-name"),
+  "transform-es2015-literals": require("babel-plugin-transform-es2015-literals"),
+  "transform-es2015-modules-amd": require("babel-plugin-transform-es2015-modules-amd"),
+  "transform-es2015-modules-commonjs": require("babel-plugin-transform-es2015-modules-commonjs"),
+  "transform-es2015-modules-systemjs": require("babel-plugin-transform-es2015-modules-systemjs"),
+  "transform-es2015-modules-umd": require("babel-plugin-transform-es2015-modules-umd"),
+  "transform-es2015-object-super": require("babel-plugin-transform-es2015-object-super"),
+  "transform-es2015-parameters": require("babel-plugin-transform-es2015-parameters"),
+  "transform-es2015-shorthand-properties": require("babel-plugin-transform-es2015-shorthand-properties"),
+  "transform-es2015-spread": require("babel-plugin-transform-es2015-spread"),
+  "transform-es2015-sticky-regex": require("babel-plugin-transform-es2015-sticky-regex"),
+  "transform-es2015-template-literals": require("babel-plugin-transform-es2015-template-literals"),
+  "transform-es2015-typeof-symbol": require("babel-plugin-transform-es2015-typeof-symbol"),
+  "transform-es2015-unicode-regex": require("babel-plugin-transform-es2015-unicode-regex"),
+  "transform-exponentiation-operator": require("babel-plugin-transform-exponentiation-operator"),
+  "transform-new-target": require("babel-plugin-transform-new-target"),
+  "transform-object-rest-spread": require("babel-plugin-transform-object-rest-spread"),
+  "transform-optional-catch-binding": require("babel-plugin-transform-optional-catch-binding"),
+  "transform-regenerator": require("babel-plugin-transform-regenerator"),
+  "transform-unicode-property-regex": require("babel-plugin-transform-unicode-property-regex"),
+};

experimental/babel-preset-env/src/built-in-definitions.js

@@ -0,0 +1,109 @@
+// TODO: this is the opposite of built-in-features so maybe generate one from the other?
+export const definitions = {
+  builtins: {
+    DataView: "es6.typed.data-view",
+    Int8Array: "es6.typed.int8-array",
+    Uint8Array: "es6.typed.uint8-array",
+    Uint8ClampedArray: "es6.typed.uint8-clamped-array",
+    Int16Array: "es6.typed.int16-array",
+    Uint16Array: "es6.typed.uint16-array",
+    Int32Array: "es6.typed.int32-array",
+    Uint32Array: "es6.typed.uint32-array",
+    Float32Array: "es6.typed.float32-array",
+    Float64Array: "es6.typed.float64-array",
+    Map: "es6.map",
+    Set: "es6.set",
+    WeakMap: "es6.weak-map",
+    WeakSet: "es6.weak-set",
+    Promise: "es6.promise",
+    Symbol: "es6.symbol",
+  },
+
+  instanceMethods: {
+    name: ["es6.function.name"],
+    fromCodePoint: ["es6.string.from-code-point"],
+    codePointAt: ["es6.string.code-point-at"],
+    repeat: ["es6.string.repeat"],
+    startsWith: ["es6.string.starts-with"],
+    endsWith: ["es6.string.ends-with"],
+    includes: ["es6.string.includes", "es7.array.includes"],
+    flags: ["es6.regexp.flags"],
+    match: ["es6.regexp.match"],
+    replace: ["es6.regexp.replace"],
+    split: ["es6.regexp.split"],
+    search: ["es6.regexp.search"],
+    copyWithin: ["es6.array.copy-within"],
+    find: ["es6.array.find"],
+    findIndex: ["es6.array.find-index"],
+    fill: ["es6.array.fill"],
+    padStart: ["es7.string.pad-start"],
+    padEnd: ["es7.string.pad-end"],
+  },
+
+  staticMethods: {
+    Array: {
+      from: "es6.array.from",
+      of: "es6.array.of",
+    },
+
+    Object: {
+      assign: "es6.object.assign",
+      is: "es6.object.is",
+      getOwnPropertySymbols: "es6.object.get-own-property-symbols",
+      setPrototypeOf: "es6.object.set-prototype-of",
+      values: "es7.object.values",
+      entries: "es7.object.entries",
+      getOwnPropertyDescriptors: "es7.object.get-own-property-descriptors",
+    },
+
+    Math: {
+      acosh: "es6.math.acosh",
+      asinh: "es6.math.asinh",
+      atanh: "es6.math.atanh",
+      cbrt: "es6.math.cbrt",
+      clz32: "es6.math.clz32",
+      cosh: "es6.math.cosh",
+      expm1: "es6.math.expm1",
+      fround: "es6.math.fround",
+      hypot: "es6.math.hypot",
+      imul: "es6.math.imul",
+      log1p: "es6.math.log1p",
+      log10: "es6.math.log10",
+      log2: "es6.math.log2",
+      sign: "es6.math.sign",
+      sinh: "es6.math.sinh",
+      tanh: "es6.math.tanh",
+      trunc: "es6.math.trunc",
+    },
+
+    String: {
+      raw: "es6.string.raw",
+    },
+
+    Number: {
+      isFinite: "es6.number.is-finite",
+      isInteger: "es6.number.is-integer",
+      isSafeInteger: "es6.number.is-safe-integer",
+      isNaN: "es6.number.is-nan",
+      EPSILON: "es6.number.epsilon",
+      MIN_SAFE_INTEGER: "es6.number.min-safe-integer",
+      MAX_SAFE_INTEGER: "es6.number.max-safe-integer",
+    },
+
+    Reflect: {
+      apply: "es6.reflect.apply",
+      construct: "es6.reflect.construct",
+      defineProperty: "es6.reflect.define-property",
+      deleteProperty: "es6.reflect.delete-property",
+      get: "es6.reflect.get",
+      getOwnPropertyDescriptor: "es6.reflect.get-own-property-descriptor",
+      getPrototypeOf: "es6.reflect.get-prototype-of",
+      has: "es6.reflect.has",
+      isExtensible: "es6.reflect.is-extensible",
+      ownKeys: "es6.reflect.own-keys",
+      preventExtensions: "es6.reflect.prevent-extensions",
+      set: "es6.reflect.set",
+      setPrototypeOf: "es6.reflect.set-prototype-of",
+    },
+  },
+};