v7.7.0

* perf: remove this.inList assignment

* perf: convert NodePath.parentKey into accessor function

* perf: compress shouldSkip/shouldStop/removed traverse flags

* perf: lazy initialize this.skipKeys

* perf: lazily initialize NodePath.data

* add code comments before bit operations

* remove unused typeAnnotation property

# Conflicts:
#	packages/babel-traverse/src/path/index.js

* early return when visitor keys are empty

.babelrc

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

.circleci/config.yml

@@ -0,0 +1,121 @@
+version: 2
+aliases:
+  - &restore-node-modules-cache
+    keys:
+      - v1-yarn-deps-{{ checksum "yarn.lock" }}
+
+  - &restore-yarn-cache
+    keys:
+      - v1-yarn-cache
+
+  - &save-node-modules-cache
+    paths:
+      - node_modules
+    key: v1-yarn-deps-{{ checksum "yarn.lock" }}
+
+  - &save-yarn-cache
+    paths:
+      - ~/.yarn-cache
+    key: v1-yarn-cache
+
+  - &artifact_babel
+    path: ~/babel/packages/babel-standalone/babel.js
+
+  - &artifact_babel_min
+    path: ~/babel/packages/babel-standalone/babel.min.js
+
+  - &artifact_env
+    path: ~/babel/packages/babel-preset-env-standalone/babel-preset-env.js
+
+  - &artifact_env_min
+    path: ~/babel/packages/babel-preset-env-standalone/babel-preset-env.min.js
+
+  - &test262_workdir
+    working_directory: ~/babel/babel-test262-runner
+
+  - &artifact_test262_tap
+    path: ~/test262.tap
+
+  - &artifact_test262_xunit
+    path: ~/test-results
+
+jobs:
+  test:
+    working_directory: ~/babel
+    docker:
+      - image: circleci/node:13
+    steps:
+      - checkout
+      - restore-cache: *restore-yarn-cache
+      - restore-cache: *restore-node-modules-cache
+      - run: yarn --version
+      - run: make test-ci-coverage
+      # Builds babel-standalone with the regular Babel config
+      - run: IS_PUBLISH=true 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.
+      - run: ./node_modules/.bin/jest packages/babel-standalone/test/
+      - run: ./node_modules/.bin/jest packages/babel-preset-env-standalone/test/
+      - store_artifacts: *artifact_babel
+      - store_artifacts: *artifact_babel_min
+      - store_artifacts: *artifact_env
+      - store_artifacts: *artifact_env_min
+      - save_cache: *save-node-modules-cache
+      - save_cache: *save-yarn-cache
+  test262:
+    working_directory: ~/babel
+    docker:
+      - image: circleci/node:12
+    steps:
+      - checkout
+      - restore-cache: *restore-yarn-cache
+      - restore-cache: *restore-node-modules-cache
+      - run:
+          name: Build Babel
+          command: BABEL_ENV=test make bootstrap
+      - run:
+          name: Link Babel
+          command: |
+            cd packages
+            for package in */; do
+              cd $package
+              yarn link
+              cd ..
+            done
+      - run:
+          name: Setup Test Runner
+          command: |
+            git clone --recurse-submodules https://github.com/babel/babel-test262-runner
+            cd babel-test262-runner
+            yarn
+            yarn add tap-mocha-reporter --dev
+            curl -L https://github.com/stedolan/jq/releases/download/jq-1.5/jq-linux64 > jq
+            chmod +x ./jq
+            for package in ../packages/*/package.json; do
+              yarn link $(./jq -j ".name" $package)
+            done
+            node lib/download-node
+      - run:
+          name: Run Test262
+          command: node lib/run-tests I_AM_SURE | tee ~/test262.tap
+          <<: *test262_workdir
+      - store_artifacts: *artifact_test262_tap
+      - run:
+          name: Output test262 results
+          command: |
+            cat ~/test262.tap | $(npm bin)/tap-mocha-reporter spec || true
+          <<: *test262_workdir
+
+workflows:
+  version: 2
+  test:
+    jobs:
+      - test
+  master:
+    jobs:
+      - test262:
+          filters:
+            branches:
+              only:
+                - master

.editorconfig

@@ -6,6 +6,12 @@ charset = utf-8
 trim_trailing_whitespace = true
 end_of_line = lf
 
-[*.{js,json}]
+[*.{js,json,ts,tsx}]
 indent_style = space
 indent_size = 2
+
+[Makefile]
+indent_style = tab
+
+[*.{md,markdown}]
+trim_trailing_whitespace = false

.eslintignore

@@ -1 +1,26 @@
-src/babel/transformation/templates
+/lib
+/build
+/.git
+package.json
+lerna.json
+packages/babel-runtime
+!packages/babel-plugin-transform-runtime/scripts
+packages/babel-runtime-corejs2
+packages/babel-runtime-corejs3
+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
+packages/babel-preset-env/data
+packages/babel-preset-env/test/debug-fixtures
+packages/babel-preset-env-standalone/babel-preset-env.js
+packages/babel-preset-env-standalone/babel-preset-env.min.js
+packages/babel-standalone/babel.js
+packages/babel-standalone/babel.min.js
+packages/babel-parser/test/expressions

.eslintrc

@@ -1,22 +0,0 @@
-{
-  "parser": "babel-eslint",
-  "rules": {
-    "strict": 0,
-    "no-underscore-dangle": 0,
-    "no-unused-vars": 0,
-    "curly": 0,
-    "no-multi-spaces": 0,
-    "key-spacing": 0,
-    "no-return-assign": 0,
-    "consistent-return": 0,
-    "no-shadow": 0,
-    "no-comma-dangle": 0,
-    "no-use-before-define": 0,
-    "no-empty": 0,
-    "new-parens": 0,
-    "no-cond-assign": 0
-  },
-  "env": {
-    "node": true
-  }
-}

.eslintrc.json

@@ -0,0 +1,41 @@
+{
+  "root": true,
+  "plugins": ["prettier", "@babel/development", "import"],
+  "extends": "babel",
+  "rules": {
+    "prettier/prettier": "error"
+  },
+  "env": {
+    "node": true
+  },
+  "overrides": [
+    {
+      "files": ["packages/*/src/**/*.js", "codemods/*/src/**/*.js"],
+      "rules": {
+        "@babel/development/no-undefined-identifier": "error",
+        "@babel/development/no-deprecated-clone": "error",
+        "import/no-extraneous-dependencies": "error",
+        "guard-for-in": "error"
+      }
+    },
+    {
+      "files": [
+        "packages/*/test/**/*.js",
+        "codemods/*/test/**/*.js",
+        "packages/babel-helper-transform-fixture-test-runner/src/helpers.js",
+        "test/**/*.js"
+      ],
+      "env": {
+        "jest": true
+      }
+    },
+    {
+      "files": ["packages/babel-plugin-*/src/index.js"],
+      "excludedFiles": ["packages/babel-plugin-transform-regenerator/**/*.js"],
+      "rules": {
+        "@babel/development/plugin-name": "error",
+        "eqeqeq": ["error", "always", { "null": "ignore" }]
+      }
+    }
+  ]
+}

.flowconfig

@@ -0,0 +1,29 @@
+[ignore]
+<PROJECT_ROOT>/build/.*
+<PROJECT_ROOT>/packages/.*/lib
+<PROJECT_ROOT>/packages/.*/test
+<PROJECT_ROOT>/codemods/.*/lib
+<PROJECT_ROOT>/codemods/.*/test
+<PROJECT_ROOT>/node_modules/module-deps/
+
+[include]
+packages/*/src
+codemods/*/src
+
+[libs]
+lib/file.js
+lib/parser.js
+lib/third-party-libs.js.flow
+packages/babel-types/lib/index.js.flow
+
+[options]
+include_warnings=true
+suppress_comment= \\(.\\|\n\\)*\\$FlowFixMe
+suppress_comment= \\(.\\|\n\\)*\\$FlowIssue
+suppress_comment= \\(.\\|\n\\)*\\$FlowIgnore
+suppress_type=$FlowFixMe
+suppress_type=$FlowSubtype
+esproposal.export_star_as=enable
+esproposal.optional_chaining=enable
+esproposal.nullish_coalescing=enable
+module.name_mapper='^@babel\/\([a-zA-Z0-9_\-]+\)$' -> '<PROJECT_ROOT>/packages/babel-\1/src/index'

.gitattributes

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

.github/CHANGELO-preset-env-v0-v1.md

@@ -0,0 +1,668 @@
+# Changelog
+
+## v1.6.1 (2017-10-17)
+
+### :bug: Bug Fix
+
+- Update compat table to fix two small issues ([#445](https://github.com/babel/babel-preset-env/pull/445)) (@danez)
+
+ES2015 destructuring is not fully supported in Edge 15 and the polyfill required again. `es6.math.imul` is supported on Android as of version 4.4
+
+- Add polyfills for ES6 static Object methods ([#441](https://github.com/babel/babel-preset-env/pull/441)) (@danez)
+
+Functions such as `Object.keys`, `Object.freeze`, ... do already exist in ES5, but their behaviour changed in ES2015. `babel-preset-env` with `builtIns: true` now adds the core-js polyfills for this methods if the browser only supports the ES5 variant of the method (like IE11 for example)
+
+- Normalize module format of plugins/built-ins data ([#376](https://github.com/babel/babel-preset-env/pull/376)) (@rtsao)
+
+## 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/experimental/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/experimental/babel-preset-env/blob/master/data/plugin-features.js) and [/data/built-in-features.js](https://github.com/babel/experimental/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/experimental/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)

.github/CHANGELOG-6to5.md

@@ -84,7 +84,7 @@
   * More performance improvements.
   * Parsing is now ~30% faster thanks to [marijnh/acorn@7264bc0178e7e6af7cfe02e9e0c6b26ee0e6007f](https://github.com/marijnh/acorn/commit/7264bc0178e7e6af7cfe02e9e0c6b26ee0e6007f).
  * **New Feature**
-  * Optional `es6.blockScopingTDZ` is now completely functional and handles all edgecases.
+  * Optional `es6.blockScopingTDZ` is now completely functional and handles all edge cases.
   * `super` in object literals.
   * Tail call optimisation. Thanks [@RReverser](https://github.com/RReverser)!
 
@@ -122,7 +122,7 @@
   * Restructure transformers so they're only ran if the AST contains nodes that they need to worry about. Improves transpilation speed significantly.
  * **Bug Fix**
   * Fix source maps not tracking end of node locations.
- * **Spec Compliancy**
+ * **Spec Compliance**
   * Use static super references as the home object is actually done at definition time.
  * **Polish**
   * Force the `es6.destructuring` transformer to be whitelisted when the `es7.objectSpread` transformer is.
@@ -474,12 +474,12 @@
  * **Polish**
   * Rest parameters now allocate the array before populating.
  * **Internal**
-  * `for...in` loops have been changed to optimized `for` loops - better performance and no enumeration of protoype keys.
+  * `for...in` loops have been changed to optimized `for` loops - better performance and no enumeration of prototype keys.
   * Parts of the code generator have now been optimized thanks to [gaearon](https://github.com/gaearon).
 
 ## 2.12.3
 
- * **Spec Compliancy**
+ * **Spec Compliance**
   * Optional `typeof` transformer checks for `undefined` before passing it to the helper.
   * Class methods are now named.
 
@@ -551,7 +551,7 @@
   * Add `classesFastSuper` optional transformer that doesn't support parent getters and prototype changing.
   * Add `forOfFast` transformer that speeds up `for...of` on arrays but produces more code.
   * Add `--react-compat` to `bin/6to5`.
- * **Spec Compliancy**
+ * **Spec Compliance**
   * Disallow setters without a single parameter.
   * Add `configurable` and `writable` to defined properties.
   * Use define instead of assignment for class methods.
@@ -619,7 +619,7 @@
 
 ## 2.7.0
 
- * **Spec Compliancy**
+ * **Spec Compliance**
   * Disallow reassignments of imports.
  * **New Feature**
   * `reactCompat` option to enable pre-v0.12 react components.
@@ -643,7 +643,7 @@
 
  * **Bug Fix**
   * Better handling of number literal property keys.
-  * Handle `NewExpression` paren insertion edegcases better.
+  * Handle `NewExpression` paren insertion edge cases better.
  * **Internal**
   * Fix incorrect AST node `identifier("this")`.
   * Better `toIdentifier` method that handles reserved words.
@@ -662,7 +662,7 @@
  * **Polish**
   * Move `"use strict";` to inside module bodies instead of at the top of the file.
   * Better handling of dynamic imports.
- * **Spec Compliancy**
+ * **Spec Compliance**
   * Class inheritance now has a `function` or `null` type check.
   * Add `interopRequireWildcard` around wildcard imports and exports to handle non-object exports.
 
@@ -850,7 +850,7 @@
 
 ## 1.14.10
 
- * Fix let scoping unneccesary override.
+ * Fix let scoping unnecessary override.
 
 ## 1.14.6
 
@@ -973,7 +973,7 @@
 
 ## 1.12.21
 
- * Fix unneccesary let scoping replacement.
+ * Fix unnecessary let scoping replacement.
  * Add `commonInterop` module formatter. Thanks [@Naddiseo](https://github.com/Naddiseo).
  * Fix `return` outside of function body bug. Thanks [@brentburg](https://github.com/brentburg).
  * Add more flexible option types.
@@ -1020,7 +1020,7 @@
 
 ## 1.12.12
 
- * Make scope tracker more reliable to handle all edgecases.
+ * Make scope tracker more reliable to handle all edge cases.
 
 ## 1.12.11
 

.github/CHANGELOG-v4.md

@@ -0,0 +1,287 @@
+# Babel v4 Changelog
+
+## 4.7.16
+
+ * **Bug Fix**
+  * Fix constructor spreading of typed arrays.
+  * Fix break/continue/return aliasing of non-loops in block scoping transformer.
+
+## 4.7.15
+
+ * **Bug Fix**
+  * Fix constructor spreading of collections.
+
+## 4.7.14
+
+ * **Bug Fix**
+  * Fix constructor spreading of `Promise`.
+ * **Internal**
+  * Deprecate remaining playground transformers and abstract references.
+
+## 4.7.13
+
+ * **Bug Fix**
+  * Handle comments on use strict directives.
+  * Fix assignment patterns with a left side pattern.
+ * **Polish**
+  * Special case `this` when doing expression memoisation.
+
+## 4.7.12
+
+ * **Bug Fix**
+  * Deprecate `playground.methodBinding`.
+
+## 4.7.11
+
+ * **Bug Fix**
+  * Fix unicode regexes stripping their unicode flag before being passed on two `regexpu`.
+
+## 4.7.10
+
+ * **Internal**
+  * Deprecate `playground.methodBinding` and `playground.objectGetterMemoization`.
+ * **Bug Fix**
+  * Fix `inputSourceMap` option. Thanks [@Rich-Harris](https://github.com/Rich-Harris)!
+
+## 4.7.9
+
+ * **Polish**
+  * Allow `inputSourceMap` to be set to `false` to skip the source map inference.
+  * Infer computed literal property names.
+ * **Bug Fix**
+  * Fix nested labeled for-ofs.
+  * Fix block scoping `break` colliding with the parent switch case.
+ * **Internal**
+  * Upgrade `acorn-babel`.
+
+## 4.7.8
+
+ * **Bug Fix**
+  * Fix computed classes not properly setting symbols.
+
+## 4.7.7
+
+ * **Bug Fix**
+  * Fix `types` API exposure.
+
+## 4.7.6
+
+ * **Bug Fix**
+  * Fix non-Identifier/Literal computed class methods.
+ * **Polish**
+  * Add a fallback if `stack` on an error is unconfigurable.
+  * Hoist `esModule` module declarations to the top of the file to handle circular dependencies better.
+
+## 4.7.5
+
+ * **Bug Fix**
+  * Don't remap` break`s to call the iterator return.
+ * **Polish**
+  * Use a different helper for computed classes for much nicer output. Also fixes a bug in symbols being non-enumerable so they wouldn't be set on the class.
+
+## 4.7.4
+
+ * **Bug Fix**
+  * Rewrite named function expressions in optional async function transformers.
+  * Hoist directives.
+  * Remove `Number` from the list of valid `runtime` constructors.
+ * **Internal**
+  * `spec.typeofSymbol` transformer has been renamed to `es6.symbols`.
+
+## 4.7.2
+
+ * **New Feature**
+  * `"both"` option for `sourceMap`.
+  * Add output types to external helpers. Thanks [@neVERberleRfellerER](https://github.com/neVERberleRfellerER)!
+ * **Bug Fix**
+  * Fix node duplication sometimes resulting in a recursion error.
+  * Ignore `break`s within cases inside `for...of`.
+ * **Polish**
+  * Split up variable declarations and export declarations to allow easier transformation.
+
+## 4.7.0
+
+ * **Bug Fix**
+  * Add `alternate` to list of `STATEMENT_OR_BLOCK` keys.
+  * Add support for module specifiers to `t.isReferenced`.
+ * **New Feature**
+  * Add `inputSourceMap` option.
+ * **Polish**
+  * Throw an error on different `babel` and `babel-runtime` versions.
+  * Replicate module environment for `babel-node` eval.
+  * Clean up classes output.
+ * **Spec Compliance**
+  * Make it illegal to use a rest parameter on a setter.
+
+## 4.6.6
+
+ * **Bug Fix**
+  * Fix incorrect method call in `utility.deadCodeElimination` transformer.
+  * Fix `es6.blockScopingTDZ` transformer duplicating binding nodes.
+
+## 4.6.5
+
+ * **Internal**
+  * `useStrict` transformer has been renamed to `strict`.
+
+## 4.6.4
+
+ * **Bug Fix**
+  * Fix `ForOfStatement` not properly inheriting labels.
+  * When in closure mode in block scoping transformer, properly check for variable shadowing.
+ * **New Feature**
+  * New `utility.inlineEnvironmentVariables` and `utility.inlineExpression` transformers.
+
+## 4.6.3
+
+ * **Bug Fix**
+  * Fix `arguments` being incorrectly aliased in arrow function rest parameter optimisation.
+  * Make deoptimisation trigger safer.
+ * **New Feature**
+  * Flow types are now retained when blacklisting the `flow` transformer.
+
+## 4.6.1
+
+ * **Bug Fix**
+  * Fix generators in template directory being transformed.
+  * Fix exposure of `util` for plugins.
+
+## 4.6.0
+
+ * **New Feature**
+  * Desugar sticky regexes to a new constructor expression so it can be handled by a polyfill.
+ * **Spec Compliance**
+  * `for...of` now outputs in a lengthy `try...catch` this is to ensure spec compliance in regards to iterator returns and abrupt completions. See [google/traceur-compiler#1773](https://github.com/google/traceur-compiler/issues/1773) and [babel/babel/#838](https://github.com/babel/babel/issues/838) for more information.
+ * **Polish**
+  * Rest parameters that are only referred to via number properties on member expressions are desugared into a direct `arguments` reference. Thanks [@neVERberleRfellerER](https://github.com/neVERberleRfellerER)!
+  * `$ babel` no longer exits on syntax errors.
+ * **Internal**
+  * Upgrade `browserify`.
+  * Upgrade `source-map`.
+  * Publicly expose more internals.
+
+## 4.5.5
+
+ * **Polish**
+  * Delete old extensions when overriding them in `babel/register`.
+
+## 4.5.3
+
+ * **Bug Fix**
+  * Fix whitelisting logic for helper build script.
+
+## 4.5.2
+
+ * **New Feature**
+  * `returnUsedHelpers` option and add whitelist to `buildHelpers`.
+ * **Bug Fix**
+  * Fix function arity on self referencing inferred named functions.
+ * **Internal**
+  * Bump `acorn-babel`.
+  * Start converting source to ES6...
+
+## 4.5.1
+
+**Babel now compiles itself!**
+
+![holy shit](http://gifsec.com/wp-content/uploads/GIF/2014/03/OMG-GIF_2.gif)
+
+## 4.5.0
+
+ * **New Feature**
+  * Add `.babelrc` support.
+ * **Bug Fix**
+  * Move use strict directives to the module formatter bodies.
+ * **Internal**
+  * Make default `bin/babel` behaviour to ignore non-compilable files and add a `--copy-files` flag to revert to the old behaviour.
+
+## 4.4.6
+
+ * **Bug Fix**
+  * Fix extending a class expression with no methods/only constructor. Thanks [@neVERberleRfellerER](https://github.com/neVERberleRfellerER)!
+  * Allow `MemberExpression` as a valid `left` of `ForOfStatement`.
+ * **Polish**
+  * Throw an error when people try and transpile code with the `@jsx React.DOM` pragma as it conflicts with the custom jsx constructo method detection.
+  * Crawl all comments for `@jsx` pragma.
+ * **Internal**
+  * Upgrade `chalk`.
+  * Upgrade `core-js`.
+
+## 4.4.5
+
+ * **Internal**
+  * Remove function self reference optimisation.
+
+## 4.4.4
+
+ * **Bug Fix**
+  * Handle inferred function ids to be reassigned and deopt to a slower but working equivalent.
+  * Don't unpack array patterns that have more elements than their right hand array expression.
+ * **Polish**
+  * Improve syntax highlighting in the code frame. Thanks [@lydell](https://github.com/lydell)!
+ * **Internal**
+  * Upgrade `acorn-babel`.
+
+## 4.4.3
+
+ * **Bug Fix**
+  * Fix `for...of` iterator break returns being duplicated.
+  * Only call `return` on the iterator if it exists.
+ * **Internal**
+  * Rename `selfContained` transformer to `runtime`.
+
+## 4.4.2
+
+ * **New Feature**
+  * Add `moduleId` option for specifying a custom module id.
+
+## 4.4.0
+
+ * **New Feature**
+  * `/*** @jsx NAMESPACE **/` comments are now honored by the `react` transformer.
+  * `getModuleName` option.
+  * Infer function expression names. Thanks [@RReverser](https://github.com/RReverser)!
+ * **Bug Fix**
+  * Add proper control flow for tail recursion optimisation.
+ * **Internal**
+  * Remove useless `format` options and move the `format.compact` option to `format`.
+ * **Polish**
+  * Newline handling of the code generator has been heavily improved.
+  * Code generator now deopts whitespace if the input size is >100KB.
+
+## 4.3.0
+
+ * **Breaking Change**
+  * Remove `commonStandard` module formatter and make it the default behaviour of all the strict module formatters.
+
+## 4.2.1
+
+ * **Polish**
+  * Add auxiliary comment to let scoping closure flow control.
+
+## 4.2.0
+
+ * **Polish**
+  * Use an assignment instead of a define for `__esModule` in loose mode.
+ * **Internal**
+  * Add error for `eval();` usage and enable strict mode for parsing.
+
+## 4.1.0
+
+ * **New Feature**
+  * Add `BABEL_CACHE_PATH` and `BABEL_DISABLE_CACHE` environment variables.
+ * **Internal**
+  * Replace many internal util functions with modules. Thanks [@sindresorhus](https://github.com/sindresorhus)!
+
+## 4.0.2
+
+ * **Bug Fix**
+  * Fix generators not properly propagating their internal declarations.
+ * **Polish**
+  * Update setter param length error message.
+  * Use ranges on dependencies.
+
+## 4.0.0
+
+ * 6to5 is now known as Babel.
+ * Global helpers/runtime has now been given the more descriptive name of "external helpers".

.github/CHANGELOG-v5.md

@@ -0,0 +1,838 @@
+# Babel v5 Changelog
+
+## 5.8.26
+
+ * **Internal**
+  * Republish to get fix for runtime `typeof-react-element` helper.
+
+## 5.8.25
+
+ * **Internal**
+  * Rename `define` method to avoid webpack assuming those files are AMD.
+
+## 5.8.24
+
+ * **Spec Compliance**
+  * Updated `optimisation.react.inlineElements` transformer to React 0.14 output. Thanks [@spicyj](https://github.com/spicyj)!
+ * **Polish**
+  * Add support for evaluating more static nodes. Thanks [@hzoo](https://github.com/hzoo)!
+
+## 5.8.23
+
+ * **Bug Fix**
+  * Fix a bug where pushed scope bindings weren't properly being registered.
+
+## 5.8.22
+
+ * **Bug Fix**
+  * Fix bug causing regexes to cause a syntax error after a block.
+ * **Internal**
+  * Expose `File`.
+
+## 5.8.21
+
+ * **New Feature**
+  * Add support for Flow export types.
+ * **Bug Fix**
+  * Fix flow type annotations on object properties being lost.
+  * Fix bug effecting nested arrow functions.
+  * Check valid `export default` `function`/`class` token when parsing export default before converting to a declaration to avoid turning expressions into declarations.
+ * **Polish**
+  * Add an exception to non-existent bindings when checking if we need to wrap block scoping blocks in a closure.
+  * Make comment retainment for multiple replacement nodes more predictable.
+ * **Internal**
+  * Remove `operator` property from `AssignmentPattern` nodes.
+  * Update `es7.asyncFunctions` and `es7.objectRestSpread` to stage 2.
+
+## 5.8.13-5.8.20
+
+**The CHANGELOG was broken for these releases. Git tags were not pushed in the correct order and are therefore incorrect. It's recommended you NOT use any versions within this range.**
+
+ * **New Feature**
+  * Add `es6.spec.modules` transformer.
+ * **Bug Fix**
+  * Don't register export declarations as a module binding.
+  * Register import bindings to the specifier instead of the declaration.
+  * `export *` should not export `default`.
+  * Clear `rawValue from JSX attribute values to avoid outputting the raw source verbatim.
+  * Add support for boolean flow literals.
+  * Fix bug where files that babel can compile weren't being written when ignored with the `--copy-files` flag.
+  * Create new raw identifiers instead of cloning the original user one when exploding export specifiers to fix source map issues resulting in incorrect locations.
+  * Break on hitting a terminator paren triggering character to avoid pushing multiple starting parens.
+  * Consider comment starting character to be a terminatorless separator to avoid starting comments breaking terminatorless nodes.
+ * **Internal**
+  * Use `json5` for parsing `.babelrc` files and `JSON` for `package.json`.
+  * Update Regenerator dependency to `0.8.35`.
+  * Remove flow types from being scope tracked.
+ * **Polish**
+  * Only register export declarations in scope tracking if they're of a valid type.
+  * Only output code frame and message on syntax errors in CLI.
+  * Set decorated initialisers that have no `initialiser` to `undefined`.
+  * Optimise common `typeof` cases in `es6.spec.symbols` transformer.
+
+## 5.8.12
+
+ * **Bug Fix**
+  * Fix bug in lookahead causing decorators to be cleared.
+
+## 5.8.11
+
+ * **Bug Fix**
+  * Check if module options are nully instead of falsy to allow empty strings as `moduleRoot` etc.
+  * Fix bug where reassigning the rest parameter wouldn't result in a deoptimisation.
+
+## 5.8.9
+
+ * **Bug Fix**
+  * Fix issue in parser where the flow plugin wasn't using state to refer to whether it as in a type or not causing lookaheads to cause breakages.
+
+## 5.8.8
+
+ * **Bug Fix**
+  * Fix comments not being attached if they're touching the start of their node.
+
+## 5.8.7
+
+ * Never published, environment issues, again.
+
+## 5.8.6
+
+ * **Bug Fix**
+  * Remove `rawValue` for JSX inner text.
+
+## 5.8.5
+
+ * **Polish**
+  * Rewrite parentheses insertion for terminatorless nodes such as `BreakStatement` to be much more stable and cleaner.
+  * Use `Object.setPrototypeOf` and fallback to `__proto__` in `inherits` helper.
+
+## 5.8.2-5.8.4
+
+Issues with publish process.
+
+## 5.8.1
+
+ * **Bug Fix**
+  * Fix regression where async arrow functions couldn't have type annotation parameters.
+  * Output type annotations of type instantiation parameters.
+ * **Polish**
+  * Prepend to highest loop when performing rest parameter allocation optimisation.
+  * Add comment attachment to parser.
+  * Add support for retaining inner comments of empty blocks.
+
+## 5.8.0
+
+ * Never released due to publish environment issues.
+
+## 5.7.4
+
+ * **Bug Fix**
+  * Fix comments containg `@flow` being completely removed from output rather than just the specific directive.
+
+## 5.7.3
+
+ * **Bug Fix**
+  * Add shim file for broken file path that old versions of the CLI would attempt to use.
+
+## 5.7.2
+
+ * **Bug Fix**
+  * Fix performance issue in code generator when comment columns would attempt to match up in `compact` mode causing large amounts of whitespace.
+  * Fix single line comments not outputting a newline in `compact` mode.
+ * **Polish**
+  * Add support for flow return types for arrow functions.
+
+## 5.7.1
+
+ * **Bug Fix**
+  * Add back mistakenly removed `replaceWithSourceString` method.
+
+## 5.7.0
+
+ * **Bug Fix**
+  * Deopt on spread elements when performing array destructuring unpack optimisation.
+ * **New Feature**
+  * Add `shouldPrintComment` option to control comment output.
+  * Add `.babelignore` file to be consistent with other tools.
+  * Allow `.babelrc` configs to be specified via `package.json`.
+ * **Polish**
+  * Don't ignore comments when using `compact: true` option.
+  * Add support for Flow `import typeof`.
+  * Fix incorrect inheritance method position when using loose mode classes and constructor isn't the first item.
+ * **Internal**
+  * Completely fork Acorn with `babylon`.
+  * Rewrite build system to accommodate for multiple packages.
+
+## 5.6.17
+
+ * **Bug Fix**
+  * Fix `CodeGenerator.findCommonStringDelimiter` causing a stack overflow.
+
+## 5.6.16
+
+ * **Internal**
+  * Fix `recast` version to avoid pulling in a newer version.
+ * **New Feature**
+  * Add support for functions in `util.shouldIgnore`.
+ * **Polish**
+  * Strip flow directives in flow transformer.
+  * Add a check for out of bounds default parameters, drastically improving performance and removes engine deoptimisations.
+  * Various performance optimisations by [@samccone](https://github.com/samccone) 💅✨
+  * Delay `this` assignment when referencing this inside an arrow function pre-bare super in derived class constructors.
+  * Split up class body pushing if the constructor is in the wrong order.
+ * **Bug Fix**
+  * Fix hoisting of `ForInStatement` `init` variables in `system` module formatter.
+  * `PathHoister`: Don't hoist to the same function as their original paths function parent.
+  * `PathHoister`: Push each violation paths ancestry to the breakOnScopePaths collection to avoid constant hoisting to nested paths.fix tail call recursion on functions with less arguments than parameters.
+  * Disallow `super.*` before `super()` in derived class constructors.
+  * Properly regenerate scope for replaced nodes. Thanks [@loganfsmyth](https://github.com/loganfsmyth)!
+  * Move up template literal simplification logic to avoid breaking on single elements.
+
+## 5.6.13-5.6.15
+
+ * Setting up automatic Travis releases.
+
+## 5.6.12
+
+ * **Bug Fix**
+  * Fix finding parent for top-level shadowed functions.
+
+## 5.6.11
+
+ ** **Internal**
+  * Merge `es6.parameters.rest` and `es6.parameters.default` transformers. See commit [c0fd4c1f9e0b18231f585c4fa793e4cb0e01aed1](https://github.com/babel/babel/commit/c0fd4c1f9e0b18231f585c4fa793e4cb0e01aed1) for more info.
+
+## 5.6.10
+
+ * **Bug Fix**
+  * Fix faulty internal require check.
+ * **Polish**
+  * Add support for trailing commas in arrow function parameter lists.
+
+## 5.6.8
+
+ * **Bug Fix**
+  * Fix binary expressions colliding with unary expression operators in compact mode.
+  * Fix node properties being set to `null` when using computed properties.
+
+## 5.6.7
+
+ * **Bug Fix**
+  * Fix hoisting of `ForXStatement` `left` `var`s when inserting a block scoping IIFE.
+ * **Polish**
+  * Combine all leading computed property initialisers into the root object in loose mode.
+ * **Internal**
+  * Deprecate returning of replacement strings from visitor methods.
+
+## 5.6.6
+
+ * **Bug Fix**
+  * Fix weird parser bug where `void` type annotations were being parsed as keywords causing the tokeniser to lose track of context.
+
+## 5.6.5
+
+ * **Bug Fix**
+  * Fix nested functions causing rest parameter optimisation to not properly detect when it should deopt on a reference.
+ * **Internal**
+  * Update Regenerator `0.8.31`.
+
+## 5.6.4
+
+ * **Internal**
+  * Add `ParenthesizedExpression` node type.
+
+## 5.6.3
+
+ * **Bug Fix**
+  * Fix rest parameter array allocation loop being incorrectly aliased.
+
+## 5.6.2
+
+ * **Bug Fix**
+  * Fix method key literals not turning into computed member expression in loose mode.
+  * Elect rest parameters in spread element position as candidates instead of replacing them in place.
+
+## 5.6.0
+
+ * **Bug Fix**
+  * Fix istanbul interop for register hook when registering for non-existence extension.
+  * Fix super class constructor call differing for no constructor in derived classes.
+  * Disable module import receiver when in loose mode.
+  * Fix duplicate filenames when using `babel` CLI when passing multiple matching patterns.
+  * Register labels as bindings to fix undeclared variable checks.
+ * **Polish**
+  * Remove unnecessary string binary expressions when transforming template literals.
+  * Support module live bindings in arbitrary positions not in Program statement position.
+  * Throw error when attempting to replace a `Program` root node with another node not of type `Program`.
+  * Optimise rest parameters in spread element position and allocate rest array at the earliest common ancestor of all references.
+  * Generate original number representation when value was not changed.
+  * Check for invalid binding identifiers when generating inferred method names.
+  * Don't terminate CLI when watching files fail compilation on init.
+ * **New Feature**
+  * Add new plugin API.
+ * **Internal**
+  * Split react displayName addition into a plugin.
+  * Add check for `JSXMemberExpression` to `t.isReferenced`.
+  * Move `validation.undeclaredVariableCheck` transformer up.
+  * Start great core-to-plugin exodus.
+  * Add `BindingIdentifier` virtual type.
+  * Hidden class optimisations.
+  * Array allocation optimisations.
+  * Update `regenerator`.
+  * Update `js-tokens`.
+  * Sync with upstream Acorn.
+
+## 5.5.8
+
+ * **Internal**
+  * Remove extremely unprofessional and harsh error message for those hotlinking to `resolve-rc`.
+
+## 5.5.7
+
+ * **Bug Fix**
+  * Push newline after decorators when doing code gen.
+  * Rewriting error handling to normalise options before merging them.
+  * Remove duplicate keys in `alias-keys.json` causing errors in strict mode.
+  * Fix `$ babel --help` not showing optional transformers as such.
+ * **New Feature**
+  * Add `auxiliaryCommentBefore` and `auxiliaryCommentAfter` options.
+
+## 5.5.6
+
+ * **Bug Fix**
+  * Fix `let` binding collision in loop head not properly replacing `AssignmentExpression`s.
+
+## 5.5.5
+
+ * **Bug Fix**
+  * Fix `file.opts` not being set before `file.log.deprecate` was called causing a `ReferenceError` as it was checking for a property on it.
+
+## 5.5.4
+
+ * **Bug Fix**
+  * Add back missing `shouldIgnore` check.
+  * Log message on deprecated options rather than throw an error.
+  * Fix name of `auxiliaryComment` option when attempting Istanbul interop in `babel/register`.
+
+## 5.5.3
+
+ * **Bug Fix**
+  * Fix weird state bug when traversing overa  `node` `ClassProperty` instead of `path` in the `es6.classes` transformer.
+
+## 5.5.2
+
+ * **Bug Fix**
+  * Fix `NodePath#isPure` on `Property` nodes.
+  * Use cwd instead of entry file directory when working out relative directory for `babel/register`.
+ * **Internal**
+  * Add scary warning for those few who choose to use the WIP experimental transformers.
+
+## 5.5.1
+
+ * **Bug Fix**
+  * Remove `ClassProperty` nodes always in the `Flow` transformer. This is fine now since class properties aren't supported in any engine that supports classes but the `es7.classProperties` transformer will need to be updated in the future to desugar to ES6 classes instead of relying on the `es6.classes` transformer from being ran.
+
+## 5.5.0
+
+ * **Bug Fix**
+  * Allow pushing declarations to `SwitchStatement`s.
+  * Fix `minification.removeDebugger` to remove `DebuggerStatement`s rather than `ExpressionStatement`s with an identifier of `debugger`.
+  * Check LHS in `ForInStatement` and `ForOfStatement` for constant violations.
+  * Register function `id` as a reference when naming methods to avoid collisions.
+  * Support key literals when checking for the existence of `displayName` property when attempting to add it for `React.createClass`.
+  * Remove `ExportDefaultSpecifier` check from `t.isDefaultSpecifier`.
+  * Don't consider `JSXIdentifier` HTML tag identifiers to be references.
+ * **Polish**
+  * Update `minification.deadCodeElimination` transformer to remove all statements after completion statements.
+  * Update `minification.deadCodeElimination` transformer to not inline single used bindings that exist in different scopes.
+  * When performing Istanbul interop in `babel/register`, add the auxiliary comment `"istanbul ignore text"` to get more accurate coverage.
+  * Add `--nolazy` argument to `babel-node`.
+  * Add support for `cluster` forking.
+  * Perform scope tracking in a single pass instead of multiple.
+  * Smarten up type inferrence and resolution to support the whole array of language constructs.
+  * Optimise module metadata retrieval into a single pass.
+  * Ignore trailing commas when inferring newlines.
+  * Rename `minification.inlineExpressions` transformer to `minification.constantFolding`.
+  * Check path relative to entry file when checking to see if we're inside `node_modules` when using `babel/register`.
+  * Upgrade `regenerator`.
+
+## 5.4.7
+
+ * **Bug Fix**
+  * Don't consider `JSXAttribute` `names` to be valid `ReferencedIdentifier`s.
+
+## 5.4.6
+
+ * **Bug Fix**
+  * Fix `spec.functionName` transformer incorrectly attempting to rename a binding that doesn't exist as it's a global.
+ * **Internal**
+  * Deprecate custom module formatters.
+
+## 5.4.5
+
+ * **Bug Fix**
+  * Add `JSXIdentifier` as a valid `ReferencedIdentifier` visitor virtual type.
+  * Ignore `CallExpression` `_prettyCall` when the `retainLines` option is enabled.
+  * Inherit comments to new declaration node when exploding module declarations.
+  * Fix `es6.tailCall` transformer failing on calls that exceed the max parameters of the function.
+
+## 5.4.4
+
+ * **Bug Fix**
+  * Fix bug where replacing variable declarations in the head of a `for` loop would turn them into `ExpressionStatement`s.
+  * Fix renaming of assignment expressions that were non-identifiers ie. patterns.
+  * Force space before `class` `id` to avoid breaking named classes when using `compact` mode.
+  * Add assignment pattern explosion to avoid initial duplicate nodes.
+  * Ignore this and arguments when performing TCO on shadowed functions.
+ * **Polish**
+  * Rename `sourceMapName` option to `sourceMapTarget`. Thanks [@getify](https://github.com/getify)!
+  * Better detection of completion records, ignore those in `Function`s.
+  * Clarified descriptions of the options that are enabled by default.
+  * Resolve `\`babel-plugin-${name}\`` plugin names **before** just checking the `name`. Thanks [@jquense](https://github.com/jquense)!
+  * Update AMD module formatter to add import default remapping.
+
+## 5.4.3
+
+ * **Bug Fix**
+  * Fix `module` being incorrectly rewritten when used as in an export declaration.
+  * When performing single-reference inlining, ensure that the single reference isn't a child of the binding itself.
+  * Fix a bug in `minification.deadCodeElimination` where a new binding instance was being created for local class bindings instead of just inheriting the parent one.
+  * Fix bug with paren printing in `compact` and `retainLines` mode where a left paren was already printed before catching up.
+ * **Internal**
+  * Handle contexts for paths much better. This will ensure that the path node location info is in sync.
+
+## 5.4.2
+
+ * **Polish**
+  * `ignore` and `only` patterns are now **very** liberal. The pattern can now exist anywhere in the path.
+
+## 5.4.1
+
+ * **Bug Fix**
+  * Add missing `slash` dependency. Thanks [@browncolyn](https://github.com/browncolyn)!
+ * **Polish**
+  * Clean up `shouldIgnore` algorithm to work how you'd expect rather than being a hacky piece of shit. It now crawls the entire path, checking each section of it against the input ignore/only patterns. This means that the pattern `foo` will ignore the paths `foo/bar.js`, `bar/foo` etc.
+
+## 5.4.0
+
+ * **New Feature**
+  * Added [function bind syntax](https://github.com/zenparsing/es-function-bind) behind stage 0. Thanks [@RReverser](https://github.com/rreverser)!
+  * Added `env` option. Especially handy when using the `.babelrc`.
+ * **Bug Fix**
+  * Fix files not properly being ignored when `babel.transform` ignores them when using `$ babel`.
+  * Fix scope tracking registering loop head bindings to their `VariableDeclaration` instead of `VariableDeclarator`.
+ * **Polish**
+  * Normalise path separators for souce map paths when using `$ babel`.
+  * Rework `PathHoister` to ignore global references and to not deopt on reassignments to referenced bindings, instead it tries to hoist to the highest scope.
+  * Added missing exponential operator inlining. Thanks [@nkt](https://github.com/nkt)!
+  * Optimise `regenerator` transformer. Thanks [@benjamn](https://github.com/benjamn)!
+
+## 5.3.3
+
+ * **Bug Fix**
+  * Fix `minification.deadCodeElimination` transformer incorrectly trying to inline import declarations.
+  * Fix `minification.inlineExpression` transformer getting into an infinite loop.
+
+## 5.3.2
+
+ * **Bug Fix**
+  * Fix patterns not being considered when hoisting variables in the `es6.blockScoping` transformer.
+
+## 5.3.1
+
+ * **Bug Fix**
+  * Fix unique export specifiers not being cloned when exploding class and function exports,
+ * **Polish**
+  * Turn import remaps to sequence expressions to remove their context and improve performance.
+
+## 5.3.0
+
+**Speeeeeeed**
+
+![gifs lol](https://31.media.tumblr.com/568205a0e37ae15eca510fa639589a59/tumblr_n8kw8kpcSb1sg6cg8o1_500.gif)
+
+ * **Spec Compliance**
+  * Allow trailing param commas for methods when using the `es7.trailingCommas` transformer.
+ * **Bug Fix**
+  * Fix `es6.blockScoping` transformer not properly ignoring `break` in `SwitchCase`.
+  * Fix lookahead context saving to avoid weird tokenizer state.
+  * Explode duplicate identifiers in export/import specifiers and property shorthand to create unique objects.
+  * Skip loose mode for class methods when they have decorators.
+  * When removing nodes, share their comments with their siblings.
+  * Properly hoist temp param declarations when doing TCO.
+ * **Internal**
+  * Add `--harmony_generators` flag to `$ babel-node`.
+  * Internal AST traversals have been minimised **drastically**. Transformers have been grouped together which means entire tree traversals are much fewer. Visiting nodes is now also skipped if the traversal context can detect that the handler is a noop. This sames precious cycles as it avoids constructing traversal paths and creating a new traversal context. See issues [#1472](https://github.com/babel/babel/issues/1472) and [#1486](https://github.com/babel/babel/issues/1486) for related discussion.
+ * **Polish**
+  * Move many `utility` transformers to `minification`.
+
+## 5.2.17
+
+ * **Bug Fix**
+  * Fix auxiliary comments not properly being attached to function declaration helpers.
+  * Add `Super` node type to `ast-types` patch.
+  * Ignore parameter bindings when attempting to inline them in the `minification.deadCodeElimination` transformer.
+  * Correct `extensions` arguments when using the Babel CLI.
+
+## 5.2.16
+
+ * **Bug Fix**
+  * Fix plugins being disabled when using the whitelist.
+  * Fix correct function scope being passed to `nameMethod.property` when inferring the function name for class methods.
+  * Fix incorrect extensions reference causing weird issues when using the Babel CLI.
+  * Fix destructuring param reference replacements not inheriting from their original param.
+ * **Spec Compliance**
+  * Fix order that method decorators are ran in.
+
+## 5.2.15
+
+ * **Bug Fix**
+  * Fix initializer descriptor add attempt if it doesn't exist.
+
+## 5.2.14
+
+ * **Bug Fix**
+  * Fix bug with initializer decorators where the descriptors weren't being defined if there was no `initializer` property.
+ * **Internal**
+  * Expose `retainLines` option to CLI.
+  * Fix `retainLines` option not being taken into consideration when doing multiple variable declaration declarators generation.
+  * Expose minified and unminified copies of dist scripts.
+
+## 5.2.13
+
+ * **Bug Fix**
+  * Fix `ExportDeclaration`s being incorrectly removed when using the `utility.deadCodeElimination` transformer.
+  * Fix position of `utility` transformers.
+ * **New Feature**
+  * Add built-in `esquery` support.
+ * **Internal**
+  * Consolidate notion of "virtual types".
+
+## 5.2.12
+
+ * **Polish**
+  * Make UID generation based on module declarations **much** nicer.
+ * **Internal**
+  * Remove internal check for traversal path replacement of self. This is a pattern that **could** come up in the wild and it could lead to pretty nasty code and may lead to internal regressions as the test coverage isn't 100% :( Instead, just put it in the fast path.
+
+## 5.2.11
+
+ * **Internal**
+  * Rename `getModuleName` option to `getModuleId`, doh.
+
+## 5.2.10
+
+ * **Bug Fix**
+  * Fix numerous issues in `replaceWithSourceString`. Thanks [@pangratz](https://github.com/pangratz)!
+ * **New Feature**
+  * Add `getModuleName` option. Thanks [@jayphelps](https://github.com/jayphelps)!
+
+## 5.2.9
+
+ * **Bug Fix**
+  * Fix `_blockHoist` transformer incorrectly sorting nodes on shitty environments that aren't spec compliant in their key order.
+  * Fix broken `parse` API method reference to an undeclared import.
+
+## 5.2.7
+
+ * **Bug Fix**
+  * Move `utility.deadCodeElimination` transformer up to avoid race conditions.
+  * Fix shorthand property scope binding renaming.
+ * **Polish**
+  * Turn helper variable declarations into function declarations if possible.
+ * **Internal**
+  * Removed native inheritance support from classes.
+  * Added `replaceWithSourceString` path API.
+  * Split up `es3.propertyLiterals` and `es3.memberExpressionLiterals` transformers to `minification.propertyLiterals` and `es3.memberExpressionLiterals`.
+
+## 5.2.6
+
+ * **Internal**
+  * Fix transformer aliases being accidentally set as deprecated ones.
+  * Expose `Pipeline` as `TransformerPipeline` instead.
+
+## 5.2.5
+
+ * **Bug Fix**
+  * Fix `parse` API not adding all the correct pipeline transformers.
+
+## 5.2.4
+
+ * **Bug Fix**
+  * Fix race condition with the Node API being loaded awkwardly and not being able to initialise itself when used in the browser.
+ * **Internal**
+  * Expose `transform.pipeline`.
+
+## 5.2.3
+
+ * **Bug Fix**
+  * Fix plugin containers being called with an undefined import. Thanks [@timbur](https://github.com/timbur)!
+  * Allow Flow object separators to be commas. Thanks [@monsanto](https://github.com/monsanto)!
+  * Add missing `Statement` and `Declaration` node aliases to flow types.
+
+## 5.2.2
+
+ * **Internal**
+  * Allow `util.arrayify` to take arbitrary types and coerce it into an array.
+
+## 5.2.1
+
+ * **Bug Fix**
+  * Fix regression in `node/register` that caused `node_modules` to not be ignored.
+
+## 5.2.0
+
+ * **Bug Fix**
+  * Fix plugin strings splitting arbitrarily on `:` which caused full paths on Windows to fail as they include `:` after the drive letter.
+  * Call class property `initializer`s with their target instead of their descriptor.
+  * Fix `ignore` and `only` not properly working on Windows path separators. Thanks [@stagas](https://github.com/stagas)!
+  * Fix `resolveRc` running on files twice causing issues. Thanks [@lukescott](https://github.com/lukescott)!
+  * Fix shorthand properties not correctly being target for `isReferenced` checks. Thanks [@monsanto](https://github.com/monsanto)!
+ * **Polish**
+  * Allow passing an array of globs to `babel/register` `only` and `ignore` options. Thanks [@Mark-Simulacrum](https://github.com/Mark-Simulacrum)!
+  * When inferring function names that collide with upper bindings, instead of doing the wrapper, instead rename them.
+  * Consider constant-like variable declaration functions to always refer to themselves so TOC can be performed.
+  * Process globs manually when using `$ babel` as some shells such as Windows don't explode them. Thanks [@jden](https://github.com/jden)!
+  * Add alternative way to execute plugins via a closure that's called with the current Babel instance.
+ * **Internal**
+  * Remove multiple internal transformers in favor of directly doing things when we need to. Previously, declarations such as `_ref` that we needed to create in specific scopes were done at the very end via the `_declarations` transformer. Now, they're done and added to the scope **right** when they're needed. This gets rid of the crappy `_declarations` property on scope nodes and fixes the crappy regenerator bug where it was creating a new `BlockStatement` so the declarations were being lost.
+  * Rework transformer traversal optimisation. Turns out that calling a `check` function for **every single node** in the AST is ridiculously expensive. 300,000 nodes timesed by ~30 transformers meant that it took tens of seconds to perform while it's quicker to just do the unnecessary traversal. Seems obvious in hindsight.
+ * **New Feature**
+  * Add `jscript` transformer that turns named function expressions into function declarations to get around [JScript's horribly broken function expression semantics](https://kangax.github.io/nfe/#jscript-bugs). Thanks [@kondi](https://github.com/kondi)!
+  * Add `@@hasInstance` support to objects when using the `es6.spec.symbols` transformer.
+  * Add `retainLines` option that retains the line (but not the columns!) of the input code.
+
+## 5.1.13
+
+ * **Polish**
+  * Remove symbol check from `defineProperty` helper.
+
+## 5.1.12
+
+ * **Bug Fix**
+  * Fix `resolveModuleSource` not being ran on `ExportAllDeclaration`s.
+  * Fix `.babelrc` being resolved multiple times when using the require hook.
+  * Fix parse error on spread properties in assignment position.
+  * Fix `externalHelpers` option being incorrectly listed as type `string`.
+ * **Internal**
+  * Upgrade `core-js` to `0.9.0`.
+ * **Spec Compliance**
+  * Fix object decorators not using the `initializer` pattern.
+  * Remove property initializer descriptor reflection.
+
+## 5.1.11
+
+ * **Bug Fix**
+  * Memoise and bind member expression decorators.
+  * Move JSX children cleaning to opening element visitor. Fixes elements not being cleaned in certain scenarios.
+  * Consider `SwitchStatement`s to be `Scopable`.
+  * Fix `bluebirdCoroutines` calling `interopRequireWildcard` before it's defined.
+  * Add space to `do...while` code generation.
+  * Validate `super` use before `this` on `super` exit rather than entrance.
+ * **Polish**
+  * Add Babel name to logger.
+
+## 5.1.10
+
+ * **Bug Fix**
+  * Remove `makePredicate` from acorn in favor of an `indexOf`.
+  * Remove statements to expression explosion when inserting a block statement.
+ * **Internal**
+  * Remove runtime compatibility check.
+
+## 5.1.9
+
+ * **Bug Fix**
+  * Fix class property initializers with `undefined` values not being correctly writable.
+  * Fix self inferring generators incorrectly causing a stack error.
+  * Fix default export specifiers not triggering AMD `module` argument inclusion.
+  * Fix assignments not having their module references properly remapped.
+ * **Internal**
+  * Upgrade to latest `acorn`.
+ * **Polish**
+  * Make invalid LHS pattern error messages nicer.
+
+## 5.1.8
+
+ * **Bug Fix**
+  * Only make parenthesized object pattern LHS illegal.
+
+## 5.1.7
+
+ * **Internal**
+  * Add `parse` node API.
+
+## 5.1.6
+
+ * **Bug Fix**
+  * Fix `runtime` built-in catchall not properly checking for local variables.
+
+## 5.1.5
+
+ * **Internal**
+  * Bump `core-js` version.
+
+## 5.1.4
+
+ * **Polish**
+  * Add missing `Reflect` methods to runtime transformer.
+
+## 5.1.3
+
+ * **Internal**
+  * Switch entirely to vanilla regenerator.
+  * Clean up and make the parsing of decorators stateless.
+ * **Bug Fix**
+  * Don't do TCO on generators and async functions.
+  * Add missing `core-js` runtime definitions.
+
+## 5.1.2
+
+ * **Bug Fix**
+  * Add `getIterator` and `isIterable` to `babel-runtime` build script.
+
+## 5.1.1
+
+ * **Bug Fix**
+  * Add missing runtime symbol definitions.
+
+## 5.1.0
+
+ * **Bug Fix**
+  * Fix super reference when using decorators.
+  * Don't do array unpack optimisation when member expressions are present.
+  * Add missing descriptors for undecorated class properties.
+  * Don't consider `arguments` and `eval` valid function names when doing function name inferrence.
+  * Fix scope tracking of constants in loop heads.
+  * Parse `AwaitExpression` as a unary instead of an assignment.
+  * Fix regex evaluation when attempting static evaluation.
+  * Don't emit tokens when doing a lookahead.
+  * Add missing `test` declaration to `utility.deadCodeElimination` transformer.
+ * **Internal**
+  * Upgrade `regenerator` to the latest and use my branch with the hope of eventually switching to vanilla regenerator.
+  * Add support for the replacement of for loop `init`s with statements.
+  * Upgrade dependencies.
+ * **Polish**
+  * When adding the scope IIFE when using default parameters, don't shadow the function expression, just `apply` `this` and `arguments` if necessary.
+  * Use path basename as non-default import fallback.
+ * **New Feature**
+  * Add [trailing function comma proposal](https://github.com/jeffmo/es-trailing-function-commas). Thanks [@AluisioASG](https://github.com/AluisioASG)!
+  * Add support for object literal decorators.
+  * Make core-js modular when using the `runtime` transformer.
+
+## 5.0.12
+
+ * **Bug Fix**
+  * Fix incorrect remapping of module references inside of a function id redirection container.
+
+## 5.0.11
+
+ * **Bug Fix**
+  * Fix new `for...of` loops not properly inheriting their original loop.
+ * **Internal**
+  * Disable scope instance cache.
+ * **Polish**
+  * Allow comments in `.babelrc` JSON.
+
+## 5.0.9
+
+ * **Polish**
+  * Use `moduleId` for UMD global name if available.
+ * **Bug Fix**
+  * Fix UMD global `module` variable shadowing the `amd`/`common` `module` variable.
+  * Fix Flow param type annotation regression.
+  * Fix function name collision `toString` wrapper. Thanks [@alawatthe](https://github.com/alawatthe)!
+
+## 5.0.8
+
+ * **Bug Fix**
+  * Fix falsy static class properties not being writable.
+  * Fix block scoping collisions not properly detecting modules and function clashes.
+  * Skip `this` before `super` for derived constructors on functions.
+
+## 5.0.7
+
+ * **New Feature**
+  * Add `--ignore` and `--only` support to the CLI.
+ * **Bug Fix**
+  * Remove `HOMEPATH` environment variable from home resolution in `babel/register` cache.
+ * **Internal**
+  * Disable WIP path resolution introducing infinite recursion in some code examples.
+ * **Polish**
+  * Add live binding to CommonJS default imports.
+
+## 5.0.6
+
+ * **Bug Fix**
+  * Fix mangling of import references that collide with properties on `Object.prototype`.
+  * Fix duplicate declarations incorrectly being reported for `var`.
+
+## 5.0.5
+
+ * **Internal**
+  * Upgrade `core-js`.
+ * **Bug Fix**
+  * Fix arrays not being supported in `util.list`.
+
+## 5.0.4
+
+ * **Polish**
+  * Check for top level `breakConfig` in `resolveRc`.
+
+## 5.0.3
+
+ * **Bug Fix**
+  * Make relative location absolute before calling `resolveRc`.
+ * **Internal**
+  * Switch to global UID registry.
+  * Add `breakConfig` option to prevent Babel from erroring when hitting that option.
+
+## 5.0.1
+
+ * **Bug Fix**
+  * Fix duplicate declaration regression.
+  * Fix not being able to call non-writable methods.
+
+## 5.0.0
+
+ * **New Feature**
+  * Decorators based on [@wycat's](https://github.com/wycats) [stage 1 proposal](https://github.com/wycats/javascript-decorators).
+  * Class property initializers based on [@jeffmo's](https://github.com/jeffmo) [stage 0 proposal](https://gist.github.com/jeffmo/054df782c05639da2adb).
+  * Export extensions based on [@leebyron's](https://github.com/leebyron) [stage 1 proposal](https://github.com/leebyron/ecmascript-more-export-from).
+  * UMD module formatter now supports globals.
+  * Add `es3.runtime`, `optimisation.react.inlineElements` and `optimisation.react.constantElements` transformers.
+  * Add stage option that replaces the experimental one.
+  * Allow ES7 transformer to be enabled via `optional` instead of only via `stage`.
+  * Infer string quotes to use in the code generator.
+  * Consider `export { foo as default  };` to be the same as `export default foo;`.
+  * Add `nonStandard` option that can be set to `false` to remove parser support for JSX and Flow.
+  * Add `jsxPragma` option.
+  * Automatically generate CLI options based on internal API options.
+  * Add support for `.babelrc` on absolute paths.
+  * Plugin API!
+ * **Internal**
+  * Export `options` in browser API.
+  * Rewritten parser.
+  * Don't block hoist when runtime transformer is enabled in system module formatter.
+  * Rewritten the internal traversal and node replacement API to use "paths" that abstracts out node relationships.
+ * **Polish**
+  * JSX output is now more inline with the official JSX transformer.
+  * Hoist block scoping IIFE - this improves memory usage and performance.
+  * Better IIFE detection - references are now checked to see if they're referencing the binding we're searching for.
+  * Check for import reassignments in constants transformer.
+  * Make method definitions with expression bodies illegal.
+  * Save register cache on tick instead of `SIGINT`.
+  * Enable strict mode on babel-node eval flag.
+ * **Bug Fixes**
+  * Add support for live bindings. This change also increases the reliability of export specifier renaming.
+  * Add support for super update and non equals assignment expressions.
+  * Rename shadow constructor binding in classes.
+  * Seed next iteration bindings with previous fresh bindings when reassigning loop block scoped variables.
+  * Fix new expression spread referencing the wrong constructor.
+  * Call `resolveModuleSource` on dynamic imports.
+  * Added `param` to list of duplicate declaration kinds.
+ * **Breaking Changes**
+  * The Babel playground has been removed.
+  * ES7 Abstract References have been removed.
+  * Experimental option has been removed in favor of a stage option.
+  * Rename `returnUsedHelpers` to `metadataUsedHelpers`.

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,6 @@
+<!---
+Thanks for filing an issue 😄 ! Before you submit, please read the following:
+
+Check the other issue templates if you are trying to submit a bug report, feature request, or question
+Search open/closed issues before submitting since someone might have asked the same thing before!
+-->

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -0,0 +1,44 @@
+---
+name: "\U0001F41B Bug Report"
+about: "If something isn't working as expected \U0001F914."
+title: ''
+labels: 'i: bug, i: needs triage'
+assignees: ''
+
+---
+
+## Bug Report
+
+**Current Behavior**
+A clear and concise description of the behavior.
+
+**Input Code**
+- REPL or Repo link if applicable:
+
+```js
+var your => (code) => here;
+```
+
+**Expected behavior/code**
+A clear and concise description of what you expected to happen (or code).
+
+**Babel Configuration (.babelrc, package.json, cli command)**
+
+```js
+{
+  "your": { "config": "here" }
+}
+```
+
+**Environment**
+- Babel version(s): [e.g. v6.0.0, v7.0.0-beta.34]
+- Node/npm version: [e.g. Node 8/npm 5]
+- OS: [e.g. OSX 10.13.4, Windows 10]
+- Monorepo: [e.g. yes/no/Lerna]
+- How you are using Babel: [e.g. `cli`, `register`, `loader`]
+
+**Possible Solution**
+<!--- Only if you have suggestions on a fix for the bug -->
+
+**Additional context/Screenshots**
+Add any other context about the problem here. If applicable, add screenshots to help explain.

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -0,0 +1,23 @@
+---
+name: "\U0001F680 Feature Request"
+about: "I have a suggestion (and may want to implement it \U0001F642)!"
+title: ''
+labels: 'i: enhancement, i: needs triage'
+assignees: ''
+
+---
+
+## Feature Request
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I have an issue when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen. Add any considered drawbacks.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Teachability, Documentation, Adoption, Migration Strategy**
+If you can, explain how users will be able to use this and possibly write out a version the docs.
+Maybe a screenshot or design?

.github/ISSUE_TEMPLATE/Regression-v7.md

@@ -0,0 +1,45 @@
+---
+name: "\U0001F4A5 v7 Regression"
+about: Report an unexpected behavior in v7 from v6 (Check the upgrade guide first
+  ✌️)
+title: ''
+labels: 'i: bug, 7.x: regression, i: needs triage'
+assignees: ''
+
+---
+
+# v7 Regression
+
+> First check out: https://babeljs.io/docs/en/v7-migration
+> Also a partial upgrade tool: https://github.com/babel/babel-upgrade
+
+**Potential Commit/PR that introduced the regression**
+If you have time to investigate, what PR/date introduced this issue.
+
+**Describe the regression**
+A clear and concise description of what the regression is.
+
+**Input Code**
+<!--- 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)**
+
+```js
+{
+  "your": { "config": "here" }
+}
+```
+
+**Expected behavior/code**
+A clear and concise description of what you expected to happen (or code).
+
+**Environment**
+- Babel version(s): [e.g. v6.0.0, v7.0.0-beta.34]
+- Node/npm version: [e.g. Node 8/npm 5]
+- OS: [e.g. OSX 10.13.4, Windows 10]
+- Monorepo [e.g. yes/no/Lerna]
+- How you are using Babel: [e.g. `cli`, `register`, `loader`]

.github/ISSUE_TEMPLATE/Support_question.md

@@ -0,0 +1,19 @@
+---
+name: "\U0001F917 Support Question"
+about: "If you have a question \U0001F4AC, please check out our Slack or StackOverflow!"
+title: ''
+labels: 'i: question, i: needs triage'
+assignees: ''
+
+---
+
+--------------^ Click "Preview" for a nicer view!
+We primarily use GitHub as an issue tracker; for usage and support questions, please check out these resources below. Thanks! 😁.
+
+---
+
+* Slack Community Chat: https://babeljs.slack.com (you can sign-up at https://slack.babeljs.io/ for an invite)
+* StackOverflow: https://stackoverflow.com/questions/tagged/babeljs using the tag `babeljs`
+* Twitter: If it's just a quick question you can ping our Twitter: https://twitter.com/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

.github/ISSUE_TEMPLATE/Support_us.md

@@ -0,0 +1,28 @@
+---
+name: "\U0001F91D Support us on Babel"
+about: "If you would like to support our efforts in maintaining this community-driven
+  project \U0001F64C!"
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+--------------^ Click "Preview" for a nicer view!
+> Open Collective: https://opencollective.com/babel
+> Henry's Patreon: https://www.patreon.com/henryzhu
+
+Help support Babel!
+
+Babel has always been a community project, not really backed or owned by any single (or group) of companies. While some maintainers used to work at Facebook (and Henry at Adobe) no one was working on it full time and there certainly isn't a huge company or team anywhere doing all this work.
+
+---
+
+As a group of volunteers you can help us in a few ways
+
+- Giving developer time on the project. (Message us on [Twitter](https://twitter.com/babeljs) or [Slack](https://slack.babeljs.io/) for guidance). Companies should be paying their employees to contribute back to the open source projects they use everyday.
+- Giving funds by becoming one of our sponsors/donators!
+
+If you'd like to sustain the future of the project as a whole, we have an [Open Collective](https://opencollective.com/babel) that you can donate to. This is a way for funds to be allocated to the core team.
+
+You can also support [Henry](https://github.com/hzoo) directly since I [left my job to work on Babel and Open Source full time](https://twitter.com/left_pad/status/969793227862790144) at my [Patreon](https://www.patreon.com/henryzhu).

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,23 @@
+<!--
+Before making a PR, please read our contributing guidelines
+https://github.com/babel/babel/blob/master/CONTRIBUTING.md
+
+Please note that the Babel Team requires two approvals before merging most PRs.
+
+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)
+
+If you are making a change that should have a docs update: submit another PR to https://github.com/babel/website
+-->
+
+| Q                        | A <!--(Can use an emoji 👍) -->
+| ------------------------ | ---
+| Fixed Issues?            | `Fixes #1, Fixes #2` <!-- remove the (`) quotes and write "Fixes" before the number to link the issues -->
+| Patch: Bug Fix?          |
+| Major: Breaking Change?  |
+| Minor: New Feature?      |
+| Tests Added + Pass?      | Yes
+| Documentation PR Link    | <!-- If only readme change, add `[skip ci]` to your commits -->
+| Any Dependency Changes?  |
+| License                  | MIT
+
+<!-- Describe your changes below in as much detail as possible -->

.github/lock.yml

@@ -0,0 +1,12 @@
+# Configuration for lock-threads - https://github.com/dessant/lock-threads
+
+# Number of days of inactivity before a closed issue or pull request is locked
+daysUntilLock: 91
+# Comment to post before locking. Set to `false` to disable
+lockComment: false
+# The label to be applied when an issue is locked
+lockLabel: 'outdated'
+
+# Issues or pull requests with these labels will not be locked
+# exemptLabels:
+#   - no-locking

.github/workflows/issue-triage.yml

@@ -0,0 +1,81 @@
+name: Issue Triage
+
+on:
+  issues:
+    types: [opened, labeled]
+
+jobs:
+  welcome:
+    name: Welcome comment
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check if Babel member
+        id: is_babel_member
+        if: github.event.action == 'opened'
+        uses: babel/actions/is-org-member@v2
+        with:
+          org: babel
+          username: ${{ github.event.issue.user.login }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Create Welcome Comment
+        uses: babel/actions/create-comment@v2
+        if: |
+          github.event.action == 'opened' &&
+          steps.is_babel_member.outputs.result == 0
+        with:
+          token: ${{ secrets.BOT_TOKEN }}
+          issue: ${{ github.event.issue.number }}
+          comment: >
+            Hey @${{ github.event.issue.user.login }}!
+            We really appreciate you taking the time to report an issue. The 
+            collaborators on this project attempt to help as many people as 
+            possible, but we're a limited number of volunteers, so it's 
+            possible this won't be addressed swiftly.
+
+
+            If you need any help, or just have general Babel or JavaScript questions, we have a 
+            vibrant [Slack community](https://babeljs.slack.com) that typically always has someone 
+            willing to help. You can sign-up [here](https://slack.babeljs.io/) for an invite."
+
+  needs_info:
+    name: Needs Info
+    runs-on: ubuntu-latest
+    steps:
+      - name: Create Needs Info Comment
+        uses: babel/actions/create-comment@v2
+        if: |
+          github.event.action == 'labeled' &&
+          github.event.label.name == 'Needs Info'
+        with:
+          token: ${{ secrets.BOT_TOKEN }}
+          issue: ${{ github.event.issue.number }}
+          comment: >
+            Hi @${{ github.event.issue.user.login }}!
+            This issue is missing some important information we'll need
+            to be able to reproduce this issue.
+
+
+            Please understand that we receive a high volume of issues,
+            and there are only a limited number of volunteers that help
+            maintain this project. The easier it is for us to decipher an
+            issue with the info provided, the more likely it is that we'll
+            be able to help.
+
+
+            Please make sure you have the following information documented in
+            this ticket:
+            
+            1. Your Babel configuration (typically from `.babelrc` or `babel.config.js`)
+
+            2. The current (incorrect) behavior you're seeing
+
+            3. The behavior you expect
+
+            4. A [short, self-contained example](http://sscce.org/)
+
+
+            Please provide either a link to the problem via the
+            [`repl`](https://babeljs.io/repl/), or if the `repl` is
+            insufficient, a new and minimal repository with instructions on
+            how to build/replicate the issue.
+        

.github/workflows/release.yml

@@ -0,0 +1,53 @@
+name: Release
+
+on:
+  push:
+    tags: ["v*"]
+
+jobs:
+  github_release:
+    name: Trigger GitHub release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the new tag
+        uses: actions/checkout@v1.0.0
+
+      - name: Get tag info
+        id: tags
+        uses: babel/actions/get-release-tags@v2
+
+      - name: Generate the changelog
+        id: changelog
+        uses: babel/actions/generate-lerna-changelog@v2
+        with:
+          from: ${{ steps.tags.outputs.old }}
+          to: ${{ steps.tags.outputs.new }}
+        env:
+          GITHUB_AUTH: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Create a draft GitHub release
+        uses: babel/actions/publish-github-release@v2
+        with:
+          tag: ${{ steps.tags.outputs.new }}
+          changelog: ${{ steps.changelog.outputs.changelog }}
+          token: ${{ secrets.BOT_TOKEN }}
+
+      - name: Check if releasing from master
+        id: is_master
+        uses: babel/actions/ref-matches-branch@v2
+        with:
+          name: master
+
+      - name: Update CHANGELOG.md
+        if: steps.is_master.outputs.result == 1
+        uses: babel/actions/update-changelog@v2
+        with:
+          changelog: ${{ steps.changelog.outputs.changelog }}
+
+      - name: Commit CHANGELOG.md
+        if: steps.is_master.outputs.result == 1
+        run: |
+          git add CHANGELOG.md
+          git -c user.name="Babel Bot" -c user.email="babel-bot@users.noreply.github.com" \
+            commit -m "Add ${{ steps.tags.outputs.new }} to CHANGELOG.md [skip ci]" --no-verify --quiet
+          git push "https://babel-bot:${{ secrets.BOT_TOKEN }}@github.com/${GITHUB_REPOSITORY}.git" master

.gitignore

@@ -1,17 +1,62 @@
+.npmrc
+
 .DS_Store
-node_modules
-test/core/tmp
+/node_modules
+/.github/actions/*/node_modules
+/packages/*/node_modules
+/packages/*/LICENSE
+!/packages/babel-parser/LICENSE
+!/packages/babel-plugin-transform-object-assign/LICENSE
 *.log
 *.cache
-/templates.json
-/tests.json
+/build
+/.eslintcache
 /browser.js
 /browser-polyfill.js
 /runtime.js
 coverage
 dist
-.package.json
-packages/babel-runtime/core-js
-packages/babel-runtime/helpers/*.js
-packages/babel-runtime/regenerator/*.js
-lib
+/.package.json
+package-lock.json
+!/.github/actions/*/package-lock.json
+
+/packages/babel-runtime/helpers/*.js
+!/packages/babel-runtime/helpers/toArray.js
+!/packages/babel-runtime/helpers/iterableToArray.js
+!/packages/babel-runtime/helpers/temporalRef.js
+/packages/babel-runtime/helpers/esm/*.js
+!/packages/babel-runtime/helpers/esm/toArray.js
+!/packages/babel-runtime/helpers/esm/iterableToArray.js
+!/packages/babel-runtime/helpers/esm/temporalRef.js
+
+/packages/babel-runtime-corejs2/helpers/*.js
+!/packages/babel-runtime-corejs2/helpers/toArray.js
+!/packages/babel-runtime-corejs2/helpers/iterableToArray.js
+!/packages/babel-runtime-corejs2/helpers/temporalRef.js
+/packages/babel-runtime-corejs2/helpers/esm/*.js
+!/packages/babel-runtime-corejs2/helpers/esm/toArray.js
+!/packages/babel-runtime-corejs2/helpers/esm/iterableToArray.js
+!/packages/babel-runtime-corejs2/helpers/esm/temporalRef.js
+/packages/babel-runtime-corejs2/core-js/**/*.js
+!/packages/babel-runtime-corejs2/core-js/map.js
+
+/packages/babel-runtime-corejs3/helpers/*.js
+/packages/babel-runtime-corejs3/helpers/esm/*.js
+/packages/babel-runtime-corejs3/core-js/**/*.js
+/packages/babel-runtime-corejs3/core-js-stable/**/*.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
+packages/babel-preset-env-standalone/babel-preset-env.js
+packages/babel-preset-env-standalone/babel-preset-env.min.js
+/codemods/*/lib
+/codemods/*/node_modules
+/packages/babel-parser/build
+.idea/
+/.changelog

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "vendor/traceur"]
-	path = vendor/traceur
-	url = https://github.com/google/traceur-compiler

.istanbul.yml

@@ -1,2 +0,0 @@
-instrumentation:
-  root: lib

.npmignore

@@ -1,15 +0,0 @@
-*.log
-*.cache
-.*
-/lib/babel/transformation/templates
-/test
-/benchmark
-/Makefile
-/dist
-/tests.json
-/CHANGELOG.md
-/.package.json
-/coverage
-/vendor
-/packages
-/src

.prettierignore

@@ -0,0 +1,5 @@
+package.json
+packages/babel-preset-env/data
+packages/*/test/fixtures/**/input.*
+packages/*/test/fixtures/**/exec.*
+packages/*/test/fixtures/**/output.*

.prettierrc

@@ -0,0 +1,23 @@
+{
+  "arrowParens": "avoid",
+  "trailingComma": "es5",
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": false,
+  "bracketSpacing": true,
+  "jsxBracketSameLine": false,
+  "tabWidth": 2,
+  "printWidth": 80,
+  "overrides": [{
+    "files": [
+      "**/codemods/*/src/**/*.js",
+      "**/codemods/*/test/**/*.js",
+      "**/packages/*/src/**/*.js",
+      "**/packages/*/test/**/*.js"
+    ],
+    "parser": "babylon",
+    "options": {
+      "trailingComma": "all"
+    }
+  }]
+}

.travis.yml

@@ -1,19 +1,60 @@
-#sudo: false
+git:
+  depth: 5
 language: node_js
 cache:
-  directories:
-    - node_modules
-node_js:
-  - "0.12"
-  - "iojs"
+  yarn: true
 
-before_script: "npm install -g codeclimate-test-reporter"
-script: "make test-travis"
+os: linux
+
+env:
+  global:
+    - PATH=$HOME/.yarn/bin:$PATH
+    - JOB=test
+
+install: skip
+before_script:
+  - curl -o- -L https://yarnpkg.com/install.sh | bash
+  - if [ "$TRAVIS_OS_NAME" = "windows" ]; then choco install make; fi
+
+script:
+  - if [ "$JOB" = "test" ]; then make -j test-ci; fi
+  - if [ "$JOB" = "lint" ]; then make -j code-quality-ci; fi
+  - if [ "$JOB" = "babel-parser-flow-tests" ]; then make -j test-flow-ci; fi
+  - if [ "$JOB" = "babel-parser-test262-tests" ]; then make -j test-test262-ci; fi
+
+matrix:
+  fast_finish: true
+  include:
+    - node_js: "node"
+      env: JOB=lint
+    # We test the latest version on circleci
+    - node_js: "12"
+    # Move `windows` build to be the third since it is slow
+    - os: windows
+      node_js: "node"
+      env:
+        - JOB=test
+        # https://travis-ci.community/t/build-doesnt-finish-after-completing-tests/288/9
+        - YARN_GPG=no
+    # Continue node_js matrix
+    - node_js: "6"
+    - node_js: "10"
+    - node_js: "8"
+    - node_js: "node"
+      env: JOB=babel-parser-flow-tests
+    - node_js: "node"
+      env: JOB=babel-parser-test262-tests
 
 notifications:
-  webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/acf1870e9d223c65e8d5
-    on_success: always
+  slack:
+    on_success: change
     on_failure: always
-    on_start: false
+    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:
+    - /^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 make 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 Henry Zhu <hi@henryzoo.com>, Logan Smyth <loganfsmyth@gmail.com> or one of the other [Babel core team members](https://babeljs.io/team). 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

@@ -1,27 +1,53 @@
-<p align="center">
+----
+
+<p align="center" class="toc">
    <strong><a href="#setup">Setup</a></strong>
    |
-   <strong><a href="#running-tests">Running tests</a></strong>
+   <strong><a href="#running-lintingtests">Running linting/tests</a></strong>
    |
-   <strong><a href="#workflow">Workflow</a></strong>
+   <strong><a href="#writing-tests">Writing tests</a></strong>
    |
-   <strong><a href="#dependencies">Dependencies</a></strong>
+   <strong><a href="#debugging-code">Debugging code</a></strong>
    |
-   <strong><a href="#code-standards">Code Standards</a></strong>
+   <strong><a href="#internals">Internals</a></strong>
 </p>
 
 ----
 
+
 # Contributing
 
 Contributions are always welcome, no matter how large or small. Before
 contributing, please read the
 [code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
 
+## Not sure where to start?
+
+- 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/babel/blob/master/packages/babel-parser/ast/spec.md) is a bit different from [ESTree](https://github.com/estree/estree). The differences are listed [here](https://babeljs.io/docs/en/next/babel-parser.html#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](https://babeljs.slack.com) (you can sign-up [here](https://slack.babeljs.io/)
+    for an invite), 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)
+- You can contribute by triaging issues which may include reproducing bug reports or asking for vital information, such as version numbers or reproduction instructions. If you would like to start triaging issues, one easy way to get started is to [subscribe to babel on CodeTriage](https://www.codetriage.com/babel/babel). [![Open Source Helpers](https://www.codetriage.com/babel/babel/badges/users.svg)](https://www.codetriage.com/babel/babel)
+
+## Chat
+
+Feel free to check out the `#discussion`/`#development` channels on our [Slack](https://slack.babeljs.io) (you can sign-up [here](https://slack.babeljs.io/) for an invite). Some of us are always online to chat!
 
 ## Developing
 
-#### Setup
+**Note:** Versions `< 5.1.10` can't be built.
+
+Babel is built for Node 6 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
@@ -32,138 +58,267 @@ $ make bootstrap
 Then you can either run:
 
 ```sh
-$ make build-core
+$ make build
 ```
 
 to build Babel **once** or:
 
 ```sh
-$ make watch-core
+$ make watch
 ```
 
-to have Babel build itself then incrementally build files on change.
+to have Babel build itself and incrementally build files on change.
 
-#### Running tests
+You can access the built files for individual packages from `packages/<package-name>/lib`.
 
-You can run tests via:
+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
 ```
 
-This is mostly overkill and you can limit the tests to a select few by directly
-running them with `mocha`:
+If you just want to run all tests:
 
 ```sh
-$ mocha test/core/transformation.js
+# ~40 sec on a MacBook Pro (Mid 2015)
+$ make test-only
 ```
 
-Use mocha's `--grep` option to run a subset of tests by name:
+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
-$ mocha test/core/transformation.js --grep es7
+$ TEST_ONLY=babel-cli make test
 ```
 
-If you don't have `mocha` installed globally, you can still use it from Babel's
-dependencies in `node_modules`, but make sure `node_modules/.bin` is added to
-your [`$PATH`](http://unix.stackexchange.com/questions/26047/how-to-correctly-add-a-path-to-path) environment variable.
+`TEST_ONLY` will also match substrings of the package name:
 
+```sh
+# Run tests for the @babel/plugin-transform-classes package.
+$ TEST_ONLY=babel-plugin-transform-classes make test
+```
 
-#### Workflow
+Use the `TEST_GREP` variable to run a subset of tests by name:
 
-* Fork the repository
-* Clone your fork and change directory to it (`git clone git@github.com:yourUserName/babel.git && cd babel`)
-* Install the project dependencies (`make bootstrap`)
-* Link your forked clone (`npm link`)
-* Develop your changes ensuring you're fetching updates from upstream often
-* Ensure the test are passing (`make test`)
-* Create new pull request explaining your proposed change or reference an issue in your commit message
+```sh
+$ TEST_GREP=transformation make test
+```
 
+Substitute spaces for hyphens and forward slashes when targeting specific test names:
 
-#### Dependencies
+```sh
+$ TEST_GREP="arrow functions destructuring parameters" make test
+```
 
-+ [ast-types](http://ghub.io/ast-types) This is required to monkeypatch regenerators AST definitions. Could be improved in the future.
+To enable the Node.js debugger added in v6.3.0, set the `TEST_DEBUG` environment variable:
 
-+ [chalk](http://ghub.io/chalk) This is used for terminal color highlighting for syntax errors.
+```sh
+$ TEST_DEBUG=true make test
+```
 
-+ [convert-source-map](http://ghub.io/convert-source-map) Turns a source map object into a comment etc.
+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).
 
-+ [core-js](http://ghub.io/core-js) Used for the polyfill.
+To overwrite any test fixtures when fixing a bug or anything, add the env variable `OVERWRITE=true`
 
-+ [debug](http://ghub.io/debug) Used to output debugging information when NODE_DEBUG is set to babel.
+```sh
+$ OVERWRITE=true TEST_ONLY=babel-plugin-transform-classes make test-only
+```
 
-+ [detect-indent](http://ghub.io/detect-indent) This is used in the code generator so it can infer indentation.
+To test the code coverage, use:
 
-+ [estraverse](http://ghub.io/estraverse) The only method on this is attachComments. I'd like to implement our own comment attachment algorithm eventually though.
+```sh
+$ BABEL_ENV=cov make build
+$ ./scripts/test-cov.sh
+```
 
-+ [esutils](http://ghub.io/esutils) Various ES related utilities. Check whether something is a keyword etc.
+#### Troubleshooting Tests
 
-+ [fs-readdir-recursive](http://ghub.io/fs-readdir-recursive) Recursively search a directory for.
+In case you're not able to reproduce an error on CI locally, it may be due to
 
-+ [globals](http://ghub.io/globals) A list of JavaScript global variables. This is used by the scope tracking to check for colliding variables.
+ - 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
 
-+ [is-integer](http://ghub.io/is-integer) Checks if something is an integer.
+In case you're locally getting errors which are not on the CI, it may be due to
 
-+ [js-tokens](http://ghub.io/js-tokens) This is used to get tokens for syntax error highlighting.
+ - Updates in Dependencies: Make sure you run `make bootstrap` before you run `make build` or `make watch` before you run the tests.
 
-+ [leven](http://ghub.io/leven) A levenstein algorithm to determine how close a word is to another. This is used to offer suggestions when using the utility.undeclaredVariableCheck transformer.
+### Writing tests
 
-+ [line-numbers](http://ghub.io/line-numbers) Used to produce the code frames in syntax errors.
+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).
 
-+ [lodash](http://ghub.io/lodash) Used for various utilities.
+#### `@babel/plugin-x`
 
-+ [minimatch](http://ghub.io/minimatch) This is used to match glob-style ignore/only filters.
+All the Babel plugins (and other packages) that have a `/test/fixtures` are written in a similar way.
 
-+ [output-file-sync](http://ghub.io/output-file-sync) Synchronously writes a file and create its ancestor directories if needed.
+For example, in [`@babel/plugin-transform-exponentiation-operator/test`](https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-exponentiation-operator/test):
 
-+ [path-is-absolute](http://ghub.io/path-is-absolute) Checks if a path is absolute. C:\foo and \foo are considered absolute.
+- 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": ["@babel/plugin-transform-exponentiation-operator"] }`.
+   - If necessary, you can have an `options.json` with different options in each subfolder.
 
-+ [regenerator](http://ghub.io/regenerator) This is used to transform generators/async functions.
+- 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 [`input.js`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/binary/input.js) file and an [`output.js`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/binary/output.js) file. This kind of test only works in sub-subdirectories of `/fixtures`, i.e. `/fixtures/exponentian-operator/binary/input.js` and **not** `/fixtures/exponentian-operator/input.js`.
+   - If you need to expect an error, you can ignore creating the `output.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.
 
-+ [regexpu](http://ghub.io/regexpu) Used to transform unicode regex patterns.
+In a fixture test, you simply write out the code you want to transform in `input.js`.
 
-+ [repeating](http://ghub.io/repeating) Repeats a string.
+```js
+// input.js
+2 ** 2;
+```
 
-+ [shebang-regex](http://ghub.io/shebang-regex) Literally just a regex that matches shebangs.
+and the expected output after transforming it with your `options.json` in `output.js`.
 
-+ [slash](http://ghub.io/slash) Normalises path separators.
+```js
+// output.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.
 
-+ [source-map](http://ghub.io/source-map) Generates sourcemaps.
+```js
+// exec.js
+expect(2 ** 3).toBe(8);
+expect(3 * 2 ** 3).toBe(24);
+```
 
-+ [source-map-support](http://ghub.io/source-map-support) Adds source map support to babel-node/babel/register.
+If you need to check for an error that is thrown you can add to the `options.json`
 
-+ [strip-json-comments](http://ghub.io/strip-json-comments) Remove comments from a JSON string. This is used for .babelrc files.
+```js
+// options.json example
+{
+  "plugins": [["@babel/plugin-proposal-object-rest-spread", { "useBuiltIns": "invalidOption" }]],
+  "throws": "@babel/plugin-proposal-object-rest-spread currently only accepts a boolean option for useBuiltIns (defaults to false)"
+}
+```
 
-+ [to-fast-properties](http://ghub.io/to-fast-properties) A V8 trick to put an object into fast properties mode.
+If the test requires a minimum Node version, you can add `minNodeVersion` (must be in semver format).
 
-+ [trim-right](http://ghub.io/trim-right) Trims the rightside whitespace.
+```js
+// options.json example
+{
+  "minNodeVersion": "5.0.0"
+}
+```
 
-+ [user-home](http://ghub.io/user-home) Gets the users home directory. This is used to resolve the babel-node/babel/register cache.
+#### `@babel/parser` (babylon)
 
+Writing tests for the babel parser is very
+similar to the other packages.
+Inside the `packages/babel-parser/test/fixtures` folder are categories/groupings of test fixtures (es2015, flow,
+etc.). To add a test, create a folder under one of these groupings (or create a new one) with a
+descriptive name, and add the following:
 
-#### Code Standards
+* Create an `input.js` file that contains the code you want the babel parser to parse.
 
- * **General**
-   * Max of five arguments for functions
-   * Max depth of four nested blocks
-   * 2-spaced soft tabs
+* Add an `output.json` file with the expected parser output. For added convenience, if there is no `output.json` present, the test runner will generate one for you.
 
- * **Naming**
-   * CamelCase all class names
-   * camelBack all variable names
+After writing tests for @babel/parser, just build it by running:
 
- * **Spacing**
-   * Spaces after all keywords
-   * Spaces before all left curly braces
+```sh
+$ make build
+```
 
- * **Comments**
-   * Use JSDoc-style comments for methods
-   * Single-line comments for ambiguous code
+Then, to run the tests, use:
 
- * **Quotes**
-   * Always use double quotes
-   * Only use single quotes when the string contains a double quote
+```sh
+$ TEST_ONLY=babel-parser make test-only
+```
 
- * **Declaration**
-   * No unused variables
-   * No pollution of global variables and prototypes
+#### Bootstrapping expected output
+
+For both `@babel/plugin-x` and `@babel/parser`, you can easily generate an `output.js`/`output.json` automatically by just providing `input.js` and running the tests as you usually would.
+
+```
+// Example
+- packages
+  - babel-parser
+    - test
+      - fixtures
+        - comments
+          - basic
+            - block-trailing-comment
+              - input.js
+              - output.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.
+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.
+
+## Creating a new plugin (`spec-new`)
+
+> Example: https://github.com/babel/babylon/pull/541
+
+- Create a new issue that describes the proposal (ex: [#538](https://github.com/babel/babylon/issues/538)). Include any relevant information like proposal repo/author, examples, parsing approaches, meeting notes, presentation slides, and more.
+- The pull request should include:
+  - [ ] An update to the [plugins](https://github.com/babel/babel/tree/master/packages/babel-parser#plugins) part of the readme. Add a new entry to that list for the new plugin flag (and link to the proposal)
+  - [ ] If any new nodes or modifications need to be added to the AST, update [ast/spec.md](https://github.com/babel/babel/blob/master/packages/babel-parser/ast/spec.md)
+  - [ ] Make sure you use the `this.hasPlugin("plugin-name-here")` check in the babel parser so that your new plugin code only runs when that flag is turned on (not default behavior)
+  - [ ] Add failing/passing tests according to spec behavior
+- Start working about the Babel transform itself!
+
+## Internals
+- AST spec ([babel-parser/ast/spec.md](https://github.com/babel/babel/blob/master/packages/babel-parser/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 +1,168 @@
+"use strict";
+
+const plumber = require("gulp-plumber");
+const through = require("through2");
+const chalk = require("chalk");
+const newer = require("gulp-newer");
+const babel = require("gulp-babel");
+const gulpWatch = require("gulp-watch");
+const fancyLog = require("fancy-log");
+const filter = require("gulp-filter");
+const gulp = require("gulp");
+const path = require("path");
+const webpack = require("webpack");
+const rollup = require("rollup");
+const rollupBabel = require("rollup-plugin-babel");
+const rollupNodeResolve = require("rollup-plugin-node-resolve");
+const rollupReplace = require("rollup-plugin-replace");
+const { registerStandalonePackageTask } = require("./scripts/gulp-tasks");
+
+const defaultSourcesGlob = "./@(codemods|packages)/*/src/**/*.js";
+
+function swapSrcWithLib(srcPath) {
+  const parts = srcPath.split(path.sep);
+  parts[2] = "lib";
+  return parts.join(path.sep);
+}
+
+function getIndexFromPackage(name) {
+  return `${name}/src/index.js`;
+}
+
+function compilationLogger() {
+  return through.obj(function(file, enc, callback) {
+    fancyLog(`Compiling '${chalk.cyan(file.relative)}'...`);
+    callback(null, file);
+  });
+}
+
+function errorsLogger() {
+  return plumber({
+    errorHandler(err) {
+      fancyLog(err.stack);
+    },
+  });
+}
+
+function rename(fn) {
+  return through.obj(function(file, enc, callback) {
+    file.path = fn(file);
+    callback(null, file);
+  });
+}
+
+function buildBabel(exclude, sourcesGlob = defaultSourcesGlob) {
+  const base = __dirname;
+
+  let stream = gulp.src(sourcesGlob, { base: __dirname });
+
+  if (exclude) {
+    const filters = exclude.map(p => `!**/${p}/**`);
+    filters.unshift("**");
+    stream = stream.pipe(filter(filters));
+  }
+
+  return stream
+    .pipe(errorsLogger())
+    .pipe(newer({ dest: base, map: swapSrcWithLib }))
+    .pipe(compilationLogger())
+    .pipe(babel())
+    .pipe(
+      // Passing 'file.relative' because newer() above uses a relative
+      // path and this keeps it consistent.
+      rename(file => path.resolve(file.base, swapSrcWithLib(file.relative)))
+    )
+    .pipe(gulp.dest(base));
+}
+
+function buildRollup(packages) {
+  return Promise.all(
+    packages.map(pkg => {
+      const input = getIndexFromPackage(pkg);
+      fancyLog(`Compiling '${chalk.cyan(input)}' with rollup ...`);
+      return rollup
+        .rollup({
+          input,
+          plugins: [
+            rollupReplace({
+              "process.env.NODE_ENV": JSON.stringify(process.env.NODE_ENV),
+            }),
+            rollupBabel({
+              envName: "babel-parser",
+            }),
+            rollupNodeResolve(),
+          ],
+        })
+        .then(bundle => {
+          return bundle.write({
+            file: path.join(pkg, "lib/index.js"),
+            format: "cjs",
+            name: "babel-parser",
+            sourcemap: process.env.NODE_ENV !== "production",
+          });
+        });
+    })
+  );
+}
+
+const bundles = ["packages/babel-parser"];
+
+gulp.task("build-rollup", () => buildRollup(bundles));
+gulp.task("build-babel", () => buildBabel(/* exclude */ bundles));
+gulp.task("build-babel-types", () =>
+  buildBabel(/* exclude */ bundles, "packages/babel-types/src/**/*.js")
+);
+gulp.task("build", gulp.parallel("build-rollup", "build-babel"));
+
+gulp.task("default", gulp.series("build"));
+
+gulp.task("build-no-bundle", () => buildBabel());
+
+gulp.task(
+  "watch",
+  gulp.series("build-no-bundle", function watch() {
+    gulpWatch(
+      defaultSourcesGlob,
+      { debounceDelay: 200 },
+      gulp.task("build-no-bundle")
+    );
+  })
+);
+
+registerStandalonePackageTask(
+  gulp,
+  "babel",
+  "Babel",
+  path.join(__dirname, "packages"),
+  require("./packages/babel-standalone/package.json").version
+);
+
+const presetEnvWebpackPlugins = [
+  new webpack.NormalModuleReplacementPlugin(
+    /\.\/available-plugins/,
+    require.resolve(
+      path.join(
+        __dirname,
+        "./packages/babel-preset-env-standalone/src/available-plugins"
+      )
+    )
+  ),
+  new webpack.NormalModuleReplacementPlugin(
+    /caniuse-lite\/data\/regions\/.+/,
+    require.resolve(
+      path.join(
+        __dirname,
+        "./packages/babel-preset-env-standalone/src/caniuse-lite-regions"
+      )
+    )
+  ),
+];
+
+registerStandalonePackageTask(
+  gulp,
+  "babel-preset-env",
+  "babelPresetEnv",
+  path.join(__dirname, "packages"),
+  require("./packages/babel-preset-env-standalone/package.json").version,
+  presetEnvWebpackPlugins
+);

LICENSE

@@ -1,7 +1,7 @@
-Copyright (c) 2014-2015 Sebastian McKenzie <sebmck@gmail.com>
-
 MIT License
 
+Copyright (c) 2014-present Sebastian McKenzie and other contributors
+
 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

@@ -1,125 +1,256 @@
-MAKEFLAGS = -j1
-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
-#UGLIFY_CMD = node_modules/uglify-js/bin/uglifyjs --mangle sort
-MOCHA_CMD = node_modules/mocha/bin/_mocha
-BABEL_CMD = node_modules/babel/bin/babel
+FLOW_COMMIT = 09669846b7a7ca5a6c23c12d56bb3bebdafd67e9
+TEST262_COMMIT = 8688c4ab79059c3097098605e69f1ee5eda6c409
 
-export NODE_ENV = test
+# Fix color output until TravisCI fixes https://github.com/travis-ci/travis-ci/issues/7967
+export FORCE_COLOR = true
 
-.PHONY: clean test test-cov test-clean test-travis test-simple test-all test-browser test-parser publish build bootstrap publish-core publish-runtime build-core watch-core build-core-test clean-core
+SOURCES = packages codemods
 
-build-core: clean-core
-	node $(BABEL_CMD) src --out-dir lib --copy-files
+.PHONY: build build-dist watch lint fix clean test-clean test-only test test-ci publish bootstrap
 
-build-core-test: clean-core
-	node $(BABEL_CMD) src --out-dir lib --copy-files --auxiliary-comment "istanbul ignore next"
+build: build-bundle
+ifneq ("$(BABEL_COVERAGE)", "true")
+	$(MAKE) build-standalone
+endif
 
-watch-core: clean-core
-	node $(BABEL_CMD) src --out-dir lib --watch --copy-files
+build-bundle: clean clean-lib
+	yarn gulp build
+	$(MAKE) generate-standalone generate-type-helpers
+	# call build again as the generated files might need to be compiled again.
+	yarn gulp build
+	$(MAKE) build-typings
+	$(MAKE) build-dist
 
-clean-core:
-	rm -rf lib
+build-bundle-ci: bootstrap-only
+	$(MAKE) build-bundle
 
-build:
-	mkdir -p dist
-	make build-core
+generate-standalone:
+	node packages/babel-standalone/scripts/generate.js
 
-	node tools/cache-templates
+generate-type-helpers:
+	node packages/babel-types/scripts/generateTypeHelpers.js
 
-	node $(BROWSERIFY_CMD) -e lib/babel/polyfill.js >dist/polyfill.js
-	node $(UGLIFY_CMD) dist/polyfill.js >dist/polyfill.min.js
+build-typings: build-flow-typings build-typescript-typings
 
-	node $(BROWSERIFY_CMD) lib/babel/api/browser.js -s babel >dist/babel.js
-	node $(UGLIFY_CMD) dist/babel.js >dist/babel.min.js
+build-flow-typings:
+	node packages/babel-types/scripts/generators/flow.js > packages/babel-types/lib/index.js.flow
 
-	node packages/babel-cli/bin/babel-external-helpers >dist/external-helpers.js
-	node $(UGLIFY_CMD) dist/external-helpers.js >dist/external-helpers.min.js
+build-typescript-typings:
+	node packages/babel-types/scripts/generators/typescript.js > packages/babel-types/lib/index.d.ts
 
-	rm -rf templates.json
+build-standalone: build-babel-standalone build-preset-env-standalone
 
-clean:
-	rm -rf coverage templates.json test/tmp dist lib
+build-standalone-ci: build-bundle-ci
+	$(MAKE) build-standalone
+
+build-babel-standalone:
+	yarn gulp build-babel-standalone
+
+build-preset-env-standalone:
+	yarn gulp build-babel-preset-env-standalone
+
+prepublish-build-standalone:
+	BABEL_ENV=production IS_PUBLISH=true yarn gulp build-babel-standalone
+
+prepublish-build-preset-env-standalone:
+	BABEL_ENV=production IS_PUBLISH=true yarn gulp build-babel-preset-env-standalone
+
+build-dist: build-polyfill-dist build-plugin-transform-runtime-dist
+
+build-polyfill-dist:
+	cd packages/babel-polyfill; \
+	scripts/build-dist.sh
+
+build-plugin-transform-runtime-dist:
+	cd packages/babel-plugin-transform-runtime; \
+	node scripts/build-dist.js
+
+build-no-bundle: clean clean-lib
+	BABEL_ENV=development yarn gulp build-no-bundle
+	# Ensure that build artifacts for types are created during local
+	# development too.
+	$(MAKE) generate-type-helpers
+	$(MAKE) build-typings
+
+watch: build-no-bundle
+	BABEL_ENV=development yarn gulp watch
+
+code-quality-ci: flowcheck-ci lint-ci
+
+flowcheck-ci: bootstrap-flowcheck
+	$(MAKE) flow
+
+code-quality: flow lint
+
+flow:
+	yarn flow check --strip-root
+
+bootstrap-flowcheck: bootstrap-only
+	yarn gulp build-babel-types
+	$(MAKE) build-typings
+
+lint-ci: lint-js-ci lint-ts-ci
+
+lint-js-ci: bootstrap-only
+	$(MAKE) lint-js
+
+lint-ts-ci: bootstrap-flowcheck
+	$(MAKE) lint-ts
+
+lint: lint-js lint-ts
+
+lint-js:
+	yarn eslint scripts $(SOURCES) '*.js' --format=codeframe
+
+lint-ts:
+	scripts/tests/typescript/lint.sh
+
+fix: fix-json fix-js
+
+fix-js:
+	yarn eslint scripts $(SOURCES) '*.js' --format=codeframe --fix
+
+fix-json:
+	yarn prettier "{packages,codemod}/*/test/fixtures/**/options.json" --write --loglevel warn
+
+clean: test-clean
+	rm -f .npmrc
+	rm -rf packages/babel-polyfill/browser*
+	rm -rf packages/babel-polyfill/dist
+	rm -rf coverage
+	rm -rf packages/*/npm-debug*
 
 test-clean:
-	rm -rf test/tmp
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-test, $(source)))
 
-test: test-parser
-	node $(MOCHA_CMD) test/core
-	make test-clean
+# Does not work on Windows; use "yarn jest" instead
+test-only:
+	BABEL_ENV=test ./scripts/test.sh
+	$(MAKE) test-clean
 
-test-all:
-	export ALL_BABEL_TESTS=1; \
-	make test
+test: lint test-only
 
-test-cov:
-	rm -rf coverage
-	make build-core-test
-	node $(ISTANBUL_CMD) $(MOCHA_CMD) -- test/core
+test-ci: jest-ci
 
-test-parser:
-	node test/acorn/run.js
+jest-ci: build-standalone-ci
+	BABEL_ENV=test yarn jest --maxWorkers=4 --ci
+	$(MAKE) test-clean
 
-test-travis: bootstrap build test
+# Does not work on Windows
+test-ci-coverage: SHELL:=/bin/bash
+test-ci-coverage:
+	BABEL_COVERAGE=true BABEL_ENV=test $(MAKE) bootstrap
+	BABEL_ENV=test TEST_TYPE=cov ./scripts/test-cov.sh
+	bash <(curl -s https://codecov.io/bash) -f coverage/coverage-final.json
 
-test-browser:
-	mkdir -p dist
+bootstrap-flow:
+	rm -rf build/flow
+	mkdir -p build
+	git clone --branch=master --single-branch --shallow-since=2018-11-01 https://github.com/facebook/flow.git build/flow
+	cd build/flow && git checkout $(FLOW_COMMIT)
 
-	node tools/cache-templates
-	node tools/build-tests
-	node $(BROWSERIFY_CMD) -e test/core/_browser.js >dist/babel-test.js
-	rm -rf templates.json tests.json
+test-flow:
+	node scripts/tests/flow/run_babel_parser_flow_tests.js
 
-	test -n "`which open`" && open test/browser.html
+test-flow-ci: build-bundle-ci bootstrap-flow
+	$(MAKE) test-flow
 
-publish:
+test-flow-update-whitelist:
+	node scripts/tests/flow/run_babel_parser_flow_tests.js --update-whitelist
+
+bootstrap-test262:
+	rm -rf build/test262
+	mkdir -p build
+	git clone --branch=master --single-branch --shallow-since=2019-09-01 https://github.com/tc39/test262.git build/test262
+	cd build/test262 && git checkout $(TEST262_COMMIT)
+
+test-test262:
+	node scripts/tests/test262/run_babel_parser_test262.js
+
+test-test262-ci: build-bundle-ci bootstrap-test262
+	$(MAKE) test-test262
+
+test-test262-update-whitelist:
+	node scripts/tests/test262/run_babel_parser_test262.js --update-whitelist
+
+# Does not work on Windows
+clone-license:
+	./scripts/clone-license.sh
+
+prepublish-build: clean-lib clean-runtime-helpers
+	NODE_ENV=production BABEL_ENV=production $(MAKE) build
+	$(MAKE) clone-license
+
+prepublish:
+	$(MAKE) bootstrap-only
+	$(MAKE) prepublish-build
+	$(MAKE) test
+
+new-version:
 	git pull --rebase
+	yarn lerna version --force-publish="@babel/runtime,@babel/runtime-corejs2,@babel/runtime-corejs3,@babel/standalone,@babel/preset-env-standalone"
 
-	make test
+# NOTE: Run make new-version first
+publish: prepublish
+	yarn lerna publish from-git
+	$(MAKE) clean
 
-	read -p "Version: " version; \
-	npm version $$version --message "v%s"
+publish-ci: prepublish
+ifneq ("$(NPM_TOKEN)", "")
+	echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" > .npmrc
+else
+	echo "Missing NPM_TOKEN env var"
+	exit 1
+endif
+	yarn lerna publish from-git --yes
+	rm -f .npmrc
+	$(MAKE) clean
 
-	make build
+bootstrap-only: lerna-bootstrap
 
-	cp dist/babel.js browser.js
-	cp dist/babel.min.js browser.min.js
+yarn-install: clean-all
+	yarn --ignore-engines
 
-	cp dist/polyfill.js browser-polyfill.js
-	cp dist/polyfill.min.js browser-polyfill.min.js
+lerna-bootstrap: yarn-install
+	yarn lerna bootstrap
 
-	cp dist/external-helpers.js external-helpers.js
-	cp dist/external-helpers.min.js external-helpers.min.js
+bootstrap: bootstrap-only
+	$(MAKE) build
 
-	node tools/cache-templates
-	test -f templates.json
+clean-lib:
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-lib, $(source)))
 
-	npm publish
+clean-runtime-helpers:
+	rm -rf packages/babel-runtime/helpers
+	rm -rf packages/babel-runtime-corejs2/helpers
+	rm -rf packages/babel-runtime-corejs2/core-js
 
-	git push --follow-tags
+clean-all:
+	rm -rf node_modules
+	rm -rf package-lock.json
+	rm -rf .changelog
 
-	make publish-cli
-	make publish-runtime
+	$(foreach source, $(SOURCES), \
+		$(call clean-source-all, $(source)))
 
-	rm -rf templates.json browser.js browser.min.js browser-polyfill.js browser-polyfill.min.js external-helpers.js external-helpers.min.js
+	$(MAKE) clean
 
-publish-runtime:
-	cd packages; \
-	node build-runtime.js; \
-	cd babel-runtime; \
-	npm publish
+define clean-source-lib
+	rm -rf $(1)/*/lib
 
-publish-cli:
-	cd packages; \
-	node build-cli.js; \
-	cd babel-cli; \
-	npm publish
+endef
 
-bootstrap:
-	npm list --global --depth 1 babel >/dev/null 2>&1 && npm uninstall -g babel || true
-	npm install
-	npm link
-	cd packages/babel-cli && npm install && npm link && npm link babel-core
-	git submodule update --init
-	make build
+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

README.md

@@ -1,17 +1,121 @@
 <p align="center">
   <a href="https://babeljs.io/">
-    <img alt="babel" src="https://raw.githubusercontent.com/babel/logo/master/logo.png" width="546">
+    <img alt="babel" src="https://raw.githubusercontent.com/babel/logo/master/babel.png" width="546">
   </a>
 </p>
 
 <p align="center">
-  <strong>Babel</strong> is a compiler for writing next generation JavaScript.
+  The compiler for writing next generation JavaScript.
 </p>
 
 <p align="center">
-  For questions and support please visit the <a href="https://gitter.im/babel/babel">gitter room</a> or <a href="http://stackoverflow.com/questions/tagged/babeljs">StackOverflow</a>. The Babel issue tracker is <strong>exclusively</strong> for bug reports and feature requests.
+    <a href="https://www.npmjs.com/package/@babel/core"><img alt="v7 npm Downloads" src="https://img.shields.io/npm/dm/@babel/core.svg?maxAge=43200&label=v7%20downloads"></a>
+  <a href="https://www.npmjs.com/package/babel-core"><img alt="v6 npm Downloads" src="https://img.shields.io/npm/dm/babel-core.svg?maxAge=43200&label=v6%20downloads"></a>
+</p>
+<p align="center">
+  <a href="https://travis-ci.com/babel/babel"><img alt="Travis Status" src="https://img.shields.io/travis/com/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://twitter.com/intent/follow?screen_name=babeljs"><img alt="Follow on Twitter" src="https://img.shields.io/twitter/follow/babeljs.svg?style=social&label=Follow"></a>
 </p>
 
+<h2 align="center">Supporting Babel</h2>
+
 <p align="center">
-  For documentation and website issues please visit the <a href="https://github.com/babel/babel.github.io">babel.github.io</a> repo.
+  <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 (pronounced ["babble"](https://soundcloud.com/sebmck/how-to-pronounce-babel))  is a community-driven project used by many companies and projects, and is maintained by a group of [volunteers](https://babeljs.io/team). If you'd like to help support the future of the project, please consider:
+
+- Giving developer time on the project. (Message us on [Twitter](https://twitter.com/babeljs) or [Slack](https://slack.babeljs.io/) for guidance!)
+- Giving funds by becoming a sponsor on [Open Collective](https://opencollective.com/babel) or [Patreon](https://www.patreon.com/henryzhu)!
+
+## Sponsors
+
+Our top sponsors are shown below! [[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>
+
+## 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
+
+### Who maintains Babel?
+
+Mostly a handful of volunteers, funded by you! Please check out our [team page](https://babeljs.io/team)!
+
+### Is there a Babel song?
+
+I'm so glad you asked: [Hallelujah —— In Praise of Babel](SONG.md) by [@angus-c](https://github.com/angus-c), [audio version](https://youtu.be/40abpedBKK8) by [@swyx](https://twitter.com/@swyx). Tweet us your recordings!
+
+### Looking for support?
+
+For questions and support please join our [Slack Community](https://slack.babeljs.io/) (you can sign-up [here](https://slack.babeljs.io/) for an invite), ask a question on [Stack Overflow](https://stackoverflow.com/questions/tagged/babeljs), or ping us on [Twitter](https://twitter.com/babeljs).
+
+### Where are the docs?
+
+Check out our website: [babeljs.io](https://babeljs.io/), and report issues/features at [babel/website](https://github.com/babel/website/issues).
+
+### Want to report a bug or request a feature?
+
+Please read through our [CONTRIBUTING.md](CONTRIBUTING.md) and fill out the issue template at [babel/issues](https://github.com/babel/babel/issues)!
+
+### Want to contribute to Babel?
+
+Check out:
+
+- Our [#development](https://babeljs.slack.com/messages/development) Slack channel and say hi ([signup](https://slack.babeljs.io))!
+- 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. We suggest also looking at the [closed ones](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aclosed+label%3A%22good+first+issue%22) to get a sense of the kinds of issues you can tackle.
+
+Some resources:
+
+- Our [CONTRIBUTING.md](CONTRIBUTING.md) to get started with setting up the repo.
+- Our discussions/notes/roadmap: [babel/notes](https://github.com/babel/notes)
+- Our progress on TC39 proposals: [babel/proposals](https://github.com/babel/proposals)
+- Our blog which contains release posts and explainations: [/blog](https://babeljs.io/blog)
+- Our videos page with talks about open source and Babel: [/videos](https://babeljs.io/videos)
+- Our [podcast](https://podcast.babeljs.io)
+
+### How is the repo structured?
+
+The Babel repo is managed as a [monorepo](doc/design/monorepo.md) that is composed of many [npm packages](packages/README.md).
+
+## License
+
+[MIT](LICENSE)

SECURITY.md

@@ -0,0 +1,19 @@
+# Security Policy
+
+## Supported Versions
+
+This is the list of versions of `babel` which are
+currently being supported with security updates.
+
+| Version  | Supported          |
+| -------- | ------------------ |
+| 7.x      | :white_check_mark: |
+| 6.26.x   | :white_check_mark: |
+| < 6.26.0 | :x:                |
+
+## Reporting a Vulnerability
+
+To report a vulnerability please send an email with the details to security@babeljs.io. 
+This will help us to assess the risk and start the necessary steps.
+
+Thanks for helping to keep babel secure.

SONG.md

@@ -0,0 +1,80 @@
+## Hallelujah—In Praise of Babel
+
+➤ [🎶 Audio version here!](https://youtu.be/40abpedBKK8)
+
+I heard there was a clever trick  
+That rewrote all your JavaScript  
+But you don’t really care for magic, do you  
+Well it goes like this: the source, the dist  
+The ES five, the ES six  
+The sacred script transforming Hallelujah  
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+So I added all the shiny things  
+Classes, spreads and template strings  
+Through syntax sugared code I tried to woo you  
+Generators, const and let  
+I used them all without regret  
+And it’s a terse and a destructured Hallelujah  
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+Well my faith was strong but I needed proof  
+The standard was my source of truth  
+But TC39 meant nothing to you  
+So even though you weren’t impressed  
+I checked the build against the spec  
+And it’s a more-or-less compliant Hallelujah  
+
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+Now you say the build step’s too complex  
+And you claim no need for ES Next  
+Well I used to think that way before I knew you  
+But your code grows older with each line  
+It’s a joyless dirge on a withered vine  
+It’s a threnody for a bygone Hallelujah  
+
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+Yes I learned about the danger signs  
+How they’d polyfilled a thousand lines  
+The cost of using Maps and Symbols threw you  
+Still I disregarded common sense  
+Now my source is small but the build’s immense  
+And it’s a slow and unresponsive Hallelujah  
+
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+There was a time when they let me know  
+What’s really going on below  
+But now there’s only source maps there to school you  
+And debugging’s not a progress march  
+It’s a frenzied fumble in the dark  
+It’s a labyrinthine search for Hallelujah  
+
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+Well, maybe there’s a god up there  
+But all I ever got from prayers  
+Was broken builds and errors that would spook you  
+And that anguished cry you hear at night  
+Is the plugin I forgot to write  
+It’s a cold and it’s a broken Hallelujah  
+
+
+Hallelujah, Hallelujah  
+Hallelujah, Hallelujah
+
+[Angus Croll](https://github.com/angus-c)  

babel.config.js

@@ -0,0 +1,140 @@
+"use strict";
+
+module.exports = function(api) {
+  const env = api.env();
+
+  const includeCoverage = process.env.BABEL_COVERAGE === "true";
+
+  const envOptsNoTargets = {
+    loose: true,
+    modules: false,
+    exclude: ["transform-typeof-symbol"],
+  };
+  const envOpts = Object.assign({}, envOptsNoTargets);
+
+  let convertESM = true;
+  let ignoreLib = true;
+  let includeRuntime = false;
+  const nodeVersion = "6.9";
+
+  switch (env) {
+    // Configs used during bundling builds.
+    case "babel-parser":
+      convertESM = false;
+      ignoreLib = false;
+      envOpts.targets = {
+        node: nodeVersion,
+      };
+      break;
+    case "standalone":
+      convertESM = false;
+      ignoreLib = false;
+      includeRuntime = true;
+      break;
+    case "production":
+      // Config during builds before publish.
+      envOpts.targets = {
+        node: nodeVersion,
+      };
+      break;
+    case "development":
+      envOpts.debug = true;
+      envOpts.targets = {
+        node: "current",
+      };
+      break;
+    case "test":
+      envOpts.targets = {
+        node: "current",
+      };
+      break;
+  }
+
+  const config = {
+    // Our dependencies are all standard CommonJS, along with all sorts of
+    // other random files in Babel's codebase, so we use script as the default,
+    // and then mark actual modules as modules farther down.
+    sourceType: "script",
+    comments: false,
+    ignore: [
+      // These may not be strictly necessary with the newly-limited scope of
+      // babelrc searching, but including them for now because we had them
+      // in our .babelignore before.
+      "packages/*/test/fixtures",
+      ignoreLib ? "packages/*/lib" : null,
+      "packages/babel-standalone/babel.js",
+      "packages/babel-preset-env-standalone/babel-preset-env.js",
+    ].filter(Boolean),
+    presets: [["@babel/env", envOpts]],
+    plugins: [
+      // TODO: Use @babel/preset-flow when
+      // https://github.com/babel/babel/issues/7233 is fixed
+      "@babel/plugin-transform-flow-strip-types",
+      ["@babel/proposal-class-properties", { loose: true }],
+      "@babel/proposal-export-namespace-from",
+      "@babel/proposal-numeric-separator",
+      [
+        "@babel/proposal-object-rest-spread",
+        { useBuiltIns: true, loose: true },
+      ],
+      "@babel/plugin-proposal-optional-chaining",
+      "@babel/plugin-proposal-nullish-coalescing-operator",
+
+      convertESM ? "@babel/transform-modules-commonjs" : null,
+    ].filter(Boolean),
+    overrides: [
+      {
+        test: "packages/babel-parser",
+        plugins: [
+          "babel-plugin-transform-charcodes",
+          ["@babel/transform-for-of", { assumeArray: true }],
+        ],
+      },
+      {
+        test: ["./packages/babel-cli", "./packages/babel-core"],
+        plugins: [
+          // Explicitly use the lazy version of CommonJS modules.
+          convertESM
+            ? ["@babel/transform-modules-commonjs", { lazy: true }]
+            : null,
+        ].filter(Boolean),
+      },
+      {
+        test: "./packages/babel-polyfill",
+        presets: [["@babel/env", envOptsNoTargets]],
+      },
+      {
+        // The vast majority of our src files are modules, but we use
+        // unambiguous to keep things simple until we get around to renaming
+        // the modules to be more easily distinguished from CommonJS
+        test: [
+          "packages/*/src",
+          "packages/*/test",
+          "codemods/*/src",
+          "codemods/*/test",
+        ],
+        sourceType: "unambiguous",
+      },
+      {
+        // The runtime transform shouldn't process its own runtime or core-js.
+        exclude: [
+          "packages/babel-runtime",
+          /[\\/]node_modules[\\/](?:@babel\/runtime|babel-runtime|core-js)[\\/]/,
+        ],
+        plugins: [
+          includeRuntime
+            ? ["@babel/transform-runtime", { version: "7.4.4" }]
+            : null,
+        ].filter(Boolean),
+      },
+    ].filter(Boolean),
+  };
+
+  // we need to do this as long as we do not test everything from source
+  if (includeCoverage) {
+    config.auxiliaryCommentBefore = "istanbul ignore next";
+    config.plugins.push("babel-plugin-istanbul");
+  }
+
+  return config;
+};

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": [
+
+        ]
+    }]
+}

codecov.yml

@@ -0,0 +1,12 @@
+coverage:
+  parsers:
+    javascript:
+      enable_partials: yes
+  status:
+    project:
+      default:
+        target: "80%"
+    patch:
+      enabled: false
+ignore:
+  - packages/babel-types/src/*/generated/index.js

codemods/babel-plugin-codemod-object-assign-to-object-spread/.npmignore

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

codemods/babel-plugin-codemod-object-assign-to-object-spread/README.md

@@ -0,0 +1,57 @@
+# @babel/plugin-codemod-object-assign-to-object-spread
+
+Transforms old code that uses `Object.assign` with an Object Literal as
+the first param to use Object Spread syntax.
+
+## Examples
+
+```js
+const obj = Object.assign({
+  test1: 1,
+}, other, {
+  test2: 2,
+}, other2);
+```
+
+Is transformed to:
+
+```js
+const obj = {
+  test1: 1,
+  ...other,
+  test2: 2,
+  ...other2,
+};
+```
+
+## Installation
+
+```sh
+npm install --save-dev @babel/plugin-codemod-object-assign-to-object-spread
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```jsonc
+{
+  "plugins": ["@babel/plugin-codemod-object-assign-to-object-spread"]
+}
+```
+
+### Via CLI
+
+```sh
+babel --plugins @babel/plugin-codemod-object-assign-to-object-spread script.js
+```
+
+### Via Node API
+
+```javascript
+require("@babel/core").transform("code", {
+  plugins: ["@babel/plugin-codemod-object-assign-to-object-spread"]
+});
+```

codemods/babel-plugin-codemod-object-assign-to-object-spread/package.json

@@ -0,0 +1,28 @@
+{
+  "name": "@babel/plugin-codemod-object-assign-to-object-spread",
+  "version": "7.0.0",
+  "description": "Transforms Object.assign into object spread syntax",
+  "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-object-assign-to-object-spread",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "lib/index.js",
+  "keywords": [
+    "@babel/codemod",
+    "@babel/plugin"
+  ],
+  "dependencies": {
+    "@babel/plugin-syntax-object-rest-spread": "^7.0.0"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0-0"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.0.0",
+    "@babel/helper-plugin-test-runner": "^7.0.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/src/index.js

@@ -0,0 +1,35 @@
+import syntaxObjectRestSpread from "@babel/plugin-syntax-object-rest-spread";
+
+export default function({ types: t }) {
+  return {
+    inherits: syntaxObjectRestSpread,
+
+    visitor: {
+      CallExpression(path) {
+        if (!path.get("callee").matchesPattern("Object.assign")) return;
+
+        const args = path.get("arguments");
+        if (args.length === 0) return;
+
+        const [objPath] = args;
+        if (!objPath.isObjectExpression()) return;
+
+        const obj = objPath.node;
+        const { properties } = obj;
+
+        for (let i = 1; i < args.length; i++) {
+          const arg = args[i];
+          const { node } = arg;
+
+          if (arg.isObjectExpression()) {
+            properties.push(...node.properties);
+          } else {
+            properties.push(t.spreadElement(node));
+          }
+        }
+
+        path.replaceWith(obj);
+      },
+    },
+  };
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1}, {test: 2});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/options.json

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

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/output.js

@@ -0,0 +1,4 @@
+({
+  test: 1,
+  test: 2
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1}, test2, {test: 2}, test3);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/options.json

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

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/output.js

@@ -0,0 +1,6 @@
+({
+  test: 1,
+  ...test2,
+  test: 2,
+  ...test3
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/input.js

@@ -0,0 +1 @@
+Object.assign(test);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/options.json

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

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/output.js

@@ -0,0 +1 @@
+Object.assign(test);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/options.json

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

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/output.js

@@ -0,0 +1,3 @@
+({
+  test: 1
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/index.js

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

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 +1,59 @@
+# @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**
+
+```jsonc
+{
+  "plugins": ["@babel/plugin-codemod-optional-catch-binding"]
+}
+```
+
+### Via CLI
+
+```sh
+babel --plugins @babel/plugin-codemod-optional-catch-binding script.js
+```
+
+### Via Node API
+
+```javascript
+require("@babel/core").transform("code", {
+  plugins: ["@babel/plugin-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 +1,25 @@
+{
+  "name": "@babel/plugin-codemod-optional-catch-binding",
+  "version": "7.0.0",
+  "description": "Remove unused catch bindings",
+  "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-remove-unused-catch-binding",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "lib/index.js",
+  "keywords": [
+    "@babel/codemod",
+    "@babel/plugin"
+  ],
+  "dependencies": {
+    "@babel/plugin-syntax-optional-catch-binding": "^7.0.0"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0-0"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.0.0",
+    "@babel/helper-plugin-test-runner": "^7.0.0"
+  }
+}

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

@@ -0,0 +1,23 @@
+import syntaxOptionalCatchBinding from "@babel/plugin-syntax-optional-catch-binding";
+
+export default function({ types: t }) {
+  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-null-binding/input.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-null-binding/output.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-array-pattern-binding/input.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-array-pattern-binding/output.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-binding/input.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/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/output.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-object-pattern-binding/input.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-unused-object-pattern-binding/output.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-used-array-pattern-binding/input.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-array-pattern-binding/output.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-binding-variable/input.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-variable/output.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/input.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-binding/output.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-object-pattern-binding/input.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-block-used-object-pattern-binding/output.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-finally-unused-binding/input.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/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/output.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-used-binding/input.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/fixtures/codemod-optional-catch-binding/try-catch-finally-used-binding/output.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/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/babel/blob/master/packages/babel-parser/ast/spec.md) has been moved to the babel parser package, `packages/babel-parser`.

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 6 and newer 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 run together which finds bugs that touch multiple modules more easily.
+
+**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.

lerna.json

@@ -0,0 +1,37 @@
+{
+  "version": "7.7.0",
+  "changelog": {
+    "repo": "babel/babel",
+    "cacheDir": ".changelog",
+    "labels": {
+      "PR: Spec Compliance :eyeglasses:": ":eyeglasses: Spec Compliance",
+      "PR: Breaking Change :boom:": ":boom: Breaking Change",
+      "PR: New Feature :rocket:": ":rocket: New Feature",
+      "PR: Bug Fix :bug:": ":bug: Bug Fix",
+      "PR: Polish :nail_care:": ":nail_care: Polish",
+      "PR: Docs :memo:": ":memo: Documentation",
+      "PR: Internal :house:": ":house: Internal",
+      "PR: Performance :running_woman:": ":running_woman: Performance"
+    }
+  },
+  "command": {
+    "publish": {
+      "ignoreChanges": [
+        "*.md",
+        "*.txt",
+        "test/**",
+        "codemods/**",
+        "# We ignore every JSON file, except for built-in-modules, built-ins and plugins defined in babel-preset-env/data.",
+        "@(!(built-in-modules|built-ins|plugins|package)).json"
+      ]
+    }
+  },
+  "packages": [
+    "codemods/*",
+    "packages/*"
+  ],
+  "npmClient": "yarn",
+  "npmClientArgs": [
+    "--no-lockfile"
+  ]
+}