v7.0.0-beta.54

Treat string ignore/only/test/include/exclude values as paths with only basic pattern matching

.babelignore

@@ -1,5 +0,0 @@
-# Ensure babel-register won't compile fixtures, or try to recompile compiled code.
-packages/*/test/fixtures
-packages/*/lib
-packages/babel-standalone/babel.js
-packages/babel-preset-env-standalone/babel-preset-env.js

.babelrc.js

@@ -1,80 +0,0 @@
-"use strict";
-
-module.exports = function(api) {
-  const env = api.env();
-
-  const includeCoverage = process.env.BABEL_COVERAGE === "true";
-
-  const envOpts = {
-    loose: true,
-    modules: false,
-    exclude: ["transform-typeof-symbol"],
-  };
-
-  let convertESM = true;
-
-  switch (env) {
-    // Configs used during bundling builds.
-    case "babylon":
-    case "standalone":
-      convertESM = false;
-      break;
-    case "production":
-      // Config during builds before publish.
-      break;
-    case "development":
-      envOpts.debug = true;
-      envOpts.targets = {
-        node: "current",
-      };
-      break;
-    case "test":
-      envOpts.targets = {
-        node: "current",
-      };
-      break;
-  }
-
-  const config = {
-    comments: false,
-    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 }],
-
-      // Explicitly use the lazy version of CommonJS modules.
-      convertESM ? ["@babel/transform-modules-commonjs", { lazy: true }] : null,
-    ].filter(Boolean),
-    overrides: [
-      {
-        test: "packages/babylon",
-        plugins: [
-          "babel-plugin-transform-charcodes",
-          ["@babel/transform-for-of", { assumeArray: true }],
-        ],
-      },
-      {
-        test: "./packages/babel-register",
-        plugins: [
-          // Override the root options to disable lazy imports for babel-register
-          // because otherwise the require hook will try to lazy-import things
-          // leading to dependency cycles.
-          convertESM ? "@babel/transform-modules-commonjs" : null,
-        ].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;
-};

.circleci/config.yml

@@ -18,11 +18,6 @@ aliases:
       - ~/.yarn-cache
     key: v1-yarn-cache
 
-  - &yarn-install
-    run: |
-      sudo npm i -g yarn@^1.5.1
-      yarn --version
-
   - &artifact_babel
     path: ~/babel/packages/babel-standalone/babel.js
 
@@ -39,12 +34,12 @@ jobs:
   build:
     working_directory: ~/babel
     docker:
-      - image: circleci/node:9
+      - image: circleci/node:10
     steps:
       - checkout
       - restore-cache: *restore-yarn-cache
       - restore-cache: *restore-node-modules-cache
-      - *yarn-install
+      - run: yarn --version
       - run: make test-ci-coverage
       # Builds babel-standalone with the regular Babel config
       - run: make build
@@ -58,4 +53,4 @@ jobs:
       - store_artifacts: *artifact_env
       - store_artifacts: *artifact_env_min
       - save_cache: *save-node-modules-cache
-      - save_cache: *save-yarn-cache
+      - save_cache: *save-yarn-cache

.eslintignore

@@ -1,6 +1,8 @@
 /lib
 /build
+/.git
 package.json
+lerna.json
 packages/babel-runtime
 !packages/babel-runtime/scripts
 !packages/babel-runtime/core-js.js
@@ -20,4 +22,4 @@ 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/babylon/test/expressions
+packages/babel-parser/test/expressions

.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 Compliancy**
+  * 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 proplery 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 Compliancy**
+  * `for...of` now outputs in a lengthy `try...catch` this is to ensure spec compliancy 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 refered 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 +1,839 @@
+# 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 Compliancy**
+  * 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 arbitary positions not in Program statement position.
+  * Throw error when attemping 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 Compliancy**
+  * 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 Compliancy**
+  * 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 `minfication.propertyLiterals` and `es3.memberExpressionLiterals`.
+
+## 5.2.6
+
+ * **Internal**
+  * Fix transformer aliases being accidently 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 Compliancy**
+  * Fix object decorators not using the `initializer` pattern.
+  * Remove property initializer descriptor reflection.
+
+## 5.1.11
+
+ * **Bug Fix**
+  * Memoise and bind member expression decorators.
+  * Move JSX children cleaning to opening element visitor. Fixes elements not being cleaned in certain scenarios.
+  * Consider `SwitchStatement`s to be `Scopable`.
+  * Fix `bluebirdCoroutines` calling `interopRequireWildcard` before it's defined.
+  * Add space to `do...while` code generation.
+  * Validate `super` use before `this` on `super` exit rather than entrance.
+ * **Polish**
+  * Add Babel name to logger.
+
+## 5.1.10
+
+ * **Bug Fix**
+  * Remove `makePredicate` from acorn in favor of an `indexOf`.
+  * Remove statements to expression explosion when inserting a block statement.
+ * **Internal**
+  * Remove runtime compatibility check.
+
+## 5.1.9
+
+ * **Bug Fix**
+  * Fix class property initializers with `undefined` values not being correctly writable.
+  * Fix self inferring generators incorrectly causing a stack error.
+  * Fix default export specifiers not triggering AMD `module` argument inclusion.
+  * Fix assignments not having their module references properly remapped.
+ * **Internal**
+  * Upgrade to latest `acorn`.
+ * **Polish**
+  * Make invalid LHS pattern error messages nicer.
+
+## 5.1.8
+
+ * **Bug Fix**
+  * Only make parenthesized object pattern LHS illegal.
+
+## 5.1.7
+
+ * **Internal**
+  * Add `parse` node API.
+
+## 5.1.6
+
+ * **Bug Fix**
+  * Fix `runtime` built-in catchall not properly checking for local variables.
+
+## 5.1.5
+
+ * **Internal**
+  * Bump `core-js` version.
+
+## 5.1.4
+
+ * **Polish**
+  * Add missing `Reflect` methods to runtime transformer.
+
+## 5.1.3
+
+ * **Internal**
+  * Switch entirely to vanilla regenerator.
+  * Clean up and make the parsing of decorators stateless.
+ * **Bug Fix**
+  * Don't do TCO on generators and async functions.
+  * Add missing `core-js` runtime definitions.
+
+## 5.1.2
+
+ * **Bug Fix**
+  * Add `getIterator` and `isIterable` to `babel-runtime` build script.
+
+## 5.1.1
+
+ * **Bug Fix**
+  * Add missing runtime symbol definitions.
+
+## 5.1.0
+
+ * **Bug Fix**
+  * Fix super reference when using decorators.
+  * Don't do array unpack optimisation when member expressions are present.
+  * Add missing descriptors for undecorated class properties.
+  * Don't consider `arguments` and `eval` valid function names when doing function name inferrence.
+  * Fix scope tracking of constants in loop heads.
+  * Parse `AwaitExpression` as a unary instead of an assignment.
+  * Fix regex evaluation when attempting static evaluation.
+  * Don't emit tokens when doing a lookahead.
+  * Add missing `test` declaration to `utility.deadCodeElimination` transformer.
+ * **Internal**
+  * Upgrade `regenerator` to the latest and use my branch with the hope of eventually switching to vanilla regenerator.
+  * Add support for the replacement of for loop `init`s with statements.
+  * Upgrade dependencies.
+ * **Polish**
+  * When adding the scope IIFE when using default parameters, don't shadow the function expression, just `apply` `this` and `arguments` if necessary.
+  * Use path basename as non-default import fallback.
+ * **New Feature**
+  * Add [trailing function comma proposal](https://github.com/jeffmo/es-trailing-function-commas). Thanks [@AluisioASG](https://github.com/AluisioASG)!
+  * Add support for object literal decorators.
+  * Make core-js modular when using the `runtime` transformer.
+
+## 5.0.12
+
+ * **Bug Fix**
+  * Fix incorrect remapping of module references inside of a function id redirection container.
+
+## 5.0.11
+
+ * **Bug Fix**
+  * Fix new `for...of` loops not properly inheriting their original loop.
+ * **Internal**
+  * Disable scope instance cache.
+ * **Polish**
+  * Allow comments in `.babelrc` JSON.
+
+## 5.0.9
+
+ * **Polish**
+  * Use `moduleId` for UMD global name if available.
+ * **Bug Fix**
+  * Fix UMD global `module` variable shadowing the `amd`/`common` `module` variable.
+  * Fix Flow param type annotation regression.
+  * Fix function name collision `toString` wrapper. Thanks [@alawatthe](https://github.com/alawatthe)!
+
+## 5.0.8
+
+ * **Bug Fix**
+  * Fix falsy static class properties not being writable.
+  * Fix block scoping collisions not properly detecting modules and function clashes.
+  * Skip `this` before `super` for derived constructors on functions.
+
+## 5.0.7
+
+ * **New Feature**
+  * Add `--ignore` and `--only` support to the CLI.
+ * **Bug Fix**
+  * Remove `HOMEPATH` environment variable from home resolution in `babel/register` cache.
+ * **Internal**
+  * Disable WIP path resolution introducing infinite recursion in some code examples.
+ * **Polish**
+  * Add live binding to CommonJS default imports.
+
+## 5.0.6
+
+ * **Bug Fix**
+  * Fix mangling of import references that collide with properties on `Object.prototype`.
+  * Fix duplicate declarations incorrectly being reported for `var`.
+
+## 5.0.5
+
+ * **Internal**
+  * Upgrade `core-js`.
+ * **Bug Fix**
+  * Fix arrays not being supported in `util.list`.
+
+## 5.0.4
+
+ * **Polish**
+  * Check for top level `breakConfig` in `resolveRc`.
+
+## 5.0.3
+
+ * **Bug Fix**
+  * Make relative location absolute before calling `resolveRc`.
+ * **Internal**
+  * Switch to global UID registry.
+  * Add `breakConfig` option to prevent Babel from erroring when hitting that option.
+
+## 5.0.1
+
+ * **Bug Fix**
+  * Fix duplicate declaration regression.
+  * Fix not being able to call non-writable methods.
+
+## 5.0.0
+
+ * **New Feature**
+  * 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 reliablity 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 reassinging 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

@@ -1,63 +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!
-
-If you have a support request or question please submit them to one of this resources:
-
-* Slack Community: https://slack.babeljs.io/
-* StackOverflow: http://stackoverflow.com/questions/tagged/babeljs using the tag `babeljs`
-* Also have a look at the readme for more information on how to get support:
-  https://github.com/babel/babel/blob/master/README.md
-
-Issues on GitHub are only related to problems of Babel itself and we cannot answer 
-support questions here.
 -->
-
-Choose one: is this a bug report or feature request?
-
-<!--- Provide a general summary of the issue in the title above -->
-
-### Input Code
-<!--- If you're describing a bug, please let us know which sample code reproduces your problem -->
-<!--- If you have link to our REPL or a standalone repo please link that! -->
-
-```js
-var your => (code) => here;
-```
-
-### Babel/Babylon Configuration (.babelrc, package.json, cli command)
-<!--- If describing a bug, tell us what your babel configuration looks like -->
-
-```js
-{
-  "your": { "config": "here" }
-}
-```
-
-### Expected Behavior
-<!--- If you're describing a bug, tell us what should happen -->
-<!--- If you're suggesting a change/improvement, tell us how it should work -->
-
-### Current Behavior
-<!--- If describing a bug, tell us what happens instead of the expected behavior -->
-<!--- If suggesting a change/improvement, explain the difference from current behavior -->
-
-### Possible Solution
-<!--- Not obligatory, but suggest a fix/reason for the bug, -->
-<!--- or ideas how to implement the addition or change -->
-
-### Context
-<!--- How has this issue affected you? What are you trying to accomplish? -->
-<!--- Providing context helps us come up with a solution that is most useful in the real world -->
-
-### Your Environment
-<!--- Include as many relevant details about the environment you experienced the bug in -->
-
-| software         | version(s)
-| ---------------- | -------
-| Babel            |  
-| Babylon          | <!-- This is only needed if you are using Babylon directly -->
-| node             | 
-| npm              | 
-| Operating System | 

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -0,0 +1,41 @@
+---
+name: 🐛 Bug Report
+about: If something isn't working as expected 🤔.
+
+---
+
+## 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 +1,20 @@
+---
+name: 🚀 Feature Request
+about: I have a suggestion (and may want to implement it 🙂)!
+
+---
+
+## 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 +1,41 @@
+---
+name: 💥 v7 Regression
+about: Report an unexpected behavior in v7 from v6 (Check the upgrade guide first ✌️)
+
+---
+
+# v7 Regression
+
+> First check out: https://new.babeljs.io/docs/en/next/v7-migration.html
+> 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 +1,16 @@
+---
+name: 🤗 Support Question
+about: If you have a question 💬, please check out our Slack or StackOverflow!
+
+---
+
+--------------^ 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 +1,24 @@
+---
+name: 🤝 Support us on Babel
+about: If you would like to support our efforts in maintaining this community-driven project 🙌!
+
+---
+
+--------------^ 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

@@ -1,8 +1,10 @@
 <!--
-Before making a PR please make sure to read our contributing guidelines
+Before making a PR, please read our contributing guidelines
 https://github.com/babel/babel/blob/master/CONTRIBUTING.md
 
-For issue references: Add a comma-separated list of a [closing word](https://help.github.com/articles/closing-issues-via-commit-messages/) followed by the ticket number fixed by the PR. It should be underlined in the preview if done correctly.
+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 👍) -->
@@ -12,7 +14,7 @@ For issue references: Add a comma-separated list of a [closing word](https://hel
 | Major: Breaking Change?  |
 | Minor: New Feature?      |
 | Tests Added + Pass?      | Yes
-| Documentation PR         | <!-- If so, add `[skip ci]` to your commit message to skip CI -->
+| Documentation PR Link    | <!-- If only readme change, add `[skip ci]` to your commits -->
 | Any Dependency Changes?  |
 | License                  | MIT
 

.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
+only: issues
+lockLabel: 'outdated'
+
+# Issues or pull requests with these labels will not be locked
+# exemptLabels:
+#   - no-locking

.gitignore

@@ -42,5 +42,6 @@ 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/babylon/build
+/packages/babel-parser/build
 .idea/
+/.changelog

.prettierignore

@@ -1 +1,2 @@
 package.json
+packages/babel-preset-env/data

.travis.yml

@@ -5,12 +5,12 @@ language: node_js
 cache:
   yarn: true
   directories:
-  - node_modules
+    - node_modules
 node_js:
   # We test the latest version on circleci
+  - '9'
   - '8'
   - '6'
-  - '4'
 
 env:
   global:
@@ -23,14 +23,14 @@ before_install:
 install: yarn --ignore-engines
 
 before_script:
-  - 'if [ "$JOB" = "babylon-flow-tests" ]; then make bootstrap-flow; fi'
-  - 'if [ "$JOB" = "babylon-test262-tests" ]; then make bootstrap-test262; fi'
+  - 'if [ "$JOB" = "babel-parser-flow-tests" ]; then make bootstrap-flow; fi'
+  - 'if [ "$JOB" = "babel-parser-test262-tests" ]; then make bootstrap-test262; fi'
 
 script:
   - 'if [ "$JOB" = "test" ]; then make test-ci; fi'
   - 'if [ "$JOB" = "lint" ]; then make lint && make flow; fi'
-  - 'if [ "$JOB" = "babylon-flow-tests" ]; then make test-flow-ci; fi'
-  - 'if [ "$JOB" = "babylon-test262-tests" ]; then make test-test262-ci; fi'
+  - 'if [ "$JOB" = "babel-parser-flow-tests" ]; then make test-flow-ci; fi'
+  - 'if [ "$JOB" = "babel-parser-test262-tests" ]; then make test-test262-ci; fi'
 
 matrix:
   fast_finish: true
@@ -38,9 +38,9 @@ matrix:
     - node_js: "node"
       env: JOB=lint
     - node_js: "node"
-      env: JOB=babylon-flow-tests
+      env: JOB=babel-parser-flow-tests
     - node_js: "node"
-      env: JOB=babylon-test262-tests
+      env: JOB=babel-parser-test262-tests
 
 notifications:
   slack:

CONTRIBUTING.md

@@ -24,23 +24,24 @@ contributing, please read the
 ## 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/babylon/ast/spec.md) is a bit different from [ESTree](https://github.com/estree/estree). The differences are listed [here](https://github.com/babel/babel/tree/master/packages/babylon#output).
+ - [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://github.com/babel/babel/tree/master/packages/babel-parser#output).
  - Check out [`/doc`](https://github.com/babel/babel/tree/master/doc) for information about Babel's internals
  - Check out [the Babel Plugin Handbook](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#babel-plugin-handbook) - core plugins are written the same way as any other plugin!
  - Check out [AST Explorer](http://astexplorer.net/#/scUfOmVOG5) to learn more about ASTs or make your own plugin in the browser
 - When you feel ready to jump into the Babel source code, a good place to start is to look for issues tagged with [help wanted](https://github.com/babel/babel/labels/help%20wanted) and/or [good first issue](https://github.com/babel/babel/labels/good%20first%20issue).
-- Follow along with what we are working on by joining our Slack, following our announcements on [Twitter](https://twitter.com/babeljs), and reading (or participating!) in our [meeting notes](https://github.com/babel/notes).
+- 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)
 
 ## Chat
 
-Feel free to check out the `#discussion`/`#development` channels on our [Slack](https://slack.babeljs.io). Some of us are always online to 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
 
 **Note:** Versions `< 5.1.10` can't be built.
 
-Babel is built for Node 4 and up but we develop using Node 8 and yarn. You can check this with `node -v`.
+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.
@@ -139,6 +140,12 @@ $ TEST_DEBUG=true make test
 
 You can combine `TEST_DEBUG` with `TEST_GREP` or `TEST_ONLY` to debug a subset of tests. If you plan to stay long in the debugger (which you'll likely do!), you may increase the test timeout by editing [test/mocha.opts](https://github.com/babel/babel/blob/master/test/mocha.opts).
 
+To overwrite any test fixtures when fixing a bug or anything, add the env variable `OVERWRITE=true`
+
+```sh
+$ OVERWRITE=true TEST_ONLY=babel-plugin-transform-classes make test-only
+```
+
 To test the code coverage, use:
 
 ```sh
@@ -196,8 +203,8 @@ In an `exec.js` test, we run or check that the code actually does what it's supp
 
 ```js
 // exec.js
-assert.equal(8, 2 ** 3);
-assert.equal(24, 3 * 2 ** 3);
+expect(2 ** 3).toBe(8);
+expect(3 * 2 ** 3).toBe(24);
 ```
 
 If you need to check for an error that is thrown you can add to the `options.json`
@@ -219,19 +226,19 @@ If the test requires a minimum Node version, you can add `minNodeVersion` (must
 }
 ```
 
-#### `babylon`
+#### `@babel/parser` (babylon)
 
-Writing tests for Babylon is very
+Writing tests for the babel parser is very
 similar to the other packages.
-Inside the `packages/babylon/tests/fixtures` folder are categories/groupings of test fixtures (es2015, flow,
+Inside the `packages/babel-parser/tests/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:
 
-* Create an `input.js` file that contains the code you want Babylon to parse.
+* Create an `input.js` file that contains the code you want the babel parser to parse.
 
 * 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.
 
-After writing tests for babylon, just build it by running:
+After writing tests for @babel/parser, just build it by running:
 
 ```sh
 $ make build
@@ -240,17 +247,17 @@ $ make build
 Then, to run the tests, use:
 
 ```sh
-$ TEST_ONLY=babylon make test-only
+$ TEST_ONLY=babel-parser make test-only
 ```
 
 #### Bootstrapping expected output
 
-For both `@babel/plugin-x` and `babylon`, you can easily generate an `output.js`/`output.json` automatically by just providing `input.js` and running the tests as you usually would.
+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
-  - babylon
+  - babel-parser
     - test
       - fixtures
         - comments
@@ -302,14 +309,14 @@ Note that the code shown in Chrome DevTools is compiled code and therefore diffe
 
 - 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/babylon#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/bloc/master/packages/babylon/ast/spec.md)
-  - [ ] Make sure you use the `this.hasPlugin("plugin-name-here")` check in Babylon so that your new plugin code only runs when that flag is turned on (not default behavior)
+  - [ ] 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/bloc/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 ([babylon/ast/spec.md](https://github.com/babel/babel/blob/master/packages/babylon/ast/spec.md))
+- 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))

Gulpfile.js

@@ -5,7 +5,7 @@ const through = require("through2");
 const chalk = require("chalk");
 const newer = require("gulp-newer");
 const babel = require("gulp-babel");
-const watch = require("gulp-watch");
+const gulpWatch = require("gulp-watch");
 const gutil = require("gulp-util");
 const filter = require("gulp-filter");
 const gulp = require("gulp");
@@ -98,9 +98,7 @@ function buildRollup(packages) {
         format: "cjs",
         plugins: [
           rollupBabel({
-            envName: "babylon",
-            babelrc: false,
-            extends: "./.babelrc.js",
+            envName: "babel-parser",
           }),
           rollupNodeResolve(),
         ],
@@ -114,21 +112,26 @@ function buildRollup(packages) {
   );
 }
 
-gulp.task("default", ["build"]);
-
 gulp.task("build", function() {
-  const bundles = ["packages/babylon"];
+  const bundles = ["packages/babel-parser"];
 
   return merge([buildBabel(/* exclude */ bundles), buildRollup(bundles)]);
 });
 
+gulp.task("default", gulp.series("build"));
+
 gulp.task("build-no-bundle", () => buildBabel());
 
-gulp.task("watch", ["build-no-bundle"], function() {
-  watch(sources.map(getGlobFromSource), { debounceDelay: 200 }, function() {
-    gulp.start("build-no-bundle");
-  });
-});
+gulp.task(
+  "watch",
+  gulp.series("build-no-bundle", function watch() {
+    gulpWatch(
+      sources.map(getGlobFromSource),
+      { debounceDelay: 200 },
+      gulp.task("build-no-bundle")
+    );
+  })
+);
 
 registerStandalonePackageTask(
   gulp,

Makefile

@@ -1,8 +1,6 @@
 MAKEFLAGS = -j1
-FLOW_COMMIT = 622bbc4f07acb77eb1109830c70815f827401d90
-TEST262_COMMIT = 52f70e2f637731aae92a9c9a2d831310c3ab2e1e
-
-export BABEL_ENV = test
+FLOW_COMMIT = 395e045c18d537fcbbc552a96ef2cdcd70b4ab52
+TEST262_COMMIT = f90a52b39609a620c0854e0bd0b3a906c930fd17
 
 # Fix color output until TravisCI fixes https://github.com/travis-ci/travis-ci/issues/7967
 export FORCE_COLOR = true
@@ -19,8 +17,6 @@ build: clean clean-lib
 	# generate flow and typescript typings
 	node scripts/generators/flow.js > ./packages/babel-types/lib/index.js.flow
 	node scripts/generators/typescript.js > ./packages/babel-types/lib/index.d.ts
-	# generate docs
-	node scripts/generators/docs.js > ./packages/babel-types/README.md
 ifneq ("$(BABEL_COVERAGE)", "true")
 	make build-standalone
 	make build-preset-env-standalone
@@ -51,12 +47,10 @@ flow:
 	./node_modules/.bin/flow check --strip-root
 
 lint:
-	./node_modules/.bin/eslint scripts $(SOURCES) '*.js' '**/.*.js' --format=codeframe --rulesdir="./scripts/eslint_rules"
+	./node_modules/.bin/eslint scripts $(SOURCES) '*.js' --format=codeframe --rulesdir="./scripts/eslint_rules"
 
 fix:
-	# The config is hardcoded because otherwise prettier searches for it and also picks up some broken package.json files from tests
-	./node_modules/.bin/prettier --config .prettierrc --write --ignore-path .eslintignore '**/*.json'
-	./node_modules/.bin/eslint scripts $(SOURCES) '*.js' '**/.*.js' --format=codeframe --fix --rulesdir="./scripts/eslint_rules"
+	./node_modules/.bin/eslint scripts $(SOURCES) '*.js' --format=codeframe --fix --rulesdir="./scripts/eslint_rules"
 
 clean: test-clean
 	rm -rf packages/babel-polyfill/browser*
@@ -69,7 +63,7 @@ test-clean:
 		$(call clean-source-test, $(source)))
 
 test-only:
-	./scripts/test.sh
+	BABEL_ENV=test ./scripts/test.sh
 	make test-clean
 
 test: lint test-only
@@ -79,7 +73,7 @@ test-ci: bootstrap test-only
 test-ci-coverage: SHELL:=/bin/bash
 test-ci-coverage:
 	BABEL_COVERAGE=true BABEL_ENV=test make bootstrap
-	TEST_TYPE=cov ./scripts/test-cov.sh
+	BABEL_ENV=test TEST_TYPE=cov ./scripts/test-cov.sh
 	bash <(curl -s https://codecov.io/bash) -f coverage/coverage-final.json
 
 bootstrap-flow:
@@ -89,12 +83,12 @@ bootstrap-flow:
 	cd build/flow && git checkout $(FLOW_COMMIT)
 
 test-flow:
-	node scripts/tests/flow/run_babylon_flow_tests.js
+	node scripts/tests/flow/run_babel_parser_flow_tests.js
 
 test-flow-ci: bootstrap test-flow
 
 test-flow-update-whitelist:
-	node scripts/tests/flow/run_babylon_flow_tests.js --update-whitelist
+	node scripts/tests/flow/run_babel_parser_flow_tests.js --update-whitelist
 
 bootstrap-test262:
 	rm -rf ./build/test262
@@ -103,12 +97,12 @@ bootstrap-test262:
 	cd build/test262 && git checkout $(TEST262_COMMIT)
 
 test-test262:
-	node scripts/tests/test262/run_babylon_test262.js
+	node scripts/tests/test262/run_babel_parser_test262.js
 
 test-test262-ci: bootstrap test-test262
 
 test-test262-update-whitelist:
-	node scripts/tests/test262/run_babylon_test262.js --update-whitelist
+	node scripts/tests/test262/run_babel_parser_test262.js --update-whitelist
 
 publish:
 	git pull --rebase
@@ -136,6 +130,7 @@ clean-lib:
 clean-all:
 	rm -rf node_modules
 	rm -rf package-lock.json
+	rm -rf .changelog
 
 	$(foreach source, $(SOURCES), \
 		$(call clean-source-all, $(source)))

README.md

@@ -24,108 +24,12 @@
   <a href="https://medium.com/friendship-dot-js/i-peeked-into-my-node-modules-directory-and-you-wont-believe-what-happened-next-b89f63d21558"><img alt="Business Strategy Status" src="https://img.shields.io/badge/business%20model-flavortown-green.svg"></a>
 </p>
 
-Babel is community-driven and thus mostly maintained by a group of [volunteers](https://babeljs.io/team). It has a lot of [companies and projects](https://babeljs.io/users) using it but almost no sponsors/people funded to work on it. If you'd like to help maintain the future of the project, please consider:
+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/))
-- [Giving funds by becoming a backer/sponsor on OpenCollective](https://opencollective.com/babel)
+- 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 (see below)!
 
-## Intro
-
-Babel is a tool that helps you write code in the latest version of JavaScript. When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
-
-**In**
-
-```js
-// ES2015 arrow function
-[1, 2, 3].map((n) => n + 1);
-```
-
-**Out**
-
-```js
-[1, 2, 3].map(function(n) {
-  return n + 1;
-});
-```
-
-Try it out at our [REPL](https://babeljs.io/repl/build/master#?code_lz=NoRgNATGDMC6B0BbAhgBwBQDsAEBeAfNjgNTYgCUA3EA&lineWrap=true&presets=es2015%2Ces2016%2Ces2017&version=7.0.0-beta.2).
-
-- [FAQ](#faq)
-- [Backers](#backers)
-- [Sponsors](#sponsors)
-- [License](#license)
-
-## FAQ
-
-### Who maintains Babel?
-
-Mostly a handful of volunteers! Please check out our [team page](https://babeljs.io/team)!
-
-### Looking for support?
-
-For questions and support please visit join our [Slack Community](https://slack.babeljs.io/), ask a question on [Stack Overflow](https://stackoverflow.com/questions/tagged/babeljs), or ping us on [Twitter](https://twitter.com/babeljs).
-
-### 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). Tweet us your recordings!
-
-### 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 [CONTRIBUTING.md](CONTRIBUTING.md) to get started with setting up the repo.
-
-- If you have already joined Slack, join our [#development](https://babeljs.slack.com/messages/development) channel and say hi!
-- Check out the issues with the [good first issue](https://github.com/babel/babel/labels/good%20first%20issue) and [help wanted](https://github.com/babel/babel/labels/help%20wanted) label. We suggest also looking at the closed ones to get a sense of the kinds of issues you can tackle.
-- Our discussions/notes/roadmap: [babel/notes](https://github.com/babel/notes)
-- Our progress on TC39 proposals: [babel/proposals](https://github.com/babel/proposals)
-
-### How is the repo structured?
-
-The Babel repo is managed as a [monorepo](doc/design/monorepo.md) that is composed of many [npm packages](packages/README.md).
-
-## Backers
-
-Support us with a monthly donation and help us continue our activities. [[Become a backer](https://opencollective.com/babel#backer)]
-
-<a href="https://opencollective.com/babel/backer/0/website" target="_blank"><img src="https://opencollective.com/babel/backer/0/avatar.svg"></a>
-<a href="https://opencollective.com/babel/backer/1/website" target="_blank"><img src="https://opencollective.com/babel/backer/1/avatar.svg"></a>
-<a href="https://opencollective.com/babel/backer/2/website" target="_blank"><img src="https://opencollective.com/babel/backer/2/avatar.svg"></a>
-<a href="https://opencollective.com/babel/backer/3/website" target="_blank"><img src="https://opencollective.com/babel/backer/3/avatar.svg"></a>
-<a href="https://opencollective.com/babel/backer/4/website" target="_blank"><img src="https://opencollective.com/babel/backer/4/avatar.svg"></a>
-<a href="https://opencollective.com/babel/backer/5/website" target="_blank"><img src="https://opencollective.com/babel/backer/5/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/6/website" target="_blank"><img src="https://opencollective.com/babel/backer/6/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/7/website" target="_blank"><img src="https://opencollective.com/babel/backer/7/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/8/website" target="_blank"><img src="https://opencollective.com/babel/backer/8/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/9/website" target="_blank"><img src="https://opencollective.com/babel/backer/9/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/10/website" target="_blank"><img src="https://opencollective.com/babel/backer/10/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/11/website" target="_blank"><img src="https://opencollective.com/babel/backer/11/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/12/website" target="_blank"><img src="https://opencollective.com/babel/backer/12/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/13/website" target="_blank"><img src="https://opencollective.com/babel/backer/13/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/14/website" target="_blank"><img src="https://opencollective.com/babel/backer/14/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/15/website" target="_blank"><img src="https://opencollective.com/babel/backer/15/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/16/website" target="_blank"><img src="https://opencollective.com/babel/backer/16/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/17/website" target="_blank"><img src="https://opencollective.com/babel/backer/17/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/18/website" target="_blank"><img src="https://opencollective.com/babel/backer/18/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/19/website" target="_blank"><img src="https://opencollective.com/babel/backer/19/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/20/website" target="_blank"><img src="https://opencollective.com/babel/backer/20/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/21/website" target="_blank"><img src="https://opencollective.com/babel/backer/21/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/22/website" target="_blank"><img src="https://opencollective.com/babel/backer/22/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/23/website" target="_blank"><img src="https://opencollective.com/babel/backer/23/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/24/website" target="_blank"><img src="https://opencollective.com/babel/backer/24/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/25/website" target="_blank"><img src="https://opencollective.com/babel/backer/25/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/26/website" target="_blank"><img src="https://opencollective.com/babel/backer/26/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/27/website" target="_blank"><img src="https://opencollective.com/babel/backer/27/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/28/website" target="_blank"><img src="https://opencollective.com/babel/backer/28/avatar.svg"></a>
-  <a href="https://opencollective.com/babel/backer/29/website" target="_blank"><img src="https://opencollective.com/babel/backer/29/avatar.svg"></a>
-
-## Sponsors
+## Open Collective Sponsors
 
 Become a sponsor and get your logo on our README on Github with a link to your site. [[Become a sponsor](https://opencollective.com/babel#sponsor)]
 
@@ -160,6 +64,72 @@ Become a sponsor and get your logo on our README on Github with a link to your s
   <a href="https://opencollective.com/babel/sponsor/28/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/28/avatar.svg"></a>
   <a href="https://opencollective.com/babel/sponsor/29/website" target="_blank"><img src="https://opencollective.com/babel/sponsor/29/avatar.svg"></a>
 
+## Patreon Sponsors
+
+Become a sponsor and get your logo on our README on Github with a link to your site. [[Become a sponsor](https://www.patreon.com/henryzhu)]
+
+## Bronze
+
+<a href="http://teamextension.io/" target="_blank"><img src="https://teamextension.io/dist/img/logo/te-logo-compact.png" height="64"></a>
+<a href="https://webflow.com/" target="_blank"><img src="https://opencollective.com/proxy/images/?src=https%3A%2F%2Fopencollective-production.s3-us-west-1.amazonaws.com%2F4a5024b0-8cf2-11e7-b1a2-b30b1de1463c.png&height=64"></a>
+<p><a href="https://twitter.com/mikesherov">Mike Sherov</a></p>
+
+## 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! Please check out our [team page](https://babeljs.io/team)!
+
+### Looking for support?
+
+For questions and support please visit 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).
+
+### 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!
+
+### 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 [CONTRIBUTING.md](CONTRIBUTING.md) to get started with setting up the repo.
+
+- If you have already joined Slack, join our [#development](https://babeljs.slack.com/messages/development) channel and say hi!
+- Check out the issues with the [good first issue](https://github.com/babel/babel/labels/good%20first%20issue) and [help wanted](https://github.com/babel/babel/labels/help%20wanted) label. We suggest also looking at the closed ones to get a sense of the kinds of issues you can tackle.
+- Our discussions/notes/roadmap: [babel/notes](https://github.com/babel/notes)
+- Our progress on TC39 proposals: [babel/proposals](https://github.com/babel/proposals)
+
+### How is the repo structured?
+
+The Babel repo is managed as a [monorepo](doc/design/monorepo.md) that is composed of many [npm packages](packages/README.md).
+
 ## License
 
 [MIT](LICENSE)

SONG.md

@@ -1,5 +1,7 @@
 ## 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  

babel.config.js

@@ -0,0 +1,97 @@
+"use strict";
+
+module.exports = function(api) {
+  const env = api.env();
+
+  const includeCoverage = process.env.BABEL_COVERAGE === "true";
+
+  const envOpts = {
+    loose: true,
+    modules: false,
+    exclude: ["transform-typeof-symbol"],
+  };
+
+  let convertESM = true;
+  let ignoreLib = true;
+
+  switch (env) {
+    // Configs used during bundling builds.
+    case "babel-parser":
+    case "standalone":
+      convertESM = false;
+      ignoreLib = false;
+      break;
+    case "production":
+      // Config during builds before publish.
+      envOpts.targets = {
+        node: "6.9",
+      };
+      break;
+    case "development":
+      envOpts.debug = true;
+      envOpts.targets = {
+        node: "current",
+      };
+      break;
+    case "test":
+      envOpts.targets = {
+        node: "current",
+      };
+      break;
+  }
+
+  const config = {
+    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 },
+      ],
+
+      // Explicitly use the lazy version of CommonJS modules.
+      convertESM ? ["@babel/transform-modules-commonjs", { lazy: true }] : null,
+    ].filter(Boolean),
+    overrides: [
+      {
+        test: "packages/babel-parser",
+        plugins: [
+          "babel-plugin-transform-charcodes",
+          ["@babel/transform-for-of", { assumeArray: true }],
+        ],
+      },
+      {
+        test: "./packages/babel-register",
+        plugins: [
+          // Override the root options to disable lazy imports for babel-register
+          // because otherwise the require hook will try to lazy-import things
+          // leading to dependency cycles.
+          convertESM ? "@babel/transform-modules-commonjs" : null,
+        ].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;
+};

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**
+
+```json
+{
+  "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 +1,25 @@
+{
+  "name": "@babel/plugin-codemod-object-assign-to-object-spread",
+  "version": "7.0.0-beta.54",
+  "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",
+  "main": "lib/index.js",
+  "keywords": [
+    "@babel/codemod",
+    "@babel/plugin"
+  ],
+  "dependencies": {
+    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.54"
+  },
+  "peerDependencies": {
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
+  },
+  "devDependencies": {
+    "@babel/core": "7.0.0-beta.54",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.54"
+  },
+  "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-optional-catch-binding/package.json

@@ -1,21 +1,22 @@
 {
   "name": "@babel/plugin-codemod-optional-catch-binding",
-  "version": "7.0.0-beta.43",
+  "version": "7.0.0-beta.54",
   "description": "Remove unused catch bindings",
-  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-remove-unused-catch-binding",
+  "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-remove-unused-catch-binding",
   "license": "MIT",
   "main": "lib/index.js",
   "keywords": [
+    "@babel/codemod",
     "@babel/plugin"
   ],
   "dependencies": {
-    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.43"
+    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.54"
   },
   "peerDependencies": {
-    "@babel/core": "7.0.0-beta.43"
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0-beta.43",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.43"
+    "@babel/core": "7.0.0-beta.54",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.54"
   }
 }

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

@@ -1,7 +1,6 @@
 import syntaxOptionalCatchBinding from "@babel/plugin-syntax-optional-catch-binding";
-import { types as t } from "@babel/core";
 
-export default function() {
+export default function({ types: t }) {
   return {
     inherits: syntaxOptionalCatchBinding,
 

doc/ast/spec.md

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

@@ -7,7 +7,7 @@
 The Babel compiler is **only** supported in these environments:
 
  - Modern browsers such as Chrome, Firefox, Safari, Edge etc.
- - Node.js 4 and upper versions
+ - Node.js 6 and newer versions
 
 ## Unsupported environments
 

lerna.json

@@ -1,8 +1,9 @@
 {
-  "lerna": "2.0.0-rc.4",
-  "version": "7.0.0-beta.43",
+  "lerna": "2.11.0",
+  "version": "7.0.0-beta.54",
   "changelog": {
     "repo": "babel/babel",
+    "cacheDir": ".changelog",
     "labels": {
       "PR: Spec Compliancy :eyeglasses:": ":eyeglasses: Spec Compliancy",
       "PR: Breaking Change :boom:": ":boom: Breaking Change",
@@ -13,7 +14,6 @@
       "PR: Internal :house:": ":house: Internal"
     }
   },
-  "cacheDir": ".changelog",
   "commands": {
     "publish": {
       "ignore": [

lib/third-party-libs.js.flow

@@ -26,22 +26,124 @@ declare module "lodash/defaults" {
 
 declare module "lodash/clone" {
   declare export default <T>(obj: T) => T;
- }
+}
 
 declare module "lodash/merge" {
   declare export default <T: Object>(T, Object) => T;
 }
 
-declare module "convert-source-map" {
+declare module "source-map" {
   declare export type SourceMap = {
     version: 3,
     file: ?string,
+    sourceRoot: ?string,
     sources: [?string],
     sourcesContent: [?string],
     names: [?string],
     mappings: string,
   };
 
+  declare module.exports: {
+    SourceMapConsumer: typeof SourceMapConsumer,
+    SourceMapGenerator: typeof SourceMapGenerator,
+  }
+
+  declare class SourceMapConsumer {
+    static GENERATED_ORDER: 1;
+    static ORIGINAL_ORDER: 2;
+
+    file: string | null;
+    sourceRoot: string | null;
+    sources: Array<string>;
+
+    constructor(?SourceMap): this;
+
+    computeColumnSpans(): string;
+    originalPositionFor({
+      line: number,
+      column: number,
+    }): {|
+      source: string,
+      line: number,
+      column: number,
+      name: string | null
+    |} | {|
+      source: null,
+      line: null,
+      column: null,
+      name: null
+    |};
+
+    generatedPositionFor({
+      source: string,
+      line: number,
+      column: number,
+    }): {|
+      line: number,
+      column: number,
+      lastColumn: number | null | void,
+    |} | {|
+      line: null,
+      column: null,
+      lastColumn: null | void,
+    |};
+
+    allGeneratedPositionsFor({
+      source: string,
+      line: number,
+      column: number,
+    }): Array<{|
+      line: number,
+      column: number,
+      lastColumn: number,
+    |}>;
+
+    sourceContentFor(string, boolean | void): string | null;
+
+    eachMapping(
+      ({|
+        generatedLine: number,
+        generatedColumn: number,
+        source: string,
+        originalLine: number,
+        originalColumn: number,
+        name: string | null,
+      |} | {|
+        generatedLine: number,
+        generatedColumn: number,
+        source: null,
+        originalLine: null,
+        originalColumn: null,
+        name: null,
+      |}) => mixed,
+      context: mixed,
+      order: ?(1 | 2),
+    ): void;
+  }
+
+  declare class SourceMapGenerator {
+    constructor(?{
+      file?: string | null,
+      sourceRoot?: string | null,
+      skipValidation?: boolean | null,
+    }): this;
+
+    addMapping({
+      generated: {
+        line: number,
+        column: number,
+      }
+    }): void;
+
+    setSourceContent(string, string): void;
+
+    toJSON(): SourceMap;
+  }
+}
+
+declare module "convert-source-map" {
+  import type { SourceMap } from "source-map";
+
   declare class Converter {
     toJSON(): string;
     toBase64(): string;
@@ -58,9 +160,15 @@ declare module "convert-source-map" {
     fromComment(str: string): Converter,
     fromMapFileComment(str: string): Converter,
     fromSource(str: string): Converter,
-    fromMapFileSource(str: string): Converter,
+    fromMapFileSource(str: string, dir: string): Converter,
     removeComments(str: string): string,
     removeMapFileComments(str: string): string,
     generateMapFileComment(path: string, options?: ?{ multiline: boolean }): string,
   };
 }
+
+declare module "js-levenshtein" {
+  declare module.exports: {
+    (string, string): number,
+  };
+}

package.json

@@ -10,33 +10,31 @@
     "test": "make test"
   },
   "devDependencies": {
-    "@babel/cli": "7.0.0-beta.42",
-    "@babel/core": "7.0.0-beta.42",
-    "@babel/plugin-transform-modules-commonjs": "7.0.0-beta.42",
-    "@babel/preset-env": "7.0.0-beta.42",
-    "@babel/preset-flow": "7.0.0-beta.42",
-    "@babel/preset-stage-0": "7.0.0-beta.42",
-    "@babel/register": "7.0.0-beta.42",
+    "@babel/cli": "7.0.0-beta.52",
+    "@babel/core": "7.0.0-beta.52",
+    "@babel/plugin-transform-modules-commonjs": "7.0.0-beta.52",
+    "@babel/preset-env": "7.0.0-beta.52",
+    "@babel/preset-flow": "7.0.0-beta.52",
+    "@babel/preset-stage-0": "7.0.0-beta.52",
+    "@babel/register": "7.0.0-beta.52",
     "babel-core": "^7.0.0-0",
-    "babel-eslint": "^8.0.1",
+    "babel-eslint": "^8.2.5",
     "babel-jest": "^22.4.1",
     "babel-loader": "8.0.0-beta.0",
     "babel-plugin-transform-charcodes": "^0.1.0",
-    "babylon": "7.0.0-beta.42",
     "browserify": "^13.1.1",
     "bundle-collapser": "^1.2.1",
-    "chai": "^4.1.0",
     "chalk": "^2.3.2",
     "charcodes": "^0.1.0",
     "derequire": "^2.0.2",
     "enhanced-resolve": "^3.0.0",
-    "eslint": "^4.18.2",
+    "eslint": "^5.0.1",
     "eslint-config-babel": "^7.0.2",
-    "eslint-plugin-flowtype": "^2.20.0",
-    "eslint-plugin-prettier": "^2.5.0",
-    "flow-bin": "^0.66.0",
+    "eslint-plugin-flowtype": "^2.49.3",
+    "eslint-plugin-prettier": "^2.6.1",
+    "flow-bin": "^0.75.0",
     "graceful-fs": "^4.1.11",
-    "gulp": "^3.9.0",
+    "gulp": "^4.0.0",
     "gulp-babel": "^8.0.0-beta.2",
     "gulp-filter": "^5.1.0",
     "gulp-newer": "^1.0.0",
@@ -44,22 +42,22 @@
     "gulp-rename": "^1.2.2",
     "gulp-uglify": "^3.0.0",
     "gulp-util": "^3.0.7",
-    "gulp-watch": "^4.3.5",
+    "gulp-watch": "^5.0.0",
     "husky": "^0.14.3",
     "jest": "^22.4.2",
-    "lerna": "2.0.0",
+    "lerna": "^2.11.0",
     "lerna-changelog": "^0.5.0",
     "lint-staged": "^6.0.1",
-    "lodash": "^4.2.0",
+    "lodash": "^4.17.5",
     "merge-stream": "^1.0.1",
     "output-file-sync": "^2.0.0",
-    "prettier": "1.11.1",
+    "prettier": "1.13.2",
     "pump": "^1.0.2",
     "rimraf": "^2.4.3",
     "rollup-plugin-babel": "^4.0.0-beta.0",
     "rollup-plugin-node-resolve": "^3.0.2",
     "rollup-stream": "^1.24.1",
-    "test262-stream": "^1.1.0",
+    "test262-stream": "^1.2.0",
     "through2": "^2.0.0",
     "uglify-js": "^2.4.16",
     "vinyl-buffer": "^1.0.1",
@@ -69,7 +67,7 @@
     "webpack-stream": "^4.0.0"
   },
   "engines": {
-    "node": ">= 4.x <= 9.x",
+    "node": ">= 6.9.0 <= 11.0.0-0",
     "npm": ">= 2.x <= 5.x",
     "yarn": ">=0.27.5 || >=1.0.0-20170811"
   },
@@ -90,7 +88,7 @@
       "/node_modules/",
       "/test/fixtures/",
       "/test/debug-fixtures/",
-      "/babylon/test/expressions/",
+      "/babel-parser/test/expressions/",
       "/test/tmp/",
       "/test/__data__/",
       "/test/helpers/",
@@ -107,6 +105,12 @@
       "/test/(fixtures|tmp|__data__)/",
       "<rootDir>/(packages|codemods)/[^/]+/lib/"
     ],
+    "coveragePathIgnorePatterns": [
+      "/node_modules/",
+      "<rootDir>/packages/babel-standalone/babel(\\.min)?\\.js",
+      "<rootDir>/packages/babel-preset-env-standalone/babel-preset-env(\\.min)?\\.js",
+      "/test/(fixtures|tmp|__data__)/"
+    ],
     "modulePathIgnorePatterns": [
       "/test/fixtures/",
       "/test/tmp/",

packages/README.md

@@ -14,21 +14,21 @@ A monorepo, muhahahahahaha. See the [monorepo design doc](/doc/design/monorepo.m
 | Package | Version | Dependencies |
 |--------|-------|------------|
 | [`@babel/core`](/packages/babel-core) | [![npm](https://img.shields.io/npm/v/@babel/core.svg?maxAge=2592000)](https://www.npmjs.com/package/@babel/core) | [![Dependency Status](https://david-dm.org/babel/babel.svg?path=packages/babel-core)](https://david-dm.org/babel/babel?path=packages/babel-core) |
-| [`babylon`](/packages/babylon) | [![npm](https://img.shields.io/npm/v/babylon.svg?maxAge=2592000)](https://www.npmjs.com/package/babylon) | [![Dependency Status](https://david-dm.org/babel/babel.svg?path=packages/babylon)](https://david-dm.org/babel/babel?path=packages/babylon) |
+| [`@babel/parser`](/packages/@babel/parser) | [![npm](https://img.shields.io/npm/v/@babel/parser.svg?maxAge=2592000)](https://www.npmjs.com/package/@babel/parser) | [![Dependency Status](https://david-dm.org/babel/babel.svg?path=packages/babel-parser)](https://david-dm.org/babel/babel?path=packages/babel-parser) |
 | [`@babel/traverse`](/packages/babel-traverse) | [![npm](https://img.shields.io/npm/v/@babel/traverse.svg?maxAge=2592000)](https://www.npmjs.com/package/@babel/traverse) | [![Dependency Status](https://david-dm.org/babel/babel.svg?path=packages/babel-traverse)](https://david-dm.org/babel/babel?path=packages/babel-traverse) |
 | [`@babel/generator`](/packages/babel-generator) | [![npm](https://img.shields.io/npm/v/@babel/generator.svg?maxAge=2592000)](https://www.npmjs.com/package/@babel/generator) | [![Dependency Status](https://david-dm.org/babel/babel.svg?path=packages/babel-generator)](https://david-dm.org/babel/babel?path=packages/babel-generator) |
 
 [`@babel/core`](/packages/babel-core) is the Babel compiler itself; it exposes the `babel.transform` method, where `transformedCode = transform(src).code`.
 
 The compiler can be broken down into 3 parts:
-- The parser: [`babylon`](/packages/babylon)
+- The parser: [`@babel/parser`](/packages/babel-parser)
 - The transformer[s]: All the plugins/presets
   - These all use [`@babel/traverse`](/packages/babel-traverse) to traverse through the AST
 - The generator: [`@babel/generator`](/packages/babel-generator)
 
 The flow goes like this:
 
-input string -> `babylon` parser -> `AST` -> transformer[s] -> `AST` -> `@babel/generator` -> output string
+input string -> `@babel/parser` parser -> `AST` -> transformer[s] -> `AST` -> `@babel/generator` -> output string
 
 Check out the [`babel-handbook`](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#introduction) for more information on this.
 

packages/babel-cli/README.md

@@ -2,20 +2,18 @@
 
 > Babel command line.
 
-In addition, various entry point scripts live in the top-level package at `@babel/cli/bin`.
-
-There is a shell-executable utility script, `babel-external-helpers.js`, and the main Babel cli script, `babel.js`.
+See our website [@babel/cli](https://babeljs.io/docs/en/next/babel-cli.html) for more information or the [issues](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3A%22pkg%3A%20cli%22+is%3Aopen) associated with this package.
 
 ## Install
 
-```sh
-npm install --save-dev @babel/core @babel/cli
-```
-
-## Usage
+Using npm:
 
 ```sh
-babel script.js
+npm install --save-dev @babel/cli
 ```
 
-For more in depth documentation see: http://babeljs.io/docs/usage/cli/
+or using yarn:
+
+```sh
+yarn add @babel/cli --dev
+```

packages/babel-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/cli",
-  "version": "7.0.0-beta.43",
+  "version": "7.0.0-beta.54",
   "description": "Babel command line.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
@@ -20,20 +20,21 @@
     "convert-source-map": "^1.1.0",
     "fs-readdir-recursive": "^1.0.0",
     "glob": "^7.0.0",
-    "lodash": "^4.2.0",
+    "lodash": "^4.17.5",
+    "mkdirp": "^0.5.1",
     "output-file-sync": "^2.0.0",
     "slash": "^1.0.0",
     "source-map": "^0.5.0"
   },
   "optionalDependencies": {
-    "chokidar": "^1.6.1"
+    "chokidar": "^2.0.3"
   },
   "peerDependencies": {
-    "@babel/core": "7.0.0-beta.43"
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0-beta.43",
-    "@babel/helper-fixtures": "7.0.0-beta.43"
+    "@babel/core": "7.0.0-beta.54",
+    "@babel/helper-fixtures": "7.0.0-beta.54"
   },
   "bin": {
     "babel": "./bin/babel.js",

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

@@ -1,170 +1,140 @@
 import defaults from "lodash/defaults";
 import outputFileSync from "output-file-sync";
+import { sync as mkdirpSync } from "mkdirp";
 import slash from "slash";
 import path from "path";
 import fs from "fs";
 
 import * as util from "./util";
 
-let compiledFiles = 0;
+export default async function({ cliOptions, babelOptions }) {
+  const filenames = cliOptions.filenames;
 
-export default function(commander, filenames, opts) {
-  function write(src, relative, base, callback) {
-    if (typeof base === "function") {
-      callback = base;
-      base = undefined;
-    }
-    if (!util.isCompilableExtension(relative, commander.extensions)) {
-      return process.nextTick(callback);
+  async function write(src, base) {
+    let relative = path.relative(base, src);
+
+    if (!util.isCompilableExtension(relative, cliOptions.extensions)) {
+      return false;
     }
 
     // remove extension and then append back on .js
-    relative = util.adjustRelative(relative, commander.keepFileExtension);
+    relative = util.adjustRelative(relative, cliOptions.keepFileExtension);
 
-    const dest = getDest(commander, relative, base);
+    const dest = getDest(relative, base);
 
-    util.compile(
-      src,
-      defaults(
-        {
-          sourceFileName: slash(path.relative(dest + "/..", src)),
-        },
-        opts,
-      ),
-      function(err, res) {
-        if (err) return callback(err);
-        if (!res) return callback();
+    try {
+      const res = await util.compile(
+        src,
+        defaults(
+          {
+            sourceFileName: slash(path.relative(dest + "/..", src)),
+          },
+          babelOptions,
+        ),
+      );
 
-        // we've requested explicit sourcemaps to be written to disk
-        if (
-          res.map &&
-          commander.sourceMaps &&
-          commander.sourceMaps !== "inline"
-        ) {
-          const mapLoc = dest + ".map";
-          res.code = util.addSourceMappingUrl(res.code, mapLoc);
-          res.map.file = path.basename(relative);
-          outputFileSync(mapLoc, JSON.stringify(res.map));
-        }
+      if (!res) return false;
 
-        outputFileSync(dest, res.code);
-        util.chmod(src, dest);
+      // we've requested explicit sourcemaps to be written to disk
+      if (
+        res.map &&
+        babelOptions.sourceMaps &&
+        babelOptions.sourceMaps !== "inline"
+      ) {
+        const mapLoc = dest + ".map";
+        res.code = util.addSourceMappingUrl(res.code, mapLoc);
+        res.map.file = path.basename(relative);
+        outputFileSync(mapLoc, JSON.stringify(res.map));
+      }
 
-        compiledFiles += 1;
+      outputFileSync(dest, res.code);
+      util.chmod(src, dest);
 
-        util.log(src + " -> " + dest);
-        return callback(null, true);
-      },
+      if (cliOptions.verbose) {
+        console.log(src + " -> " + dest);
+      }
+
+      return true;
+    } catch (err) {
+      if (cliOptions.watch) {
+        console.error(err);
+        return false;
+      }
+
+      throw err;
+    }
+  }
+
+  function getDest(filename, base) {
+    if (cliOptions.relative) {
+      return path.join(base, cliOptions.outDir, filename);
+    }
+    return path.join(cliOptions.outDir, filename);
+  }
+
+  async function handleFile(src, base) {
+    const written = await write(src, base);
+
+    if (!written && cliOptions.copyFiles) {
+      const filename = path.relative(base, src);
+      const dest = getDest(filename, base);
+      outputFileSync(dest, fs.readFileSync(src));
+      util.chmod(src, dest);
+    }
+    return written;
+  }
+
+  async function handle(filenameOrDir) {
+    if (!fs.existsSync(filenameOrDir)) return 0;
+
+    const stat = fs.statSync(filenameOrDir);
+
+    if (stat.isDirectory(filenameOrDir)) {
+      const dirname = filenameOrDir;
+
+      let count = 0;
+
+      const files = util.readdir(dirname, cliOptions.includeDotfiles);
+      for (const filename of files) {
+        const src = path.join(dirname, filename);
+
+        const written = await handleFile(src, dirname);
+        if (written) count += 1;
+      }
+
+      return count;
+    } else {
+      const filename = filenameOrDir;
+      const written = await handleFile(filename, path.dirname(filename));
+
+      return written ? 1 : 0;
+    }
+  }
+
+  if (!cliOptions.skipInitialBuild) {
+    if (cliOptions.deleteDirOnStart) {
+      util.deleteDir(cliOptions.outDir);
+    }
+
+    mkdirpSync(cliOptions.outDir);
+
+    let compiledFiles = 0;
+    for (const filename of cliOptions.filenames) {
+      compiledFiles += await handle(filename);
+    }
+
+    console.log(
+      `Successfully compiled ${compiledFiles} ${
+        compiledFiles !== 1 ? "files" : "file"
+      } with Babel.`,
     );
   }
 
-  function getDest(commander, filename, base) {
-    if (commander.relative) return path.join(base, commander.outDir, filename);
-    return path.join(commander.outDir, filename);
-  }
-
-  function outputDestFolder(outDir) {
-    const outDirPath = path.resolve(outDir);
-    if (!fs.existsSync(outDirPath)) {
-      fs.mkdirSync(outDirPath);
-    }
-  }
-
-  function handleFile(src, filename, base, callback) {
-    if (typeof base === "function") {
-      callback = base;
-      base = undefined;
-    }
-
-    write(src, filename, base, function(err, res) {
-      if (err) return callback(err);
-      if (!res && commander.copyFiles) {
-        const dest = getDest(commander, filename, base);
-        outputFileSync(dest, fs.readFileSync(src));
-        util.chmod(src, dest);
-      }
-
-      return callback();
-    });
-  }
-
-  function sequentialHandleFile(files, dirname, index, callback) {
-    if (files.length === 0) {
-      outputDestFolder(commander.outDir);
-      return;
-    }
-
-    if (typeof index === "function") {
-      callback = index;
-      index = 0;
-    }
-
-    const filename = files[index];
-    const src = path.join(dirname, filename);
-
-    handleFile(src, filename, dirname, function(err) {
-      if (err) return callback(err);
-      index++;
-      if (index !== files.length) {
-        sequentialHandleFile(files, dirname, index, callback);
-      } else {
-        callback();
-      }
-    });
-  }
-
-  function handle(filename, callback) {
-    if (!fs.existsSync(filename)) return;
-
-    const stat = fs.statSync(filename);
-
-    if (stat.isDirectory(filename)) {
-      const dirname = filename;
-
-      if (commander.deleteDirOnStart) {
-        util.deleteDir(commander.outDir);
-      }
-
-      const files = util.readdir(dirname, commander.includeDotfiles);
-      sequentialHandleFile(files, dirname, callback);
-    } else {
-      write(
-        filename,
-        path.basename(filename),
-        path.dirname(filename),
-        callback,
-      );
-    }
-  }
-
-  function sequentialHandle(filenames, index = 0) {
-    const filename = filenames[index];
-
-    handle(filename, function(err) {
-      if (err) throw new Error(err);
-      index++;
-      if (index !== filenames.length) {
-        sequentialHandle(filenames, index);
-      } else {
-        util.log(
-          `🎉  Successfully compiled ${compiledFiles} ${
-            compiledFiles > 1 ? "files" : "file"
-          } with Babel.`,
-          true,
-        );
-      }
-    });
-  }
-
-  if (!commander.skipInitialBuild) {
-    sequentialHandle(filenames);
-  }
-
-  if (commander.watch) {
+  if (cliOptions.watch) {
     const chokidar = util.requireChokidar();
 
-    filenames.forEach(function(dirname) {
-      const watcher = chokidar.watch(dirname, {
+    filenames.forEach(function(filenameOrDir) {
+      const watcher = chokidar.watch(filenameOrDir, {
         persistent: true,
         ignoreInitial: true,
         awaitWriteFinish: {
@@ -175,14 +145,14 @@ export default function(commander, filenames, opts) {
 
       ["add", "change"].forEach(function(type) {
         watcher.on(type, function(filename) {
-          const relative = path.relative(dirname, filename) || filename;
-          try {
-            handleFile(filename, relative, function(err) {
-              if (err) throw err;
-            });
-          } catch (err) {
-            console.error(err.stack);
-          }
+          handleFile(
+            filename,
+            filename === filenameOrDir
+              ? path.dirname(filenameOrDir)
+              : filenameOrDir,
+          ).catch(err => {
+            console.error(err);
+          });
         });
       });
     });

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

@@ -7,26 +7,22 @@ import fs from "fs";
 
 import * as util from "./util";
 
-export default function(commander, filenames, opts) {
-  if (commander.sourceMaps === "inline") {
-    opts.sourceMaps = true;
-  }
-
-  let results = [];
-
-  const buildResult = function() {
+export default async function({ cliOptions, babelOptions }) {
+  function buildResult(fileResults) {
     const map = new sourceMap.SourceMapGenerator({
       file:
-        commander.sourceMapTarget ||
-        path.basename(commander.outFile || "") ||
+        cliOptions.sourceMapTarget ||
+        path.basename(cliOptions.outFile || "") ||
         "stdout",
-      sourceRoot: opts.sourceRoot,
+      sourceRoot: babelOptions.sourceRoot,
     });
 
     let code = "";
     let offset = 0;
 
-    results.forEach(function(result) {
+    for (const result of fileResults) {
+      if (!result) continue;
+
       code += result.code + "\n";
 
       if (result.map) {
@@ -61,13 +57,13 @@ export default function(commander, filenames, opts) {
 
         offset = code.split("\n").length - 1;
       }
-    });
+    }
 
     // add the inline sourcemap comment if we've either explicitly asked for inline source
     // maps, or we've requested them without any output file
     if (
-      commander.sourceMaps === "inline" ||
-      (!commander.outFile && commander.sourceMaps)
+      babelOptions.sourceMaps === "inline" ||
+      (!cliOptions.outFile && babelOptions.sourceMaps)
     ) {
       code += "\n" + convertSourceMap.fromObject(map).toComment();
     }
@@ -76,57 +72,62 @@ export default function(commander, filenames, opts) {
       map: map,
       code: code,
     };
-  };
+  }
 
-  const output = function() {
-    const result = buildResult();
+  function output(fileResults) {
+    const result = buildResult(fileResults);
 
-    if (commander.outFile) {
+    if (cliOptions.outFile) {
       // we've requested for a sourcemap to be written to disk
-      if (commander.sourceMaps && commander.sourceMaps !== "inline") {
-        const mapLoc = commander.outFile + ".map";
+      if (babelOptions.sourceMaps && babelOptions.sourceMaps !== "inline") {
+        const mapLoc = cliOptions.outFile + ".map";
         result.code = util.addSourceMappingUrl(result.code, mapLoc);
         fs.writeFileSync(mapLoc, JSON.stringify(result.map));
       }
 
-      fs.writeFileSync(commander.outFile, result.code);
+      fs.writeFileSync(cliOptions.outFile, result.code);
     } else {
       process.stdout.write(result.code + "\n");
     }
-  };
+  }
 
-  const stdin = function() {
-    let code = "";
+  function readStdin() {
+    return new Promise((resolve, reject) => {
+      let code = "";
 
-    process.stdin.setEncoding("utf8");
+      process.stdin.setEncoding("utf8");
 
-    process.stdin.on("readable", function() {
-      const chunk = process.stdin.read();
-      if (chunk !== null) code += chunk;
+      process.stdin.on("readable", function() {
+        const chunk = process.stdin.read();
+        if (chunk !== null) code += chunk;
+      });
+
+      process.stdin.on("end", function() {
+        resolve(code);
+      });
+      process.stdin.on("error", reject);
     });
+  }
 
-    process.stdin.on("end", function() {
-      util.transform(
-        commander.filename,
-        code,
-        defaults(
-          {
-            sourceFileName: "stdin",
-          },
-          opts,
-        ),
-        function(err, res) {
-          if (err) throw err;
-          results.push(res);
-          output();
+  async function stdin() {
+    const code = await readStdin();
+
+    const res = await util.transform(
+      cliOptions.filename,
+      code,
+      defaults(
+        {
+          sourceFileName: "stdin",
         },
-      );
-    });
-  };
+        babelOptions,
+      ),
+    );
 
-  const walk = function() {
+    output([res]);
+  }
+
+  async function walk(filenames) {
     const _filenames = [];
-    results = [];
 
     filenames.forEach(function(filename) {
       if (!fs.existsSync(filename)) return;
@@ -136,7 +137,7 @@ export default function(commander, filenames, opts) {
         const dirname = filename;
 
         util
-          .readdirForCompilable(filename, commander.includeDotfiles)
+          .readdirForCompilable(filename, cliOptions.includeDotfiles)
           .forEach(function(filename) {
             _filenames.push(path.join(dirname, filename));
           });
@@ -145,46 +146,54 @@ export default function(commander, filenames, opts) {
       }
     });
 
-    let filesProcessed = 0;
+    const results = await Promise.all(
+      _filenames.map(async function(filename) {
+        let sourceFilename = filename;
+        if (cliOptions.outFile) {
+          sourceFilename = path.relative(
+            path.dirname(cliOptions.outFile),
+            sourceFilename,
+          );
+        }
+        sourceFilename = slash(sourceFilename);
 
-    _filenames.forEach(function(filename, index) {
-      let sourceFilename = filename;
-      if (commander.outFile) {
-        sourceFilename = path.relative(
-          path.dirname(commander.outFile),
-          sourceFilename,
-        );
-      }
-      sourceFilename = slash(sourceFilename);
-
-      util.compile(
-        filename,
-        defaults(
-          {
-            sourceFileName: sourceFilename,
-          },
-          opts,
-        ),
-        function(err, res) {
-          if (err) throw err;
-
-          filesProcessed++;
-          if (res) results[index] = res;
-
-          if (filesProcessed === _filenames.length) {
-            output();
+        try {
+          return await util.compile(
+            filename,
+            defaults(
+              {
+                sourceFileName: sourceFilename,
+                // Since we're compiling everything to be merged together,
+                // "inline" applies to the final output file, but to the individual
+                // files being concatenated.
+                sourceMaps:
+                  babelOptions.sourceMaps === "inline"
+                    ? true
+                    : babelOptions.sourceMaps,
+              },
+              babelOptions,
+            ),
+          );
+        } catch (err) {
+          if (!cliOptions.watch) {
+            throw err;
           }
-        },
-      );
-    });
-  };
 
-  const files = function() {
-    if (!commander.skipInitialBuild) {
-      walk();
+          console.error(err);
+          return null;
+        }
+      }),
+    );
+
+    output(results);
+  }
+
+  async function files(filenames) {
+    if (!cliOptions.skipInitialBuild) {
+      await walk(filenames);
     }
 
-    if (commander.watch) {
+    if (cliOptions.watch) {
       const chokidar = util.requireChokidar();
       chokidar
         .watch(filenames, {
@@ -196,25 +205,26 @@ export default function(commander, filenames, opts) {
           },
         })
         .on("all", function(type, filename) {
-          if (!util.isCompilableExtension(filename, commander.extensions)) {
+          if (!util.isCompilableExtension(filename, cliOptions.extensions)) {
             return;
           }
 
           if (type === "add" || type === "change") {
-            util.log(type + " " + filename);
-            try {
-              walk();
-            } catch (err) {
-              console.error(err.stack);
+            if (cliOptions.verbose) {
+              console.log(type + " " + filename);
             }
+
+            walk(filenames).catch(err => {
+              console.error(err);
+            });
           }
         });
     }
-  };
+  }
 
-  if (filenames.length) {
-    files();
+  if (cliOptions.filenames.length) {
+    await files(cliOptions.filenames);
   } else {
-    stdin();
+    await stdin();
   }
 }

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

@@ -1,269 +1,13 @@
 #!/usr/bin/env node
 
-import fs from "fs";
-import commander from "commander";
-import { version } from "@babel/core";
-import uniq from "lodash/uniq";
-import glob from "glob";
-
+import parseArgv from "./options";
 import dirCommand from "./dir";
 import fileCommand from "./file";
 
-import pkg from "../../package.json";
+const opts = parseArgv(process.argv);
 
-function booleanify(val: any): boolean | any {
-  if (val === "true" || val == 1) {
-    return true;
-  }
-
-  if (val === "false" || val == 0 || !val) {
-    return false;
-  }
-
-  return val;
-}
-
-function collect(value, previousValue): Array<string> {
-  // If the user passed the option with no value, like "babel file.js --presets", do nothing.
-  if (typeof value !== "string") return previousValue;
-
-  const values = value.split(",");
-
-  return previousValue ? previousValue.concat(values) : values;
-}
-
-// Standard Babel input configs.
-commander.option(
-  "-f, --filename [filename]",
-  "filename to use when reading from stdin - this will be used in source-maps, errors etc",
-);
-commander.option(
-  "--presets [list]",
-  "comma-separated list of preset names",
-  collect,
-);
-commander.option(
-  "--plugins [list]",
-  "comma-separated list of plugin names",
-  collect,
-);
-commander.option("--config-file [path]", "Path a to .babelrc file to use");
-commander.option(
-  "--env-name [name]",
-  "The name of the 'env' to use when loading configs and plugins. " +
-    "Defaults to the value of BABEL_ENV, or else NODE_ENV, or else 'development'.",
-);
-
-// Basic file input configuration.
-commander.option("--source-type [script|module]", "");
-commander.option(
-  "--no-babelrc",
-  "Whether or not to look up .babelrc and .babelignore files",
-);
-commander.option(
-  "--ignore [list]",
-  "list of glob paths to **not** compile",
-  collect,
-);
-commander.option(
-  "--only [list]",
-  "list of glob paths to **only** compile",
-  collect,
-);
-
-// Misc babel config.
-commander.option(
-  "--no-highlight-code",
-  "enable/disable ANSI syntax highlighting of code frames (on by default)",
-);
-
-// General output formatting.
-commander.option(
-  "--no-comments",
-  "write comments to generated output (true by default)",
-);
-commander.option(
-  "--retain-lines",
-  "retain line numbers - will result in really ugly code",
-);
-commander.option(
-  "--compact [true|false|auto]",
-  "do not include superfluous whitespace characters and line terminators",
-  booleanify,
-);
-commander.option("--minified", "save as much bytes when printing [true|false]");
-commander.option(
-  "--auxiliary-comment-before [string]",
-  "print a comment before any injected non-user code",
-);
-commander.option(
-  "--auxiliary-comment-after [string]",
-  "print a comment after any injected non-user code",
-);
-
-// General soucemap formatting.
-commander.option("-s, --source-maps [true|false|inline|both]", "", booleanify);
-commander.option(
-  "--source-map-target [string]",
-  "set `file` on returned source map",
-);
-commander.option(
-  "--source-file-name [string]",
-  "set `sources[0]` on returned source map",
-);
-commander.option(
-  "--source-root [filename]",
-  "the root from which all sources are relative",
-);
-
-// Config params for certain module output formats.
-commander.option(
-  "--module-root [filename]",
-  "optional prefix for the AMD module formatter that will be prepend to the filename on module definitions",
-);
-commander.option("-M, --module-ids", "insert an explicit id for modules");
-commander.option(
-  "--module-id [string]",
-  "specify a custom name for module ids",
-);
-
-// "babel" command specific arguments that are not passed to @babel/core.
-commander.option(
-  "-x, --extensions [extensions]",
-  "List of extensions to compile when a directory has been input [.es6,.js,.es,.jsx,.mjs]",
-  collect,
-);
-commander.option(
-  "--keep-file-extension",
-  "Preserve the file extensions of the input files",
-);
-commander.option("-w, --watch", "Recompile files on changes");
-commander.option(
-  "--skip-initial-build",
-  "Do not compile files before watching",
-);
-commander.option(
-  "-o, --out-file [out]",
-  "Compile all input files into a single file",
-);
-commander.option(
-  "-d, --out-dir [out]",
-  "Compile an input directory of modules into an output directory",
-);
-commander.option(
-  "--relative",
-  "Compile into an output directory relative to input directory or file. Requires --out-dir [out]",
-);
-commander.option(
-  "-D, --copy-files",
-  "When compiling a directory copy over non-compilable files",
-);
-commander.option(
-  "--include-dotfiles",
-  "Include dotfiles when compiling and copying non-compilable files",
-);
-commander.option("--verbose", "Log everything");
-commander.option(
-  "--delete-dir-on-start",
-  "Delete the out directory before compilation",
-);
-
-commander.version(pkg.version + " (@babel/core " + version + ")");
-commander.usage("[options] <files ...>");
-commander.parse(process.argv);
-
-//
-
-const errors = [];
-
-let filenames = commander.args.reduce(function(globbed, input) {
-  let files = glob.sync(input);
-  if (!files.length) files = [input];
-  return globbed.concat(files);
-}, []);
-
-filenames = uniq(filenames);
-
-filenames.forEach(function(filename) {
-  if (!fs.existsSync(filename)) {
-    errors.push(filename + " doesn't exist");
-  }
+const fn = opts.cliOptions.outDir ? dirCommand : fileCommand;
+fn(opts).catch(err => {
+  console.error(err);
+  process.exit(1);
 });
-
-if (commander.outDir && !filenames.length) {
-  errors.push("filenames required for --out-dir");
-}
-
-if (commander.outFile && commander.outDir) {
-  errors.push("cannot have --out-file and --out-dir");
-}
-
-if (commander.relative && !commander.outDir) {
-  errors.push("output directory required for --relative");
-}
-
-if (commander.watch) {
-  if (!commander.outFile && !commander.outDir) {
-    errors.push("--watch requires --out-file or --out-dir");
-  }
-
-  if (!filenames.length) {
-    errors.push("--watch requires filenames");
-  }
-}
-
-if (commander.skipInitialBuild && !commander.watch) {
-  errors.push("--skip-initial-build requires --watch");
-}
-if (commander.deleteDirOnStart && !commander.outDir) {
-  errors.push("--delete-dir-on-start requires --out-dir");
-}
-
-if (
-  !commander.outDir &&
-  filenames.length === 0 &&
-  typeof commander.filename !== "string" &&
-  commander.babelrc !== false
-) {
-  errors.push(
-    "stdin compilation requires either -f/--filename [filename] or --no-babelrc",
-  );
-}
-
-if (errors.length) {
-  console.error(errors.join(". "));
-  process.exit(2);
-}
-
-//
-
-const opts = commander.opts();
-//the configFile CLI option maps to the extends option in the node API
-if (opts.configFile) {
-  opts.extends = opts.configFile;
-}
-
-// Delete options that are specific to @babel/cli and shouldn't be passed to @babel/core.
-delete opts.version;
-delete opts.extensions;
-delete opts.watch;
-delete opts.skipInitialBuild;
-delete opts.outFile;
-delete opts.outDir;
-delete opts.copyFiles;
-delete opts.includeDotfiles;
-delete opts.verbose;
-delete opts.configFile;
-delete opts.deleteDirOnStart;
-delete opts.keepFileExtension;
-delete opts.relative;
-delete opts.sourceMapTarget;
-
-// Commander will default the "--no-" arguments to true, but we want to leave them undefined so that
-// @babel/core can handle the default-assignment logic on its own.
-if (opts.babelrc === true) opts.babelrc = undefined;
-if (opts.comments === true) opts.comments = undefined;
-if (opts.highlightCode === true) opts.highlightCode = undefined;
-
-const fn = commander.outDir ? dirCommand : fileCommand;
-fn(commander, filenames, opts);

packages/babel-cli/src/babel/options.js

@@ -0,0 +1,283 @@
+import fs from "fs";
+
+import commander from "commander";
+import { version } from "@babel/core";
+import uniq from "lodash/uniq";
+import glob from "glob";
+
+import pkg from "../../package.json";
+
+// Standard Babel input configs.
+commander.option(
+  "-f, --filename [filename]",
+  "filename to use when reading from stdin - this will be used in source-maps, errors etc",
+);
+commander.option(
+  "--presets [list]",
+  "comma-separated list of preset names",
+  collect,
+);
+commander.option(
+  "--plugins [list]",
+  "comma-separated list of plugin names",
+  collect,
+);
+commander.option("--config-file [path]", "Path a to .babelrc file to use");
+commander.option(
+  "--env-name [name]",
+  "The name of the 'env' to use when loading configs and plugins. " +
+    "Defaults to the value of BABEL_ENV, or else NODE_ENV, or else 'development'.",
+);
+
+// Basic file input configuration.
+commander.option("--source-type [script|module]", "");
+commander.option(
+  "--no-babelrc",
+  "Whether or not to look up .babelrc and .babelignore files",
+);
+commander.option(
+  "--ignore [list]",
+  "list of glob paths to **not** compile",
+  collect,
+);
+commander.option(
+  "--only [list]",
+  "list of glob paths to **only** compile",
+  collect,
+);
+
+// Misc babel config.
+commander.option(
+  "--no-highlight-code",
+  "enable/disable ANSI syntax highlighting of code frames (on by default)",
+);
+
+// General output formatting.
+commander.option(
+  "--no-comments",
+  "write comments to generated output (true by default)",
+);
+commander.option(
+  "--retain-lines",
+  "retain line numbers - will result in really ugly code",
+);
+commander.option(
+  "--compact [true|false|auto]",
+  "do not include superfluous whitespace characters and line terminators",
+  booleanify,
+);
+commander.option("--minified", "save as much bytes when printing [true|false]");
+commander.option(
+  "--auxiliary-comment-before [string]",
+  "print a comment before any injected non-user code",
+);
+commander.option(
+  "--auxiliary-comment-after [string]",
+  "print a comment after any injected non-user code",
+);
+
+// General soucemap formatting.
+commander.option("-s, --source-maps [true|false|inline|both]", "", booleanify);
+commander.option(
+  "--source-map-target [string]",
+  "set `file` on returned source map",
+);
+commander.option(
+  "--source-file-name [string]",
+  "set `sources[0]` on returned source map",
+);
+commander.option(
+  "--source-root [filename]",
+  "the root from which all sources are relative",
+);
+
+// Config params for certain module output formats.
+commander.option(
+  "--module-root [filename]",
+  "optional prefix for the AMD module formatter that will be prepend to the filename on module definitions",
+);
+commander.option("-M, --module-ids", "insert an explicit id for modules");
+commander.option(
+  "--module-id [string]",
+  "specify a custom name for module ids",
+);
+
+// "babel" command specific arguments that are not passed to @babel/core.
+commander.option(
+  "-x, --extensions [extensions]",
+  "List of extensions to compile when a directory has been input [.es6,.js,.es,.jsx,.mjs]",
+  collect,
+);
+commander.option(
+  "--keep-file-extension",
+  "Preserve the file extensions of the input files",
+);
+commander.option("-w, --watch", "Recompile files on changes");
+commander.option(
+  "--skip-initial-build",
+  "Do not compile files before watching",
+);
+commander.option(
+  "-o, --out-file [out]",
+  "Compile all input files into a single file",
+);
+commander.option(
+  "-d, --out-dir [out]",
+  "Compile an input directory of modules into an output directory",
+);
+commander.option(
+  "--relative",
+  "Compile into an output directory relative to input directory or file. Requires --out-dir [out]",
+);
+commander.option(
+  "-D, --copy-files",
+  "When compiling a directory copy over non-compilable files",
+);
+commander.option(
+  "--include-dotfiles",
+  "Include dotfiles when compiling and copying non-compilable files",
+);
+commander.option("--verbose", "Log everything");
+commander.option(
+  "--delete-dir-on-start",
+  "Delete the out directory before compilation",
+);
+
+commander.version(pkg.version + " (@babel/core " + version + ")");
+commander.usage("[options] <files ...>");
+
+export default function parseArgv(args: Array<string>) {
+  //
+  commander.parse(args);
+
+  const errors = [];
+
+  let filenames = commander.args.reduce(function(globbed, input) {
+    let files = glob.sync(input);
+    if (!files.length) files = [input];
+    return globbed.concat(files);
+  }, []);
+
+  filenames = uniq(filenames);
+
+  filenames.forEach(function(filename) {
+    if (!fs.existsSync(filename)) {
+      errors.push(filename + " doesn't exist");
+    }
+  });
+
+  if (commander.outDir && !filenames.length) {
+    errors.push("filenames required for --out-dir");
+  }
+
+  if (commander.outFile && commander.outDir) {
+    errors.push("cannot have --out-file and --out-dir");
+  }
+
+  if (commander.relative && !commander.outDir) {
+    errors.push("output directory required for --relative");
+  }
+
+  if (commander.watch) {
+    if (!commander.outFile && !commander.outDir) {
+      errors.push("--watch requires --out-file or --out-dir");
+    }
+
+    if (!filenames.length) {
+      errors.push("--watch requires filenames");
+    }
+  }
+
+  if (commander.skipInitialBuild && !commander.watch) {
+    errors.push("--skip-initial-build requires --watch");
+  }
+  if (commander.deleteDirOnStart && !commander.outDir) {
+    errors.push("--delete-dir-on-start requires --out-dir");
+  }
+
+  if (
+    !commander.outDir &&
+    filenames.length === 0 &&
+    typeof commander.filename !== "string" &&
+    commander.babelrc !== false
+  ) {
+    errors.push(
+      "stdin compilation requires either -f/--filename [filename] or --no-babelrc",
+    );
+  }
+
+  if (errors.length) {
+    console.error(errors.join(". "));
+    process.exit(2);
+  }
+
+  const opts = commander.opts();
+
+  return {
+    babelOptions: {
+      presets: opts.presets,
+      plugins: opts.plugins,
+      configFile: opts.configFile,
+      envName: opts.envName,
+      sourceType: opts.sourceType,
+      ignore: opts.ignore,
+      only: opts.only,
+      retainLines: opts.retainLines,
+      compact: opts.compact,
+      minified: opts.minified,
+      auxiliaryCommentBefore: opts.auxiliaryCommentBefore,
+      auxiliaryCommentAfter: opts.auxiliaryCommentAfter,
+      sourceMaps: opts.sourceMaps,
+      sourceFileName: opts.sourceFileName,
+      sourceRoot: opts.sourceRoot,
+      moduleRoot: opts.moduleRoot,
+      moduleIds: opts.moduleIds,
+      moduleId: opts.moduleId,
+
+      // Commander will default the "--no-" arguments to true, but we want to
+      // leave them undefined so that @babel/core can handle the
+      // default-assignment logic on its own.
+      babelrc: opts.babelrc === true ? undefined : opts.babelrc,
+      highlightCode:
+        opts.highlightCode === true ? undefined : opts.highlightCode,
+      comments: opts.comments === true ? undefined : opts.comments,
+    },
+    cliOptions: {
+      filename: opts.filename,
+      filenames,
+      extensions: opts.extensions,
+      keepFileExtension: opts.keepFileExtension,
+      watch: opts.watch,
+      skipInitialBuild: opts.skipInitialBuild,
+      outFile: opts.outFile,
+      outDir: opts.outDir,
+      relative: opts.relative,
+      copyFiles: opts.copyFiles,
+      includeDotfiles: opts.includeDotfiles,
+      verbose: opts.verbose,
+      deleteDirOnStart: opts.deleteDirOnStart,
+      sourceMapTarget: opts.sourceMapTarget,
+    },
+  };
+}
+
+function booleanify(val: any): boolean | any {
+  if (val === "true" || val == 1) {
+    return true;
+  }
+
+  if (val === "false" || val == 0 || !val) {
+    return false;
+  }
+
+  return val;
+}
+
+function collect(value, previousValue): Array<string> {
+  // If the user passed the option with no value, like "babel file.js --presets", do nothing.
+  if (typeof value !== "string") return previousValue;
+
+  const values = value.split(",");
+
+  return previousValue ? previousValue.concat(values) : values;
+}

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

@@ -1,4 +1,3 @@
-import commander from "commander";
 import readdirRecursive from "fs-readdir-recursive";
 import * as babel from "@babel/core";
 import includes from "lodash/includes";
@@ -46,29 +45,26 @@ export function addSourceMappingUrl(code, loc) {
   return code + "\n//# sourceMappingURL=" + path.basename(loc);
 }
 
-export function log(msg, force) {
-  if (force === true || commander.verbose) console.log(msg);
-}
-
-export function transform(filename, code, opts, callback) {
-  opts = Object.assign({}, opts, {
+export function transform(filename, code, opts) {
+  opts = {
+    ...opts,
     filename,
-  });
+  };
 
-  babel.transform(code, opts, callback);
+  return new Promise((resolve, reject) => {
+    babel.transform(code, opts, (err, result) => {
+      if (err) reject(err);
+      else resolve(result);
+    });
+  });
 }
 
-export function compile(filename, opts, callback) {
-  babel.transformFile(filename, opts, function(err, res) {
-    if (err) {
-      if (commander.watch) {
-        console.error(err);
-        return callback(null, null);
-      } else {
-        return callback(err);
-      }
-    }
-    return callback(null, res);
+export function compile(filename, opts) {
+  return new Promise((resolve, reject) => {
+    babel.transformFile(filename, opts, (err, result) => {
+      if (err) reject(err);
+      else resolve(result);
+    });
   });
 }
 

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles with ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles with only/stdout.txt

@@ -1,3 +1,3 @@
 src/foo/.foo.js -> lib/foo/.foo.js
 src/foo/bar.js -> lib/foo/bar.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles/stdout.txt

@@ -1,4 +1,4 @@
 src/.foo.js -> lib/.foo.js
 src/bar/index.js -> lib/bar/index.js
 src/foo/foo.js -> lib/foo/foo.js
-🎉  Successfully compiled 3 files with Babel.
+Successfully compiled 3 files with Babel.

packages/babel-cli/test/fixtures/babel/--copy-files with ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/--copy-files with only/stdout.txt

@@ -1,2 +1,2 @@
 src/foo/bar.js -> lib/foo/bar.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/--copy-files/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/index.js -> lib/bar/index.js
 src/foo/foo.js -> lib/foo/foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/--ignore complete/stdout.txt

@@ -1,2 +1,2 @@
 src/foobar/foo.js -> lib/foobar/foo.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/--ignore glob/stdout.txt

@@ -2,4 +2,4 @@ src/a.js -> lib/a.js
 src/b.js -> lib/b.js
 src/baz/c.js -> lib/baz/c.js
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 4 files with Babel.
+Successfully compiled 4 files with Babel.

packages/babel-cli/test/fixtures/babel/--ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/bar/index.js -> lib/bar/index.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/--only glob/stdout.txt

@@ -1,3 +1,3 @@
 src/a.foo.js -> lib/a.foo.js
 src/baz/b.foo.js -> lib/baz/b.foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/--only/stdout.txt

@@ -1,2 +1,2 @@
 src/bar/index.js -> lib/bar/index.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --copy-files/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --keep-file-extension/stdout.txt

@@ -1,3 +1,3 @@
 src/bar.mjs -> lib/bar.mjs
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/in-files/package1/src/bar/bar1.js

@@ -1,3 +1 @@
-class Test1 {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/in-files/package2/src/bar/bar2.js

@@ -1,3 +1 @@
-class Test2 {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/out-files/package1/lib/bar/bar1.js

@@ -1,9 +1,5 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test1 = function Test1() {
-  _classCallCheck(this, Test1);
-};
+(function () {
+  return 42;
+});

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/out-files/package2/lib/bar/bar2.js

@@ -1,9 +1,5 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test2 = function Test2() {
-  _classCallCheck(this, Test2);
-};
+(function () {
+  return 42;
+});

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/stdout.txt

@@ -2,4 +2,4 @@ package1/src/bar/bar1.js -> package1/lib/bar/bar1.js
 package1/src/foo1.js -> package1/lib/foo1.js
 package2/src/bar/bar2.js -> package2/lib/bar/bar2.js
 package2/src/foo2.js -> package2/lib/foo2.js
-🎉  Successfully compiled 4 files with Babel.
+Successfully compiled 4 files with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps inline/in-files/src/bar/bar.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps inline/out-files/lib/bar/bar.js

@@ -1,10 +1,6 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIi4uLy4uL3NyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbIlRlc3QiXSwibWFwcGluZ3MiOiI7Ozs7OztJQUFNQSxJIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG5cbn0iXX0=
+(function () {
+  return 42;
+});
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIi4uLy4uL3NyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsQ0FBQztBQUFBLFNBQU0sRUFBTjtBQUFBLENBQUQiLCJzb3VyY2VzQ29udGVudCI6WyIoKCkgPT4gNDIpIl19

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps inline/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps/in-files/src/bar/bar.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps/out-files/lib/bar/bar.js

@@ -1,10 +1,6 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});
 //# sourceMappingURL=bar.js.map

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps/out-files/lib/bar/bar.js.map

@@ -1 +1 @@
-{"version":3,"sources":["../../src/bar/bar.js"],"names":["Test"],"mappings":";;;;;;IAAMA,I","sourcesContent":["class Test {\n\n}"],"file":"bar.js"}
+{"version":3,"sources":["../../src/bar/bar.js"],"names":[],"mappings":";;AAAA,CAAC;AAAA,SAAM,EAAN;AAAA,CAAD","sourcesContent":["(() => 42)"],"file":"bar.js"}

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir --verbose/in-files/src/bar/bar.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir --verbose/out-files/lib/bar/bar.js

@@ -1,9 +1,5 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});

packages/babel-cli/test/fixtures/babel/dir --out-dir --verbose/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/dir --out-dir/in-files/src/bar/bar.js

@@ -1,3 +1 @@
-class Test {
-
-}
+ (() => 42)

packages/babel-cli/test/fixtures/babel/dir --out-dir/out-files/lib/bar/bar.js

@@ -1,9 +1,5 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});

packages/babel-cli/test/fixtures/babel/dir --out-dir/stdout.txt

@@ -1 +1 @@
-🎉  Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-cli/test/fixtures/babel/empty dir --out-dir/stdout.txt

@@ -0,0 +1 @@
+Successfully compiled 0 files with Babel.

packages/babel-cli/test/fixtures/babel/filename --out-dir --relative/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/filename --out-dir/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-🎉  Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-cli/test/fixtures/babel/filename-sourcemap --out-file --source-maps inline/in-files/script.js

@@ -1,5 +1,3 @@
-var foo = function () {
-  return 4;
-};
+arr.map(x => x * MULTIPLIER);
 
 //# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIm9yaWdpbmFsLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiJBQUFBLFVBQVUsWTtTQUFNLEM7Q0FBQyIsInNvdXJjZXNDb250ZW50IjpbInZhciBmb28gPSAoKSA9PiA0OyJdfQ==

packages/babel-cli/test/fixtures/babel/filename-sourcemap --out-file --source-maps inline/out-files/script2.js

@@ -1,7 +1,7 @@
 "use strict";
 
-var foo = function foo() {
-  return 4;
-};
+arr.map(function (x) {
+  return x * MULTIPLIER;
+});
 
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIm9yaWdpbmFsLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsVUFBVSxlO1MsQUFBTTtBQUFDIiwiZmlsZSI6InNjcmlwdDIuanMiLCJzb3VyY2VzQ29udGVudCI6WyJ2YXIgZm9vID0gKCkgPT4gNDsiXX0=
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIm9yaWdpbmFsLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsSUFBQSxHQUFBLENBQUE7QUFBQSxTQUFVLElBQUEsVUFBVjtBQUFBLENBQUEiLCJmaWxlIjoic2NyaXB0Mi5qcyIsInNvdXJjZXNDb250ZW50IjpbInZhciBmb28gPSAoKSA9PiA0OyJdfQ==

packages/babel-cli/test/fixtures/babel/filenames --out-file --source-maps inline/in-files/script.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/filenames --out-file --source-maps inline/out-files/script3.js

@@ -1,16 +1,12 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});
 "use strict";
 
 arr.map(function (x) {
   return x * MULTIPLIER;
 });
 
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7Ozs7O0lBQU0sSTs7Ozs7QUNBTixJQUFJLEdBQUosQ0FBUTtBQUFBLFNBQUssSUFBSSxVQUFUO0FBQUEsQ0FBUiIsImZpbGUiOiJzY3JpcHQzLmpzIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG5cbn0iLCJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7QUFBQSxDQUFDO0FBQUEsU0FBTSxFQUFOO0FBQUEsQ0FBRDs7O0FDQUEsSUFBSSxHQUFKLENBQVE7QUFBQSxTQUFLLElBQUksVUFBVDtBQUFBLENBQVIiLCJmaWxlIjoic2NyaXB0My5qcyIsInNvdXJjZXNDb250ZW50IjpbIigoKSA9PiA0MikiLCJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==

packages/babel-cli/test/fixtures/babel/filenames --out-file --source-maps/in-files/script.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/filenames --out-file --source-maps/out-files/script3.js

@@ -1,12 +1,8 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});
 "use strict";
 
 arr.map(function (x) {

packages/babel-cli/test/fixtures/babel/filenames --out-file --source-maps/out-files/script3.js.map

@@ -1 +1 @@
-{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":";;;;;;IAAM,I;;;;;ACAN,IAAI,GAAJ,CAAQ;AAAA,SAAK,IAAI,UAAT;AAAA,CAAR","file":"script3.js","sourcesContent":["class Test {\n\n}","arr.map(x => x * MULTIPLIER);"]}
+{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":";;AAAA,CAAC;AAAA,SAAM,EAAN;AAAA,CAAD;;;ACAA,IAAI,GAAJ,CAAQ;AAAA,SAAK,IAAI,UAAT;AAAA,CAAR","file":"script3.js","sourcesContent":["(() => 42)","arr.map(x => x * MULTIPLIER);"]}

packages/babel-cli/test/fixtures/babel/filenames --out-file/in-files/script.js

@@ -1,3 +1 @@
-class Test {
-
-}
+(() => 42)

packages/babel-cli/test/fixtures/babel/filenames --out-file/out-files/script3.js

@@ -1,12 +1,8 @@
 "use strict";
 
-function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
-
-function _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
-
-var Test = function Test() {
-  _classCallCheck(this, Test);
-};
+(function () {
+  return 42;
+});
 "use strict";
 
 arr.map(function (x) {