v7.0.0-beta.51

* isConstantExpression should return true for immuable bindings

* New test

* Don't return undefined

.circleci/config.yml

@@ -34,7 +34,7 @@ jobs:
   build:
     working_directory: ~/babel
     docker:
-      - image: circleci/node:9
+      - image: circleci/node:10
     steps:
       - checkout
       - restore-cache: *restore-yarn-cache

.eslintignore

@@ -22,4 +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

.gitignore

@@ -42,6 +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

.travis.yml

@@ -8,6 +8,7 @@ cache:
     - node_modules
 node_js:
   # We test the latest version on circleci
+  - '9'
   - '8'
   - '6'
 
@@ -22,14 +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
@@ -37,9 +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

@@ -24,7 +24,7 @@ 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
@@ -226,19 +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
@@ -247,17 +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
@@ -309,14 +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

@@ -98,7 +98,7 @@ function buildRollup(packages) {
         format: "cjs",
         plugins: [
           rollupBabel({
-            envName: "babylon",
+            envName: "babel-parser",
           }),
           rollupNodeResolve(),
         ],
@@ -113,7 +113,7 @@ function buildRollup(packages) {
 }
 
 gulp.task("build", function() {
-  const bundles = ["packages/babylon"];
+  const bundles = ["packages/babel-parser"];
 
   return merge([buildBabel(/* exclude */ bundles), buildRollup(bundles)]);
 });

Makefile

@@ -1,6 +1,6 @@
 MAKEFLAGS = -j1
 FLOW_COMMIT = 395e045c18d537fcbbc552a96ef2cdcd70b4ab52
-TEST262_COMMIT = 40883f4c6ae17e073dfd03e34f73a6bf8c855595
+TEST262_COMMIT = f90a52b39609a620c0854e0bd0b3a906c930fd17
 
 # Fix color output until TravisCI fixes https://github.com/travis-ci/travis-ci/issues/7967
 export FORCE_COLOR = true
@@ -17,8 +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
@@ -52,8 +50,6 @@ lint:
 	./node_modules/.bin/eslint scripts $(SOURCES) '*.js' '**/.*.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"
 
 clean: test-clean
@@ -87,12 +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
@@ -101,12 +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

babel.config.js

@@ -16,7 +16,7 @@ module.exports = function(api) {
 
   switch (env) {
     // Configs used during bundling builds.
-    case "babylon":
+    case "babel-parser":
     case "standalone":
       convertESM = false;
       ignoreLib = false;
@@ -24,7 +24,7 @@ module.exports = function(api) {
     case "production":
       // Config during builds before publish.
       envOpts.targets = {
-        node: 6,
+        node: "6.9",
       };
       break;
     case "development":
@@ -69,7 +69,7 @@ module.exports = function(api) {
     ].filter(Boolean),
     overrides: [
       {
-        test: "packages/babylon",
+        test: "packages/babel-parser",
         plugins: [
           "babel-plugin-transform-charcodes",
           ["@babel/transform-for-of", { assumeArray: true }],

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

@@ -1,6 +1,6 @@
 {
   "name": "@babel/plugin-codemod-object-assign-to-object-spread",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "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",
@@ -10,14 +10,14 @@
     "@babel/plugin"
   ],
   "dependencies": {
-    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.47"
+    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.51"
   },
   "peerDependencies": {
-    "@babel/core": "7.0.0-beta.47"
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0-beta.47",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.47"
+    "@babel/core": "7.0.0-beta.51",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.51"
   },
   "publishConfig": {
     "access": "public"

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

@@ -1,6 +1,6 @@
 {
   "name": "@babel/plugin-codemod-optional-catch-binding",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "description": "Remove unused catch bindings",
   "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-remove-unused-catch-binding",
   "license": "MIT",
@@ -10,13 +10,13 @@
     "@babel/plugin"
   ],
   "dependencies": {
-    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.47"
+    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.51"
   },
   "peerDependencies": {
-    "@babel/core": "7.0.0-beta.47"
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0-beta.47",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.47"
+    "@babel/core": "7.0.0-beta.51",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.51"
   }
 }

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`.

lerna.json

@@ -1,6 +1,6 @@
 {
-  "lerna": "2.0.0-rc.4",
-  "version": "7.0.0-beta.47",
+  "lerna": "2.11.0",
+  "version": "7.0.0-beta.51",
   "changelog": {
     "repo": "babel/babel",
     "cacheDir": ".changelog",

lib/third-party-libs.js.flow

@@ -166,3 +166,9 @@ declare module "convert-source-map" {
     generateMapFileComment(path: string, options?: ?{ multiline: boolean }): string,
   };
 }
+
+declare module "js-levenshtein" {
+  declare module.exports: {
+    (string, string): number,
+  };
+}

package.json

@@ -10,19 +10,18 @@
     "test": "make test"
   },
   "devDependencies": {
-    "@babel/cli": "7.0.0-beta.46",
-    "@babel/core": "7.0.0-beta.46",
-    "@babel/plugin-transform-modules-commonjs": "7.0.0-beta.46",
-    "@babel/preset-env": "7.0.0-beta.46",
-    "@babel/preset-flow": "7.0.0-beta.46",
-    "@babel/preset-stage-0": "7.0.0-beta.46",
-    "@babel/register": "7.0.0-beta.46",
+    "@babel/cli": "7.0.0-beta.48",
+    "@babel/core": "7.0.0-beta.48",
+    "@babel/plugin-transform-modules-commonjs": "7.0.0-beta.48",
+    "@babel/preset-env": "7.0.0-beta.48",
+    "@babel/preset-flow": "7.0.0-beta.48",
+    "@babel/preset-stage-0": "7.0.0-beta.48",
+    "@babel/register": "7.0.0-beta.48",
     "babel-core": "^7.0.0-0",
     "babel-eslint": "^8.0.1",
     "babel-jest": "^22.4.1",
     "babel-loader": "8.0.0-beta.0",
     "babel-plugin-transform-charcodes": "^0.1.0",
-    "babylon": "7.0.0-beta.46",
     "browserify": "^13.1.1",
     "bundle-collapser": "^1.2.1",
     "chalk": "^2.3.2",
@@ -32,8 +31,8 @@
     "eslint": "^4.18.2",
     "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-prettier": "^2.6.0",
+    "flow-bin": "^0.73.0",
     "graceful-fs": "^4.1.11",
     "gulp": "^4.0.0",
     "gulp-babel": "^8.0.0-beta.2",
@@ -46,19 +45,19 @@
     "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": "^4.17.5",
     "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",
@@ -68,7 +67,7 @@
     "webpack-stream": "^4.0.0"
   },
   "engines": {
-    "node": ">= 6.x <= 9.x",
+    "node": ">= 6.9.0 <= 11.0.0-0",
     "npm": ">= 2.x <= 5.x",
     "yarn": ">=0.27.5 || >=1.0.0-20170811"
   },
@@ -89,7 +88,7 @@
       "/node_modules/",
       "/test/fixtures/",
       "/test/debug-fixtures/",
-      "/babylon/test/expressions/",
+      "/babel-parser/test/expressions/",
       "/test/tmp/",
       "/test/__data__/",
       "/test/helpers/",
@@ -106,6 +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://new.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 @babel/cli
 ```
 
-For more in depth documentation see: http://babeljs.io/docs/usage/cli/
+or using yarn:
+
+```sh
+yarn add --save @babel/cli
+```

packages/babel-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/cli",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "description": "Babel command line.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
@@ -29,11 +29,11 @@
     "chokidar": "^2.0.3"
   },
   "peerDependencies": {
-    "@babel/core": "7.0.0-beta.47"
+    "@babel/core": ">=7.0.0-beta.50 <7.0.0-rc.0"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0-beta.47",
-    "@babel/helper-fixtures": "7.0.0-beta.47"
+    "@babel/core": "7.0.0-beta.51",
+    "@babel/helper-fixtures": "7.0.0-beta.51"
   },
   "bin": {
     "babel": "./bin/babel.js",

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

@@ -6,149 +6,143 @@ 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, base, callback) {
+  async function write(src, base) {
     let relative = path.relative(base, src);
-    if (!util.isCompilableExtension(relative, commander.extensions)) {
-      return process.nextTick(callback);
+
+    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(commander, filename, base) {
-    if (commander.relative) return path.join(base, commander.outDir, filename);
-    return path.join(commander.outDir, filename);
+  function getDest(filename, base) {
+    if (cliOptions.relative) {
+      return path.join(base, cliOptions.outDir, filename);
+    }
+    return path.join(cliOptions.outDir, filename);
   }
 
   function outputDestFolder(outDir) {
     const outDirPath = path.resolve(outDir);
-    if (!fs.existsSync(outDirPath)) {
+
+    try {
       fs.mkdirSync(outDirPath);
+    } catch (err) {
+      // Testing for the directory and then creating it can lead to race
+      // conditions if there are multiple processes, so we try to create it
+      // and bail if it already exists.
+      if (err.code !== "EEXIST") throw err;
     }
   }
 
-  function handleFile(src, base, callback) {
-    write(src, base, function(err, res) {
-      if (err) return callback(err);
-      if (!res && commander.copyFiles) {
-        const filename = path.relative(base, src);
-        const dest = getDest(commander, filename, base);
-        outputFileSync(dest, fs.readFileSync(src));
-        util.chmod(src, dest);
-      }
+  async function handleFile(src, base) {
+    const written = await write(src, base);
 
-      return callback();
-    });
+    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;
   }
 
-  function sequentialHandleFile(files, dirname, index, callback) {
-    if (files.length === 0) {
-      outputDestFolder(commander.outDir);
-      return;
-    }
+  async function handle(filenameOrDir) {
+    if (!fs.existsSync(filenameOrDir)) return 0;
 
-    if (typeof index === "function") {
-      callback = index;
-      index = 0;
-    }
+    const stat = fs.statSync(filenameOrDir);
 
-    const filename = files[index];
-    const src = path.join(dirname, filename);
+    if (stat.isDirectory(filenameOrDir)) {
+      const dirname = filenameOrDir;
 
-    handleFile(src, dirname, function(err) {
-      if (err) return callback(err);
-      index++;
-      if (index !== files.length) {
-        sequentialHandleFile(files, dirname, index, callback);
-      } else {
-        callback();
-      }
-    });
-  }
+      let count = 0;
 
-  function handle(filename, callback) {
-    if (!fs.existsSync(filename)) return;
+      const files = util.readdir(dirname, cliOptions.includeDotfiles);
+      for (const filename of files) {
+        const src = path.join(dirname, filename);
 
-    const stat = fs.statSync(filename);
-
-    if (stat.isDirectory(filename)) {
-      const dirname = filename;
-
-      if (commander.deleteDirOnStart) {
-        util.deleteDir(commander.outDir);
+        const written = await handleFile(src, dirname);
+        if (written) count += 1;
       }
 
-      const files = util.readdir(dirname, commander.includeDotfiles);
-      sequentialHandleFile(files, dirname, callback);
+      return count;
     } else {
-      write(filename, path.dirname(filename), callback);
+      const filename = filenameOrDir;
+      const written = await handleFile(filename, path.dirname(filename));
+
+      return written ? 1 : 0;
     }
   }
 
-  function sequentialHandle(filenames, index = 0) {
-    const filename = filenames[index];
+  if (!cliOptions.skipInitialBuild) {
+    if (cliOptions.deleteDirOnStart) {
+      util.deleteDir(cliOptions.outDir);
+    }
 
-    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,
-        );
-      }
-    });
+    outputDestFolder(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.`,
+    );
   }
 
-  if (!commander.skipInitialBuild) {
-    sequentialHandle(filenames);
-  }
-
-  if (commander.watch) {
+  if (cliOptions.watch) {
     const chokidar = util.requireChokidar();
 
     filenames.forEach(function(filenameOrDir) {
@@ -168,10 +162,9 @@ export default function(commander, filenames, opts) {
             filename === filenameOrDir
               ? path.dirname(filenameOrDir)
               : filenameOrDir,
-            function(err) {
-              if (err) console.error(err.stack);
-            },
-          );
+          ).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

@@ -1,264 +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();
-
-// 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.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";
@@ -46,30 +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) {
+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/empty dir --out-dir/stdout.txt

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

packages/babel-cli/test/fixtures/babel/stdin --filename/stderr.txt

@@ -1 +1 @@
-SyntaxError: test.js: Unexpected token, expected ";" (2:10)
+SyntaxError: <CWD>/test.js: Unexpected token, expected ";" (2:10)

packages/babel-cli/test/index.js

@@ -1,4 +1,3 @@
-const includes = require("lodash/includes");
 const readdir = require("fs-readdir-recursive");
 const helper = require("@babel/helper-fixtures");
 const rimraf = require("rimraf");
@@ -37,7 +36,9 @@ const readDir = function(loc, filter) {
 
 const saveInFiles = function(files) {
   // Place an empty .babelrc in each test so tests won't unexpectedly get to repo-level config.
-  outputFileSync(".babelrc", "{}");
+  if (!fs.existsSync(".babelrc")) {
+    outputFileSync(".babelrc", "{}");
+  }
 
   Object.keys(files).forEach(function(filename) {
     const content = files[filename];
@@ -45,13 +46,26 @@ const saveInFiles = function(files) {
   });
 };
 
-const assertTest = function(stdout, stderr, opts) {
+const replacePaths = function(str, cwd) {
+  let prev;
+  do {
+    prev = str;
+    str = str.replace(cwd, "<CWD>");
+  } while (str !== prev);
+
+  return str;
+};
+
+const assertTest = function(stdout, stderr, opts, cwd) {
+  stdout = replacePaths(stdout, cwd);
+  stderr = replacePaths(stderr, cwd);
+
   const expectStderr = opts.stderr.trim();
   stderr = stderr.trim();
 
   if (opts.stderr) {
     if (opts.stderrContains) {
-      expect(includes(stderr, expectStderr)).toBe(true);
+      expect(stderr).toContain(expectStderr);
     } else {
       expect(stderr).toBe(expectStderr);
     }
@@ -65,7 +79,7 @@ const assertTest = function(stdout, stderr, opts) {
 
   if (opts.stdout) {
     if (opts.stdoutContains) {
-      expect(includes(stdout, expectStdout)).toBe(true);
+      expect(stdout).toContain(expectStdout);
     } else {
       expect(stdout).toBe(expectStdout);
     }
@@ -137,7 +151,7 @@ const buildTest = function(binName, testName, opts) {
       let err;
 
       try {
-        assertTest(stdout, stderr, opts);
+        assertTest(stdout, stderr, opts, tmpLoc);
       } catch (e) {
         err = e;
       }

packages/babel-code-frame/README.md

@@ -2,141 +2,18 @@
 
 > Generate errors that contain a code frame that point to source locations.
 
+See our website [@babel/code-frame](https://new.babeljs.io/docs/en/next/babel-code-frame.html) for more information.
+
 ## Install
 
+Using npm:
+
 ```sh
-npm install --save-dev @babel/code-frame
+npm install --save @babel/code-frame
 ```
 
-## Usage
+or using yarn:
 
-```js
-import { codeFrameColumns } from '@babel/code-frame';
-
-const rawLines = `class Foo {
-  constructor()
-}`;
-const location = { start: { line: 2, column: 16 } };
-
-const result = codeFrameColumns(rawLines, location, { /* options */ });
-
-console.log(result);
-```
-
-```
-  1 | class Foo {
-> 2 |   constructor()
-    |                ^
-  3 | }
-```
-
-If the column number is not known, you may omit it.
-
-You can also pass an `end` hash in `location`.
-
-```js
-import { codeFrameColumns } from '@babel/code-frame';
-
-const rawLines = `class Foo {
-  constructor() {
-    console.log("hello");
-  }
-}`;
-const location = { start: { line: 2, column: 17 }, end: { line: 4, column: 3 } };
-
-const result = codeFrameColumns(rawLines, location, { /* options */ });
-
-console.log(result);
-```
-
-```
-  1 | class Foo {
-> 2 |   constructor() {
-    |                 ^
-> 3 |     console.log("hello");
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^
-> 4 |   }
-    | ^^^
-  5 | };
-```
-
-## Options
-
-### `highlightCode`
-
-`boolean`, defaults to `false`.
-
-Toggles syntax highlighting the code as JavaScript for terminals.
-
-
-### `linesAbove`
-
-`number`, defaults to `2`.
-
-Adjust the number of lines to show above the error.
-
-### `linesBelow`
-
-`number`, defaults to `3`.
-
-Adjust the number of lines to show below the error.
-
-### `forceColor`
-
-`boolean`, defaults to `false`.
-
-Enable this to forcibly syntax highlight the code as JavaScript (for non-terminals); overrides `highlightCode`.
-
-### `message`
-
-`string`, otherwise nothing
-
-Pass in a string to be displayed inline (if possible) next to the highlighted
-location in the code. If it can't be positioned inline, it will be placed above
-the code frame.
-
-```
-1 | class Foo {
-> 2 |   constructor()
-  |                ^ Missing {
-3 | };
-```
-
-## Upgrading from prior versions
-
-Prior to version 7, the only API exposed by this module was for a single line and optional column pointer. The old API will now log a deprecation warning.
-
-The new API takes a `location` object, similar to what is available in an AST.
-
-This is an example of the deprecated (but still available) API:
-
-```js
-import codeFrame from '@babel/code-frame';
-
-const rawLines = `class Foo {
-  constructor()
-}`;
-const lineNumber = 2;
-const colNumber = 16;
-
-const result = codeFrame(rawLines, lineNumber, colNumber, { /* options */ });
-
-console.log(result);
-```
-
-To get the same highlighting using the new API:
-
-```js
-import { codeFrameColumns } from '@babel/code-frame';
-
-const rawLines = `class Foo {
-  constructor() {
-    console.log("hello");
-  }
-}`;
-const location = { start: { line: 2, column: 16 } };
-
-const result = codeFrameColumns(rawLines, location, { /* options */ });
-
-console.log(result);
+```sh
+yarn add --save @babel/code-frame
 ```

packages/babel-code-frame/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/code-frame",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "description": "Generate errors that contain a code frame that point to source locations.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
@@ -8,7 +8,7 @@
   "repository": "https://github.com/babel/babel/tree/master/packages/babel-code-frame",
   "main": "lib/index.js",
   "dependencies": {
-    "@babel/highlight": "7.0.0-beta.47"
+    "@babel/highlight": "7.0.0-beta.51"
   },
   "devDependencies": {
     "chalk": "^2.0.0",

packages/babel-core/README.md

@@ -2,249 +2,18 @@
 
 > Babel compiler core.
 
+See our website [@babel/core](https://new.babeljs.io/docs/en/next/babel-core.html) for more information or the [issues](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3A%22pkg%3A%20core%22+is%3Aopen) associated with this package.
 
-```javascript
-var babel = require("@babel/core");
-import { transform } from "@babel/core";
-import * as babel from "@babel/core";
+## Install
+
+Using npm:
+
+```sh
+npm install --save @babel/core
 ```
 
-All transformations will use your local configuration files (`.babelrc` or in `package.json`). See [options](#options) to disable it.
+or using yarn:
 
-
-## babel.transform(code: string, [options?](#options): Object, callback: Function)
-
-Transforms the passed in `code`. Calling a callback with an object with the generated code,
-source map, and AST.
-
-```js
-babel.transform(code, options, function(err, result) {
-  result; // => { code, map, ast }
-});
+```sh
+yarn add --save @babel/core
 ```
-
-**Example**
-
-```js
-babel.transform("code();", options, function(err, result) {
-  result.code;
-  result.map;
-  result.ast;
-});
-```
-
-### Compat Note:
-
-In Babel 6, this method was synchronous and `transformSync` did not exist. For backward-compatibility,
-this function will behave synchronously if no callback is given. If you're starting with Babel 7
-and need synchronous behavior, please use `transformSync` since this backward-compat may be dropped in
-future major versions of Babel.
-
-
-## babel.transformSync(code: string, [options?](#options): Object)
-
-Transforms the passed in `code`. Returning an object with the generated code,
-source map, and AST.
-
-```js
-babel.transformSync(code, options) // => { code, map, ast }
-```
-
-**Example**
-
-```js
-var result = babel.transformSync("code();", options);
-result.code;
-result.map;
-result.ast;
-```
-
-
-## babel.transformFile(filename: string, [options?](#options): Object, callback: Function)
-
-Asynchronously transforms the entire contents of a file.
-
-```js
-babel.transformFile(filename, options, callback)
-```
-
-**Example**
-
-```js
-babel.transformFile("filename.js", options, function (err, result) {
-  result; // => { code, map, ast }
-});
-```
-
-
-## babel.transformFileSync(filename: string, [options?](#options): Object)
-
-Synchronous version of `babel.transformFile`. Returns the transformed contents of
-the `filename`.
-
-```js
-babel.transformFileSync(filename, options) // => { code, map, ast }
-```
-
-**Example**
-
-```js
-babel.transformFileSync("filename.js", options).code;
-```
-
-
-## babel.transformFromAst(ast: Object, code?: string, [options?](#options): Object, callback: Function): FileNode | null
-
-Given an [AST](https://astexplorer.net/), transform it.
-
-```js
-const sourceCode = "if (true) return;";
-const parsedAst = babylon.parse(sourceCode, { allowReturnOutsideFunction: true });
-babel.transformFromAst(parsedAst, sourceCode, options, function(err, result) {
-  const { code, map, ast } = result;
-});
-```
-
-### Compat Note:
-
-In Babel 6, this method was synchronous and `transformFromAstSync` did not exist. For backward-compatibility,
-this function will behave synchronously if no callback is given. If you're starting with Babel 7
-and need synchronous behavior, please use `transformFromAstSync` since this backward-compat may be dropped in
-future major versions of Babel.
-
-
-## babel.transformFromAstSync(ast: Object, code?: string, [options?](#options): Object)
-
-Given an [AST](https://astexplorer.net/), transform it.
-
-```js
-const sourceCode = "if (true) return;";
-const parsedAst = babylon.parse(sourceCode, { allowReturnOutsideFunction: true });
-const { code, map, ast } = babel.transformFromAstSync(parsedAst, sourceCode, options);
-```
-
-## babel.parse(code: string, [options?](#options): Object)
-
-Given some code, parse it using Babel's standard behavior. Referenced presets and
-plugins will be loaded such that optional syntax plugins are automatically
-enabled.
-
-
-## Advanced APIs
-
-Many systems that wrap Babel like to automatically inject plugins and presets,
-or override options. To accomplish this goal, Babel exposes several functions
-that aid in loading the configuration part-way without transforming.
-
-### babel.loadOptions([options?](#options): Object)
-
-Resolve Babel's options fully, resulting in an options object where:
-
-* `opts.plugins` is a full list of `Plugin` instances.
-* `opts.presets` is empty and all presets are flattened into `opts`.
-* It can be safely passed back to Babel. Fields like `babelrc` have been set to 
-  false so that later calls to Babel will not make a second attempt to load
-  config files.
-
-`Plugin` instances aren't meant to be manipulated directly, but often
-callers will serialize this `opts` to JSON to use it as a cache key representing
-the options Babel has received. Caching on this isn't 100% guaranteed to
-invalidate properly, but it is the best we have at the moment.
-
-
-### babel.loadPartialConfig([options?](#options): Object): PartialConfig
-
-To allow systems to easily manipulate and validate a user's config, this function
-resolves the plugins and presets and proceeds no further. The expectation is
-that callers will take the config's `.options`, manipulate it as then see fit
-and pass it back to Babel again.
-
-* `babelrc: string | void` - The path of the `.babelrc` file, if there was one.
-* `babelignore: string | void` - The path of the `.babelignore` file, if there was one.
-* `options: ValidatedOptions` - The partially resolved options, which can be manipulated and passed back to Babel again.
-  * `plugins: Array<ConfigItem>` - See below.
-  * `presets: Array<ConfigItem>` - See below.
-  * It can be safely passed back to Babel. Fields like `babelrc` have been set
-    to false so that later calls to Babel will not make a second attempt to 
-    load config files.
-* `hasFilesystemConfig(): boolean` - Check if the resolved config loaded any settings from the filesystem.
-
-[`ConfigItem`](#configitem-type) instances expose properties to introspect the values, but each
-item should be treated as immutable. If changes are desired, the item should be
-removed from the list and replaced with either a normal Babel config value, or
-with a replacement item created by `babel.createConfigItem`. See that
-function for information about `ConfigItem` fields.
-
-
-### babel.createConfigItem(value: string | {} | Function | [string | {} | Function, {} | void], { dirname?: string, type?: "preset" | "plugin" }): ConfigItem
-
-Allows build tooling to create and cache config items up front. If this function
-is called multiple times for a given plugin, Babel will call the plugin's function itself
-multiple times. If you have a clear set of expected plugins and presets to
-inject, pre-constructing the config items would be recommended.
-
-
-### `ConfigItem` type
-
-Each `ConfigItem` exposes all of the information Babel knows. The fields are:
-
-* `value: {} | Function` - The resolved value of the plugin.
-* `options: {} | void` - The options object passed to the plugin.
-* `dirname: string` - The path that the options are relative to.
-* `name: string | void` - The name that the user gave the plugin instance, e.g. `plugins: [ ['env', {}, 'my-env'] ]` 
-* `file: Object | void` - Information about the plugin's file, if Babel knows it.
-  * `request: string` - The file that the user requested, e.g. `"@babel/env"`
-  * `resolved: string` - The full path of the resolved file, e.g. `"/tmp/node_modules/@babel/preset-env/lib/index.js"`
-
-
-## Options
-
-<blockquote class="babel-callout babel-callout-info">
-  <h4>Babel CLI</h4>
-  <p>
-    You can pass these options from the Babel CLI like so:
-  </p>
-  <p>
-    <code>babel --option-name<span class="o">=</span>value</code>
-  </p>
-</blockquote>
-
-Following is a table of the options you can use:
-
-| Option                   | Default              | Description                     |
-| ------------------------ | -------------------- | ------------------------------- |
-| `ast`                    | `false`              | Include the AST in the returned object |
-| `auxiliaryCommentAfter`  | `null`               | Attach a comment after all non-user injected code |
-| `auxiliaryCommentBefore` | `null`               | Attach a comment before all non-user injected code |
-| `root`                   | `"."`                | Specify the "root" folder that defines the location to search for "babel.config.js", and the default folder to allow `.babelrc` files inside of.|
-| `configFile`             | `undefined`          | The config file to load Babel's config from. Defaults to searching for "babel.config.js" inside the "root" folder. `false` will disable searching for config files.|
-| `babelrc`                | `true`               | Specify whether or not to use .babelrc and .babelignore files. Not available when using the CLI, [use `--no-babelrc` instead](https://babeljs.io/docs/usage/cli/#babel-ignoring-babelrc) |
-| `babelrcRoots`           | `(root)`             | Specify which packages should be search for .babelrc files when they are being compiled. `true` to _always_ search, or a path string or an array of paths to packages to search inside of. Defaults to only searching the "root" package. |
-| `envName`                | env vars             | Defaults to environment variable `BABEL_ENV` if set, or else `NODE_ENV` if set, or else it defaults to `"development"` |
-| `code`                   | `true`               | Enable code generation |
-| `comments`               | `true`               | Output comments in generated output |
-| `compact`                | `"auto"`             | Do not include superfluous whitespace characters and line terminators. When set to `"auto"` compact is set to `true` on input sizes of >500KB |
-| `env`                    | `{}`                 | This is an object of keys that represent different environments. For example, you may have: `{ env: { production: { /* specific options */ } } }` which will use those options when the `envName` is `production` |
-| `extends`                | `null`               | A path to a `.babelrc` file to extend |
-| `filename`               | `"unknown"`          | Filename for use in errors etc |
-| `filenameRelative`       | `(filename)`         | Filename relative to `sourceRoot` |
-| `generatorOpts`          | `{}`                 | An object containing the options to be passed down to the babel code generator, @babel/generator |
-| `getModuleId`            | `null`               | Specify a custom callback to generate a module id with. Called as `getModuleId(moduleName)`. If falsy value is returned then the generated module id is used |
-| `highlightCode`          | `true`               | ANSI highlight syntax error code frames |
-| `ignore`                 | `null`               | Opposite to the `only` option. `ignore` is disregarded if `only` is specified |
-| `inputSourceMap`         | `null`               | A source map object that the output source map will be based on |
-| `minified`               | `false`              | Should the output be minified (not printing last semicolons in blocks, printing literal string values instead of escaped ones, stripping `()` from `new` when safe) |
-| `moduleId`               | `null`               | Specify a custom name for module ids |
-| `moduleIds`              | `false`              | If truthy, insert an explicit id for modules. By default, all modules are anonymous. (Not available for `common` modules) |
-| `moduleRoot`             | `(sourceRoot)`       | Optional prefix for the AMD module formatter that will be prepend to the filename on module definitions |
-| `only`                   | `null`               | A [glob](https://github.com/isaacs/minimatch), regex, or mixed array of both, matching paths to **only** compile. Can also be an array of arrays containing paths to explicitly match. When attempting to compile a non-matching file it's returned verbatim |
-| `parserOpts`             | `{}`                 | An object containing the options to be passed down to the babel parser, babylon |
-| `plugins`                | `[]`                 | List of [plugins](https://babeljs.io/docs/plugins/) to load and use |
-| `presets`                | `[]`                 | List of [presets](https://babeljs.io/docs/plugins/#presets) (a set of plugins) to load and use |
-| `retainLines`            | `false`              | Retain line numbers. This will lead to wacky code but is handy for scenarios where you can't use source maps. (**NOTE:** This will not retain the columns) |
-| `shouldPrintComment`     | `null`               | An optional callback that controls whether a comment should be output or not. Called as `shouldPrintComment(commentContents)`. **NOTE:** This overrides the `comment` option when used |
-| `sourceFileName`         | `(filenameRelative)` | Set `sources[0]` on returned source map |
-| `sourceMaps`             | `false`              | If truthy, adds a `map` property to returned output. If set to `"inline"`, a comment with a sourceMappingURL directive is added to the bottom of the returned code. If set to `"both"` then a `map` property is returned as well as a source map comment appended. **This does not emit sourcemap files by itself!** To have sourcemaps emitted using the CLI, you must pass it the `--source-maps` option |
-| `sourceRoot`             | `(moduleRoot)`       | The root from which all sources are relative |
-| `sourceType`             | `"module"`           | Indicate the mode the code should be parsed in. Can be one of "script", "module", or "unambiguous". `"unambiguous"` will make Babel attempt to _guess_, based on the presence of ES6 `import` or `export` statements. Files with ES6 `import`s and `export`s are considered `"module"` and are otherwise `"script"`. |
-| `wrapPluginVisitorMethod`| `null`               | An optional callback that can be used to wrap visitor methods. **NOTE:** This is useful for things like introspection, and not really needed for implementing anything. Called as `wrapPluginVisitorMethod(pluginAlias, visitorType, callback)`.

packages/babel-core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/core",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "description": "Babel compiler core.",
   "main": "lib/index.js",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
@@ -22,30 +22,32 @@
     "babel-core",
     "compiler"
   ],
+  "engines": {
+    "node": ">=6.9.0"
+  },
   "browser": {
     "./lib/config/files/index.js": "./lib/config/files/index-browser.js",
-    "./lib/transform-file.js": "./lib/transform-file-browser.js",
-    "./lib/transform-file-sync.js": "./lib/transform-file-sync-browser.js"
+    "./lib/transform-file.js": "./lib/transform-file-browser.js"
   },
   "dependencies": {
-    "@babel/code-frame": "7.0.0-beta.47",
-    "@babel/generator": "7.0.0-beta.47",
-    "@babel/helpers": "7.0.0-beta.47",
-    "@babel/template": "7.0.0-beta.47",
-    "@babel/traverse": "7.0.0-beta.47",
-    "@babel/types": "7.0.0-beta.47",
-    "babylon": "7.0.0-beta.47",
+    "@babel/code-frame": "7.0.0-beta.51",
+    "@babel/generator": "7.0.0-beta.51",
+    "@babel/helpers": "7.0.0-beta.51",
+    "@babel/parser": "7.0.0-beta.51",
+    "@babel/template": "7.0.0-beta.51",
+    "@babel/traverse": "7.0.0-beta.51",
+    "@babel/types": "7.0.0-beta.51",
     "convert-source-map": "^1.1.0",
     "debug": "^3.1.0",
     "json5": "^0.5.0",
     "lodash": "^4.17.5",
-    "micromatch": "^2.3.11",
+    "micromatch": "^3.1.10",
     "resolve": "^1.3.2",
     "semver": "^5.4.1",
     "source-map": "^0.5.0"
   },
   "devDependencies": {
-    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.47",
-    "@babel/register": "7.0.0-beta.47"
+    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.51",
+    "@babel/register": "7.0.0-beta.51"
   }
 }

packages/babel-core/src/config/config-chain.js

@@ -46,8 +46,9 @@ export type PresetInstance = {
 };
 
 export type ConfigContext = {
-  filename: string | null,
+  filename: string | void,
   cwd: string,
+  root: string,
   envName: string,
 };
 
@@ -130,18 +131,15 @@ export function buildRootChain(
   );
   if (!programmaticChain) return null;
 
-  const { root: rootDir = ".", configFile: configFileName = true } = opts;
-  let { babelrc, babelrcRoots } = opts;
-
-  const absoluteRoot = path.resolve(context.cwd, rootDir);
-
   let configFile;
-  if (typeof configFileName === "string") {
-    configFile = loadConfig(configFileName, context.cwd, context.envName);
-  } else if (configFileName === true) {
-    configFile = findRootConfig(absoluteRoot, context.envName);
+  if (typeof opts.configFile === "string") {
+    configFile = loadConfig(opts.configFile, context.cwd, context.envName);
+  } else if (opts.configFile !== false) {
+    configFile = findRootConfig(context.root, context.envName);
   }
 
+  let { babelrc, babelrcRoots } = opts;
+
   const configFileChain = emptyChain();
   if (configFile) {
     const validatedFile = validateConfigFile(configFile);
@@ -171,7 +169,7 @@ export function buildRootChain(
   if (
     (babelrc === true || babelrc === undefined) &&
     pkgData &&
-    babelrcLoadEnabled(context, pkgData, babelrcRoots, absoluteRoot)
+    babelrcLoadEnabled(context, pkgData, babelrcRoots)
   ) {
     ({ ignore: ignoreFile, config: babelrcFile } = findRelativeConfig(
       pkgData,
@@ -214,10 +212,11 @@ function babelrcLoadEnabled(
   context: ConfigContext,
   pkgData: FilePackageData,
   babelrcRoots: BabelrcSearch | void,
-  absoluteRoot: string,
 ): boolean {
   if (typeof babelrcRoots === "boolean") return babelrcRoots;
 
+  const absoluteRoot = context.root;
+
   // Fast path to avoid having to load micromatch if the babelrc is just
   // loading in the standard root directory.
   if (babelrcRoots === undefined) {
@@ -237,11 +236,13 @@ function babelrcLoadEnabled(
   return micromatch(pkgData.directories, babelrcPatterns).length > 0;
 }
 
-const validateConfigFile = makeWeakCache((file: ConfigFile): ValidatedFile => ({
-  filepath: file.filepath,
-  dirname: file.dirname,
-  options: validate("configfile", file.options),
-}));
+const validateConfigFile = makeWeakCache(
+  (file: ConfigFile): ValidatedFile => ({
+    filepath: file.filepath,
+    dirname: file.dirname,
+    options: validate("configfile", file.options),
+  }),
+);
 
 const validateBabelrcFile = makeWeakCache(
   (file: ConfigFile): ValidatedFile => ({
@@ -251,11 +252,13 @@ const validateBabelrcFile = makeWeakCache(
   }),
 );
 
-const validateExtendFile = makeWeakCache((file: ConfigFile): ValidatedFile => ({
-  filepath: file.filepath,
-  dirname: file.dirname,
-  options: validate("extendsfile", file.options),
-}));
+const validateExtendFile = makeWeakCache(
+  (file: ConfigFile): ValidatedFile => ({
+    filepath: file.filepath,
+    dirname: file.dirname,
+    options: validate("extendsfile", file.options),
+  }),
+);
 
 /**
  * Build a config chain for just the programmatic options passed into Babel.
@@ -576,7 +579,7 @@ function configFieldIsApplicable(
   test: ConfigApplicableTest,
   dirname: string,
 ): boolean {
-  if (context.filename === null) {
+  if (typeof context.filename !== "string") {
     throw new Error(
       `Configuration contains explicit test/include/exclude checks, but no filename was passed to Babel`,
     );
@@ -602,7 +605,7 @@ function shouldIgnore(
   dirname: string,
 ): boolean {
   if (ignore) {
-    if (context.filename === null) {
+    if (typeof context.filename !== "string") {
       throw new Error(
         `Configuration contains ignore checks, but no filename was passed to Babel`,
       );
@@ -621,7 +624,7 @@ function shouldIgnore(
   }
 
   if (only) {
-    if (context.filename === null) {
+    if (typeof context.filename !== "string") {
       throw new Error(
         `Configuration contains ignore checks, but no filename was passed to Babel`,
       );
@@ -696,7 +699,7 @@ function matchesPatterns(
 
 const getPossibleDirs = makeWeakCache((context: ConfigContextNamed) => {
   let current = context.filename;
-  if (current === null) return [];
+  if (typeof current !== "string") return [];
 
   const possibleDirs = [current];
   while (true) {

packages/babel-core/src/config/config-descriptors.js

@@ -277,7 +277,7 @@ function assertNoDuplicates(items: Array<UnloadedDescriptor>): void {
         [
           `Duplicate plugin/preset detected.`,
           `If you'd like to use two separate instances of a plugin,`,
-          `they neen separate names, e.g.`,
+          `they need separate names, e.g.`,
           ``,
           `  plugins: [`,
           `    ['some-plugin', {}],`,

packages/babel-core/src/config/files/configuration.js

@@ -198,8 +198,9 @@ const readConfigJS = makeStrongCache(
 
 const packageToBabelConfig = makeWeakCache(
   (file: ConfigFile): ConfigFile | null => {
-    if (typeof file.options.babel === "undefined") return null;
-    const babel = file.options.babel;
+    const babel = file.options[("babel": string)];
+
+    if (typeof babel === "undefined") return null;
 
     if (typeof babel !== "object" || Array.isArray(babel) || babel === null) {
       throw new Error(`${file.filepath}: .babel property must be an object`);

packages/babel-core/src/config/index.js

@@ -17,10 +17,3 @@ export function loadOptions(opts: {}): Object | null {
 
   return config ? config.options : null;
 }
-
-// For easier backward-compatibility, provide an API like the one we exposed in Babel 6.
-export class OptionManager {
-  init(opts: {}) {
-    return loadOptions(opts);
-  }
-}

packages/babel-core/src/config/partial.js

@@ -28,12 +28,17 @@ export default function loadPrivatePartialConfig(
 
   const args = inputOpts ? validate("arguments", inputOpts) : {};
 
-  const { envName = getEnv(), cwd = "." } = args;
+  const { envName = getEnv(), cwd = ".", root: rootDir = "." } = args;
   const absoluteCwd = path.resolve(cwd);
+  const absoluteRootDir = path.resolve(absoluteCwd, rootDir);
 
   const context: ConfigContext = {
-    filename: args.filename ? path.resolve(cwd, args.filename) : null,
+    filename:
+      typeof args.filename === "string"
+        ? path.resolve(cwd, args.filename)
+        : undefined,
     cwd: absoluteCwd,
+    root: absoluteRootDir,
     envName,
   };
 
@@ -50,9 +55,12 @@ export default function loadPrivatePartialConfig(
   // to not change behavior.
   options.babelrc = false;
   options.configFile = false;
-  options.envName = envName;
-  options.cwd = absoluteCwd;
   options.passPerPreset = false;
+  options.envName = context.envName;
+  options.cwd = context.cwd;
+  options.root = context.root;
+  options.filename =
+    typeof context.filename === "string" ? context.filename : undefined;
 
   options.plugins = configChain.plugins.map(descriptor =>
     createItemFromDescriptor(descriptor),

packages/babel-core/src/config/validation/options.js

@@ -57,27 +57,10 @@ const NONPRESET_VALIDATORS: ValidatorSet = {
   extends: (assertString: Validator<
     $PropertyType<ValidatedOptions, "extends">,
   >),
-  env: (assertEnvSet: Validator<$PropertyType<ValidatedOptions, "env">>),
   ignore: (assertIgnoreList: Validator<
     $PropertyType<ValidatedOptions, "ignore">,
   >),
   only: (assertIgnoreList: Validator<$PropertyType<ValidatedOptions, "only">>),
-  overrides: (assertOverridesList: Validator<
-    $PropertyType<ValidatedOptions, "overrides">,
-  >),
-
-  // We could limit these to 'overrides' blocks, but it's not clear why we'd
-  // bother, when the ability to limit a config to a specific set of files
-  // is a fairly general useful feature.
-  test: (assertConfigApplicableTest: Validator<
-    $PropertyType<ValidatedOptions, "test">,
-  >),
-  include: (assertConfigApplicableTest: Validator<
-    $PropertyType<ValidatedOptions, "include">,
-  >),
-  exclude: (assertConfigApplicableTest: Validator<
-    $PropertyType<ValidatedOptions, "exclude">,
-  >),
 };
 
 const COMMON_VALIDATORS: ValidatorSet = {
@@ -96,6 +79,25 @@ const COMMON_VALIDATORS: ValidatorSet = {
   passPerPreset: (assertBoolean: Validator<
     $PropertyType<ValidatedOptions, "passPerPreset">,
   >),
+
+  env: (assertEnvSet: Validator<$PropertyType<ValidatedOptions, "env">>),
+  overrides: (assertOverridesList: Validator<
+    $PropertyType<ValidatedOptions, "overrides">,
+  >),
+
+  // We could limit these to 'overrides' blocks, but it's not clear why we'd
+  // bother, when the ability to limit a config to a specific set of files
+  // is a fairly general useful feature.
+  test: (assertConfigApplicableTest: Validator<
+    $PropertyType<ValidatedOptions, "test">,
+  >),
+  include: (assertConfigApplicableTest: Validator<
+    $PropertyType<ValidatedOptions, "include">,
+  >),
+  exclude: (assertConfigApplicableTest: Validator<
+    $PropertyType<ValidatedOptions, "exclude">,
+  >),
+
   retainLines: (assertBoolean: Validator<
     $PropertyType<ValidatedOptions, "retainLines">,
   >),

packages/babel-core/src/index.js

@@ -13,26 +13,22 @@ export * as types from "@babel/types";
 export { default as traverse } from "@babel/traverse";
 export { default as template } from "@babel/template";
 
-export { loadPartialConfig, loadOptions, OptionManager } from "./config";
-
 export { createConfigItem } from "./config/item";
 
-export function Plugin(alias: string) {
-  throw new Error(
-    `The (${alias}) Babel 5 plugin is being run with an unsupported Babel version.`,
-  );
-}
+export { loadPartialConfig, loadOptions } from "./config";
 
-export { default as transform } from "./transform";
-export { default as transformSync } from "./transform-sync";
-
-export { default as transformFile } from "./transform-file";
-export { default as transformFileSync } from "./transform-file-sync";
-
-export { default as transformFromAst } from "./transform-ast";
-export { default as transformFromAstSync } from "./transform-ast-sync";
-
-export { default as parse } from "./parse";
+export { transform, transformSync, transformAsync } from "./transform";
+export {
+  transformFile,
+  transformFileSync,
+  transformFileAsync,
+} from "./transform-file";
+export {
+  transformFromAst,
+  transformFromAstSync,
+  transformFromAstAsync,
+} from "./transform-ast";
+export { parse, parseSync, parseAsync } from "./parse";
 
 /**
  * Recommended set of compilable extensions. Not used in @babel/core directly, but meant as
@@ -45,3 +41,17 @@ export const DEFAULT_EXTENSIONS = Object.freeze([
   ".es",
   ".mjs",
 ]);
+
+// For easier backward-compatibility, provide an API like the one we exposed in Babel 6.
+import { loadOptions } from "./config";
+export class OptionManager {
+  init(opts: {}) {
+    return loadOptions(opts);
+  }
+}
+
+export function Plugin(alias: string) {
+  throw new Error(
+    `The (${alias}) Babel 5 plugin is being run with an unsupported Babel version.`,
+  );
+}

packages/babel-core/src/parse.js

@@ -6,17 +6,79 @@ import normalizeOptions from "./transformation/normalize-opts";
 
 type AstRoot = BabelNodeFile | BabelNodeProgram;
 
-export default function parse(
-  code: string,
-  opts: InputOptions,
-): AstRoot | null {
+export type ParseResult = AstRoot;
+
+export type FileParseCallback = {
+  (Error, null): any,
+  (null, ParseResult | null): any,
+};
+
+type Parse = {
+  (code: string, callback: FileParseCallback): void,
+  (code: string, opts: ?InputOptions, callback: FileParseCallback): void,
+
+  // Here for backward-compatibility. Ideally use ".parseSync" if you want
+  // a synchronous API.
+  (code: string, opts: ?InputOptions): ParseResult | null,
+};
+
+export const parse: Parse = (function parse(code, opts, callback) {
+  if (typeof opts === "function") {
+    opts = undefined;
+    callback = opts;
+  }
+
+  // For backward-compat with Babel 7's early betas, we allow sync parsing when
+  // no callback is given. Will be dropped in some future Babel major version.
+  if (callback === undefined) return parseSync(code, opts);
+
   const config = loadConfig(opts);
 
   if (config === null) {
     return null;
   }
 
-  const file = normalizeFile(config.passes, normalizeOptions(config), code);
+  // Reassign to keep Flowtype happy.
+  const cb = callback;
 
-  return file.ast;
+  // Just delaying the transform one tick for now to simulate async behavior
+  // but more async logic may land here eventually.
+  process.nextTick(() => {
+    let ast = null;
+    try {
+      const cfg = loadConfig(opts);
+      if (cfg === null) return cb(null, null);
+
+      ast = normalizeFile(cfg.passes, normalizeOptions(cfg), code).ast;
+    } catch (err) {
+      return cb(err);
+    }
+
+    cb(null, ast);
+  });
+}: Function);
+
+export function parseSync(
+  code: string,
+  opts?: InputOptions,
+): ParseResult | null {
+  const config = loadConfig(opts);
+
+  if (config === null) {
+    return null;
+  }
+
+  return normalizeFile(config.passes, normalizeOptions(config), code).ast;
+}
+
+export function parseAsync(
+  code: string,
+  opts?: InputOptions,
+): Promise<ParseResult | null> {
+  return new Promise((res, rej) => {
+    parse(code, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
 }

packages/babel-core/src/transform-ast-sync.js

@@ -1,18 +0,0 @@
-// @flow
-import loadConfig, { type InputOptions } from "./config";
-import { runSync, type FileResult } from "./transformation";
-
-type AstRoot = BabelNodeFile | BabelNodeProgram;
-
-export default function transformFromAstSync(
-  ast: AstRoot,
-  code: string,
-  opts: ?InputOptions,
-): FileResult | null {
-  const config = loadConfig(opts);
-  if (config === null) return null;
-
-  if (!ast) throw new Error("No AST given");
-
-  return runSync(config, code, ast);
-}

packages/babel-core/src/transform-ast.js

@@ -2,16 +2,15 @@
 
 import loadConfig, { type InputOptions } from "./config";
 import {
+  runSync,
   runAsync,
   type FileResult,
   type FileResultCallback,
 } from "./transformation";
 
-import transformAstSync from "./transform-ast-sync";
-
 type AstRoot = BabelNodeFile | BabelNodeProgram;
 
-type TransformAst = {
+type TransformFromAst = {
   (ast: AstRoot, code: string, callback: FileResultCallback): void,
   (
     ast: AstRoot,
@@ -25,7 +24,12 @@ type TransformAst = {
   (ast: AstRoot, code: string, opts: ?InputOptions): FileResult | null,
 };
 
-export default ((function transformFromAst(ast, code, opts, callback) {
+export const transformFromAst: TransformFromAst = (function transformFromAst(
+  ast,
+  code,
+  opts,
+  callback,
+) {
   if (typeof opts === "function") {
     opts = undefined;
     callback = opts;
@@ -33,7 +37,7 @@ export default ((function transformFromAst(ast, code, opts, callback) {
 
   // For backward-compat with Babel 6, we allow sync transformation when
   // no callback is given. Will be dropped in some future Babel major version.
-  if (callback === undefined) return transformAstSync(ast, code, opts);
+  if (callback === undefined) return transformFromAstSync(ast, code, opts);
 
   // Reassign to keep Flowtype happy.
   const cb = callback;
@@ -53,4 +57,30 @@ export default ((function transformFromAst(ast, code, opts, callback) {
 
     runAsync(cfg, code, ast, cb);
   });
-}: Function): TransformAst);
+}: Function);
+
+export function transformFromAstSync(
+  ast: AstRoot,
+  code: string,
+  opts: ?InputOptions,
+): FileResult | null {
+  const config = loadConfig(opts);
+  if (config === null) return null;
+
+  if (!ast) throw new Error("No AST given");
+
+  return runSync(config, code, ast);
+}
+
+export function transformFromAstAsync(
+  ast: AstRoot,
+  code: string,
+  opts: ?InputOptions,
+): Promise<FileResult | null> {
+  return new Promise((res, rej) => {
+    transformFromAst(ast, code, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
+}

packages/babel-core/src/transform-file-sync.js

@@ -1,25 +0,0 @@
-// @flow
-import fs from "fs";
-
-import loadConfig, { type InputOptions } from "./config";
-import { runSync, type FileResult } from "./transformation";
-
-export default function transformFileSync(
-  filename: string,
-  opts: ?InputOptions,
-): FileResult | null {
-  let options;
-  if (opts == null) {
-    options = { filename };
-  } else if (opts && typeof opts === "object") {
-    options = {
-      ...opts,
-      filename,
-    };
-  }
-
-  const config = loadConfig(options);
-  if (config === null) return null;
-
-  return runSync(config, fs.readFileSync(filename, "utf8"));
-}

packages/babel-core/src/transform-file.js

@@ -2,14 +2,23 @@
 import fs from "fs";
 
 import loadConfig, { type InputOptions } from "./config";
-import { runAsync, type FileResultCallback } from "./transformation";
+import {
+  runSync,
+  runAsync,
+  type FileResult,
+  type FileResultCallback,
+} from "./transformation";
 
 type TransformFile = {
   (filename: string, callback: FileResultCallback): void,
   (filename: string, opts: ?InputOptions, callback: FileResultCallback): void,
 };
 
-export default ((function transformFile(filename, opts, callback) {
+export const transformFile: TransformFile = (function transformFile(
+  filename,
+  opts,
+  callback,
+) {
   let options;
   if (typeof opts === "function") {
     callback = opts;
@@ -43,4 +52,36 @@ export default ((function transformFile(filename, opts, callback) {
       runAsync(config, code, null, callback);
     });
   });
-}: Function): TransformFile);
+}: Function);
+
+export function transformFileSync(
+  filename: string,
+  opts: ?InputOptions,
+): FileResult | null {
+  let options;
+  if (opts == null) {
+    options = { filename };
+  } else if (opts && typeof opts === "object") {
+    options = {
+      ...opts,
+      filename,
+    };
+  }
+
+  const config = loadConfig(options);
+  if (config === null) return null;
+
+  return runSync(config, fs.readFileSync(filename, "utf8"));
+}
+
+export function transformFileAsync(
+  filename: string,
+  opts: ?InputOptions,
+): Promise<FileResult | null> {
+  return new Promise((res, rej) => {
+    transformFile(filename, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
+}

packages/babel-core/src/transform-sync.js

@@ -1,13 +0,0 @@
-// @flow
-import loadConfig, { type InputOptions } from "./config";
-import { runSync, type FileResult } from "./transformation";
-
-export default function transformSync(
-  code: string,
-  opts: ?InputOptions,
-): FileResult | null {
-  const config = loadConfig(opts);
-  if (config === null) return null;
-
-  return runSync(config, code);
-}

packages/babel-core/src/transform.js

@@ -1,13 +1,12 @@
 // @flow
 import loadConfig, { type InputOptions } from "./config";
 import {
+  runSync,
   runAsync,
   type FileResult,
   type FileResultCallback,
 } from "./transformation";
 
-import transformSync from "./transform-sync";
-
 type Transform = {
   (code: string, callback: FileResultCallback): void,
   (code: string, opts: ?InputOptions, callback: FileResultCallback): void,
@@ -17,7 +16,7 @@ type Transform = {
   (code: string, opts: ?InputOptions): FileResult | null,
 };
 
-export default ((function transform(code, opts, callback) {
+export const transform: Transform = (function transform(code, opts, callback) {
   if (typeof opts === "function") {
     opts = undefined;
     callback = opts;
@@ -43,4 +42,26 @@ export default ((function transform(code, opts, callback) {
 
     runAsync(cfg, code, null, cb);
   });
-}: Function): Transform);
+}: Function);
+
+export function transformSync(
+  code: string,
+  opts: ?InputOptions,
+): FileResult | null {
+  const config = loadConfig(opts);
+  if (config === null) return null;
+
+  return runSync(config, code);
+}
+
+export function transformAsync(
+  code: string,
+  opts: ?InputOptions,
+): Promise<FileResult | null> {
+  return new Promise((res, rej) => {
+    transform(code, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
+}

packages/babel-core/src/transformation/file/file.js

@@ -28,14 +28,12 @@ export default class File {
   metadata: {} = {};
   hub: Hub = new Hub(this);
   code: string = "";
-  shebang: string | null = "";
   inputMap: Object | null = null;
 
-  constructor(options: {}, { code, ast, shebang, inputMap }: NormalizedFile) {
+  constructor(options: {}, { code, ast, inputMap }: NormalizedFile) {
     this.opts = options;
     this.code = code;
     this.ast = ast;
-    this.shebang = shebang;
     this.inputMap = inputMap;
 
     this.path = NodePath.get({
@@ -48,6 +46,23 @@ export default class File {
     this.scope = this.path.scope;
   }
 
+  /**
+   * Provide backward-compatible access to the interpreter directive handling
+   * in Babel 6.x. If you are writing a plugin for Babel 7.x, it would be
+   * best to use 'program.interpreter' directly.
+   */
+  get shebang(): string {
+    const { interpreter } = this.path.node;
+    return interpreter ? interpreter.value : "";
+  }
+  set shebang(value: string): void {
+    if (value) {
+      this.path.get("interpreter").replaceWith(t.interpreterDirective(value));
+    } else {
+      this.path.get("interpreter").remove();
+    }
+  }
+
   set(key: mixed, val: mixed) {
     this._map.set(key, val);
   }

packages/babel-core/src/transformation/file/generate.js

@@ -14,7 +14,7 @@ export default function generateCode(
   outputCode: string,
   outputMap: SourceMap | null,
 } {
-  const { opts, ast, shebang, code, inputMap } = file;
+  const { opts, ast, code, inputMap } = file;
 
   const results = [];
   for (const plugins of pluginPasses) {
@@ -53,11 +53,6 @@ export default function generateCode(
 
   let { code: outputCode, map: outputMap } = result;
 
-  if (shebang) {
-    // add back shebang
-    outputCode = `${shebang}\n${outputCode}`;
-  }
-
   if (outputMap && inputMap) {
     outputMap = mergeSourceMap(inputMap.toObject(), outputMap);
   }

packages/babel-core/src/transformation/normalize-file.js

@@ -1,19 +1,19 @@
 // @flow
 
+import buildDebug from "debug";
 import * as t from "@babel/types";
 import type { PluginPasses } from "../config";
 import convertSourceMap, { typeof Converter } from "convert-source-map";
-import { parse } from "babylon";
+import { parse } from "@babel/parser";
 import { codeFrameColumns } from "@babel/code-frame";
 import File from "./file/file";
 import generateMissingPluginMessage from "./util/missing-plugin-helper";
 
-const shebangRegex = /^#!.*/;
+const debug = buildDebug("babel:transform:file");
 
 export type NormalizedFile = {
   code: string,
   ast: {},
-  shebang: string | null,
   inputMap: Converter | null,
 };
 
@@ -25,23 +25,37 @@ export default function normalizeFile(
 ): File {
   code = `${code || ""}`;
 
-  let shebang = null;
   let inputMap = null;
   if (options.inputSourceMap !== false) {
-    inputMap = convertSourceMap.fromSource(code);
-    if (inputMap) {
+    try {
+      inputMap = convertSourceMap.fromSource(code);
+
+      if (inputMap) {
+        code = convertSourceMap.removeComments(code);
+      }
+    } catch (err) {
+      debug("discarding unknown inline input sourcemap", err);
       code = convertSourceMap.removeComments(code);
-    } else if (typeof options.inputSourceMap === "object") {
+    }
+
+    if (!inputMap) {
+      try {
+        inputMap = convertSourceMap.fromMapFileSource(code);
+
+        if (inputMap) {
+          code = convertSourceMap.removeMapFileComments(code);
+        }
+      } catch (err) {
+        debug("discarding unknown file input sourcemap", err);
+        code = convertSourceMap.removeMapFileComments(code);
+      }
+    }
+
+    if (!inputMap && typeof options.inputSourceMap === "object") {
       inputMap = convertSourceMap.fromObject(options.inputSourceMap);
     }
   }
 
-  const shebangMatch = shebangRegex.exec(code);
-  if (shebangMatch) {
-    shebang = shebangMatch[0];
-    code = code.replace(shebangRegex, "");
-  }
-
   if (ast) {
     if (ast.type === "Program") {
       ast = t.file(ast, [], []);
@@ -49,13 +63,15 @@ export default function normalizeFile(
       throw new Error("AST root must be a Program or File node");
     }
   } else {
+    // The parser's AST types aren't fully compatible with the types generated
+    // by the logic in babel-types.
+    // $FlowFixMe
     ast = parser(pluginPasses, options, code);
   }
 
   return new File(options, {
     code,
     ast,
-    shebang,
     inputMap,
   });
 }

packages/babel-core/src/transformation/plugin-pass.js

@@ -7,14 +7,20 @@ export default class PluginPass {
   key: ?string;
   file: File;
   opts: Object;
+
+  // The working directory that Babel's programmatic options are loaded
+  // relative to.
+  cwd: string;
+
+  // The absolute path of the file being compiled.
   filename: string | void;
 
   constructor(file: File, key: ?string, options: ?Object) {
     this.key = key;
     this.file = file;
     this.opts = options || {};
-    this.filename =
-      typeof file.opts.filename === "string" ? file.opts.filename : undefined;
+    this.cwd = file.opts.cwd;
+    this.filename = file.opts.filename;
   }
 
   set(key: mixed, val: mixed) {

packages/babel-core/src/transformation/util/missing-plugin-helper.js

@@ -209,7 +209,7 @@ const getNameURLCombination = ({ name, url }) => `${name} (${url})`;
 
 /*
 Returns a string of the format:
-Support for the experimental syntax [babylon plugin name] isn't currently enabled ([loc]):
+Support for the experimental syntax [@babel/parser plugin name] isn't currently enabled ([loc]):
 
 [code frame]
 

packages/babel-core/test/api.js

@@ -370,6 +370,60 @@ describe("api", function() {
     );
   });
 
+  it("interpreter directive backward-compat", function() {
+    function doTransform(code, preHandler) {
+      return transform(code, {
+        plugins: [
+          {
+            pre: preHandler,
+          },
+        ],
+      }).code;
+    }
+
+    // Writes value properly.
+    expect(
+      doTransform("", file => {
+        file.shebang = "env node";
+      }),
+    ).toBe(`#!env node`);
+    expect(
+      doTransform("#!env node", file => {
+        file.shebang = "env node2";
+      }),
+    ).toBe(`#!env node2`);
+    expect(
+      doTransform("", file => {
+        file.shebang = "";
+      }),
+    ).toBe(``);
+    expect(
+      doTransform("#!env node", file => {
+        file.shebang = "";
+      }),
+    ).toBe(``);
+
+    // Reads value properly.
+    doTransform("", file => {
+      expect(file.shebang).toBe("");
+    });
+    doTransform("#!env node", file => {
+      expect(file.shebang).toBe("env node");
+    });
+
+    // Reads and writes properly.
+    expect(
+      doTransform("#!env node", file => {
+        expect(file.shebang).toBe("env node");
+
+        file.shebang = "env node2";
+        expect(file.shebang).toBe("env node2");
+
+        file.shebang = "env node3";
+      }),
+    ).toBe(`#!env node3`);
+  });
+
   it("source map merging", function() {
     const result = transform(
       [

packages/babel-core/test/config-chain.js

@@ -906,6 +906,7 @@ describe("buildConfigChain", function() {
       babelrc: false,
       configFile: false,
       cwd: process.cwd(),
+      root: process.cwd(),
       envName: "development",
       passPerPreset: false,
       plugins: [],
@@ -935,8 +936,9 @@ describe("buildConfigChain", function() {
         }),
       ).toEqual({
         ...getDefaults(),
-        filename,
+        filename: filename,
         cwd: path.dirname(filename),
+        root: path.dirname(filename),
         comments: true,
       });
     });
@@ -946,8 +948,9 @@ describe("buildConfigChain", function() {
 
       expect(loadOptions({ filename, cwd: path.dirname(filename) })).toEqual({
         ...getDefaults(),
-        filename,
+        filename: filename,
         cwd: path.dirname(filename),
+        root: path.dirname(filename),
         comments: true,
       });
     });
@@ -957,8 +960,9 @@ describe("buildConfigChain", function() {
 
       expect(loadOptions({ filename, cwd: path.dirname(filename) })).toEqual({
         ...getDefaults(),
-        filename,
+        filename: filename,
         cwd: path.dirname(filename),
+        root: path.dirname(filename),
         comments: true,
       });
     });
@@ -998,8 +1002,9 @@ describe("buildConfigChain", function() {
 
       expect(loadOptions({ filename, cwd: path.dirname(filename) })).toEqual({
         ...getDefaults(),
-        filename,
+        filename: filename,
         cwd: path.dirname(filename),
+        root: path.dirname(filename),
         comments: true,
       });
     });

packages/babel-core/test/evaluation.js

@@ -1,5 +1,5 @@
 import traverse from "@babel/traverse";
-import { parse } from "babylon";
+import { parse } from "@babel/parser";
 
 describe("evaluation", function() {
   function addTest(code, type, value, notConfident) {

packages/babel-core/test/fixtures/option-manager/presets/es2015_default_function.js

@@ -12,6 +12,11 @@ Object.defineProperty(exports, "__esModule", {
 
 exports.default = function () {
   return {
-    plugins: [require('../../../../../babel-plugin-syntax-decorators')]
+    plugins: [
+      [
+        require('../../../../../babel-plugin-syntax-decorators'),
+        { legacy: true }
+      ],
+    ]
   };
 };

packages/babel-core/test/fixtures/option-manager/presets/es2015_default_object.js

@@ -9,6 +9,11 @@
 exports.__esModule = true;
 module.exports = function() {
   return {
-    plugins: [require('../../../../../babel-plugin-syntax-decorators')]
+    plugins: [
+      [
+        require('../../../../../babel-plugin-syntax-decorators'),
+        { legacy: true }
+      ],
+    ]
   };
 };

packages/babel-core/test/fixtures/option-manager/presets/es5_function.js

@@ -1,7 +1,10 @@
 module.exports = function () {
   return {
     plugins: [
-      require('../../../../../babel-plugin-syntax-decorators'),
+      [
+        require('../../../../../babel-plugin-syntax-decorators'),
+        { legacy: true }
+      ],
     ]
   };
 };

packages/babel-core/test/fixtures/option-manager/presets/es5_object.js

@@ -1,7 +1,10 @@
 module.exports = function() {
   return {
     plugins: [
-      require('../../../../../babel-plugin-syntax-decorators'),
+      [
+        require('../../../../../babel-plugin-syntax-decorators'),
+        { legacy: true }
+      ],
     ]
   };
 };

packages/babel-core/test/fixtures/parse/output.json

@@ -26,6 +26,7 @@
         "column": 0
       }
     },
+    "interpreter": null,
     "sourceType": "module",
     "body": [
       {
@@ -57,7 +58,7 @@
                 "column": 11
               }
             },
-            "callee": {
+            "expression": {
               "type": "Identifier",
               "start": 1,
               "end": 11,

packages/babel-core/test/fixtures/transformation/misc/regression-1155/output.js

@@ -3,6 +3,8 @@ var Foo =
 function (_Bar) {
   "use strict";
 
+  babelHelpers.inherits(Foo, _Bar);
+
   function Foo(options) {
     babelHelpers.classCallCheck(this, Foo);
     var parentOptions = {};
@@ -14,6 +16,5 @@ function (_Bar) {
     return babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this, parentOptions));
   }
 
-  babelHelpers.inherits(Foo, _Bar);
   return Foo;
 }(Bar);

packages/babel-core/test/fixtures/transformation/misc/retain-lines-interpreter-directive/input.js

@@ -0,0 +1,2 @@
+#!env node
+var someFirstLine;

packages/babel-core/test/fixtures/transformation/misc/retain-lines-interpreter-directive/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["transform-strict-mode"],
+  "retainLines": true
+}

packages/babel-core/test/fixtures/transformation/misc/retain-lines-interpreter-directive/output.js

@@ -0,0 +1,2 @@
+#!env node
+"use strict";var someFirstLine;

packages/babel-core/test/fixtures/transformation/source-maps/interpreter-directive-prefix/input.js

@@ -0,0 +1,3 @@
+#!env node
+
+console.log("Hello, world!");

packages/babel-core/test/fixtures/transformation/source-maps/interpreter-directive-prefix/options.json

@@ -0,0 +1,3 @@
+{
+  "sourceMap": true
+}

packages/babel-core/test/fixtures/transformation/source-maps/interpreter-directive-prefix/output.js

@@ -0,0 +1,2 @@
+#!env node
+console.log("Hello, world!");

packages/babel-core/test/fixtures/transformation/source-maps/interpreter-directive-prefix/source-map.json

@@ -0,0 +1,14 @@
+{
+  "mappings": "AAAA;AAEAA,QAAQC,GAAR,CAAY,eAAZ",
+  "names": [
+    "console",
+    "log"
+  ],
+  "sources": [
+    "source-maps/interpreter-directive-prefix/input.js"
+  ],
+  "sourcesContent": [
+    "#!env node\n\nconsole.log(\"Hello, world!\");"
+  ],
+  "version": 3
+}

packages/babel-generator/README.md

@@ -1,78 +1,19 @@
 # @babel/generator
 
-> Turns a [Babylon AST](https://github.com/babel/babel/blob/master/packages/babylon/ast/spec.md) into code.
+> Turns an AST into code.
+
+See our website [@babel/generator](https://new.babeljs.io/docs/en/next/babel-generator.html) for more information or the [issues](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3A%22pkg%3A%20generator%22+is%3Aopen) associated with this package.
 
 ## Install
 
+Using npm:
+
 ```sh
-npm install --save-dev @babel/generator
+npm install --save @babel/generator
 ```
 
-## Usage
+or using yarn:
 
-```js
-import {parse} from 'babylon';
-import generate from '@babel/generator';
-
-const code = 'class Example {}';
-const ast = parse(code);
-
-const output = generate(ast, { /* options */ }, code);
-```
-
-## Options
-
-Options for formatting output:
-
-name                   | type     | default         | description
------------------------|----------|-----------------|--------------------------------------------------------------------------
-auxiliaryCommentBefore | string   |                 | Optional string to add as a block comment at the start of the output file
-auxiliaryCommentAfter  | string   |                 | Optional string to add as a block comment at the end of the output file
-shouldPrintComment     | function | `opts.comments` | Function that takes a comment (as a string) and returns `true` if the comment should be included in the output.  By default, comments are included if `opts.comments` is `true` or if `opts.minifed` is `false` and the comment contains `@preserve` or `@license`
-retainLines            | boolean  | `false`         | Attempt to use the same line numbers in the output code as in the source code (helps preserve stack traces)
-retainFunctionParens   | boolean  | `false`         | Retain parens around function expressions (could be used to change engine parsing behavior)
-comments               | boolean  | `true`          | Should comments be included in output
-compact                | boolean or `'auto'` | `opts.minified` | Set to `true` to avoid adding whitespace for formatting
-minified               | boolean  | `false`         | Should the output be minified
-concise                | boolean  | `false`         | Set to `true` to reduce whitespace (but not as much as `opts.compact`)
-filename               | string   |                 | Used in warning messages
-jsonCompatibleStrings  | boolean  | `false`         | Set to true to run `jsesc` with "json": true to print "\u00A9" vs. "©";
-
-Options for source maps:
-
-name                   | type     | default         | description
------------------------|----------|-----------------|--------------------------------------------------------------------------
-sourceMaps             | boolean  | `false`         | Enable generating source maps
-sourceRoot             | string   |                 | A root for all relative URLs in the source map
-sourceFileName         | string   |                 | The filename for the source code (i.e. the code in the `code` argument).  This will only be used if `code` is a string.
-
-## AST from Multiple Sources
-
-In most cases, Babel does a 1:1 transformation of input-file to output-file.  However,
-you may be dealing with AST constructed from multiple sources - JS files, templates, etc.
-If this is the case, and you want the sourcemaps to reflect the correct sources, you'll need
-to pass an object to `generate` as the `code` parameter.  Keys
-should be the source filenames, and values should be the source content.
-
-Here's an example of what that might look like:
-
-```js
-import {parse} from 'babylon';
-import generate from '@babel/generator';
-
-const a = 'var a = 1;';
-const b = 'var b = 2;';
-const astA = parse(a, { sourceFilename: 'a.js' });
-const astB = parse(b, { sourceFilename: 'b.js' });
-const ast = {
-  type: 'Program',
-  body: [].concat(astA.program.body, astB.program.body)
-};
-
-const { code, map } = generate(ast, { sourceMaps: true }, {
-  'a.js': a,
-  'b.js': b
-});
-
-// Sourcemap will point to both a.js and b.js where appropriate.
+```sh
+yarn add --save @babel/generator
 ```

packages/babel-generator/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/generator",
-  "version": "7.0.0-beta.47",
+  "version": "7.0.0-beta.51",
   "description": "Turns an AST into code.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
@@ -11,14 +11,14 @@
     "lib"
   ],
   "dependencies": {
-    "@babel/types": "7.0.0-beta.47",
+    "@babel/types": "7.0.0-beta.51",
     "jsesc": "^2.5.1",
     "lodash": "^4.17.5",
     "source-map": "^0.5.0",
     "trim-right": "^1.0.1"
   },
   "devDependencies": {
-    "@babel/helper-fixtures": "7.0.0-beta.47",
-    "babylon": "7.0.0-beta.47"
+    "@babel/helper-fixtures": "7.0.0-beta.51",
+    "@babel/parser": "7.0.0-beta.51"
   }
 }

packages/babel-generator/scripts/generate-typescript-tests.js

@@ -1,5 +1,5 @@
 /*
-Copies tests from babylon's TypeScript test suite to @babel/generator.
+Copies tests from the @babel/parser's TypeScript test suite to @babel/generator.
 */
 const {
   copySync,
@@ -10,7 +10,10 @@ const {
 } = require("fs-extra");
 const { join } = require("path");
 
-const testsFrom = join(__dirname, "../../babylon/test/fixtures/typescript");
+const testsFrom = join(
+  __dirname,
+  "../../babel-parser/test/fixtures/typescript"
+);
 const testsTo = join(__dirname, "../test/fixtures/typescript");
 
 emptyDirSync(testsTo);

packages/babel-generator/src/generators/base.js

@@ -1,4 +1,10 @@
 export function File(node: Object) {
+  if (node.program) {
+    // Print this here to ensure that Program node 'leadingComments' still
+    // get printed after the hashbang.
+    this.print(node.program.interpreter, node);
+  }
+
   this.print(node.program, node);
 }
 
@@ -44,4 +50,8 @@ export function Directive(node: Object) {
   this.semicolon();
 }
 
+export function InterpreterDirective(node: Object) {
+  this.token(`#!${node.value}\n`);
+}
+
 export { StringLiteral as DirectiveLiteral } from "./types";

packages/babel-generator/src/generators/classes.js

@@ -2,8 +2,9 @@ import * as t from "@babel/types";
 
 export function ClassDeclaration(node: Object, parent: Object) {
   if (
-    !t.isExportDefaultDeclaration(parent) &&
-    !t.isExportNamedDeclaration(parent)
+    !this.format.decoratorsBeforeExport ||
+    (!t.isExportDefaultDeclaration(parent) &&
+      !t.isExportNamedDeclaration(parent))
   ) {
     this.printJoin(node.decorators, node);
   }

packages/babel-generator/src/generators/expressions.js

@@ -67,6 +67,7 @@ export function NewExpression(node: Object, parent: Object) {
     return;
   }
 
+  this.print(node.typeArguments, node); // Flow
   this.print(node.typeParameters, node); // TS
 
   if (node.optional) {
@@ -91,7 +92,7 @@ export function Super() {
 
 export function Decorator(node: Object) {
   this.token("@");
-  this.print(node.callee, node);
+  this.print(node.expression, node);
   this.newline();
 }
 
@@ -125,6 +126,7 @@ export function OptionalMemberExpression(node: Object) {
 export function OptionalCallExpression(node: Object) {
   this.print(node.callee, node);
 
+  this.print(node.typeArguments, node); // Flow
   this.print(node.typeParameters, node); // TS
 
   if (node.optional) {
@@ -138,6 +140,7 @@ export function OptionalCallExpression(node: Object) {
 export function CallExpression(node: Object) {
   this.print(node.callee, node);
 
+  this.print(node.typeArguments, node); // Flow
   this.print(node.typeParameters, node); // TS
   this.token("(");
   this.printList(node.arguments, node);

packages/babel-generator/src/generators/flow.js

@@ -262,6 +262,18 @@ function andSeparator() {
   this.space();
 }
 
+export function InterfaceTypeAnnotation(node: Object) {
+  this.word("interface");
+  if (node.extends && node.extends.length) {
+    this.space();
+    this.word("extends");
+    this.space();
+    this.printList(node.extends, node);
+  }
+  this.space();
+  this.print(node.body, node);
+}
+
 export function IntersectionTypeAnnotation(node: Object) {
   this.printJoin(node.types, node, { separator: andSeparator });
 }
@@ -384,6 +396,7 @@ export function ObjectTypeAnnotation(node: Object) {
   const props = node.properties.concat(
     node.callProperties || [],
     node.indexers || [],
+    node.internalSlots || [],
   );
 
   if (props.length) {
@@ -413,6 +426,24 @@ export function ObjectTypeAnnotation(node: Object) {
   }
 }
 
+export function ObjectTypeInternalSlot(node: Object) {
+  if (node.static) {
+    this.word("static");
+    this.space();
+  }
+  this.token("[");
+  this.token("[");
+  this.print(node.id, node);
+  this.token("]");
+  this.token("]");
+  if (node.optional) this.token("?");
+  if (!node.method) {
+    this.token(":");
+    this.space();
+  }
+  this.print(node.value, node);
+}
+
 export function ObjectTypeCallProperty(node: Object) {
   if (node.static) {
     this.word("static");
@@ -441,6 +472,10 @@ export function ObjectTypeIndexer(node: Object) {
 }
 
 export function ObjectTypeProperty(node: Object) {
+  if (node.proto) {
+    this.word("proto");
+    this.space();
+  }
   if (node.static) {
     this.word("static");
     this.space();

packages/babel-generator/src/generators/modules.js

@@ -57,7 +57,10 @@ export function ExportAllDeclaration(node: Object) {
 }
 
 export function ExportNamedDeclaration(node: Object) {
-  if (t.isClassDeclaration(node.declaration)) {
+  if (
+    this.format.decoratorsBeforeExport &&
+    t.isClassDeclaration(node.declaration)
+  ) {
     this.printJoin(node.declaration.decorators, node);
   }
 
@@ -67,7 +70,10 @@ export function ExportNamedDeclaration(node: Object) {
 }
 
 export function ExportDefaultDeclaration(node: Object) {
-  if (t.isClassDeclaration(node.declaration)) {
+  if (
+    this.format.decoratorsBeforeExport &&
+    t.isClassDeclaration(node.declaration)
+  ) {
     this.printJoin(node.declaration.decorators, node);
   }
 

packages/babel-generator/src/generators/types.js

@@ -132,10 +132,7 @@ export function StringLiteral(node: Object) {
   }
 
   // ensure the output is ASCII-safe
-  const opts = {
-    quotes: "double",
-    wrap: true,
-  };
+  const opts = this.format.jsescOption;
   if (this.format.jsonCompatibleStrings) {
     opts.json = true;
   }
@@ -143,3 +140,12 @@ export function StringLiteral(node: Object) {
 
   return this.token(val);
 }
+
+export function BigIntLiteral(node: Object) {
+  const raw = this.getPossibleRaw(node);
+  if (!this.format.minified && raw != null) {
+    this.token(raw);
+    return;
+  }
+  this.token(node.value);
+}

packages/babel-generator/src/index.js

@@ -52,6 +52,12 @@ function normalizeOptions(code, opts): Format {
       style: "  ",
       base: 0,
     },
+    decoratorsBeforeExport: !!opts.decoratorsBeforeExport,
+    jsescOption: {
+      quotes: "double",
+      wrap: true,
+      ...opts.jsescOption,
+    },
   };
 
   if (format.minified) {

packages/babel-generator/src/node/whitespace.js

@@ -209,6 +209,22 @@ nodes.ObjectTypeIndexer = function(node: Object, parent): ?WhitespaceObject {
   }
 };
 
+nodes.ObjectTypeInternalSlot = function(
+  node: Object,
+  parent,
+): ?WhitespaceObject {
+  if (
+    parent.internalSlots[0] === node &&
+    (!parent.properties || !parent.properties.length) &&
+    (!parent.callProperties || !parent.callProperties.length) &&
+    (!parent.indexers || !parent.indexers.length)
+  ) {
+    return {
+      before: true,
+    };
+  }
+};
+
 /**
  * Returns lists from node types that need whitespace.
  */

packages/babel-generator/src/printer.js

@@ -25,6 +25,7 @@ export type Format = {
     style: string,
     base: number,
   },
+  decoratorsBeforeExport: boolean,
 };
 
 export default class Printer {

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-false/input.js

@@ -0,0 +1,3 @@
+export default @dec class Foo {}
+
+export @dec class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-false/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    ["decorators", { "decoratorsBeforeExport": false }]
+  ],
+  "decoratorsBeforeExport": false
+}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-false/output.js

@@ -0,0 +1,4 @@
+export default @dec
+class Foo {}
+export @dec
+class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-true/input.js

@@ -0,0 +1,3 @@
+export default @dec class Foo {}
+
+export @dec class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-true/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    ["decorators", { "decoratorsBeforeExport": false }]
+  ],
+  "decoratorsBeforeExport": true
+}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/false-to-true/output.js

@@ -0,0 +1,4 @@
+@dec
+export default class Foo {}
+@dec
+export class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-false/input.js

@@ -0,0 +1,5 @@
+@dec
+export default class Foo {}
+
+@dec
+export class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-false/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    ["decorators", { "decoratorsBeforeExport": true }]
+  ],
+  "decoratorsBeforeExport": false
+}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-false/output.js

@@ -0,0 +1,4 @@
+export default @dec
+class Foo {}
+export @dec
+class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-true/input.js

@@ -0,0 +1,5 @@
+@dec
+export default class Foo {}
+
+@dec
+export class Bar {}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-true/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    ["decorators", { "decoratorsBeforeExport": true }]
+  ],
+  "decoratorsBeforeExport": true
+}

packages/babel-generator/test/fixtures/decoratorsBeforeExport/true-to-true/output.js

@@ -0,0 +1,4 @@
+@dec
+export default class Foo {}
+@dec
+export class Bar {}

packages/babel-generator/test/fixtures/flow/interface-types/input.js

@@ -0,0 +1,3 @@
+type A = interface { p: string };
+type B = interface extends X { p: string };
+type C = interface extends X, Y { p: string };

packages/babel-generator/test/fixtures/flow/interface-types/output.js

@@ -0,0 +1,9 @@
+type A = interface {
+  p: string
+};
+type B = interface extends X {
+  p: string
+};
+type C = interface extends X, Y {
+  p: string
+};

packages/babel-generator/test/fixtures/flow/internal-slot/input.js

@@ -0,0 +1,7 @@
+declare class C { static [[foo]]: T }
+declare class C { [[foo]]: T }
+interface T { [[foo]]: X }
+interface T { [[foo]](): X }
+type T = { [[foo]]: X }
+type T = { [[foo]](): X }
+type T = { [[foo]]?: X }

packages/babel-generator/test/fixtures/flow/internal-slot/output.js

@@ -0,0 +1,21 @@
+declare class C {
+  static [[foo]]: T
+}
+declare class C {
+  [[foo]]: T
+}
+interface T {
+  [[foo]]: X
+}
+interface T {
+  [[foo]]() => X
+}
+type T = {
+  [[foo]]: X
+};
+type T = {
+  [[foo]]() => X
+};
+type T = {
+  [[foo]]?: X
+};

packages/babel-generator/test/fixtures/flow/typeapp-call/input.js

@@ -0,0 +1,18 @@
+// @flow
+f<T>();
+f<T><U></U>;
+new C<T>;
+f<T>(e);
+o[e]<T>();
+f<T>(x)<U>(y);
+async <T>() => {};
+async <T>(): T => {}
+new C<T>(e);
+f<T>[e];
+new C<T>();
+o.m<T>();
+f<T>.0;
+o?.m<T>(e);
+o.m?.<T>(e);
+async<T>();
+f?.<T>(e);

packages/babel-generator/test/fixtures/flow/typeapp-call/options.json

@@ -0,0 +1 @@
+{ "plugins": ["jsx", "optionalChaining", "flow"] }

packages/babel-generator/test/fixtures/flow/typeapp-call/output.js

@@ -0,0 +1,21 @@
+// @flow
+f<T>();
+f < T > <U></U>;
+new C<T>();
+f<T>(e);
+o[e]<T>();
+f<T>(x)<U>(y);
+
+async <T>() => {};
+
+async <T>(): T => {};
+
+new C<T>(e);
+f < T > [e];
+new C<T>();
+o.m<T>();
+f < T > .0;
+o?.m<T>(e);
+o.m<T>?.(e);
+async<T>();
+f<T>?.(e);

packages/babel-generator/test/fixtures/types/BigIntLiteral/input.js

@@ -0,0 +1,5 @@
+100n;
+9223372036854775807n;
+0o16432n;
+0xFFF123n;
+0b101011101n;