[core] Upgrade to babel@rc.1

.circleci/config.yml

@@ -66,9 +66,6 @@ jobs:
       - run:
           name: Lint
           command: yarn lint
-      - run:
-          name: Flow
-          command: yarn flow
       - run:
           name: TypeScript
           command: yarn typescript

.eslintrc.js

@@ -18,7 +18,7 @@ module.exports = {
     ecmaVersion: 7,
     sourceType: 'module',
   },
-  plugins: ['babel', 'import', 'jsx-a11y', 'mocha', 'flowtype', 'material-ui'],
+  plugins: ['babel', 'import', 'jsx-a11y', 'mocha', 'material-ui'],
   settings: {
     'import/resolver': {
       webpack: {
@@ -95,15 +95,6 @@ module.exports = {
     'mocha/no-pending-tests': 'error',
     'mocha/no-skipped-tests': 'error',
 
-    'flowtype/define-flow-type': 'error',
-    'flowtype/require-valid-file-annotation': 'off',
-    'flowtype/require-parameter-type': 'off',
-    'flowtype/require-return-type': 'off',
-    'flowtype/space-after-type-colon': 'off',
-    'flowtype/space-before-type-colon': 'off',
-    'flowtype/type-id-match': 'off',
-    'flowtype/use-flow-type': 'error',
-
     'jsx-a11y/label-has-associated-control': 'off',
     'jsx-a11y/label-has-for': 'off',
     'jsx-a11y/no-autofocus': 'off', // We are a library, people do what they want.

.size-limit.js

@@ -1,20 +1,17 @@
 const fs = require('fs');
 
-function getMainFile() {
-  const dirname = '.next/static/commons';
-  const files = fs.readdirSync(dirname);
-  const [file] = files
-    .reduce((result, filename) => {
-      if (!/^main-[a-f0-9]+\.js$/.test(filename)) {
-        return result;
-      }
+const buildId = fs.readFileSync('.next/BUILD_ID', 'utf8');
 
-      const path = `${dirname}/${filename}`;
-      return [...result, { path, ctime: fs.statSync(path).ctimeMs }];
-    }, [])
-    .sort((x, y) => y.ctime - x.ctime);
-  return file;
-}
+const dirname = '.next/static/chunks';
+const [main] = fs.readdirSync(dirname).reduce((result, filename) => {
+  if (filename.length === 23) {
+    return [...result, { path: `${dirname}/${filename}` }];
+  }
+
+  return result;
+}, []);
+
+console.log('-', main)
 
 module.exports = [
   {
@@ -27,18 +24,18 @@ module.exports = [
     name: 'The size of all the modules of material-ui.',
     webpack: true,
     path: 'packages/material-ui/build/index.js',
-    limit: '95.6 KB',
+    limit: '89.4 KB',
   },
   {
     name: 'The main bundle of the docs',
     webpack: false,
-    path: getMainFile().path,
-    limit: '181 KB',
+    path: main.path,
+    limit: '162 KB',
   },
   {
     name: 'The home page of the docs',
     webpack: false,
-    path: '.next/bundles/pages/index.js',
-    limit: '5.9 KB',
+    path: `.next/static/${buildId}/pages/index.js`,
+    limit: '6 KB',
   },
 ];

.babelrc.js → babel.config.js

@@ -1,10 +1,9 @@
-const ENV = process.env.BABEL_ENV;
 let defaultPresets;
 
 // We release a ES version of Material-UI.
 // It's something that matches the latest official supported features of JavaScript.
 // Nothing more (stage-1, etc), nothing less (require, etc).
-if (ENV === 'es') {
+if (process.env.BABEL_ENV === 'es') {
   defaultPresets = [];
 } else {
   defaultPresets = [
@@ -19,28 +18,29 @@ if (ENV === 'es') {
           safari: 10,
           node: '6.11',
         },
-        modules: ['modules', 'production-umd'].includes(ENV) ? false : 'commonjs',
+        modules: ['modules', 'production-umd'].includes(process.env.BABEL_ENV) ? false : 'commonjs',
       },
     ],
   ];
 }
 
 module.exports = {
-  presets: defaultPresets.concat([
-    ['@babel/preset-stage-1', { loose: true }],
-    '@babel/preset-react',
-    '@babel/flow',
-  ]),
+  presets: defaultPresets.concat(['@babel/preset-react']),
   plugins: [
+    ['@babel/plugin-proposal-class-properties', { loose: true }],
+    ['@babel/plugin-proposal-object-rest-spread', {
+      // Workaround for https://github.com/babel/babel/issues/8323
+      loose: process.env.BABEL_ENV !== 'es',
+    }],
     '@babel/plugin-transform-object-assign',
-    ['@babel/plugin-transform-runtime', { polyfill: false, useBuiltIns: true }],
+    '@babel/plugin-transform-runtime',
   ],
   env: {
     coverage: {
       plugins: [
-        'istanbul',
+        'babel-plugin-istanbul',
         [
-          'module-resolver',
+          'babel-plugin-module-resolver',
           {
             root: ['./'],
             alias: {
@@ -54,7 +54,7 @@ module.exports = {
     development: {
       plugins: [
         [
-          'module-resolver',
+          'babel-plugin-module-resolver',
           {
             alias: {
               modules: './modules',
@@ -67,7 +67,7 @@ module.exports = {
       plugins: [
         'babel-plugin-preval',
         [
-          'module-resolver',
+          'babel-plugin-module-resolver',
           {
             alias: {
               '@material-ui/core': './packages/material-ui/src',
@@ -86,7 +86,7 @@ module.exports = {
       plugins: [
         'babel-plugin-preval',
         [
-          'module-resolver',
+          'babel-plugin-module-resolver',
           {
             alias: {
               '@material-ui/core': './packages/material-ui/src',
@@ -117,7 +117,9 @@ module.exports = {
           },
         ],
       ],
-      ignore: ['**/*.test*'],
+      // It's most likely a babel bug.
+      // We are using this ignore option in the CLI command but that has no effect.
+      ignore: ['**/*.test.js'],
     },
     production: {
       plugins: [
@@ -131,7 +133,9 @@ module.exports = {
           },
         ],
       ],
-      ignore: ['**/*.test*'],
+      // It's most likely a babel bug.
+      // We are using this ignore option in the CLI command but that has no effect.
+      ignore: ['**/*.test.js'],
     },
     'production-umd': {
       plugins: [
@@ -150,7 +154,7 @@ module.exports = {
       sourceMaps: 'both',
       plugins: [
         [
-          'module-resolver',
+          'babel-plugin-module-resolver',
           {
             root: ['./'],
             alias: {
@@ -162,5 +166,4 @@ module.exports = {
       ],
     },
   },
-  ignore: ['scripts/*.js'],
 };