Remove babel-polyfill from sandbox

config/webpack.common.js

@@ -30,7 +30,6 @@ module.exports = {
   entry: {
     app: [require.resolve('./polyfills'), path.join(paths.appSrc, 'index.js')],
     sandbox: [
-      require.resolve('babel-polyfill'),
       require.resolve('./polyfills'),
       path.join(paths.sandboxSrc, 'index.js'),
     ],

package.json

@@ -19,7 +19,7 @@
     "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-latest": "^6.24.1",
     "babel-preset-react": "^6.24.1",
-    "babel-runtime": "^6.20.0",
+    "babel-runtime": "^6.26.0",
     "babili-webpack-plugin": "^0.1.1",
     "buffer-loader": "^0.0.1",
     "case-sensitive-paths-webpack-plugin": "^2.0.0",

src/sandbox/eval/loaders/dependency-resolver.js

@@ -11,6 +11,13 @@ export default function getDependency(
   dependencyPath: string,
   externals: { [key: string]: string }
 ) {
+  // This polyfill is included by default in the sandbox, no external dependency needed.
+  // This is also included in CRA by default, so we keep compatability with
+  // CRA.
+  if (dependencyPath === 'babel-runtime/regenerator') {
+    return require('babel-runtime/regenerator'); // eslint-disable-line global-require
+  }
+
   const dependencyModule =
     externals[dependencyPath] || externals[`${dependencyPath}.js`];
   if (dependencyModule) {

src/sandbox/eval/presets/create-react-app/index.js

@@ -5,7 +5,13 @@ import babelTranspiler from '../../transpilers/babel';
 import jsonTranspiler from '../../transpilers/json';
 import rawTranspiler from '../../transpilers/raw';
 
-const preset = new Preset('create-react-app');
+const preset = new Preset('create-react-app', [
+  'web.js',
+  'js',
+  'json',
+  'web.jsx',
+  'jsx',
+]);
 
 preset.registerTranspiler(module => /\.css$/.test(module.title), [
   { transpiler: stylesTranspiler },

src/sandbox/eval/transpilers/babel/babel-parser.js

@@ -10,6 +10,22 @@ const DEFAULT_BABEL_CONFIG = {
     'transform-object-rest-spread',
     'transform-decorators-legacy',
     'transform-class-properties',
+    // Polyfills the runtime needed for async/await and generators
+    [
+      'transform-runtime',
+      {
+        helpers: false,
+        polyfill: false,
+        regenerator: true,
+      },
+    ],
+    [
+      'transform-regenerator',
+      {
+        // Async functions are converted to generators by babel-preset-env
+        async: false,
+      },
+    ],
   ],
 };
 

yarn.lock

@@ -1551,7 +1551,7 @@ [email protected]:
     core-js "^2.4.0"
     regenerator-runtime "^0.10.0"
 
-[email protected], babel-runtime@^6.18.0, babel-runtime@^6.2.0, babel-runtime@^6.20.0, babel-runtime@^6.22.0:
+[email protected], babel-runtime@^6.18.0, babel-runtime@^6.2.0, babel-runtime@^6.22.0:
   version "6.25.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.25.0.tgz#33b98eaa5d482bb01a8d1aa6b437ad2b01aec41c"
   dependencies: