Enable useBuiltIns option on object-rest-spread (facebook#902)

* Enable useBuiltIns option on object-rest-spread

* note polyfill requirement

* Enable useBuiltIns with transform-react-jsx

* Add direct ref to transform-react-jsx

Author: existentialism

packages/babel-preset-react-app/README.md

@@ -23,3 +23,5 @@ Then create a file named `.babelrc` with following contents in the root folder o
     "presets": ["react-app"]
   }
   ```
+
+This preset uses the `useBuiltIns` option with [transform-object-rest-spread](http://babeljs.io/docs/plugins/transform-object-rest-spread/) and [transform-react-jsx](http://babeljs.io/docs/plugins/transform-react-jsx/), which assumes that `Object.assign` is available or polyfilled.

packages/babel-preset-react-app/index.js

@@ -13,8 +13,16 @@ var path = require('path');
 const plugins = [
     // class { handleClick = () => { } }
     require.resolve('babel-plugin-transform-class-properties'),
+    // The following two plugins use Object.assign directly, instead of Babel's
+    // extends helper. Note that this assumes `Object.assign` is available. 
     // { ...todo, completed: true }
-    require.resolve('babel-plugin-transform-object-rest-spread'),
+    [require.resolve('babel-plugin-transform-object-rest-spread'), {
+      useBuiltIns: true
+    }],
+    // Transforms JSX
+    [require.resolve('babel-plugin-transform-react-jsx'), {
+      useBuiltIns: true
+    }],
     // function* () { yield 42; yield 43; }
     [require.resolve('babel-plugin-transform-regenerator'), {
       // Async functions are converted to generators by babel-preset-latest

packages/babel-preset-react-app/package.json

@@ -14,6 +14,7 @@
     "babel-plugin-transform-class-properties": "6.16.0",
     "babel-plugin-transform-object-rest-spread": "6.19.0",
     "babel-plugin-transform-react-constant-elements": "6.9.1",
+    "babel-plugin-transform-react-jsx": "6.8.0",
     "babel-plugin-transform-react-jsx-self": "6.11.0",
     "babel-plugin-transform-react-jsx-source": "6.9.0",
     "babel-plugin-transform-regenerator": "6.16.1",