Use Object.assign directly and inject object-assign at compile

.babelrc

@@ -20,6 +20,7 @@
     "transform-es2015-block-scoping",
     "transform-es2015-modules-commonjs",
     "transform-es3-member-expression-literals",
-    "transform-es3-property-literals"
+    "transform-es3-property-literals",
+    "./scripts/babel/transform-object-assign-require"
   ]
 }

gulpfile.js

@@ -30,7 +30,15 @@ var paths = {
 
 var babelOpts = {
   plugins: [
-    [babelPluginModules, { map: require('fbjs/module-map') }],
+    [babelPluginModules, {
+      map: Object.assign(
+        {},
+        require('fbjs/module-map'),
+        {
+          'object-assign': 'object-assign',
+        }
+      ),
+    }],
   ],
 };
 

package.json

@@ -49,6 +49,7 @@
     "gzip-js": "~0.3.2",
     "jest-cli": "^0.9.0",
     "loose-envify": "^1.1.0",
+    "object-assign": "^4.0.1",
     "platform": "^1.1.0",
     "run-sequence": "^1.1.4",
     "through2": "^2.0.0",

packages/react/package.json

@@ -24,7 +24,8 @@
   },
   "dependencies": {
     "fbjs": "^0.8.0-alpha.2",
-    "loose-envify": "^1.1.0"
+    "loose-envify": "^1.1.0",
+    "object-assign": "^4.0.1"
   },
   "browserify": {
     "transform": [

scripts/babel/transform-object-assign-require.js

@@ -0,0 +1,40 @@
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
+module.exports = function autoImporter(babel) {
+  const t = babel.types;
+
+  return {
+    pre: function() {
+      // map from module to generated identifier
+      this.id = null;
+    },
+
+    visitor: {
+      CallExpression: function(path, file) {
+        if (path.get('callee').matchesPattern('Object.assign')) {
+          // generate identifier and require if it hasn't been already
+          if (!this.id) {
+            this.id = path.scope.generateUidIdentifier('assign');
+            path.scope.getProgramParent().push({
+              id: this.id,
+              init: t.callExpression(
+                t.identifier('require'),
+                [t.stringLiteral('object-assign')]
+              ),
+            });
+          }
+          path.node.callee = this.id;
+        }
+      },
+    },
+  };
+};

scripts/jest/preprocessor.js

@@ -27,7 +27,15 @@ var pathToBabelrc = path.join(__dirname, '..', '..', '.babelrc');
 // TODO: make sure this stays in sync with gulpfile
 var babelOptions = {
   plugins: [
-    [babelPluginModules, { map: moduleMap }],
+    [babelPluginModules, {
+      map: Object.assign(
+        {},
+        moduleMap,
+        {
+          'object-assign': 'object-assign',
+        }
+      ),
+    }],
   ],
   retainLines: true,
 };

src/addons/transitions/ReactCSSTransitionGroup.js

@@ -13,8 +13,6 @@
 
 var React = require('React');
 
-var assign = require('Object.assign');
-
 var ReactTransitionGroup = require('ReactTransitionGroup');
 var ReactCSSTransitionGroupChild = require('ReactCSSTransitionGroupChild');
 
@@ -87,7 +85,7 @@ var ReactCSSTransitionGroup = React.createClass({
   render: function() {
     return React.createElement(
       ReactTransitionGroup,
-      assign({}, this.props, {childFactory: this._wrapChild})
+      Object.assign({}, this.props, {childFactory: this._wrapChild})
     );
   },
 });

src/addons/transitions/ReactTransitionGroup.js

@@ -14,7 +14,6 @@
 var React = require('React');
 var ReactTransitionChildMapping = require('ReactTransitionChildMapping');
 
-var assign = require('Object.assign');
 var emptyFunction = require('emptyFunction');
 
 var ReactTransitionGroup = React.createClass({
@@ -193,7 +192,7 @@ var ReactTransitionGroup = React.createClass({
       this.performEnter(key);
     } else {
       this.setState(function(state) {
-        var newChildren = assign({}, state.children);
+        var newChildren = Object.assign({}, state.children);
         delete newChildren[key];
         return {children: newChildren};
       });

src/addons/update.js

@@ -13,7 +13,6 @@
 
 'use strict';
 
-var assign = require('Object.assign');
 var keyOf = require('keyOf');
 var invariant = require('invariant');
 var hasOwnProperty = {}.hasOwnProperty;
@@ -22,7 +21,7 @@ function shallowCopy(x) {
   if (Array.isArray(x)) {
     return x.concat();
   } else if (x && typeof x === 'object') {
-    return assign(new x.constructor(), x);
+    return Object.assign(new x.constructor(), x);
   } else {
     return x;
   }
@@ -102,7 +101,7 @@ function update(value, spec) {
       COMMAND_MERGE,
       nextValue
     );
-    assign(nextValue, spec[COMMAND_MERGE]);
+    Object.assign(nextValue, spec[COMMAND_MERGE]);
   }
 
   if (hasOwnProperty.call(spec, COMMAND_PUSH)) {

src/isomorphic/React.js

@@ -20,7 +20,6 @@ var ReactElementValidator = require('ReactElementValidator');
 var ReactPropTypes = require('ReactPropTypes');
 var ReactVersion = require('ReactVersion');
 
-var assign = require('Object.assign');
 var onlyChild = require('onlyChild');
 
 var createElement = ReactElement.createElement;
@@ -68,7 +67,7 @@ var React = {
   version: ReactVersion,
 
   // Hook for JSX spread, don't use this for anything else.
-  __spread: assign,
+  __spread: Object.assign,
 };
 
 module.exports = React;

src/isomorphic/classic/class/ReactClass.js

@@ -17,7 +17,6 @@ var ReactPropTypeLocations = require('ReactPropTypeLocations');
 var ReactPropTypeLocationNames = require('ReactPropTypeLocationNames');
 var ReactNoopUpdateQueue = require('ReactNoopUpdateQueue');
 
-var assign = require('Object.assign');
 var emptyObject = require('emptyObject');
 var invariant = require('invariant');
 var keyMirror = require('keyMirror');
@@ -331,7 +330,7 @@ var RESERVED_SPEC_KEYS = {
         ReactPropTypeLocations.childContext
       );
     }
-    Constructor.childContextTypes = assign(
+    Constructor.childContextTypes = Object.assign(
       {},
       Constructor.childContextTypes,
       childContextTypes
@@ -345,7 +344,7 @@ var RESERVED_SPEC_KEYS = {
         ReactPropTypeLocations.context
       );
     }
-    Constructor.contextTypes = assign(
+    Constructor.contextTypes = Object.assign(
       {},
       Constructor.contextTypes,
       contextTypes
@@ -373,7 +372,7 @@ var RESERVED_SPEC_KEYS = {
         ReactPropTypeLocations.prop
       );
     }
-    Constructor.propTypes = assign(
+    Constructor.propTypes = Object.assign(
       {},
       Constructor.propTypes,
       propTypes
@@ -726,7 +725,7 @@ var ReactClassMixin = {
 };
 
 var ReactClassComponent = function() {};
-assign(
+Object.assign(
   ReactClassComponent.prototype,
   ReactComponent.prototype,
   ReactClassMixin

src/isomorphic/classic/element/ReactElement.js

@@ -13,7 +13,6 @@
 
 var ReactCurrentOwner = require('ReactCurrentOwner');
 
-var assign = require('Object.assign');
 var warning = require('warning');
 var canDefineProperty = require('canDefineProperty');
 
@@ -253,7 +252,7 @@ ReactElement.cloneElement = function(element, config, children) {
   var propName;
 
   // Original props are copied
-  var props = assign({}, element.props);
+  var props = Object.assign({}, element.props);
 
   // Reserved names are extracted
   var key = element.key;

src/isomorphic/deprecated/OrderedMap.js

@@ -11,7 +11,6 @@
 
 'use strict';
 
-var assign = require('Object.assign');
 var invariant = require('invariant');
 
 var PREFIX = 'key:';
@@ -475,7 +474,7 @@ var OrderedMapMethods = {
   },
 };
 
-assign(OrderedMapImpl.prototype, OrderedMapMethods);
+Object.assign(OrderedMapImpl.prototype, OrderedMapMethods);
 
 var OrderedMap = {
   from: function(orderedMap) {

src/isomorphic/deprecated/ReactPropTransferer.js

@@ -11,7 +11,6 @@
 
 'use strict';
 
-var assign = require('Object.assign');
 var emptyFunction = require('emptyFunction');
 var joinClasses = require('joinClasses');
 
@@ -36,7 +35,7 @@ var transferStrategyMerge = createTransferStrategy(function(a, b) {
   // `merge` overrides the first object's (`props[key]` above) keys using the
   // second object's (`value`) keys. An object's style's existing `propA` would
   // get overridden. Flip the order here.
-  return assign({}, b, a);
+  return Object.assign({}, b, a);
 });
 
 /**
@@ -100,7 +99,7 @@ var ReactPropTransferer = {
    * @return {object} a new object containing both sets of props merged.
    */
   mergeProps: function(oldProps, newProps) {
-    return transferInto(assign({}, oldProps), newProps);
+    return transferInto(Object.assign({}, oldProps), newProps);
   },
 
 };

src/renderers/dom/client/ReactBrowserEventEmitter.js

@@ -16,7 +16,6 @@ var EventPluginRegistry = require('EventPluginRegistry');
 var ReactEventEmitterMixin = require('ReactEventEmitterMixin');
 var ViewportMetrics = require('ViewportMetrics');
 
-var assign = require('Object.assign');
 var getVendorPrefixedEventName = require('getVendorPrefixedEventName');
 var isEventSupported = require('isEventSupported');
 
@@ -175,7 +174,7 @@ function getListeningForDocument(mountAt) {
  *
  * @internal
  */
-var ReactBrowserEventEmitter = assign({}, ReactEventEmitterMixin, {
+var ReactBrowserEventEmitter = Object.assign({}, ReactEventEmitterMixin, {
 
   /**
    * Injectable event backend

src/renderers/dom/client/ReactEventListener.js

@@ -17,7 +17,6 @@ var PooledClass = require('PooledClass');
 var ReactDOMComponentTree = require('ReactDOMComponentTree');
 var ReactUpdates = require('ReactUpdates');
 
-var assign = require('Object.assign');
 var getEventTarget = require('getEventTarget');
 var getUnboundedScrollPosition = require('getUnboundedScrollPosition');
 
@@ -44,7 +43,7 @@ function TopLevelCallbackBookKeeping(topLevelType, nativeEvent) {
   this.nativeEvent = nativeEvent;
   this.ancestors = [];
 }
-assign(TopLevelCallbackBookKeeping.prototype, {
+Object.assign(TopLevelCallbackBookKeeping.prototype, {
   destructor: function() {
     this.topLevelType = null;
     this.nativeEvent = null;

src/renderers/dom/client/ReactReconcileTransaction.js

@@ -17,7 +17,6 @@ var ReactBrowserEventEmitter = require('ReactBrowserEventEmitter');
 var ReactInputSelection = require('ReactInputSelection');
 var Transaction = require('Transaction');
 
-var assign = require('Object.assign');
 
 /**
  * Ensures that, when possible, the selection range (currently selected text
@@ -160,7 +159,7 @@ var Mixin = {
 };
 
 
-assign(ReactReconcileTransaction.prototype, Transaction.Mixin, Mixin);
+Object.assign(ReactReconcileTransaction.prototype, Transaction.Mixin, Mixin);
 
 PooledClass.addPoolingTo(ReactReconcileTransaction);
 

src/renderers/dom/client/eventPlugins/FallbackCompositionState.js

@@ -13,7 +13,6 @@
 
 var PooledClass = require('PooledClass');
 
-var assign = require('Object.assign');
 var getTextContentAccessor = require('getTextContentAccessor');
 
 /**
@@ -33,7 +32,7 @@ function FallbackCompositionState(root) {
   this._fallbackText = null;
 }
 
-assign(FallbackCompositionState.prototype, {
+Object.assign(FallbackCompositionState.prototype, {
   destructor: function() {
     this._root = null;
     this._startText = null;

src/renderers/dom/client/syntheticEvents/SyntheticEvent.js

@@ -13,7 +13,6 @@
 
 var PooledClass = require('PooledClass');
 
-var assign = require('Object.assign');
 var emptyFunction = require('emptyFunction');
 var warning = require('warning');
 
@@ -111,7 +110,7 @@ function SyntheticEvent(dispatchConfig, targetInst, nativeEvent, nativeEventTarg
   return this;
 }
 
-assign(SyntheticEvent.prototype, {
+Object.assign(SyntheticEvent.prototype, {
 
   preventDefault: function() {
     this.defaultPrevented = true;
@@ -229,11 +228,11 @@ SyntheticEvent.augmentClass = function(Class, Interface) {
   E.prototype = Super.prototype;
   var prototype = new E();
 
-  assign(prototype, Class.prototype);
+  Object.assign(prototype, Class.prototype);
   Class.prototype = prototype;
   Class.prototype.constructor = Class;
 
-  Class.Interface = assign({}, Super.Interface, Interface);
+  Class.Interface = Object.assign({}, Super.Interface, Interface);
   Class.augmentClass = Super.augmentClass;
 
   PooledClass.addPoolingTo(Class, PooledClass.fourArgumentPooler);

src/renderers/dom/client/validateDOMNesting.js

@@ -11,7 +11,6 @@
 
 'use strict';
 
-var assign = require('Object.assign');
 var emptyFunction = require('emptyFunction');
 var warning = require('warning');
 
@@ -76,7 +75,7 @@ if (__DEV__) {
   };
 
   var updatedAncestorInfo = function(oldInfo, tag, instance) {
-    var ancestorInfo = assign({}, oldInfo || emptyAncestorInfo);
+    var ancestorInfo = Object.assign({}, oldInfo || emptyAncestorInfo);
     var info = {tag: tag, instance: instance};
 
     if (inScopeTags.indexOf(tag) !== -1) {