Set up proxy to intercept React.DOM usage

src/addons/__tests__/ReactDOMFactories-test.js

@@ -11,9 +11,13 @@
 
 'use strict';
 
-var {div} = require('ReactDOMFactories');
-
 describe('ReactDOMFactories', () => {
+  var React;
+  var {div} = require('ReactDOMFactories');
+
+  beforeEach(function () {
+    React = require('React');
+  })
 
   it('allow factories to be called without warnings', () => {
     spyOn(console, 'error');
@@ -22,4 +26,12 @@ describe('ReactDOMFactories', () => {
     expectDev(console.error.calls.count()).toBe(0);
   });
 
+  it('warns once when accessing React.DOM methods', () => {
+    spyOn(console, 'error');
+
+    React.DOM.div;
+    React.DOM.p;
+
+    expectDev(console.error.calls.count()).toBe(1);
+  });
 });

src/isomorphic/React.js

@@ -15,6 +15,7 @@ var ReactChildren = require('ReactChildren');
 var ReactComponent = require('ReactComponent');
 var ReactPureComponent = require('ReactPureComponent');
 var ReactClass = require('ReactClass');
+var ReactDOMFactories = require('ReactDOMFactories');
 var ReactElement = require('ReactElement');
 var ReactPropTypes = require('ReactPropTypes');
 var ReactVersion = require('ReactVersion');
@@ -79,10 +80,41 @@ var React = {
     return mixin;
   },
 
+  // This looks DOM specific but these are actually isomorphic helpers
+  // since they are just generating DOM strings.
+  DOM: ReactDOMFactories,
+
   version: ReactVersion,
 
   // Deprecated hook for JSX spread, don't use this for anything.
   __spread: __spread,
 };
 
+if (__DEV__) {
+  // React.DOM factories are deprecated, set up a Proxy to listen for
+  // accesses to this namespace and alert users to switch to the
+  // associated addon.
+  if (typeof Proxy === 'function') {
+    var hasWarnedOfFactories = false;
+
+    React.DOM = new Proxy(React.DOM, {
+      get: function (target, name) {
+        if (!hasWarnedOfFactories) {
+          warning(
+            false,
+            'Accessing React.DOM factories (like `React.DOM.%s`) is deprecated ' +
+            'and will be removed in the future. Please use the ' +
+            'react-addons-dom-factories package instead.',
+            name
+          );
+
+          hasWarnedOfFactories = true;
+        }
+        return target[name];
+      },
+    });
+  }
+
+}
+
 module.exports = React;