Partially revert React.createDescriptor

We still have some issues to work out when the type argument is a mock.

src/browser/ui/React.js

@@ -46,11 +46,17 @@ var onlyChild = require('onlyChild');
 
 ReactDefaultInjection.inject();
 
-var createDescriptor = ReactDescriptor.createDescriptor;
+// TODO: Restore the real create descriptor
+// var createDescriptor = ReactDescriptor.createDescriptor;
+var createDescriptor = function(type, props, children) {
+  // Because of issues with mocks, we temporarily execute the factory function
+  var args = Array.prototype.slice.call(arguments, 1);
+  return type.apply(null, args);
+};
 var createFactory = ReactDescriptor.createFactory;
 
 if (__DEV__) {
-  createDescriptor = ReactDescriptorValidator.createDescriptor;
+  // createDescriptor = ReactDescriptorValidator.createDescriptor;
   createFactory = ReactDescriptorValidator.createFactory;
 }
 

src/core/ReactDescriptorValidator.js

@@ -229,6 +229,12 @@ var ReactDescriptorValidator = {
   createDescriptor: function(type, props, children) {
     var descriptor = ReactDescriptor.createDescriptor.apply(this, arguments);
 
+    // The result can be nullish if a mock or a custom function is used.
+    // TODO: Drop this when these are no longer allowed as the type argument.
+    if (descriptor == null) {
+      return descriptor;
+    }
+
     for (var i = 2; i < arguments.length; i++) {
       validateChildKeys(arguments[i], type);
     }

src/core/__tests__/ReactDescriptor-test.js

@@ -239,12 +239,12 @@ describe('ReactDescriptor', function() {
     expect(ReactDescriptor.isValidDescriptor(Component)).toEqual(false);
   });
 
-  it('warns but allow a plain function to be immediately invoked', function() {
+  it('warns but allow a plain function in a factory to be invoked', function() {
     spyOn(console, 'warn');
     // This is a temporary helper to allow JSX with plain functions.
     // This allow you to track down these callers and replace them with regular
     // function calls.
-    var factory = ReactDescriptor.createFactory(function (x) {
+    var factory = React.createFactory(function (x) {
       return 21 + x;
     });
     expect(factory(21)).toBe(42);