ShallowRenderer supports batched updates

Author: koba04

src/ShallowWrapper.js

@@ -25,6 +25,7 @@ import {
 import {
   createShallowRenderer,
   renderToStaticMarkup,
+  batchedUpdates,
 } from './react-compat';
 
 /**
@@ -352,7 +353,9 @@ export default class ShallowWrapper {
       withSetStateAllowed(() => {
         // TODO(lmr): create/use synthetic events
         // TODO(lmr): emulate React's event propagation
-        handler(...args);
+        batchedUpdates(() => {
+          handler(...args);
+        });
         this.root.update();
       });
     }

src/react-compat.js

@@ -134,6 +134,8 @@ if (REACT013) {
   };
 }
 
+const batchedUpdates = require('react/lib/ReactUpdates').batchedUpdates;
+
 const {
   mockComponent,
   isElement,
@@ -163,4 +165,5 @@ export {
   childrenToArray,
   renderWithOptions,
   unmountComponentAtNode,
+  batchedUpdates,
 };

test/ShallowWrapper-spec.js

@@ -974,6 +974,34 @@ describe('shallow', () => {
       });
     });
 
+    it('should be batched updates', () => {
+      let renderCount = 0;
+      class Foo extends React.Component {
+        constructor(props) {
+          super(props);
+          this.state = {
+            count: 0,
+          };
+          this.onClick = this.onClick.bind(this);
+        }
+        onClick() {
+          this.setState({ count: this.state.count + 1 });
+          this.setState({ count: this.state.count + 1 });
+        }
+        render() {
+          ++renderCount;
+          return (
+            <a onClick={this.onClick}>{this.state.count}</a>
+          );
+        }
+      }
+
+      const wrapper = shallow(<Foo />);
+      wrapper.simulate('click');
+      expect(wrapper.text()).to.equal('1');
+      expect(renderCount).to.equal(2);
+    });
+
   });
 
   describe('.setState(newState)', () => {