Add callback argument for setProps()

Author: emuraton

packages/enzyme-test-suite/test/ShallowWrapper-spec.jsx

@@ -1272,9 +1272,11 @@ describe('shallow', () => {
       expect(wrapper.find('.foo')).to.have.lengthOf(1);
 
       wrapper[sym('__renderer__')].batchedUpdates(() => {
-        wrapper.setProps({ id: 'bar', foo: 'bla' });
-        expect(wrapper.find('.bar')).to.have.lengthOf(1);
+        wrapper.setProps({ id: 'bar', foo: 'bla' }, () => {
+          expect(wrapper.find('.bar')).to.have.lengthOf(1);
+        });
       });
+      expect(wrapper.find('.foo')).to.have.lengthOf(0);
     });
 
     it('should call componentWillReceiveProps, shouldComponentUpdate, componentWillUpdate, and componentDidUpdate with merged newProps', () => {

packages/enzyme/src/ShallowWrapper.js

@@ -376,13 +376,19 @@ class ShallowWrapper {
    * NOTE: can only be called on a wrapper instance that is also the root instance.
    *
    * @param {Object} props object
+   * @param {Function} cb - callback function
    * @returns {ShallowWrapper}
    */
-  setProps(props) {
+  setProps(props, callback = noop) {
     if (this[ROOT] !== this) {
       throw new Error('ShallowWrapper::setProps() can only be called on the root');
     }
-    return this.rerender(props);
+    if (typeof callback !== 'function') {
+      throw new TypeError('ShallowWrapper::setProps() expects a function as its second argument');
+    }
+    this.rerender(props);
+    callback();
+    return this;
   }
 
   /**