`SyntheticEvent.type` is undefined when received by the handler. Or the nativeEvent type for that matter.

Needs to be added in here somewhere: https://github.com/facebook/react/blob/3a4e1dbb5b2957875cab6af11a5e5934e125a0d8/src/test/ReactTestUtils.js#L496

I realize that it's not sustainable to have to set _all_ the possible fields for a simulated event, but the type at least makes sense for verification that you're getting the right _sort_ of event.

this.setState({ clicked: true });
      },
      render: function() {
        return (
          <div
            ref={() => {}}
            onClick={this.handleUserClick}
            className={this.state.clicked ? 'clicked' : ''}
          />
        );
      },
    });
    var shallowRenderer = ReactTestUtils.createRenderer();
    shallowRenderer.render(<SimpleComponent />);
    var result = shallowRenderer.getRenderOutput();
    expect(result.type).toEqual('div');
    expect(result.props.className).toEqual('');
    result.props.onClick();
    result = shallowRenderer.getRenderOutput();
    expect(result.type).toEqual('div');
    expect(result.props.className).toEqual('clicked');
  });
  it('can setState in componentWillMount when shallow rendering', function() {
    var SimpleComponent = React.createClass({
      componentWillMount() {
        this.setState({groovy: 'doovy'});
      },
      render() {
        return <div>{this.state.groovy}</div>;
      },