`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.

(constructor === type));
  },
  getRenderedChildOfCompositeComponent: function(inst) {
    if (!ReactTestUtils.isCompositeComponent(inst)) {
      return null;
    }
    var internalInstance = ReactInstanceMap.get(inst);
    return internalInstance._renderedComponent.getPublicInstance();
  },
  findAllInRenderedTree: function(inst, test) {
    if (!inst) {
      return [];
    }
    invariant(
      ReactTestUtils.isCompositeComponent(inst),
      'findAllInRenderedTree(...): instance must be a composite component'
    );
    return findAllInRenderedTreeInternal(ReactInstanceMap.get(inst), test);
  },
  /**
   * Finds all instance of components in the rendered tree that are DOM
   * components with the class name matching `className`.
   * @return {array} an array of all the matches.
   */
  scryRenderedDOMComponentsWithClass: function(root, classNames) {
    return ReactTestUtils.findAllInRenderedTree(root, function(inst) {
      if (ReactTestUtils.isDOMComponent(inst)) {
        var className = inst.className;
        if (typeof className !== 'string') {