`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._renderedOutput = element;
    this._currentElement = element;
  },
  getHostNode: function() {
    return undefined;
  },
  unmountComponent: function() {
  },
  getPublicInstance: function() {
    return null;
  },
};
var ShallowComponentWrapper = function(element) {
  
  this._debugID = nextDebugID++;
  var displayName = element.type.displayName || element.type.name || 'Unknown';
  ReactInstrumentation.debugTool.onSetDisplayName(this._debugID, displayName);
  this.construct(element);
};
Object.assign(
  ShallowComponentWrapper.prototype,
  ReactCompositeComponent.Mixin, {
    _constructComponent:
      ReactCompositeComponent.Mixin._constructComponentWithoutOwner,
    _instantiateReactComponent: function(element) {
      return new NoopInternalComponent(element);
    },
    _replaceNodeWithMarkup: function() {},
    _renderValidatedComponent:
      ReactCompositeComponent.Mixin