`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.

className = inst.getAttribute('class') || '';
        }
        var classList = className.split(/\s+/);
        if (!Array.isArray(classNames)) {
          invariant(
            classNames !== undefined,
            'TestUtils.scryRenderedDOMComponentsWithClass expects a ' +
            'className as a second argument.'
          );
          classNames = classNames.split(/\s+/);
        }
        return classNames.every(function(name) {
          return classList.indexOf(name) !== -1;
        });
      }
      return false;
    });
  },
  /**
   * Like scryRenderedDOMComponentsWithClass but expects there to be one result,
   * and returns that one result, or throws exception if there is any other
   * number of matches besides one.
   * @return {!ReactDOMComponent} The one match.
   */
  findRenderedDOMComponentWithClass: function(root, className) {
    var all =
      ReactTestUtils.scryRenderedDOMComponentsWithClass(root, className);
    if (all.length !== 1) {
      throw new Error(
        'Did not find exactly one match (found: ' + all.length + ') ' +