http://jsfiddle.net/Brj8m/

/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @emails react-core
 */
'use strict';
describe('ReactDOMButton', function() {
  var React;
  var ReactDOM;
  var ReactTestUtils;
  var onClick = jest.genMockFn();
  function expectClickThru(button) {
    onClick.mockClear();
    ReactTestUtils.Simulate.click(ReactDOM.findDOMNode(button));
    expect(onClick.mock.calls.length).toBe(1);
  }
  function expectNoClickThru(button) {