*feature*

>Warning: A component is `contentEditable` and contains `children` managed by React. It is now your responsibility to guarantee that none of those nodes are unexpectedly modified or duplicated. This is probably not intentional.

It would help heaps if I would know _which_ component is causing this.
return ReactDOMServer.renderToString(<div {...props} />);
    }
    function toHaveInnerhtml(actual, expected) {
      var re = '^' + quoteRegexp(expected) + '$';
      return new RegExp(re).test(actual);
    }
    it('should handle dangerouslySetInnerHTML', () => {
      var innerHTML = {__html: 'testContent'};
      expect(
        toHaveInnerhtml(
          genMarkup({dangerouslySetInnerHTML: innerHTML}),
          'testContent',
        ),
      );
    });
  });
  describe('mountComponent', () => {
    var mountComponent;
    beforeEach(() => {
      mountComponent = function(props) {
        var container = document.createElement('div');
        ReactDOM.render(<div {...props} />, container);
      };
    });
    it('should work error event on <source> element', () => {
      spyOn(console, 'error');
      var container = document.createElement('div');
      ReactDOM.render(
        <video>
          <source