*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.
});
    it('assigns ajaxify (an important internal FB attribute)', function() {
      var options = {toString: () => 'ajaxy'};
      var el = ReactTestUtils.renderIntoDocument(<div ajaxify={options} />);
      expect(el.getAttribute('ajaxify')).toBe('ajaxy');
    });
  });
  describe('String boolean attributes', function() {
    it('does not assign string boolean attributes for custom attributes', function() {
      spyOn(console, 'error');
      var el = ReactTestUtils.renderIntoDocument(<div whatever={true} />);
      expect(el.hasAttribute('whatever')).toBe(false);
      expectDev(console.error.calls.argsFor(0)[0]).toContain(
        'Warning: Received `true` for non-boolean attribute `whatever`.',
      );
    });
    it('stringifies the boolean true for allowed attributes', function() {
      var el = ReactTestUtils.renderIntoDocument(<div spellCheck={true} />);
      expect(el.getAttribute('spellCheck')).toBe('true');
    });
    it('stringifies the boolean false for allowed attributes', function() {
      var el = ReactTestUtils.renderIntoDocument(<div spellCheck={false} />);
      expect(el.getAttribute('spellCheck')).toBe('false');
    });
    it('stringifies implicit booleans for allowed attributes', function() {
      
      var el = ReactTestUtils.renderIntoDocument(<div spellCheck />);
      expect(el.getAttribute('spellCheck')).toBe('true');
    });
  });