*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.
describe('Hyphenated SVG elements', function() {
    it('the font-face element is not a custom element', function() {
      spyOn(console, 'error');
      var el = ReactTestUtils.renderIntoDocument(
        <svg><font-face x-height={false} /></svg>,
      );
      expect(el.querySelector('font-face').hasAttribute('x-height')).toBe(
        false,
      );
      expectDev(console.error.calls.count()).toBe(1);
      expectDev(console.error.calls.argsFor(0)[0]).toContain(
        'Warning: Invalid DOM property `x-height`. Did you mean `xHeight`',
      );
    });
    it('the font-face element does not allow unknown boolean values', function() {
      spyOn(console, 'error');
      var el = ReactTestUtils.renderIntoDocument(
        <svg><font-face whatever={false} /></svg>,
      );
      expect(el.querySelector('font-face').hasAttribute('whatever')).toBe(
        false,
      );
      expectDev(console.error.calls.count()).toBe(1);
      expectDev(console.error.calls.argsFor(0)[0]).toContain(
        'Warning: Received `false` for non-boolean attribute `whatever`.',
      );
    });
  });
});