Observed this on react@16.0.0-beta.5

```js
import React from 'react';
import { renderToString } from 'react-dom/server';

const B = () => 'b';

console.log(renderToString(<div>{'a'}<B />{'c'}</div>));
```

This renders as `<div data-reactroot="">a<!-- -->bc</div>`. If you try to hydrate this you'll get the error: Text content did not match. Server: "bc" Client: "b".
'http:i.imgur.com/w7GCRPb.png',
          );
        },
      );
      itRenders('svg child element with a badly cased alias', async render => {
        let e = await render(
          <svg><image xlinkhref="http:i.imgur.com/w7GCRPb.png" /></svg>,
          1,
        );
        e = e.firstChild;
        expect(e.hasAttributeNS('http:www.w3.org/1999/xlink', 'href')).toBe(
          false,
        );
        expect(e.getAttribute('xlinkhref')).toBe(
          'http:i.imgur.com/w7GCRPb.png',
        );
      });
      itRenders('svg element with a tabIndex attribute', async render => {
        let e = await render(<svg tabIndex="1" />);
        expect(e.tabIndex).toBe(1);
      });
      itRenders(
        'svg element with a badly cased tabIndex attribute',
        async render => {
          let e = await render(<svg tabindex="1" />, 1);
          expect(e.tabIndex).toBe(1);
        },
      );
      itRenders('a math element', async render => {
        const e = await render(<math />);