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".
type="checkbox"
              defaultChecked={false}
              checked={true}
              readOnly={true}
            />,
            1,
          );
          expect(e.checked).toBe(true);
          expect(e.getAttribute('defaultChecked')).toBe(null);
        },
      );
    });
    describe('textareas', function() {
      
      
      itRenders('a textarea with a value and an onChange', async render => {
        const e = await render(<textarea value="foo" onChange={() => {}} />);
        
        
        expect(e.getAttribute('value')).toBe(null);
        expect(e.value).toBe('foo');
      });
      itRenders('a textarea with a value and readOnly', async render => {
        const e = await render(<textarea value="foo" readOnly={true} />);
        
        
        expect(e.getAttribute('value')).toBe(null);
        expect(e.value).toBe('foo');
      });
      itRenders(