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".
expect(changeCount).toBe(1);
          expect(e.checked).toBe(false);
        });
        itClientRenders('a controlled select', async render => {
          let changeCount = 0;
          const e = await render(
            <ControlledSelect onChange={() => changeCount++} />,
          );
          expect(changeCount).toBe(0);
          expect(e.value).toBe('Hello');
          
          e.value = 'Goodbye';
          ReactTestUtils.Simulate.change(e);
          expect(changeCount).toBe(1);
          expect(e.value).toBe('Goodbye');
        });
      });
      describe('user interaction with inputs before client render', function() {
        
        
        
        
        
        const testUserInteractionBeforeClientRender = async (
          element,
          initialValue = 'Hello',
          changedValue = 'Goodbye',
          valueKey = 'value',
        ) => {
          const field = await serverRender(element);