Run the [`fixtures/ssr` test harness](https://github.com/facebook/react/tree/master/fixtures/ssr). In the terminal, the following warning is logged:

```
Warning: Unknown prop `onClick` on <a> tag. Remove this prop from the element. For details, see https://fb.me/react-unknown-prop
  in a (at Page.js:12)
  in p (at Page.js:18)
  in div (at Page.js:17)
  in Page (at App.js:12)
  in div (at App.js:10)
  in body (at Chrome.js:17)
  in html (at Chrome.js:9)
  in Chrome (at App.js:9)
  in App (at render.js:18)
```

SSR behavior should match client-side behavior and not warn for a valid attribute.
render() {
            return <div ref="foo" />;
          }
        }
        const e = await render(<RefComponent />);
        expect(e.getAttribute('ref')).toBe(null);
      });
      itRenders('no children attribute', async render => {
        const e = await render(React.createElement('div', {}, 'foo'));
        expect(e.getAttribute('children')).toBe(null);
      });
      itRenders('no key attribute', async render => {
        const e = await render(<div key="foo" />);
        expect(e.getAttribute('key')).toBe(null);
      });
      itRenders('no dangerouslySetInnerHTML attribute', async render => {
        const e = await render(
          <div dangerouslySetInnerHTML={{__html: '<foo />'}} />,
        );
        expect(e.getAttribute('dangerouslySetInnerHTML')).toBe(null);
      });
    });