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.
itRenders(
        'a newline-eating tag with content not starting with \\n',
        async render => {
          const e = await render(<pre>Hello</pre>);
          expect(e.textContent).toBe('Hello');
        },
      );
      itRenders(
        'a newline-eating tag with content starting with \\n',
        async render => {
          const e = await render(<pre>{'\nHello'}</pre>);
          expect(e.textContent).toBe('\nHello');
        },
      );
      itRenders('a normal tag with content starting with \\n', async render => {
        const e = await render(<div>{'\nHello'}</div>);
        expect(e.textContent).toBe('\nHello');
      });
    });
    describe('different component implementations', function() {
      function checkFooDiv(e) {
        expect(e.childNodes.length).toBe(1);
        expectNode(e.firstChild, TEXT_NODE_TYPE, 'foo');
      }
      itRenders('stateless components', async render => {
        const StatelessComponent = () => <div>foo</div>;
        checkFooDiv(await render(<StatelessComponent />));
      });
      itRenders('ES6 class components', async render => {
        class ClassComponent extends React.Component {