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.
return <div id={this.props.id} />;
            }
          };
          PureComponent = props => <div id={props.id} />;
          bareElement = <div id="foobarbaz" />;
        });
        it('should reconnect ES6 Class to ES6 Class', () =>
          expectMarkupMatch(
            <ES6ClassComponent id="foobarbaz" />,
            <ES6ClassComponent id="foobarbaz" />,
          ));
        it('should reconnect Pure Component to ES6 Class', () =>
          expectMarkupMatch(
            <ES6ClassComponent id="foobarbaz" />,
            <PureComponent id="foobarbaz" />,
          ));
        it('should reconnect Bare Element to ES6 Class', () =>
          expectMarkupMatch(<ES6ClassComponent id="foobarbaz" />, bareElement));
        it('should reconnect ES6 Class to Pure Component', () =>
          expectMarkupMatch(
            <PureComponent id="foobarbaz" />,
            <ES6ClassComponent id="foobarbaz" />,
          ));