React Base Fiddle (JSX)

Starting point for creating JSFiddles with React.

HTML

<script src="https://unpkg.com/react@16.7.0-alpha.0/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@16.7.0-alpha.0/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/react-dom@16.7.0-alpha.0/umd/react-dom-server.browser.development.js"></script>
<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

Babel + JSX

// This works
const Foo = () => (
	<p>{ ReactDOMServer.renderToStaticMarkup(<p>a</p>)}</p>
)

// This works
const foo = <p>{ ReactDOMServer.renderToStaticMarkup(<p>a</p>)}</p>

class Hello extends React.Component {
  render() {
    return (
    <React.Fragment>
    	<Counter />
      { /* Below line does not work */ }
      <p>{ ReactDOMServer.renderToStaticMarkup(<p>a</p>)}</p>
    </React.Fragment>
    )
  }
}

const Counter = () => {
    const [ count, setCount ] = React.useState(0)
    const incrementCount = () => setCount(count + 1)
    return(
        <div>
            <p>You clicked { count } times</p>
            <button onClick={ incrementCount }>Click Me</button>
        </div>
    )
}

ReactDOM.render(
  <Hello name="World" />,
  document.getElementById('container')
);