Child.js

var Parent = require('./Parent');
export class Child extends Parent {
  constructor(props) {
    super(props)
  }
  render() {
    super.render()
    return <span>pep pep</span>
  }
}

Impl.js

import Child from '.';
import React;
return React.render(<Child />, document.body);

// would want output like <div class="pepaw"><span>pep pep</span></div>

Parent.js

var React = require('react');
var Parent = React.createClass({
  render: function() {
    return <div className="pepaw">{this.props.children}</div>;
  }
});