title: If destructure preventDefault - with babel in react - this is undefined
body: <p>I just had the craziest bug. In my <code>onKeyDown</code> I destructred the <code>preventDefault</code> out of <code>e</code>. However when I would call <code>preventDefault()</code> I would get:</p>
  
  <blockquote>
    <p>TypeError: this is undefined[Learn More]react-dom.js:13987:5</p>
  </blockquote>
  
  <p>I am using React v15.4.1 and the line is highlighted in my screenshot below:</p>
  
  <p><img src="https://i.imgur.com/zv1Fr5I.png" alt=""></p>
  
  <p>If I don't destructure and just use <code>e.preventDefaut()</code> it works. Does anyone know why this is? Is this a bug in babel?</p>
  
  <pre><code>const El = React.createClass({
    displayName: 'El',
    onKeyDown(e) {
      let { key, preventDefault } = e;
      preventDefault();
    },
    render() {
      return React.createElement('input', { onKeyDown:this.onKeyDown });
    }
  });
  </code></pre>