title: export default vs module.exports differences
body: <p>This works:</p>
  
  <pre><code>import {bar} from './foo';
  bar();
  
  // foo.js
  module.exports = {
   bar() {}
  }
  </code></pre>
  
  <p>And this works:</p>
  
  <pre><code>import foo from './foo';
  foo.bar();
  
  // foo.js
  export default {
   bar() {}
  }
  </code></pre>
  
  <p>So why doesn't this work?</p>
  
  <pre><code>import {bar} from './foo';
  bar();
  
  // foo.js
  export default {
   bar() {}
  }
  </code></pre>
  
  <p>It throws <code>TypeError: (0 , _foo.bar) is not a function</code>.</p>