How to re-export another module's default export?
<p>I want to export some module like below way but always failed..</p>

<p><strong>foo.js</strong></p>

<pre><code>const foo = {
  a: 'b'
};
export default foo;
</code></pre>

<p><strong>index.js</strong></p>

<pre><code>export foo from './foo';  // encounter error here
export * from './foo';    // it works..
</code></pre>

<p>I don't know why can't I use the first method to export module from <code>foo.js</code>, in my opinion, I can export anything like func, class, variables etc..</p>