title: Error that an imported component is undefined despite it is imported
body: <p>i'm facing a very weird issue and i can't find a solution.
  I'm rendering a component like this:</p>
  
  <pre><code>const Trans = () =&gt;(
  &lt;div&gt;
  ....
  &lt;/div&gt;)
  export default Trans
  </code></pre>
  
  <p>Then i <code>import it as import Trans from './trans'</code>
  And i use <code>connect (mapStateToProps, mapDispatchToProps)(Trans)</code> and an error
  is showing that <code>You must pass a component to the function returned by connect. Instead received undefined</code></p>