title: Getting error while creating production build 'does not contain a default export'
body: <p>Hii I am working with language translation using <code>"react-intl": "^4.1.1",</code> but when I creating production build then code is not compiled and shows the error about default export</p>
  
  <p>Error :</p>
  
  <pre><code>Creating an optimized production build...
  Failed to compile.
  
  ./src/lang/entries/es_ES.js
  Attempted import error: '../locales/es_ES' does not contain a default export (imported as 'enMessages').
  </code></pre>
  
  <p>I am importing file like this: </p>
  
  <pre><code>import enMessages from '../locales/en_US';
  </code></pre>
  
  <p>Exporting :</p>
  
  <pre><code>export default {
     "sidebar.dashboard" : "Dashboard"
  }
  </code></pre>
  
  <p>The most important thing is its working on the local and generating issues while creating a production build and I am using <code>"react-scripts": "^3.3.0"</code> in this project. How can I solve this?</p>
  
  <p><strong>Update:</strong>
  After import enMessages</p>
  
  <pre><code>import endata from '@formatjs/intl-pluralrules/dist/locale-data/en';
  import enMessages from '../locales/en_US';
  
  const EnLang = {
     messages: {
        ...enMessages
     },
     locale: 'en-US',
     data: endata
  };
  export default EnLang;
  </code></pre>