title: import and module.exports in Vuex module show Uncaught TypeError: Cannot assign to read only property 'exports' of object
body: <p>i have a vuex module by Vue CLI</p>
  
  <pre><code>import { Sev } from "../api";
  const modules = {
    actions: {
      getData() {
        Sev();
      }
    }
  };
  
  module.exports = modules;
  </code></pre>
  
  <p>and i got an error in browser console</p>
  
  <pre><code>test.js?5df4:10 Uncaught TypeError: Cannot assign to read only property 'exports' of object '#&lt;Object&gt;'
      at Module.eval (test.js?5df4:10)
      at eval (test.js:12)
      at Module../src/config/store_modules/test.js (app.js:1263)
  </code></pre>
  
  <p>then i change the code to</p>
  
  <pre><code>import { Sev } from "../api";
  // const modules = {
  export default {
    actions: {
      getData() {
        Sev();
      }
    }
  };
  // module.exports = modules;
  
  </code></pre>
  
  <p>then work well. But i don't know what different. is it a bug ?</p>