title: es6 exported object values not updated?
body: <p>I'm exporting a factory function in ES6, which returns an object with properties.
  When calling the factory, the object is created, but its values don't update.</p>
  
  <p>Example:</p>
  
  <pre><code>// factory.js
  let counter = 1;
  let factory = () =&gt; {
      let increment = function(){
        counter++;
      }
  
    return { counter, increment };
  }
  
  export default factory;
  
  
  // main.js
  import factory from './factory';
  
  let f = factory();
  console.log(f.counter); // =&gt;1
  f.increment();
  console.log(f.counter); // =&gt; stil 1, not 2?
  </code></pre>
  
  <p>Can someone explain why this is happening? Is it an ES6 feature, or something to do with the fact that I am using webpack and babel (es2015-preset)? </p>
  
  <p>I have found this, but that doesn't describe the same use-case: <a href="http://exploringjs.com/es6/ch_modules.html#sec_imports-as-views-on-exports" rel="nofollow noreferrer">http://exploringjs.com/es6/ch_modules.html#sec_imports-as-views-on-exports</a></p>