title: await is only valid in async function
body: <p>I wrote this code in <code>lib/helper.js</code>:</p>
  <pre><code>var myfunction = async function(x,y) {
     ....
     return [variableA, variableB]
  }
  exports.myfunction = myfunction;
  </code></pre>
  <p>Then I tried to use it in another file :</p>
  <pre><code> var helper = require('./helper.js');   
   var start = function(a,b){
       ....
       const result = await helper.myfunction('test','test');
   }
   exports.start = start;
  </code></pre>
  <p>I got an error:</p>
  <pre><code>await is only valid in async function
  </code></pre>
  <p>What is the issue?</p>