title: Default Return Value for Resolved Promise
body: <p>I'm learning about writing functions that return promises in ES6, for example:</p>
  
  <pre><code>function async() {
    return new Promise(function (resolve, reject) {
      if (doStuff()) {
        resolve(value);
      } else {
        reject(error);
      }
    }
  }
  </code></pre>
  
  <p>Sometimes, there is no useful value to pass back in <code>resolve(value)</code>. In these cases, what should be the default value to return?</p>