title: ES6 Promises - Calling synchronous functions within promise chain
body: <p>I'm currently experimenting with promises and have a really basic question!</p>
  
  <p>Within a promise chain, would it be bad practice to call a synchronous function? For example:</p>
  
  <pre><code>.then(function(results) {
  
      if(checkIfResultInMemory(results) === true){
         return getTotalFromMemory()
      }
  
     return results;
  
    })
  </code></pre>
  
  <p>Or should my sync functions be refactored to return promises also?</p>