title: using express route handlers and promises -what are the best practices?
body: <p>I'm currently working on a web project and I'm trying to understand Node.js and express. I know about that for achiving asynchronous easy to maintain code we should use promises , but I'm confused about the following scenario:
  I have a route handler for REST API , should I return a promise ? even if there is no Async work done there ? 
  i.e :</p>
  
  <pre><code>dummy_router.post("/", passport.authenticationMiddleware(), (req, res) =&gt; {
    return new Promise((fulfill, reject) =&gt; {
        var result = some_simple_functionality();
        if (result) {
            fulfill(result)
        } else {
            reject(err)
        }
  
    }).catch(function (error) {
        res.status(400).send('400: failed t :: ' + error + '\n');
    });
  });
  </code></pre>
  
  <p>also second question on same issue . if I am performing some async tasks and have promises containing them then is this a good practice ?</p>
  
  <pre><code>dummy_router.post("/", passport.authenticationMiddleware(), (req, res) =&gt; {
    some_promise().then((result) =&gt; {
  
    }, (err) =&gt; {
  
    }).catch(function (error) {
      res.status(400).send('400: failed t :: ' + error + '\n');
    });
  });
  </code></pre>