title: How to watch and reload an ExpressJS app with pm2
body: <p>I'm developing an ExpressJS app.
  I use pm2 to load it:</p>
  
  <pre><code>myapp$ pm2 start bin/www
  </code></pre>
  
  <p>This works fine, except that adding the <code>--watch</code> flag doesn't seem to work; every time I change the JS source I need to explicitly restart it for my changes to take effect:</p>
  
  <pre><code>myapp$ pm2 restart www
  </code></pre>
  
  <p>What am I doing wrong? I've tried the <code>--watch</code> flag with a non-ExpressJS app and it worked as expected.</p>