title: JS asset loaded empty with 304, instead of 200 (from cache)
body: <p>I've noticed that when I refresh my app one of my JS assets is sometimes loaded with <code>304</code> response, while mostly it is loaded with <code>200 (from cache)</code>. It wouldn't be a big deal, if it would actually load it - whenever I get <code>304</code>, the file is not loaded (the response is empty) and I end up with JS error (because my var from that file is not recognized). After the error, I copy-paste the URL to a new tab and then my JS file is loaded correctly.</p>
  
  <p>But when I refresh the page instead, I have the same error, strangely not always - after several refresh attempts the file is loaded with <code>200</code> and JS error is gone.</p>
  
  <p>I wish I would know what could cause this strange behavior, or how can I force to load this file.</p>