title: Can service workers cache POST requests?
body: <p>I tried to cache a POST request in a service worker on fetch event.</p>
  
  <p>I used <code>cache.put(event.request, response)</code>, but the returned promise was rejected with <code>TypeError: Invalid request method POST.</code>.</p>
  
  <p>When I tried to hit the same POST API, <code>caches.match(event.request)</code> was giving me undefined.</p>
  
  <p>But when I did the same for GET methods, it worked: <code>caches.match(event.request)</code> for a GET request was giving me a response.</p>
  
  <p>Can service workers cache POST requests?
  In case they can't, what approach can we use to make apps truly offline?</p>