PWA dynamic caching

[Seanitzel]

I am building a pretty big app with different features, and I don't want the service worker to precache all the apps resources on initial load, which is what currently happens when running

precacheAndRoute(self.__WB_MANIFEST);

When i remove this line from the custom-service-worker and try to build I get an error:

Can't find self.__WB_MANIFEST in your SW source.

Also when not using precacheAndRoute and trying to implement my own dynamic caching instead:

self.addEventListener('fetch', (event) => {
  event.respondWith(
    caches.match(event.request).then((response) => {
      return response || fetch(event.request).then((response) => {
        return caches.open(NETWORK_CACHE).then((cache) => {
          cache.put(event.request.url, response.clone());
          return response;
        });
      });
    }),
  );
});

It doesn't work, the fetch event callback is not being fired.

How can I implement my own dynamic caching strategy?