SW Caching Strategy

sw.js

const assets = [].map(url => self.location.origin + url);

self.addEventListener("fetch", e =>
  e.respondWith(
    fetch(e.request)
      .then(res => {
        if (res.ok && assets.includes(e.request.url)) {
          caches.open("cache-name").then(cache => cache.put(e.request, res));
        }
        return res.clone();
      })
      .catch(err => caches.match(e.request).then(res => res || err))
  )
);