Productier/apps/frontend/public/sw.js

const CACHE_NAME = "productier-v1";
const PRECACHE = ["/", "/manifest.json", "/favicon.ico"];

self.addEventListener("install", event => {
  event.waitUntil(caches.open(CACHE_NAME).then(cache => cache.addAll(PRECACHE)));
});

self.addEventListener("activate", event => {
  event.waitUntil(
    caches.keys().then(keys =>
      Promise.all(keys.filter(key => key !== CACHE_NAME).map(key => caches.delete(key))),
    ),
  );
});

self.addEventListener("fetch", event => {
  if (event.request.method !== "GET") {
    return;
  }

  event.respondWith(
    caches.match(event.request).then(cached => {
      if (cached) {
        return cached;
      }

      return fetch(event.request)
        .then(response => {
          const copy = response.clone();
          caches.open(CACHE_NAME).then(cache => cache.put(event.request, copy));
          return response;
        })
        .catch(() => caches.match("/"));
    }),
  );
});