sw.js

self.addEventListener("install", function (event) {
  console.log("[Service Worker] Installing Service Worker ...", event);
  event.waitUntil(
    caches.open("static").then(function (cache) {
      console.log("precaching");
      cache.add("/index.html");
      cache.add("/");
    })
  );
});
self.addEventListener("activate", function (event) {
  console.log("[Service Worker] Activating Service Worker ...", event);
  return self.clients.claim();
});
self.addEventListener("fetch", function (event) {
  console.log("[Service Worker] Fetching something ....", event);
  event.respondWith(
    caches.match(event.request).then(function (response) {
      if (response) {
        return response;
      } else {
        return fetch(event.request);
      }
    })
  );
});

self.addEventListener("push", (event) => {
  const notification = event.data.text();
  self.registration.showNotification(notification, {});
});