text: var CACHE_NAME = "pwa-task-manager";
  var urlsToCache = ["/", "/app"];
  
  // Install a service worker
  self.addEventListener("install", (event) => {
    // Perform install steps
    event.waitUntil(
      caches.open(CACHE_NAME).then(function (cache) {
        console.log("Opened cache");
        return cache.addAll(urlsToCache);
      })
    );
  });
  
  // Cache and return requests
  self.addEventListener("fetch", (event) => {
    event.respondWith(
      caches.match(event.request).then(function (response) {
        // Cache hit - return response
        if (response) {
          return response;
        }
        return fetch(event.request);
      })
    );
  });
  
  // Update a service worker
  self.addEventListener("activate", (event) => {
    var cacheWhitelist = ["pwa-task-manager"];
    event.waitUntil(
      caches.keys().then((cacheNames) => {
        return Promise.all(
          cacheNames.map((cacheName) => {
            if (cacheWhitelist.indexOf(cacheName) === -1) {
              return caches.delete(cacheName);
            }
          })
        );
      })
    );
  });
  