lonc/public/service-worker.js

const CACHE_NAME = 'lonc-shell-v2';
const APP_SHELL = ['/', '/index.html', '/manifest.webmanifest', '/offline.html', '/icons/icon.svg', '/icons/icon-mask.svg'];

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

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

self.addEventListener('message', (event) => {
  if (event?.data?.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});

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

  const requestUrl = new URL(event.request.url);

  if (requestUrl.origin !== self.location.origin) {
    return;
  }

  if (event.request.mode === 'navigate') {
    event.respondWith(
      fetch(event.request).catch(async () => {
        const shell = await caches.match('/index.html');
        return shell || caches.match('/offline.html');
      }),
    );
    return;
  }

  if (requestUrl.pathname === '/version.json') {
    event.respondWith(fetch(event.request, { cache: 'no-store' }));
    return;
  }

  const destination = event.request.destination;
  if (
    destination === 'script' ||
    destination === 'style' ||
    destination === 'worker' ||
    requestUrl.pathname.endsWith('.js') ||
    requestUrl.pathname.endsWith('.css')
  ) {
    event.respondWith(
      fetch(event.request)
        .then((networkResponse) => {
          const clone = networkResponse.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
          return networkResponse;
        })
        .catch(() => caches.match(event.request)),
    );
    return;
  }

  event.respondWith(
    caches.match(event.request).then((response) => {
      return (
        response ||
        fetch(event.request).then((networkResponse) => {
          const clone = networkResponse.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
          return networkResponse;
        })
      );
    }),
  );
});