serviceWorker.js

self.addEventListener('install', event => {
    event.waitUntil(
        caches.open('pwa-cache').then(cache => {
            return cache.addAll([
                './',
                './index.html',
                './privacy.html',
                './styles.css',
                './script.js',
                './icon-192.png',
                './icon-512.png',
                'https://cdn.jsdelivr.net/npm/luxon@3.5.0/build/global/luxon.min.js',
                'https://cdn.jsdelivr.net/npm/tz-lookup@6.1.25/tz.min.js',
                'https://cdn.jsdelivr.net/npm/astronomy-engine@2.1.19/astronomy.browser.min.js',
                'https://cdn.jsdelivr.net/npm/flatpickr@4.6.13/dist/flatpickr.min.js',
                'https://cdn.jsdelivr.net/npm/flatpickr@4.6.13/dist/flatpickr.min.css',
                'https://cdn.jsdelivr.net/npm/flatpickr@4.6.13/dist/themes/dark.min.css'
            ]);
        })
    );
});


async function cacheFirstWithRefresh(request) {
  // launch fetch+cache in background
  const fetchResponsePromise = fetch(request).then(async (networkResponse) => {
    if (networkResponse.ok) {
      const cache = await caches.open("pwa-cache");
      cache.put(request, networkResponse.clone());
    }
    return networkResponse;
  });

  // but return cached version if available (otherwise wait the fetch)
  return (await caches.match(request)) || (await fetchResponsePromise);
}


self.addEventListener("fetch", (event) => {
  event.respondWith(cacheFirstWithRefresh(event.request));
});