import { timestamp, files, shell, routes } from "@sapper/service-worker"; const ASSETS = `cache${timestamp}`; // `shell` is an array of all the files generated by the bundler, // `files` is an array of everything in the `static` directory const to_cache = shell.concat(files); const cached = new Set(to_cache); self.addEventListener("install", (event) => { event.waitUntil( caches .open(ASSETS) .then((cache) => cache.addAll(to_cache)) .then(() => { self.skipWaiting(); }) ); }); self.addEventListener("activate", (event) => { event.waitUntil( caches.keys().then(async (keys) => { // delete old caches for (const key of keys) { if (key !== ASSETS) await caches.delete(key); } self.clients.claim(); }) ); }); self.addEventListener("fetch", (event) => { if (event.request.method !== "GET" || event.request.headers.has("range")) return; const url = new URL(event.request.url); // don't try to handle e.g. data: URIs if (!url.protocol.startsWith("http")) return; // ignore dev server requests if ( url.hostname === self.location.hostname && url.port !== self.location.port ) return; // always serve static files and bundler-generated assets from cache if (url.host === self.location.host && cached.has(url.pathname)) { event.respondWith(caches.match(event.request)); return; } // for pages, you might want to serve a shell `service-worker-index.html` file, // which Sapper has generated for you. It's not right for every // app, but if it's right for yours then uncomment this section /* if (url.origin === self.origin && routes.find(route => route.pattern.test(url.pathname))) { event.respondWith(caches.match('/service-worker-index.html')); return; } */ if (event.request.cache === "only-if-cached") return; // for everything else, try the network first, falling back to // cache if the user is offline. (If the pages never change, you // might prefer a cache-first approach to a network-first one.) event.respondWith( caches.open(`offline${timestamp}`).then(async (cache) => { try { const response = await fetch(event.request); cache.put(event.request, response.clone()); return response; } catch (err) { const response = await cache.match(event.request); if (response) return response; throw err; } }) ); });