https://letsharkness.com/sw.js

1const CACHE_NAME = 'harkness-io-v16';
2const PRECACHE_URLS = [
3  '/',
4  '/index.html',
5];
6
7// Install: precache shell — force immediate activation
8self.addEventListener('install', (event) => {
9  event.waitUntil(
10    caches.open(CACHE_NAME).then((cache) => cache.addAll(PRECACHE_URLS))
11  );
12  self.skipWaiting();
13});
14
15// Activate: clean old caches
16self.addEventListener('activate', (event) => {
17  event.waitUntil(
18    caches.keys().then((keys) =>
19      Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)))
20    )
21  );
22  self.clients.claim();
23});
24
25// Fetch: network-first for everything, fall back to cache when offline
26self.addEventListener('fetch', (event) => {
27  const url = new URL(event.request.url);
28
29  // Skip non-GET and cross-origin requests
30  if (event.request.method !== 'GET') return;
31  if (url.origin !== self.location.origin) return;
32
33  // Hashed assets (Vite build outputs) — never serve stale from cache.
34  // If the network request 404s, the asset hash has changed and the cached
35  // version (from a different filename) won't help. Let the browser handle
36  // the error so the app can reload with fresh assets.
37  const isHashedAsset = url.pathname.startsWith('/assets/');
38
39  event.respondWith(
40    fetch(event.request).then((response) => {
41      if (response.ok) {
42        const clone = response.clone();
43        caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
44      }
45      return response;
46    }).catch(() => {
47      // Offline: serve from cache (but not stale hashed assets)
48      if (isHashedAsset) {
49        return new Response('Asset unavailable offline', { status: 503 });
50      }
51      return caches.match(event.request).then((cached) => {
52        if (cached) return cached;
53        if (event.request.mode === 'navigate') {
54          return caches.match('/index.html');
55        }
56        return new Response('Offline', { status: 503 });
57      });
58    })
59  );
60});