https://bellcowfantasy.app/service-worker.js

1// #155: minimal installability + offline-safe static shell -- NOT full
2// offline data sync (that's a separate, much bigger ask if ever needed, per
3// the issue's stated scope). This exists purely so iOS "Add to Home Screen"
4// registers a real PWA (Safari requires an active service worker for a
5// standalone-display install) and so the static shell (HTML/CSS/JS/icons)
6// still loads if the network drops mid-session -- API calls are always
7// network-only, live data is never served stale from cache.
8
9const CACHE_NAME = "bellcow-shell-v1";
10const SHELL_ASSETS = [
11  "/",
12  "/static/index.html",
13  "/static/style.css",
14  "/static/app.js",
15  "/static/cowbell-logo.js",
16  "/static/manifest.json",
17  "/static/img/cowbell-static.svg",
18  "/static/img/cowbell-idle.svg",
19  "/static/icons/icon-192.png",
20  "/static/icons/icon-512.png",
21  "/static/icons/apple-touch-icon.png",
22];
23
24self.addEventListener("install", (event) => {
25  event.waitUntil(
26    caches.open(CACHE_NAME).then((cache) => cache.addAll(SHELL_ASSETS)).then(() => self.skipWaiting())
27  );
28});
29
30self.addEventListener("activate", (event) => {
31  event.waitUntil(
32    caches
33      .keys()
34      .then((keys) => Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k))))
35      .then(() => self.clients.claim())
36  );
37});
38
39self.addEventListener("fetch", (event) => {
40  const url = new URL(event.request.url);
41
42  // Anything under /api/ is always live data -- never intercept it, cache
43  // it, or let a stale/offline response stand in for a real one.
44  if (event.request.method !== "GET" || url.pathname.startsWith("/api/")) return;
45
46  // #397: network-first, cache only as an offline fallback. The previous
47  // cache-first strategy served a stale shell immediately on every visit
48  // right after a deploy -- the network fetch there only refreshed the
49  // cache for *next* time, so a normal online visit was permanently one
50  // deploy behind what it actually showed. This still satisfies #155's real
51  // goal (shell still loads if the network drops mid-session) without that
52  // lag on every ordinary visit.
53  event.respondWith(
54    fetch(event.request)
55      .then((res) => {
56        if (res.ok) caches.open(CACHE_NAME).then((cache) => cache.put(event.request, res.clone()));
57        return res;
58      })
59      .catch(() => caches.match(event.request))
60  );
61});