Tanken/public/sw.js

const CACHE = 'tanken-v7';
const STATIC = ['/', '/style.css', '/app.js', '/coverage-outlines.js', '/web-haptics.js'];

self.addEventListener('install', (e) => {
  e.waitUntil(caches.open(CACHE).then((c) => c.addAll(STATIC)));
  self.skipWaiting();
});

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

self.addEventListener('fetch', (e) => {
  const url = new URL(e.request.url);

  if (url.pathname.startsWith('/api/')) {
    // Network-first for API calls
    e.respondWith(
      fetch(e.request)
        .then((res) => {
          const clone = res.clone();
          caches.open(CACHE).then((c) => c.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request))
    );
  } else if (e.request.mode === 'navigate') {
    // Tab deep links (/stats, /history, …) are client-routed on top of the
    // app shell. Offline, the exact path isn't cached — fall back to the
    // cached shell ("/") so installed/offline deep links still open.
    e.respondWith(
      fetch(e.request)
        .then((res) => {
          const clone = res.clone();
          caches.open(CACHE).then((c) => c.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request).then((hit) => hit || caches.match('/')))
    );
  } else {
    // Network-first for static assets
    // Always fetch fresh content; fall back to cache when offline
    e.respondWith(
      fetch(e.request)
        .then((res) => {
          const clone = res.clone();
          caches.open(CACHE).then((c) => c.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request))
    );
  }
});