posimai-store/sw.js

const CACHE = 'posimai-store-v2';
const STATIC = ['/', '/index.html', '/manifest.json', '/logo.png'];

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

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

self.addEventListener('fetch', e => {
    if (e.request.method !== 'GET') return;
    if (new URL(e.request.url).origin !== location.origin) return;
    e.respondWith(
        caches.match(e.request).then(cached => cached || fetch(e.request).then(res => {
            const clone = res.clone();
            caches.open(CACHE).then(c => c.put(e.request, clone));
            return res;
        }))
    );
});