e-ticket/public/scanner/sw.js

const CACHE_NAME = 'scanner-v1';
const ASSETS = [
    '/scanner/',
    'https://cdn.jsdelivr.net/npm/html5-qrcode@2.3.8/html5-qrcode.min.js',
];

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

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

self.addEventListener('fetch', (e) => {
    if (e.request.method !== 'GET') return;
    if (e.request.url.includes('/api/')) return;
    e.respondWith(
        caches.match(e.request).then(cached => cached || fetch(e.request))
    );
});