sw.js

var cacheName = 'ezchat-v1';
var filesToCache = [
 './',
 './index.html',
 './ezchat.js',
 './ezchat_bg.wasm',
];

/* Start the service worker and cache all of the app's content */
self.addEventListener('install', (e) => {
 e.waitUntil((async () => {
 const cache = await caches.open(cacheName);

 await Promise.allSettled(filesToCache.map(async (url) => {
 try {
 const res = await fetch(url, { cache: 'no-store' });
 if (!res.ok) throw new Error(`${res.status} ${res.statusText}`);
 await cache.put(url, res);
 } catch (err) {
 console.info('[SW] precache failed:', url, err);
 }
 }));

 await self.skipWaiting();
 })());
});

/* Clean up outdated caches and take control of all clients immediately */
self.addEventListener('activate', (e) => {
 e.waitUntil((async () => {
 const keys = await caches.keys();
 await Promise.all(keys.map((k) => (k !== cacheName ? caches.delete(k) : Promise.resolve())));
 await self.clients.claim();
 })());
})

/* Serve cached content when offline */
self.addEventListener('fetch', (e) => {
 const url = new URL(e.request.url);
 const scope = new URL(self.registration.scope);

 if (url.origin !== scope.origin) return;
 if (e.request.method !== 'GET') return;

 e.respondWith((async () => {
 const cached = await caches.match(e.request);
 if (cached) return cached;

 try {
 return await fetch(e.request);
 } catch (err) {
 if (e.request.mode === 'navigate') {
 const fallback = await caches.match('./index.html');
 if (fallback) return fallback;
 }
 return Response.error();
 }
 })());
});