2_sw.js

let cacheName = 'pwa-cache';

const isValidUrl = urlString => {
    let url;
    try {
        url = new URL(urlString);
    } catch (e) {
        return false;
    }
    if (url.host === 'localhost:3000') {
        return url.protocol === "http:" || url.protocol === "https:";
    }
    return false
}

self.addEventListener("install", (event) => {
    event.waitUntil((async () => {
        const cache = await caches.open(cacheName)
        console.log('mulai caching saat install');
        await cache.addAll([
            '/index.html',
            // '/karyawan.html',
            // '/pushnotif.html',
            '/css/materialize.min.css',
            '/js/materialize.min.js',
            '/js/main.js'
        ])
        await self.skipWaiting();
    })());
});

self.addEventListener("fetch", (event) => {
    event.waitUntil((async () => {
        if (event.request.url.endsWith(".png") ||
            event.request.url.endsWith(".css") ||
            event.request.url.endsWith(".js") ||
            event.request.url.endsWith(".html")) {
            caches.open(cacheName).then((cache) => {
                // check apakah URL valid atau chrome ekstensi
                if (isValidUrl(event.request.url)) {
                    cache.add(event.request)
                }
            })
        }

        event.respondWith(caches.match(event.request)
            .then((resp) => {
                return resp || fetch(event.request);
            }))
    })());
});