Update service worker so it only caches images

sw.js

@@ -1,36 +1,75 @@
+const CACHE_NAME = 'hummingbird-anime-client';
+
+async function fromCache (request) {
+	const cache = await caches.open(CACHE_NAME);
+	return await cache.match(request);
+}
+
+async function fromNetwork (request) {
+	return await fetch(request);
+}
+
+async function update (request) {
+	const cache = await caches.open(CACHE_NAME);
+	const response = await fetch(request);
+
+	if (request.url.includes('/public/images/')) {
+		console.log('Saving to cache: ', request.url);
+		await cache.put(request, response.clone());
+	}
+
+	return response;
+}
+
+function refresh (response) {
+	return self.clients.matchAll().then(clients => {
+		clients.forEach(client => {
+			const message = {
+				type: 'refresh',
+				url: response.url,
+				eTag: response.headers.get('ETag')
+			};
+
+			client.postMessage(JSON.stringify(message));
+		})
+	});
+}
+
 self.addEventListener('install', event => {
-	console.log('Worker installed');
+	console.log('Public Folder Worker installed');
 
 	event.waitUntil(
-		caches.open('hummingbird-anime-client')
+		caches.open(CACHE_NAME)
 			.then(cache => cache.addAll([
 				'public/images/icons/favicon.ico',
-				'public/css/app.min.css',
-				'public/js/index.min.js',
-				'public/js/index-authed.min.js',
-				'public/js/tables.min.js',
+				'public/images/streaming-logos/amazon.svg',
+				'public/images/streaming-logos/crunchyroll.svg',
+				'public/images/streaming-logos/daisuki.svg',
+				'public/images/streaming-logos/funimation.svg',
+				'public/images/streaming-logos/hidive.svg',
+				'public/images/streaming-logos/hulu.svg',
+				'public/images/streaming-logos/netflix.svg',
+				'public/images/streaming-logos/tubitv.svg',
+				'public/images/streaming-logos/viewster.svg',
 			]))
-	);
+	)
 });
 
+self.addEventListener('activate', event => {
+	console.log('Public Folder Worker activated');
+});
+
+// Pull css, images, and javascript from cache
 self.addEventListener('fetch', event => {
+	fromCache(event.request).then(cached => {
+		if (cached !== undefined) {
+			event.respondWith(cached);
+		} else {
+			event.respondWith(fromNetwork(event.request));
+		}
+	});
 
-	event.respondWith(
-		caches.match(event.request).then(response => {
-			if (response !== undefined) {
-				// Return cached version
-				return response;
-			}
-
-			return fetch(event.request).then(response => {
-				const clone = response.clone();
-
-				caches.open('hummingbird-anime-client').then(cache => {
-					cache.put(event.request, clone);
-				});
-
-				return response;
-			});
-		})
+	event.waitUntil(
+		update(event.request).then(refresh)
 	);
 });