Experimenting with service workers

service-worker.js

@@ -0,0 +1,57 @@
+import {manifest, version} from '@parcel/service-worker';
+
+async function install() {
+    console.log("Installing service worker!")
+    const cache = await caches.open(version);
+    console.log("Manifest file", manifest)
+    // await cache.addAll(manifest);
+    /* await cache.add({
+         cache: "force-cache",
+         url: "http://4.bp.blogspot.com/-_vTDmo_fSTw/T3YTV0AfGiI/AAAAAAAAAX4/Zjh2HaoU5Zo/s1600/beautiful%2Bkitten.jpg",
+         destination: "image",
+     })//*/
+}
+
+addEventListener('install', e => e.waitUntil(install()));
+
+async function activate() {
+    console.log("Activating service worker")
+    /*self.registration.showNotification("SW started", {
+        actions: [{
+            action: "OK",
+            title: "Some action"
+        }]
+    })*/
+    const keys = await caches.keys();
+    await Promise.all(
+        keys.map(key => key !== version && caches.delete(key))
+    );
+}
+
+addEventListener('activate', e => e.waitUntil(activate()));
+
+self.addEventListener('fetch', (event) => {
+    try {
+
+        if (event.request.url === "http://127.0.0.1:1234/somedata") {
+            console.log("Sending hi to 'somedata'")
+            event.respondWith(new Response("Service worker is active"))
+            return
+        }
+        const origin = new URL(self.origin)
+        const requestUrl = new URL(event.request.url)
+        console.log("Testing cache", origin.host, requestUrl.host, origin.host === requestUrl.host)
+        if (origin.host !== requestUrl.host) {
+            event.respondWith(fetch(event.request));
+            return
+        }
+        event.respondWith(
+            caches.match(event.request).then(function (response) {
+                return response || fetch(event.request);
+            }),
+        );
+    } catch (e) {
+        console.error("CRASH IN SW:", e)
+        event.respondWith(fetch(event.request));
+    }
+});