Añadir 'app.js'

app.js

@@ -0,0 +1,36 @@
+class Setup {
+    async run() {
+        await this.register()
+        const p = document.createElement("p")
+        p.innerText = this.serviceWorkerStatus
+        document.body.appendChild(p)
+    }
+
+    async register() {
+        this.serviceWorkerStatus = "unavailable"
+        if ("serviceWorker" in navigator) {
+            try {
+                this.registration = navigator.serviceWorker.register(
+                    "/sw.js",
+                    {scope: "/"}
+                )
+                if (this.registration.installing) {
+                    this.serviceWorkerStatus = "installing"
+                } else if (this.registration.waiting) {
+                    this.serviceWorkerStatus = "waiting"
+                } else if (this.registration.active) {
+                    this.serviceWorkerStatus = "active"
+                } else {
+                    this.serviceWorkerStatus = "unknown"
+                }
+            } catch (err) {
+                console.error("error registering service worker", err)
+                this.serviceWorkerStatus = "error"
+            }
+        } else {
+            console.error("serviceWorker not available")
+        }
+    }
+}
+
+new Setup().run()