TF-3157 Update web socket with background service worker

TF-3157 Stub BroadcastChannel for mobile build

web/web-sockets-worker.js

@@ -0,0 +1,74 @@
+importScripts('flutter_service_worker.js?v={{flutter_service_worker_version}}');
+
+var webSocket;
+const broadcast = new BroadcastChannel("background-message");
+var intervalId;
+const pingIntervalInMs = 10000;
+
+function connect(url, ticket) {
+  webSocket = new WebSocket(`${url}?ticket=${ticket}`, "jmap");
+
+  webSocket.onopen = () => {
+    console.log("websocket open");
+    webSocket.send(
+      JSON.stringify({
+        "@type": "WebSocketPushEnable",
+        dataTypes: ["Mailbox", "Email"],
+      })
+    );
+    intervalId = setInterval(() => {
+      webSocket.send(
+        JSON.stringify({
+          "@type": "Request",
+          id: "R1",
+          using: ["urn:ietf:params:jmap:core"],
+          methodCalls: [["Core/echo", {}, "c0"]],
+        })
+      );
+    }, pingIntervalInMs);
+  };
+
+  webSocket.onmessage = (event) => {
+    console.log(`websocket received message: ${event.data}`);
+    broadcast.postMessage(event.data);
+  };
+
+  webSocket.onclose = (event) => {
+    console.log(
+      `websocket connection closed with code: "${event.code}" reason: "${event.reason}" and cleanly: "${event.wasClean}"`
+    );
+    broadcast.postMessage("webSocketClosed");
+    webSocket = null;
+    clearInterval(intervalId);
+  };
+}
+
+function disconnect() {
+  if (webSocket == null) {
+    return;
+  }
+  webSocket.close();
+}
+
+self.addEventListener("install", (event) => {
+  self.skipWaiting().then(() => {
+    console.log("Service worker installed");
+  });
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    self.clients.claim().then(() => {
+      console.log("Service worker activated");
+    })
+  );
+});
+
+self.addEventListener("message", (event) => {
+  console.log(`web socket worker received message: ${event.data}`);
+  if (event.data.action === "connect") {
+    connect(event.data.url, event.data.ticket);
+  } else if (event.data.action === "disconnect") {
+    disconnect();
+  }
+});

web/worker_service/worker_service.js

@@ -4,7 +4,6 @@ const iosPlatform = 'iOS';
 const androidPlatform = 'android';
 const otherPlatform = 'other';
 const timeoutDuration = 4000;
-var serviceWorkerVersion = null;
 var scriptLoaded = false;
 
 function loadMainDartJs() {
@@ -24,16 +23,7 @@ function fetchServiceWorker() {
     // Wait for registration to finish before dropping the <script>tag.
     // Otherwise, the browser will load the script multiple times,
     // potentially different versions.
-    navigator.serviceWorker.register('firebase-messaging-sw.js').then(serviceWorkerRegistration => {
-      console.info('[TwakeMail] fetchServiceWorker(): Service worker firebase-messaging was registered.');
-    }).catch(error => {
-      console.error(
-        '[TwakeMail] fetchServiceWorker(): An error occurred while registering the service worker firebase-messaging.'
-        );
-      console.error(error);
-    });
-    var serviceWorkerUrl = 'flutter_service_worker.js?v=' + serviceWorkerVersion;
-    navigator.serviceWorker.register(serviceWorkerUrl)
+    navigator.serviceWorker.register('web-sockets-worker.js')
       .then((reg) => {
         function waitForActivation(serviceWorker) {
           serviceWorker.addEventListener('statechange', () => {
@@ -47,12 +37,6 @@ function fetchServiceWorker() {
           // No active web worker and we have installed or are installing
           // one for the first time. Simply wait for it to activate.
           waitForActivation(reg.installing || reg.waiting);
-        } else if (!reg.active.scriptURL.endsWith(serviceWorkerVersion)) {
-          // When the app updates the serviceWorkerVersion changes, so we
-          // need to ask the service worker to update.
-          console.log('[TwakeMail] fetchServiceWorker(): New service worker available.');
-          reg.update();
-          waitForActivation(reg.installing);
         } else {
           // Existing service worker is still good.
           console.log('[TwakeMail] fetchServiceWorker(): Loading app from service worker.');