🐛 Fix Initializing the connection to the local database hang (#4375)

* fix initializing to the local db

* release notes

packages/loot-core/src/platform/client/fetch/index.browser.ts

@@ -96,11 +96,15 @@ function connectWorker(worker, onOpen, onError) {
     // ready to handle messages.
     if (msg.type === 'connect') {
       // Send any messages that were queued while closed
-      if (messageQueue.length > 0) {
+      if (messageQueue?.length > 0) {
         messageQueue.forEach(msg => worker.postMessage(msg));
         messageQueue = null;
       }
 
+      // signal to the backend that we're connected to it
+      globalWorker.postMessage({
+        name: 'client-connected-to-backend',
+      });
       onOpen();
     } else if (msg.type === 'app-init-failure') {
       onError(msg);

packages/loot-core/src/platform/server/connection/index.web.ts

@@ -44,6 +44,12 @@ export const init: T.Init = function (serverChn, handlers) {
         return;
       }
 
+      if (msg.name === 'client-connected-to-backend') {
+        // the client is indicating that it is connected to this backend. Stop attempting to connect
+        clearInterval(reconnectToClientInterval);
+        return;
+      }
+
       const { id, name, args, undoTag, catchErrors } = msg;
 
       if (handlers[name]) {
@@ -98,7 +104,19 @@ export const init: T.Init = function (serverChn, handlers) {
     false,
   );
 
-  serverChannel.postMessage({ type: 'connect' });
+  const RECONNECT_INTERVAL_MS = 200;
+  const MAX_RECONNECT_ATTEMPTS = 500;
+  let reconnectAttempts = 0;
+
+  const reconnectToClientInterval = setInterval(() => {
+    serverChannel.postMessage({ type: 'connect' });
+    reconnectAttempts++;
+    if (reconnectAttempts >= MAX_RECONNECT_ATTEMPTS) {
+      // Failed to connect to client - signal server error
+      send('server-error');
+      clearInterval(reconnectToClientInterval);
+    }
+  }, RECONNECT_INTERVAL_MS);
 };
 
 export const send: T.Send = function (name, args) {

upcoming-release-notes/4375.md

@@ -0,0 +1,6 @@
+---
+category: Bugfix
+authors: [MikesGlitch]
+---
+
+Prevent the app getting stuck on the "Initializing the connection to the local database..." screen