🤖 fix: prevent duplicate updater IPC handler registration

When window is recreated (e.g., clicking dock icon on macOS after closing
all windows), createWindow() was trying to register the same IPC handlers
again, causing 'Attempted to register a second handler' error.

Added guard flag matching the pattern used by ipcMain.register().

_Generated with mux_

Author: ammar-agent

src/desktop/main.ts

@@ -44,6 +44,7 @@ let config: Config | null = null;
 let ipcMain: IpcMain | null = null;
 // eslint-disable-next-line @typescript-eslint/consistent-type-imports
 let updaterService: typeof import("@/desktop/updater").UpdaterService.prototype | null = null;
+let updaterHandlersRegistered = false;
 const isE2ETest = process.env.MUX_E2E === "1";
 const forceDistLoad = process.env.MUX_E2E_LOAD_DIST === "1";
 
@@ -377,42 +378,47 @@ function createWindow() {
   console.log(`[${timestamp()}] [window] Registering IPC handlers...`);
   ipcMain.register(electronIpcMain, mainWindow);
 
-  // Register updater IPC handlers (available in both dev and prod)
-  electronIpcMain.handle(IPC_CHANNELS.UPDATE_CHECK, () => {
-    // Note: log interface already includes timestamp and file location
-    log.debug(`UPDATE_CHECK called (updaterService: ${updaterService ? "available" : "null"})`);
-    if (!updaterService) {
-      // Send "idle" status if updater not initialized (dev mode without DEBUG_UPDATER)
-      if (mainWindow) {
-        mainWindow.webContents.send(IPC_CHANNELS.UPDATE_STATUS, {
-          type: "idle" as const,
-        });
+  // Register updater IPC handlers once (available in both dev and prod)
+  // Guard prevents "Attempted to register a second handler" error when window is recreated
+  if (!updaterHandlersRegistered) {
+    updaterHandlersRegistered = true;
+
+    electronIpcMain.handle(IPC_CHANNELS.UPDATE_CHECK, () => {
+      // Note: log interface already includes timestamp and file location
+      log.debug(`UPDATE_CHECK called (updaterService: ${updaterService ? "available" : "null"})`);
+      if (!updaterService) {
+        // Send "idle" status if updater not initialized (dev mode without DEBUG_UPDATER)
+        if (mainWindow) {
+          mainWindow.webContents.send(IPC_CHANNELS.UPDATE_STATUS, {
+            type: "idle" as const,
+          });
+        }
+        return;
       }
-      return;
-    }
-    log.debug("Calling updaterService.checkForUpdates()");
-    updaterService.checkForUpdates();
-  });
+      log.debug("Calling updaterService.checkForUpdates()");
+      updaterService.checkForUpdates();
+    });
 
-  electronIpcMain.handle(IPC_CHANNELS.UPDATE_DOWNLOAD, async () => {
-    if (!updaterService) throw new Error("Updater not available in development");
-    await updaterService.downloadUpdate();
-  });
+    electronIpcMain.handle(IPC_CHANNELS.UPDATE_DOWNLOAD, async () => {
+      if (!updaterService) throw new Error("Updater not available in development");
+      await updaterService.downloadUpdate();
+    });
 
-  electronIpcMain.handle(IPC_CHANNELS.UPDATE_INSTALL, () => {
-    if (!updaterService) throw new Error("Updater not available in development");
-    updaterService.installUpdate();
-  });
+    electronIpcMain.handle(IPC_CHANNELS.UPDATE_INSTALL, () => {
+      if (!updaterService) throw new Error("Updater not available in development");
+      updaterService.installUpdate();
+    });
 
-  // Handle status subscription requests
-  // Note: React StrictMode in dev causes components to mount twice, resulting in duplicate calls
-  electronIpcMain.on(IPC_CHANNELS.UPDATE_STATUS_SUBSCRIBE, () => {
-    log.debug("UPDATE_STATUS_SUBSCRIBE called");
-    if (!mainWindow) return;
-    const status = updaterService ? updaterService.getStatus() : { type: "idle" };
-    log.debug("Sending current status to renderer:", status);
-    mainWindow.webContents.send(IPC_CHANNELS.UPDATE_STATUS, status);
-  });
+    // Handle status subscription requests
+    // Note: React StrictMode in dev causes components to mount twice, resulting in duplicate calls
+    electronIpcMain.on(IPC_CHANNELS.UPDATE_STATUS_SUBSCRIBE, () => {
+      log.debug("UPDATE_STATUS_SUBSCRIBE called");
+      if (!mainWindow) return;
+      const status = updaterService ? updaterService.getStatus() : { type: "idle" };
+      log.debug("Sending current status to renderer:", status);
+      mainWindow.webContents.send(IPC_CHANNELS.UPDATE_STATUS, status);
+    });
+  }
 
   // Set up updater service with the main window (only in production)
   if (updaterService) {