Improve communication error handling

Author: intitni

CommunicationBridge/ServiceDelegate.swift

@@ -63,6 +63,9 @@ actor EventHandler {
     ) async {
         rescheduleExitTask()
         #if DEBUG
+        if let endpoint, !(await testXPCListenerEndpoint(endpoint)) {
+            self.endpoint = nil
+        }
         reply(endpoint)
         #else
         if await launcher.isApplicationValid {

Core/Sources/HostApp/General.swift

@@ -30,7 +30,7 @@ struct General: ReducerProtocol {
                 return .run { send in
                     await send(.setupLaunchAgentIfNeeded)
                 }
-                
+
             case .setupLaunchAgentIfNeeded:
                 return .run { send in
                     #if DEBUG
@@ -47,7 +47,7 @@ struct General: ReducerProtocol {
                     #endif
                     await send(.reloadStatus)
                 }
-                
+
             case .openExtensionManager:
                 return .run { send in
                     let service = try getService()
@@ -76,9 +76,15 @@ struct General: ReducerProtocol {
                             ))
                         } else {
                             toast("Launching service app.", .info)
-                            try await Task.sleep(nanoseconds: 3_000_000_000)
+                            try await Task.sleep(nanoseconds: 5_000_000_000)
                             await send(.reloadStatus)
                         }
+                    } catch let error as XPCCommunicationBridgeError {
+                        toast(
+                            "Failed to reach communication bridge. \(error.localizedDescription)",
+                            .error
+                        )
+                        await send(.failedReloading)
                     } catch {
                         toast(error.localizedDescription, .error)
                         await send(.failedReloading)

Tool/Sources/XPCShared/XPCCommunicationBridge.swift

@@ -8,7 +8,7 @@ public enum XPCCommunicationBridgeError: Swift.Error, LocalizedError {
     public var errorDescription: String? {
         switch self {
         case .failedToCreateXPCConnection:
-            return "Failed to create XPC connection"
+            return "Failed to create XPC connection."
         case let .xpcServiceError(error):
             return "XPC Service error: \(error.localizedDescription)"
         }

Tool/Sources/XPCShared/XPCExtensionService.swift

@@ -9,9 +9,9 @@ public enum XPCExtensionServiceError: Swift.Error, LocalizedError {
     public var errorDescription: String? {
         switch self {
         case .failedToGetServiceEndpoint:
-            return "Failed to get service endpoint"
+            return "Waiting for service to connect to the communication bridge."
         case .failedToCreateXPCConnection:
-            return "Failed to create XPC connection"
+            return "Failed to create XPC connection."
         case let .xpcServiceError(error):
             return "XPC Service error: \(error.localizedDescription)"
         }

Tool/Sources/XPCShared/XPCService.swift

@@ -126,3 +126,21 @@ func withXPCServiceConnected<T, P>(
     return try await stream.first(where: { _ in true })!
 }
 
+@XPCServiceActor
+public func testXPCListenerEndpoint(_ endpoint: NSXPCListenerEndpoint) async -> Bool {
+    let connection = NSXPCConnection(listenerEndpoint: endpoint)
+    defer { connection.invalidate() }
+    let stream: AsyncThrowingStream<Void, Error> = AsyncThrowingStream { continuation in
+        _ = connection.remoteObjectProxyWithErrorHandler {
+            continuation.finish(throwing: $0)
+        }
+        continuation.yield(())
+        continuation.finish()
+    }
+    do {
+        try await stream.first(where: { _ in true })!
+        return true
+    } catch {
+        return false
+    }
+}