fix(swift): Add request timeout and initialization check for teardown

SDK changes:
- Add timeout parameter to sendRequest (default 30s)
- sendResourceTeardown uses 5s timeout
- Add failPendingRequest helper for clean timeout handling

Host changes:
- Check isReady() before sending teardown
- Skip teardown if bridge not yet initialized (no data to save)
- Simplified logic since SDK handles timeout internally

This prevents cards from getting stuck when closed before initialization.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ochafik

examples/basic-host-swift/Sources/BasicHostApp/McpHostViewModel.swift

@@ -515,32 +515,20 @@ class ToolCallInfo: ObservableObject, Identifiable {
         var errorMessage: String?
 
         if let bridge = appBridge {
-            logger.info("Sending teardown request...")
-
-            // Race between teardown and timeout
-            await withTaskGroup(of: String?.self) { group in
-                group.addTask {
-                    do {
-                        logger.info("Calling bridge.sendResourceTeardown()...")
-                        _ = try await bridge.sendResourceTeardown()
-                        logger.info("Teardown request completed successfully")
-                        return nil
-                    } catch {
-                        logger.error("Teardown request failed: \(String(describing: error)), type: \(type(of: error))")
-                        return "Teardown failed: app may not have saved data"
-                    }
-                }
-                group.addTask {
-                    try? await Task.sleep(nanoseconds: 5_000_000_000) // 5 second timeout
-                    logger.warning("Teardown timeout reached after 5 seconds")
-                    return "Teardown timed out: app may not have saved data"
+            // Only send teardown if the bridge is initialized
+            // If not initialized, the app hasn't done anything worth saving
+            let isReady = await bridge.isReady()
+            if isReady {
+                logger.info("Sending teardown request...")
+                do {
+                    _ = try await bridge.sendResourceTeardown()
+                    logger.info("Teardown request completed successfully")
+                } catch {
+                    logger.error("Teardown request failed: \(String(describing: error))")
+                    errorMessage = "Teardown failed: app may not have saved data"
                 }
-                // Wait for first to complete
-                if let result = await group.next() {
-                    errorMessage = result
-                }
-                logger.info("Task group completed")
-                group.cancelAll()
+            } else {
+                logger.info("Skipping teardown - bridge not yet initialized")
             }
 
             logger.info("Closing bridge...")

swift/Sources/McpApps/AppBridge.swift

@@ -231,8 +231,8 @@ public actor AppBridge {
             params: dict.mapValues { AnyCodable($0) })
     }
 
-    public func sendResourceTeardown() async throws -> McpUiResourceTeardownResult {
-        _ = try await sendRequest(method: "ui/resource-teardown", params: [:])
+    public func sendResourceTeardown(timeout: TimeInterval = 5) async throws -> McpUiResourceTeardownResult {
+        _ = try await sendRequest(method: "ui/resource-teardown", params: [:], timeout: timeout)
         return McpUiResourceTeardownResult()
     }
 
@@ -242,29 +242,40 @@ public actor AppBridge {
         try await transport?.send(.notification(JSONRPCNotification(method: method, params: params)))
     }
 
-    private func sendRequest(method: String, params: [String: AnyCodable]?) async throws -> AnyCodable {
+    private func sendRequest(method: String, params: [String: AnyCodable]?, timeout: TimeInterval = 30) async throws -> AnyCodable {
         let id = JSONRPCId.number(nextRequestId)
         nextRequestId += 1
         let request = JSONRPCRequest(id: id, method: method, params: params)
 
-        guard transport != nil else {
-            print("[AppBridge] sendRequest failed: transport is nil")
+        guard let transport = transport else {
             throw BridgeError.disconnected
         }
 
-        return try await withCheckedThrowingContinuation { continuation in
+        // Create the continuation and store it
+        let result: AnyCodable = try await withCheckedThrowingContinuation { continuation in
             pendingRequests[id] = continuation
+
+            // Start timeout task
+            Task {
+                try? await Task.sleep(nanoseconds: UInt64(timeout * 1_000_000_000))
+                // If still pending after timeout, fail it
+                await self.failPendingRequest(id: id, error: BridgeError.timeout)
+            }
+
+            // Send the request
             Task {
                 do {
-                    print("[AppBridge] Sending request: \(method)")
-                    try await transport?.send(.request(request))
-                    print("[AppBridge] Request sent successfully, waiting for response...")
+                    try await transport.send(.request(request))
                 } catch {
-                    print("[AppBridge] Transport send failed: \(error)")
-                    pendingRequests.removeValue(forKey: id)?.resume(throwing: error)
+                    await self.failPendingRequest(id: id, error: error)
                 }
             }
         }
+        return result
+    }
+
+    private func failPendingRequest(id: JSONRPCId, error: Error) {
+        pendingRequests.removeValue(forKey: id)?.resume(throwing: error)
     }
 }