fix"

Author: nytian

src/InProcessTestHost/Sidecar/Dispatcher/WorkItemDispatcher.cs

@@ -308,6 +308,12 @@ async Task ExecuteWorkItem(T workItem)
             // Execute the work item and wait for it to complete
             await this.ExecuteWorkItemAsync(workItem);
         }
+        catch (OperationCanceledException)
+        {
+            // OperationCanceledException indicates the client has disconnected or the operation was canceled.
+            // This is expected during shutdown or when tests are tearing down.
+            await this.AbandonWorkItemAsync(workItem);
+        }
         catch (Exception ex)
         {
             this.log.DispatchWorkItemFailure(

src/InProcessTestHost/Sidecar/Grpc/TaskHubGrpcServer.cs

@@ -834,15 +834,20 @@ await this.SendWorkItemToClientAsync(new P.WorkItem
 
     async Task SendWorkItemToClientAsync(P.WorkItem workItem)
     {
-        IServerStreamWriter<P.WorkItem> outputStream;
+        IServerStreamWriter<P.WorkItem>? outputStream;
 
         // Use a lock to mitigate the race condition where we signal the dispatch host to start but haven't
         // yet saved a reference to the client response stream.
         lock (this.isConnectedSignal)
         {
-            outputStream = this.workerToClientStream ??
-                // CA2201: Use specific exception types
-                throw new InvalidOperationException("TODO: No client is connected! Need to wait until a client connects before executing!");
+            outputStream = this.workerToClientStream;
+        }
+
+        // If no client is connected, throw OperationCanceledException so the dispatcher handles this gracefully.
+        // This can happen during test teardown or when a client disconnects unexpectedly.
+        if (outputStream == null)
+        {
+            throw new OperationCanceledException("No client is connected. The client may have disconnected.");
         }
 
         // The gRPC channel can only handle one message at a time, so we need to serialize access to it.