Add debug output to NamedPipeClient and fix test stderr reading

Author: yotsuda

.github/workflows/cross-platform-test.yml

@@ -317,17 +317,22 @@ jobs:
             Get-ChildItem /tmp -Filter "CoreFxPipe_*" -ErrorAction SilentlyContinue | ForEach-Object { Write-Host $_.FullName }
           }
           
+          # Kill process first, then read outputs
           if (-not $bgProcess.HasExited) {
-            Write-Host "=== Available stdout ===" -ForegroundColor Yellow
-            while ($bgProcess.StandardOutput.Peek() -ge 0) {
-              Write-Host ([char]$bgProcess.StandardOutput.Read()) -NoNewline
-            }
-            Write-Host ""
-            # Kill process to allow stderr task to complete
+            Write-Host "Killing background process..."
             $bgProcess.Kill()
             $bgProcess.WaitForExit(5000)
           }
           
+          # Now read stdout (sync, process is dead)
+          Write-Host "=== stdout ===" -ForegroundColor Yellow
+          $stdoutTask = $bgProcess.StandardOutput.ReadToEndAsync()
+          if ($stdoutTask.Wait(3000)) {
+            Write-Host $stdoutTask.Result
+          } else {
+            Write-Host "(stdout read timeout)"
+          }
+          
           # Wait for stderr task and display
           Write-Host "=== stderr (debug output) ===" -ForegroundColor Yellow
           if ($bgStderrTask.Wait(3000)) {

PowerShell.MCP.Proxy/Services/NamedPipeClient.cs

@@ -9,37 +9,50 @@ public class NamedPipeClient
 
     public async Task<string> SendRequestAsync(string arguments)
     {
+        Console.Error.WriteLine($"[DEBUG] NamedPipeClient.SendRequestAsync called");
+        Console.Error.WriteLine($"[DEBUG] Arguments length: {arguments.Length}");
+        
         try
         {
             if (!PowerShellProcessManager.IsPowerShellProcessRunning())
             {
+                Console.Error.WriteLine("[DEBUG] PowerShell process not running");
                 return $"The PowerShell 7 console is not running. Use start_powershell_console tool to start it first.";
             }
 
+            Console.Error.WriteLine($"[DEBUG] Creating NamedPipeClientStream for pipe: {PipeName}");
             using var pipeClient = new NamedPipeClientStream(".", PipeName, PipeDirection.InOut);
 
             // Attempt Named Pipe connection
             try
             {
+                Console.Error.WriteLine("[DEBUG] Connecting to Named Pipe (3s timeout)...");
                 await pipeClient.ConnectAsync(1000 * 3); // 3 second timeout
+                Console.Error.WriteLine("[DEBUG] Connected to Named Pipe successfully");
             }
             catch (TimeoutException)
             {
+                Console.Error.WriteLine("[DEBUG] Named Pipe connection timeout");
                 return $"PowerShell 7 (pwsh) is running but PowerShell.MCP module is not imported.\r\n\r\nMANDATORY STEPS - DO NOT SKIP ANY:\r\n1. Explain the situation to the user\r\n2. Present exactly these two options:\r\n   - Option 1: User imports PowerShell.MCP module manually in current console\r\n   - Option 2: I will automatically start fresh console with PowerShell.MCP imported\r\n3. STOP and wait for explicit user response - DO NOT make any choice for the user\r\n4. ONLY if user explicitly chooses option 2, execute start_powershell_console\r\n5. If user chooses option 1, provide the command: Import-Module PowerShell.MCP\r\n6. DO NOT execute any PowerShell commands until user makes their choice\r\n\r\nCRITICAL: Never assume user preference or execute start_powershell_console without explicit user consent.";
             }
 
             // Convert JSON message to UTF-8 bytes
             var messageBytes = Encoding.UTF8.GetBytes(arguments);
+            Console.Error.WriteLine($"[DEBUG] Message bytes length: {messageBytes.Length}");
 
             // Create 4-byte Little Endian message length
             var lengthBytes = BitConverter.GetBytes(messageBytes.Length);
+            Console.Error.WriteLine($"[DEBUG] Sending length prefix: {messageBytes.Length}");
 
             // Send message length prefix + JSON message body
             await pipeClient.WriteAsync(lengthBytes, 0, lengthBytes.Length);
             await pipeClient.WriteAsync(messageBytes, 0, messageBytes.Length);
+            await pipeClient.FlushAsync();
+            Console.Error.WriteLine("[DEBUG] Message sent, waiting for response...");
 
             // Receive response: proper length prefix handling
             var response = await ReceiveMessageAsync(pipeClient);
+            Console.Error.WriteLine($"[DEBUG] Response received, length: {response.Length}");
             return response;
         }
         catch (TimeoutException)
@@ -49,18 +62,22 @@ public async Task<string> SendRequestAsync(string arguments)
         }
         catch (Exception ex)
         {
-            Console.Error.WriteLine($"[ERROR] Named Pipe communication failed: {ex.Message}");
+            Console.Error.WriteLine($"[ERROR] Named Pipe communication failed: {ex.GetType().Name}: {ex.Message}");
+            Console.Error.WriteLine($"[ERROR] Stack trace: {ex.StackTrace}");
             return string.Empty;
         }
     }
 
     private async Task<string> ReceiveMessageAsync(NamedPipeClientStream pipeClient)
     {
+        Console.Error.WriteLine("[DEBUG] ReceiveMessageAsync: Reading length prefix...");
+        
         // 1. Read message length (4 bytes) reliably
         var lengthBuffer = new byte[4];
         await ReadExactAsync(pipeClient, lengthBuffer, 4);
 
         var messageLength = BitConverter.ToInt32(lengthBuffer, 0);
+        Console.Error.WriteLine($"[DEBUG] ReceiveMessageAsync: Message length = {messageLength}");
 
         // 2. Validate message length
         if (messageLength < 0)
@@ -69,11 +86,14 @@ private async Task<string> ReceiveMessageAsync(NamedPipeClientStream pipeClient)
         }
 
         // 3. Read message body reliably
+        Console.Error.WriteLine($"[DEBUG] ReceiveMessageAsync: Reading message body...");
         var messageBuffer = new byte[messageLength];
         await ReadExactAsync(pipeClient, messageBuffer, messageLength);
 
         // 4. UTF-8 decode
-        return Encoding.UTF8.GetString(messageBuffer);
+        var result = Encoding.UTF8.GetString(messageBuffer);
+        Console.Error.WriteLine($"[DEBUG] ReceiveMessageAsync: Complete");
+        return result;
     }
 
     private async Task ReadExactAsync(NamedPipeClientStream pipeClient, byte[] buffer, int count)