Logging (#11)

* Logging
Fixed bug in stdio transport argument promotion

* Logging
Fixed bug in stdio transport argument promotion

* Version bump

src/mcpdotnet/Utils/Json/JsonRpcMessageConverter.cs

@@ -1,6 +1,8 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 using McpDotNet.Protocol.Messages;
+using Microsoft.Extensions.Logging;
+using McpDotNet.Logging;
 
 namespace McpDotNet.Utils.Json;
 
@@ -9,11 +11,19 @@ namespace McpDotNet.Utils.Json;
 /// </summary>
 internal class JsonRpcMessageConverter : JsonConverter<IJsonRpcMessage>
 {
+    private readonly ILogger<JsonRpcMessageConverter> _logger;
+
+    public JsonRpcMessageConverter(ILogger<JsonRpcMessageConverter> logger)
+    {
+        _logger = logger;
+    }
+
     /// <inheritdoc/>
     public override IJsonRpcMessage? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
     {
         if (reader.TokenType != JsonTokenType.StartObject)
         {
+            _logger.JsonRpcMessageConverterExpectedStartObjectToken();
             throw new JsonException("Expected StartObject token");
         }
 
@@ -24,6 +34,7 @@ internal class JsonRpcMessageConverter : JsonConverter<IJsonRpcMessage>
         if (!root.TryGetProperty("jsonrpc", out var versionProperty) ||
             versionProperty.GetString() != "2.0")
         {
+            _logger.JsonRpcMessageConverterInvalidJsonRpcVersion();
             throw new JsonException("Invalid or missing jsonrpc version");
         }
 
@@ -40,26 +51,32 @@ internal class JsonRpcMessageConverter : JsonConverter<IJsonRpcMessage>
             // Messages with an error property are error responses
             if (hasError)
             {
+                _logger.JsonRpcMessageConverterDeserializingErrorResponse(rawText);
                 return JsonSerializer.Deserialize<JsonRpcError>(rawText, options);
             }
             // Messages with a result property are success responses
             else if (root.TryGetProperty("result", out _))
             {
+                _logger.JsonRpcMessageConverterDeserializingResponse(rawText);
                 return JsonSerializer.Deserialize<JsonRpcResponse>(rawText, options);
             }
+            _logger.JsonRpcMessageConverterResponseMustHaveResultOrError(rawText);
             throw new JsonException("Response must have either result or error");
         }
         // Messages with a method but no id are notifications
         else if (hasMethod && !hasId)
         {
+            _logger.JsonRpcMessageConverterDeserializingNotification(rawText);
             return JsonSerializer.Deserialize<JsonRpcNotification>(rawText, options);
         }
         // Messages with both method and id are requests
         else if (hasMethod && hasId)
         {
+            _logger.JsonRpcMessageConverterDeserializingRequest(rawText);
             return JsonSerializer.Deserialize<JsonRpcRequest>(rawText, options);
         }
 
+        _logger.JsonRpcMessageConverterInvalidMessageFormat(rawText);
         throw new JsonException("Invalid JSON-RPC message format");
     }
 
@@ -81,6 +98,7 @@ internal class JsonRpcMessageConverter : JsonConverter<IJsonRpcMessage>
                 JsonSerializer.Serialize(writer, error, options);
                 break;
             default:
+                _logger.JsonRpcMessageConverterWriteUnknownMessageType(value.GetType().ToString());
                 throw new JsonException($"Unknown JSON-RPC message type: {value.GetType()}");
         }
     }

src/mcpdotnet/Utils/Json/JsonSerializerOptionsExtensions.cs

@@ -1,4 +1,5 @@
-using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace McpDotNet.Utils.Json;
@@ -11,11 +12,12 @@ internal static class JsonSerializerOptionsExtensions
     /// Configures JsonSerializerOptions with MCP-specific settings and converters.
     /// </summary>
     /// <param name="options">The options to configure.</param>
+    /// <param name="loggerFactory">The logger factory to use for logging.</param>
     /// <returns>The configured options.</returns>
-    public static JsonSerializerOptions ConfigureForMcp(this JsonSerializerOptions options)
+    public static JsonSerializerOptions ConfigureForMcp(this JsonSerializerOptions options, ILoggerFactory loggerFactory)
     {
         // Add custom converters
-        options.Converters.Add(new JsonRpcMessageConverter());
+        options.Converters.Add(new JsonRpcMessageConverter(loggerFactory.CreateLogger<JsonRpcMessageConverter>()));
         options.Converters.Add(new JsonStringEnumConverter());
 
         // Configure general options