From 69e974dbb56de99032df255bf7bf468bf2fbfb7b Mon Sep 17 00:00:00 2001 From: King Star Date: Thu, 4 Jun 2026 23:37:12 +0800 Subject: [PATCH] fix: ignore empty streamable http responses --- .../StreamableHttpClientSessionTransport.cs | 5 ++- .../Transport/HttpClientTransportTests.cs | 36 ++++++++++++++++++- 2 files changed, 39 insertions(+), 2 deletions(-) diff --git a/src/ModelContextProtocol.Core/Client/StreamableHttpClientSessionTransport.cs b/src/ModelContextProtocol.Core/Client/StreamableHttpClientSessionTransport.cs index 2cebccb3b..134a33a80 100644 --- a/src/ModelContextProtocol.Core/Client/StreamableHttpClientSessionTransport.cs +++ b/src/ModelContextProtocol.Core/Client/StreamableHttpClientSessionTransport.cs @@ -115,7 +115,10 @@ internal async Task SendHttpRequestAsync(JsonRpcMessage mes if (response.Content.Headers.ContentType?.MediaType == "application/json") { var responseContent = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false); - rpcResponseOrError = await ProcessMessageAsync(responseContent, rpcRequest, cancellationToken).ConfigureAwait(false); + if (responseContent.Length > 0) + { + rpcResponseOrError = await ProcessMessageAsync(responseContent, rpcRequest, cancellationToken).ConfigureAwait(false); + } } else if (response.Content.Headers.ContentType?.MediaType == "text/event-stream") { diff --git a/tests/ModelContextProtocol.Tests/Transport/HttpClientTransportTests.cs b/tests/ModelContextProtocol.Tests/Transport/HttpClientTransportTests.cs index 60384d3c2..27e5a2af5 100644 --- a/tests/ModelContextProtocol.Tests/Transport/HttpClientTransportTests.cs +++ b/tests/ModelContextProtocol.Tests/Transport/HttpClientTransportTests.cs @@ -147,6 +147,40 @@ public async Task SendMessageAsync_Handles_Accepted_Response() Assert.True(true); } + [Fact] + public async Task StreamableHttp_NotificationWithEmptyAcceptedJsonResponse_DoesNotLogParseFailure() + { + var options = new HttpClientTransportOptions + { + Endpoint = new Uri("http://localhost:8080/mcp"), + TransportMode = HttpTransportMode.StreamableHttp, + }; + + using var mockHttpHandler = new MockHttpHandler(); + using var httpClient = new HttpClient(mockHttpHandler); + await using var transport = new HttpClientTransport(options, httpClient, LoggerFactory); + + mockHttpHandler.RequestHandler = request => + { + Assert.Equal(HttpMethod.Post, request.Method); + Assert.Equal("http://localhost:8080/mcp", request.RequestUri?.AbsoluteUri); + + return Task.FromResult(new HttpResponseMessage + { + StatusCode = HttpStatusCode.Accepted, + Content = new StringContent("", Encoding.UTF8, "application/json"), + }); + }; + + await using var session = await transport.ConnectAsync(TestContext.Current.CancellationToken); + await session.SendMessageAsync( + new JsonRpcNotification { Method = "notifications/initialized" }, + TestContext.Current.CancellationToken); + + Assert.DoesNotContain(MockLoggerProvider.LogMessages, log => + log.Message.Contains("transport message parsing failed", StringComparison.Ordinal)); + } + [Fact] public async Task SendMessageAsync_Throws_HttpRequestException_With_ResponseBody_On_ErrorStatusCode() { @@ -326,4 +360,4 @@ await session.SendMessageAsync( // Assert - Total GET requests = 1 initial connection + MaxReconnectionAttempts reconnections. Assert.Equal(1 + MaxReconnectionAttempts, getRequestCount); } -} \ No newline at end of file +}