Fix tests after rebase on MRTR: use SendRequestAsync to reach transport-level guards

MRTR (#1458) added a session-level guard in McpSessionHandler.SendMessageAsync that throws InvalidOperationException for any JsonRpcRequest, directing callers to SendRequestAsync. The two tests that exercised the transport's request-handling code paths called server.SendMessageAsync(request, ...) and so were rejected at the session layer before reaching the transport.

Switch them to SendRequestAsync, which bypasses that guard and routes through SendToRelatedTransportAsync to the transport's SendMessageAsync — the actual layer the new diagnostics live on.

For the GET-open warning test, SendRequestAsync awaits a response that the test never produces, so wrap it in a CancellationTokenSource that we cancel after confirming the request landed on the SSE wire.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: halter73

tests/ModelContextProtocol.AspNetCore.Tests/StreamableHttpServerConformanceTests.cs

@@ -419,11 +419,12 @@ public async Task SendNotificationAsync_DoesNotThrow_WhenNoGetRequestHasBeenMade
     }
 
     [Fact]
-    public async Task SendMessageAsync_Throws_OnRequest_WhenNoGetRequestHasBeenMade()
+    public async Task SendRequestAsync_Throws_WhenNoGetRequestHasBeenMade()
     {
         // A server-to-client request sent before any GET SSE stream is opened can never
-        // receive a response, so SendMessageAsync should fail fast with InvalidOperationException
-        // instead of silently dropping the message and leaving the caller hanging.
+        // receive a response, so the transport should fail fast with InvalidOperationException
+        // instead of silently dropping the message and leaving the caller hanging on the TCS
+        // registered by SendRequestAsync.
         McpServer? server = null;
 
         Builder.Services.AddMcpServer()
@@ -450,7 +451,7 @@ public async Task SendMessageAsync_Throws_OnRequest_WhenNoGetRequestHasBeenMade(
         };
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(() =>
-            server.SendMessageAsync(request, TestContext.Current.CancellationToken));
+            server.SendRequestAsync(request, TestContext.Current.CancellationToken));
 
         Assert.Contains("roots/list", ex.Message);
         Assert.Contains("no GET SSE stream", ex.Message);
@@ -502,7 +503,7 @@ public async Task SendMessageAsync_LogsWarning_OnUnexpectedResponse_WhenNoGetReq
     }
 
     [Fact]
-    public async Task SendMessageAsync_LogsWarning_OnRequest_WhenGetRequestIsOpen()
+    public async Task SendRequestAsync_LogsWarning_WhenGetRequestIsOpen()
     {
         // Even when the GET SSE stream is open and the request is delivered, server-to-client
         // requests sent via the GET path are fragile (no per-request correlation, depend on a
@@ -531,13 +532,16 @@ public async Task SendMessageAsync_LogsWarning_OnRequest_WhenGetRequestIsOpen()
         Assert.Equal(HttpStatusCode.OK, getResponse.StatusCode);
 
         // Send a request via the GET stream and assert it lands on the wire (proving behavior is unchanged).
+        // SendRequestAsync awaits a response that the test never produces, so use a CTS to cancel after
+        // confirming wire delivery.
         var request = new JsonRpcRequest
         {
             Method = "roots/list",
             Id = new RequestId(99),
         };
 
-        var sendTask = server.SendMessageAsync(request, TestContext.Current.CancellationToken);
+        using var requestCts = CancellationTokenSource.CreateLinkedTokenSource(TestContext.Current.CancellationToken);
+        var sendTask = server.SendRequestAsync(request, requestCts.Token);
 
         await foreach (var sseEvent in ReadSseAsync(getResponse.Content))
         {
@@ -547,7 +551,9 @@ public async Task SendMessageAsync_LogsWarning_OnRequest_WhenGetRequestIsOpen()
             break;
         }
 
-        await sendTask;
+        // Cancel the awaited response so SendRequestAsync completes — the wire delivery has already happened.
+        requestCts.Cancel();
+        await Assert.ThrowsAnyAsync<OperationCanceledException>(() => sendTask);
 
         Assert.Contains(MockLoggerProvider.LogMessages, log =>
             log.Category == typeof(StreamableHttpServerTransport).FullName &&