Fixed websockets message corruption after cancellation (#7768)

Author: sunghwan2789

src/StrawberryShake/Client/src/Transport.WebSockets/Messaging/SynchronizedMessageWriter.cs

@@ -31,12 +31,12 @@ public async ValueTask CommitAsync(
         Action<SocketMessageWriter> action,
         CancellationToken cancellationToken)
     {
+        await _semaphore
+            .WaitAsync(cancellationToken)
+            .ConfigureAwait(false);
+
         try
         {
-            await _semaphore
-                .WaitAsync(cancellationToken)
-                .ConfigureAwait(false);
-
             _socketMessageWriter.Reset();
             action.Invoke(_socketMessageWriter);
 

src/StrawberryShake/Client/test/Transport.WebSocket.Tests/Messaging/SynchronizedMessageWriterTests.cs

@@ -30,6 +30,14 @@ public async Task WriteObject_EmptyBuffer_ObjectParallel()
         await using var writer = new SynchronizedMessageWriter(socketClient);
 
         // act
+        var canceled = writer.CommitAsync(x =>
+            {
+                x.WriteStartObject();
+                x.WriteEndObject();
+            },
+            new(true));
+        Assert.True(canceled.IsCanceled);
+
         List<Task> tasks = [];
         for (var i = 0; i < 10; i++)
         {