test: 补充单元测试提高覆盖率

Author: ArgoZhang

test/UnitTest/Services/TcpSocketFactoryTest.cs

@@ -7,6 +7,7 @@
 using System.Net;
 using System.Net.Sockets;
 using System.Reflection;
+using System.Text;
 
 namespace UnitTest.Services;
 
@@ -161,6 +162,9 @@ public async Task SendAsync_Cancel()
         var result = await client.SendAsync("test", null, cst.Token);
         Assert.False(result);
 
+        result = await client.SendAsync("test", Encoding.UTF8, cst.Token);
+        Assert.False(result);
+
         // 关闭连接
         StopTcpServer(server);
     }