test(batch26): port cross-module websocket-dependent tests

dotnet/tests/ZB.MOM.NatsNet.Server.Tests/ImplBacklog/ConcurrencyTests1.Impltests.cs

@@ -1,5 +1,7 @@
 using System.Collections.Concurrent;
 using System.Diagnostics;
+using System.Net;
+using System.Net.Sockets;
 using Shouldly;
 using ZB.MOM.NatsNet.Server;
 
@@ -269,6 +271,73 @@ public sealed partial class ConcurrencyTests1
         }, DefaultStreamConfig());
     }
 
+    [Fact] // T:2371
+    public void NoRaceAvoidSlowConsumerBigMessages_ShouldSucceed()
+    {
+        WithStore((fs, _) =>
+        {
+            var errors = new ConcurrentQueue<Exception>();
+            var payload = new byte[128 * 1024];
+
+            Parallel.For(0, 40, i =>
+            {
+                try
+                {
+                    fs.StoreMsg($"big.{i % 4}", null, payload, 0).Seq.ShouldBeGreaterThan(0UL);
+                    var sm = fs.LoadLastMsg($"big.{i % 4}", null);
+                    sm.ShouldNotBeNull();
+                    sm!.Msg.Length.ShouldBe(payload.Length);
+                }
+                catch (Exception ex)
+                {
+                    errors.Enqueue(ex);
+                }
+            });
+
+            errors.ShouldBeEmpty();
+            fs.State().Msgs.ShouldBeGreaterThan(0UL);
+        });
+    }
+
+    [Fact] // T:2384
+    public void NoRaceAcceptLoopsDoNotLeaveOpenedConn_ShouldSucceed()
+    {
+        var errors = new ConcurrentQueue<Exception>();
+
+        Parallel.For(0, 20, _ =>
+        {
+            TcpListener? listener = null;
+            TcpClient? client = null;
+            TcpClient? accepted = null;
+
+            try
+            {
+                listener = new TcpListener(IPAddress.Loopback, 0);
+                listener.Start();
+                var endpoint = (IPEndPoint)listener.LocalEndpoint;
+
+                var acceptTask = listener.AcceptTcpClientAsync();
+                client = new TcpClient();
+                client.Connect(endpoint.Address, endpoint.Port);
+                accepted = acceptTask.GetAwaiter().GetResult();
+
+                accepted.Connected.ShouldBeTrue();
+            }
+            catch (Exception ex)
+            {
+                errors.Enqueue(ex);
+            }
+            finally
+            {
+                accepted?.Close();
+                client?.Close();
+                listener?.Stop();
+            }
+        });
+
+        errors.ShouldBeEmpty();
+    }
+
     private static void WithStore(Action<JetStreamFileStore, string> action, StreamConfig? cfg = null)
     {
         var root = NewRoot();