refactor: extract NATS.Server.Monitoring.Tests project

Move 39 monitoring, events, and system endpoint test files from
NATS.Server.Tests into a dedicated NATS.Server.Monitoring.Tests project.
Update namespaces, replace private GetFreePort/ReadUntilAsync with
TestUtilities shared helpers, add InternalsVisibleTo, and register
in the solution file. All 439 tests pass.

NatsDotNet.slnx

@@ -12,6 +12,7 @@
     <Project Path="tests/NATS.Server.LeafNodes.Tests/NATS.Server.LeafNodes.Tests.csproj" />
     <Project Path="tests/NATS.Server.Clustering.Tests/NATS.Server.Clustering.Tests.csproj" />
     <Project Path="tests/NATS.Server.Raft.Tests/NATS.Server.Raft.Tests.csproj" />
+    <Project Path="tests/NATS.Server.Monitoring.Tests/NATS.Server.Monitoring.Tests.csproj" />
     <Project Path="tests/NATS.E2E.Tests/NATS.E2E.Tests.csproj" />
   </Folder>
 </Solution>

src/NATS.Server/NATS.Server.csproj

@@ -7,6 +7,7 @@
     <InternalsVisibleTo Include="NATS.Server.LeafNodes.Tests" />
     <InternalsVisibleTo Include="NATS.Server.Clustering.Tests" />
     <InternalsVisibleTo Include="NATS.Server.Raft.Tests" />
+    <InternalsVisibleTo Include="NATS.Server.Monitoring.Tests" />
   </ItemGroup>
   <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />

tests/NATS.Server.Monitoring.Tests/EventSystemTests.cs

@@ -1,8 +1,9 @@
 using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Events;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class EventSystemTests
 {
@@ -105,17 +106,8 @@ public class EventSystemTests
 
     private static NatsServer CreateTestServer()
     {
-        var port = GetFreePort();
+        var port = TestPortAllocator.GetFreePort();
         return new NatsServer(new NatsOptions { Port = port }, NullLoggerFactory.Instance);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new System.Net.Sockets.Socket(
-            System.Net.Sockets.AddressFamily.InterNetwork,
-            System.Net.Sockets.SocketType.Stream,
-            System.Net.Sockets.ProtocolType.Tcp);
-        sock.Bind(new System.Net.IPEndPoint(System.Net.IPAddress.Loopback, 0));
-        return ((System.Net.IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Events/AuthErrorEventTests.cs

@@ -9,8 +9,9 @@ using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server;
 using NATS.Server.Events;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests for <see cref="InternalEventSystem.SendAuthErrorEvent"/>,
@@ -27,7 +28,7 @@ public class AuthErrorEventTests : IAsyncLifetime
 
     public async Task InitializeAsync()
     {
-        _port = GetFreePort();
+        _port = TestPortAllocator.GetFreePort();
         _server = new NatsServer(new NatsOptions { Port = _port }, NullLoggerFactory.Instance);
         _ = _server.StartAsync(CancellationToken.None);
         await _server.WaitForReadyAsync();
@@ -39,15 +40,6 @@ public class AuthErrorEventTests : IAsyncLifetime
         _server.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new System.Net.Sockets.Socket(
-            System.Net.Sockets.AddressFamily.InterNetwork,
-            System.Net.Sockets.SocketType.Stream,
-            System.Net.Sockets.ProtocolType.Tcp);
-        sock.Bind(new System.Net.IPEndPoint(System.Net.IPAddress.Loopback, 0));
-        return ((System.Net.IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 
     // ========================================================================
     // AuthErrorEventCount

tests/NATS.Server.Monitoring.Tests/Events/EventApiAndSubjectsParityBatch2Tests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 public class EventApiAndSubjectsParityBatch2Tests
 {

tests/NATS.Server.Monitoring.Tests/Events/EventCompressionTests.cs

@@ -4,7 +4,7 @@
 using System.Text;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests for <see cref="EventCompressor"/> — S2/Snappy compression for system event payloads.

tests/NATS.Server.Monitoring.Tests/Events/EventGoParityTests.cs

@@ -9,7 +9,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Parity tests ported from Go server/events_test.go exercising
@@ -278,7 +278,7 @@ public class EventGoParityTests
         var data = new ServerStatsData
         {
             SlowConsumers = 10,
-            SlowConsumerStats = new SlowConsumersStats
+            SlowConsumerStats = new NATS.Server.Events.SlowConsumersStats
             {
                 Clients = 5,
                 Routes = 2,
@@ -302,7 +302,7 @@ public class EventGoParityTests
         var data = new ServerStatsData
         {
             StaleConnections = 7,
-            StaleConnectionStats = new StaleConnectionStats
+            StaleConnectionStats = new NATS.Server.Events.StaleConnectionStats
             {
                 Clients = 3,
                 Routes = 1,

tests/NATS.Server.Monitoring.Tests/Events/EventPayloadTests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests that all event DTOs have complete JSON fields matching Go's output.
@@ -292,9 +292,9 @@ public class EventPayloadTests
                 InBytes = 40_000,
                 OutBytes = 50_000,
                 SlowConsumers = 2,
-                SlowConsumerStats = new SlowConsumersStats { Clients = 1, Routes = 1 },
+                SlowConsumerStats = new NATS.Server.Events.SlowConsumersStats { Clients = 1, Routes = 1 },
                 StaleConnections = 3,
-                StaleConnectionStats = new StaleConnectionStats { Clients = 2, Leafs = 1 },
+                StaleConnectionStats = new NATS.Server.Events.StaleConnectionStats { Clients = 2, Leafs = 1 },
                 ActiveServers = 3,
                 Routes = [new RouteStat { Id = 1, Name = "r1", Sent = new DataStats { Msgs = 10 }, Received = new DataStats { Msgs = 5 }, Pending = 0 }],
                 Gateways = [new GatewayStat { Id = 1, Name = "gw1", Sent = new DataStats { Msgs = 20 }, Received = new DataStats { Msgs = 15 }, InboundConnections = 2 }],

tests/NATS.Server.Monitoring.Tests/Events/EventServerInfoCapabilityParityBatch1Tests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 public class EventServerInfoCapabilityParityBatch1Tests
 {

tests/NATS.Server.Monitoring.Tests/Events/FullEventPayloadTests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests that EventBuilder produces fully-populated system event messages

tests/NATS.Server.Monitoring.Tests/Events/OcspEventTests.cs

@@ -8,7 +8,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests for <see cref="OcspPeerRejectEventMsg"/>, <see cref="OcspChainValidationEvent"/>,

tests/NATS.Server.Monitoring.Tests/Events/RemoteServerEventTests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Events;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests for remote server and leaf node event DTOs and subject constants.

tests/NATS.Server.Monitoring.Tests/Events/ServerEventTests.cs

@@ -5,8 +5,9 @@ using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server;
 using NATS.Server.Auth;
 using NATS.Server.Events;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Events;
+namespace NATS.Server.Monitoring.Tests.Events;
 
 /// <summary>
 /// Tests for server lifecycle events, stats tracking, advisory messages, and
@@ -21,7 +22,7 @@ public class ServerEventTests : IAsyncLifetime
 
     public ServerEventTests()
     {
-        _port = GetFreePort();
+        _port = TestPortAllocator.GetFreePort();
         _server = new NatsServer(new NatsOptions { Port = _port }, NullLoggerFactory.Instance);
     }
 
@@ -37,12 +38,6 @@ public class ServerEventTests : IAsyncLifetime
         _server.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 
     private async Task<Socket> ConnectAndHandshakeAsync()
     {
@@ -54,24 +49,10 @@ public class ServerEventTests : IAsyncLifetime
         // Send CONNECT + PING
         await sock.SendAsync(Encoding.ASCII.GetBytes("CONNECT {}\r\nPING\r\n"));
         // Read PONG (may include -ERR or other lines)
-        await ReadUntilAsync(sock, "PONG");
+        await SocketTestHelper.ReadUntilAsync(sock, "PONG");
         return sock;
     }
 
-    private static async Task<string> ReadUntilAsync(Socket sock, string expected, int timeoutMs = 5000)
-    {
-        using var cts = new CancellationTokenSource(timeoutMs);
-        var sb = new StringBuilder();
-        var buf = new byte[4096];
-        while (!sb.ToString().Contains(expected))
-        {
-            var n = await sock.ReceiveAsync(buf, SocketFlags.None, cts.Token);
-            if (n == 0) break;
-            sb.Append(Encoding.ASCII.GetString(buf, 0, n));
-        }
-        return sb.ToString();
-    }
-
     // -----------------------------------------------------------------------
     // Server lifecycle events
     // -----------------------------------------------------------------------
@@ -182,7 +163,7 @@ public class ServerEventTests : IAsyncLifetime
         await sock.SendAsync(pub);
         // Flush via PING/PONG
         await sock.SendAsync(Encoding.ASCII.GetBytes("PING\r\n"));
-        await ReadUntilAsync(sock, "PONG");
+        await SocketTestHelper.ReadUntilAsync(sock, "PONG");
 
         var afterMsgs = Interlocked.Read(ref _server.Stats.InMsgs);
         var afterBytes = Interlocked.Read(ref _server.Stats.InBytes);
@@ -203,17 +184,17 @@ public class ServerEventTests : IAsyncLifetime
 
         // Subscribe
         await sub.SendAsync(Encoding.ASCII.GetBytes("SUB test.out 1\r\nPING\r\n"));
-        await ReadUntilAsync(sub, "PONG");
+        await SocketTestHelper.ReadUntilAsync(sub, "PONG");
 
         var beforeOut = Interlocked.Read(ref _server.Stats.OutMsgs);
 
         var payload = "World"u8.ToArray();
         await pub.SendAsync(Encoding.ASCII.GetBytes($"PUB test.out {payload.Length}\r\nWorld\r\n"));
         await pub.SendAsync(Encoding.ASCII.GetBytes("PING\r\n"));
-        await ReadUntilAsync(pub, "PONG");
+        await SocketTestHelper.ReadUntilAsync(pub, "PONG");
 
         // Give delivery loop time to flush
-        await ReadUntilAsync(sub, "World", timeoutMs: 2000);
+        await SocketTestHelper.ReadUntilAsync(sub, "World", timeoutMs: 2000);
 
         var afterOut = Interlocked.Read(ref _server.Stats.OutMsgs);
         (afterOut - beforeOut).ShouldBeGreaterThanOrEqualTo(1L);

tests/NATS.Server.Monitoring.Tests/JszMonitorTests.cs

@@ -5,8 +5,9 @@ using System.Text;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Configuration;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class JszMonitorTests
 {
@@ -36,8 +37,8 @@ internal sealed class JetStreamMonitoringFixture : IAsyncDisposable
 
     public static async Task<JetStreamMonitoringFixture> StartWithStreamAndConsumerAsync()
     {
-        var natsPort = GetFreePort();
+        var natsPort = TestPortAllocator.GetFreePort();
-        var monitorPort = GetFreePort();
+        var monitorPort = TestPortAllocator.GetFreePort();
         var options = new NatsOptions
         {
             Host = "127.0.0.1",
@@ -103,10 +104,4 @@ internal sealed class JetStreamMonitoringFixture : IAsyncDisposable
         throw new TimeoutException("Monitoring endpoint did not become healthy.");
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new System.Net.IPEndPoint(System.Net.IPAddress.Loopback, 0));
-        return ((System.Net.IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/MonitorClusterEndpointTests.cs

@@ -2,8 +2,9 @@ using System.Net;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Configuration;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class MonitorClusterEndpointTests
 {
@@ -35,7 +36,7 @@ internal sealed class MonitorFixture : IAsyncDisposable
 
     public static async Task<MonitorFixture> StartClusterEnabledAsync()
     {
-        var monitorPort = GetFreePort();
+        var monitorPort = TestPortAllocator.GetFreePort();
         var options = new NatsOptions
         {
             Host = "127.0.0.1",
@@ -96,10 +97,4 @@ internal sealed class MonitorFixture : IAsyncDisposable
         _cts.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)socket.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/MonitorModelTests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class MonitorModelTests
 {

tests/NATS.Server.Monitoring.Tests/MonitorTests.cs

@@ -7,7 +7,7 @@ using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
 using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class MonitorTests : IAsyncLifetime
 {
@@ -19,8 +19,8 @@ public class MonitorTests : IAsyncLifetime
 
     public MonitorTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -289,12 +289,6 @@ public class MonitorTests : IAsyncLifetime
         varz.Mqtt.MaxAckPending.ShouldBe((ushort)0);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }
 
 public class MonitorTlsTests : IAsyncLifetime
@@ -309,8 +303,8 @@ public class MonitorTlsTests : IAsyncLifetime
 
     public MonitorTlsTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         (_certPath, _keyPath) = TestCertHelper.GenerateTestCertFiles();
         _server = new NatsServer(
             new NatsOptions
@@ -375,10 +369,4 @@ public class MonitorTlsTests : IAsyncLifetime
         conn.TlsCipherSuite.ShouldNotBeNullOrEmpty();
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/ClosedConnectionRingBufferTests.cs

@@ -4,7 +4,7 @@
 
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 public class ClosedConnectionRingBufferTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/ClosedReasonTests.cs

@@ -5,7 +5,7 @@
 
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 public class ClosedReasonTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzAccountFilterTests.cs

@@ -1,6 +1,6 @@
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Unit tests for account-scoped /connz filtering (Gap 10.2).

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzFilterTests.cs

@@ -6,8 +6,9 @@ using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server;
 using NATS.Server.Auth;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests for ConnzHandler filtering, sorting, pagination, and closed connection
@@ -26,7 +27,7 @@ public class ConnzFilterTests : IAsyncLifetime
     {
         _opts = new NatsOptions
         {
-            Port = GetFreePort(),
+            Port = TestPortAllocator.GetFreePort(),
             MaxClosedClients = 100,
             Users =
             [
@@ -54,12 +55,6 @@ public class ConnzFilterTests : IAsyncLifetime
         _server.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 
     private async Task<Socket> ConnectAsync(string user, string? subjectToSubscribe = null)
     {
@@ -79,7 +74,7 @@ public class ConnzFilterTests : IAsyncLifetime
         }
 
         await sock.SendAsync("PING\r\n"u8.ToArray());
-        await ReadUntilAsync(sock, "PONG");
+        await SocketTestHelper.ReadUntilAsync(sock, "PONG");
         return sock;
     }
 
@@ -395,26 +390,4 @@ public class ConnzFilterTests : IAsyncLifetime
         single.Conns[0].Stop.ShouldNotBeNull();
     }
 
-    private static async Task ReadUntilAsync(Socket sock, string expected)
-    {
-        var buf = new byte[4096];
-        var all = new StringBuilder();
-        var deadline = DateTime.UtcNow.AddSeconds(5);
-        while (DateTime.UtcNow < deadline)
-        {
-            if (sock.Available > 0)
-            {
-                var n = await sock.ReceiveAsync(buf, SocketFlags.None);
-                all.Append(Encoding.ASCII.GetString(buf, 0, n));
-                if (all.ToString().Contains(expected))
-                    return;
-            }
-            else
-            {
-                await Task.Delay(10);
-            }
-        }
-
-        throw new TimeoutException($"Did not receive '{expected}' within 5 seconds. Got: {all}");
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzParityFieldTests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using System.Text;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class ConnzParityFieldTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzParityFilterTests.cs

@@ -6,7 +6,7 @@ using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Auth;
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class ConnzParityFilterTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzParityTests.cs

@@ -7,8 +7,9 @@ using System.Net.Http.Json;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class ConnzParityTests : IAsyncLifetime
 {
@@ -20,8 +21,8 @@ public class ConnzParityTests : IAsyncLifetime
 
     public ConnzParityTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -167,10 +168,4 @@ public class ConnzParityTests : IAsyncLifetime
         }
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/ConnzSortTests.cs

@@ -1,6 +1,6 @@
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Unit tests for ConnzSortOption enum, ConnzSorter.Parse, and ConnzSorter.Sort.

tests/NATS.Server.Monitoring.Tests/Monitoring/HealthzParityTests.cs

@@ -4,8 +4,9 @@
 using System.Net;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class HealthzParityTests : IAsyncLifetime
 {
@@ -16,7 +17,7 @@ public class HealthzParityTests : IAsyncLifetime
 
     public HealthzParityTests()
     {
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = 0, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -73,10 +74,4 @@ public class HealthzParityTests : IAsyncLifetime
         body.ShouldContain("ok");
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorConnzTests.cs

@@ -26,8 +26,9 @@ using System.Net.Http.Json;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests covering /connz endpoint behavior, ported from the Go server's monitor_test.go.
@@ -42,8 +43,8 @@ public class MonitorConnzTests : IAsyncLifetime
 
     public MonitorConnzTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -816,10 +817,4 @@ public class MonitorConnzTests : IAsyncLifetime
         return sock;
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorGoParityTests.cs

@@ -10,8 +10,9 @@ using System.Net.Sockets;
 using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Parity tests ported from Go server/monitor_test.go exercising /connz
@@ -474,8 +475,8 @@ public class MonitorGoParityEndpointTests : IAsyncLifetime
 
     public MonitorGoParityEndpointTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -1808,10 +1809,4 @@ public class MonitorGoParityEndpointTests : IAsyncLifetime
         }
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorRoutezTests.cs

@@ -11,8 +11,9 @@ using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Configuration;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests covering /routez endpoint behavior, ported from the Go server's monitor_test.go.
@@ -184,7 +185,7 @@ internal sealed class RoutezFixture : IAsyncDisposable
 
     public static async Task<RoutezFixture> StartAsync()
     {
-        var monitorPort = GetFreePort();
+        var monitorPort = TestPortAllocator.GetFreePort();
         var options = new NatsOptions
         {
             Host = "127.0.0.1",
@@ -197,7 +198,7 @@ internal sealed class RoutezFixture : IAsyncDisposable
 
     public static async Task<RoutezFixture> StartWithClusterAsync()
     {
-        var monitorPort = GetFreePort();
+        var monitorPort = TestPortAllocator.GetFreePort();
         var options = new NatsOptions
         {
             Host = "127.0.0.1",
@@ -259,10 +260,4 @@ internal sealed class RoutezFixture : IAsyncDisposable
         _cts.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)socket.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorStackszTests.cs

@@ -11,8 +11,9 @@ using System.Net.Sockets;
 using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests covering miscellaneous monitoring endpoints: root, accountz, accstatz,
@@ -29,8 +30,8 @@ public class MonitorStackszTests : IAsyncLifetime
 
     public MonitorStackszTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -346,10 +347,4 @@ public class MonitorStackszTests : IAsyncLifetime
         body.ShouldContain("leafs");
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorSubszTests.cs

@@ -11,8 +11,9 @@ using System.Net.Sockets;
 using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests covering /subz (subscriptionsz) endpoint behavior,
@@ -28,8 +29,8 @@ public class MonitorSubszTests : IAsyncLifetime
 
     public MonitorSubszTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -350,10 +351,4 @@ public class MonitorSubszTests : IAsyncLifetime
         return sock;
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitorVarzTests.cs

@@ -14,8 +14,9 @@ using System.Net.Sockets;
 using System.Text.Json;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 /// <summary>
 /// Tests covering /varz endpoint behavior, ported from the Go server's monitor_test.go.
@@ -30,8 +31,8 @@ public class MonitorVarzTests : IAsyncLifetime
 
     public MonitorVarzTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -467,7 +468,7 @@ public class MonitorVarzTests : IAsyncLifetime
     [Fact]
     public async Task Monitor_not_accessible_when_port_not_configured()
     {
-        var natsPort = GetFreePort();
+        var natsPort = TestPortAllocator.GetFreePort();
         var server = new NatsServer(
             new NatsOptions { Port = natsPort, MonitorPort = 0 },
             NullLoggerFactory.Instance);
@@ -517,10 +518,4 @@ public class MonitorVarzTests : IAsyncLifetime
         return $"{(int)ts.TotalSeconds}s";
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/MonitoringHealthAndSortParityBatch1Tests.cs

@@ -1,7 +1,7 @@
 using System.Text.Json;
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 public class MonitoringHealthAndSortParityBatch1Tests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/PprofEndpointTests.cs

@@ -1,8 +1,9 @@
 using System.Net;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class PprofEndpointTests
 {
@@ -32,7 +33,7 @@ internal sealed class PprofMonitorFixture : IAsyncDisposable
 
     public static async Task<PprofMonitorFixture> StartWithProfilingAsync()
     {
-        var monitorPort = GetFreePort();
+        var monitorPort = TestPortAllocator.GetFreePort();
         var options = new NatsOptions
         {
             Host = "127.0.0.1",
@@ -83,10 +84,4 @@ internal sealed class PprofMonitorFixture : IAsyncDisposable
         _cts.Dispose();
     }
 
-    private static int GetFreePort()
-    {
-        using var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        socket.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)socket.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/PprofRuntimeParityTests.cs

@@ -1,6 +1,6 @@
 using System.Text.Json;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 public class PprofRuntimeParityTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/TlsPeerCertParityTests.cs

@@ -3,7 +3,7 @@ using System.Security.Cryptography.X509Certificates;
 using System.Text.Json;
 using NATS.Server.Monitoring;
 
-namespace NATS.Server.Tests.Monitoring;
+namespace NATS.Server.Monitoring.Tests.Monitoring;
 
 public class TlsPeerCertParityTests
 {

tests/NATS.Server.Monitoring.Tests/Monitoring/VarzParityTests.cs

@@ -6,8 +6,9 @@ using System.Net.Http.Json;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class VarzParityTests : IAsyncLifetime
 {
@@ -19,8 +20,8 @@ public class VarzParityTests : IAsyncLifetime
 
     public VarzParityTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -128,10 +129,4 @@ public class VarzParityTests : IAsyncLifetime
         varz.InBytes.ShouldBeGreaterThanOrEqualTo(5L);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/Monitoring/VarzSlowConsumerBreakdownTests.cs

@@ -1,4 +1,4 @@
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class VarzSlowConsumerBreakdownTests
 {

tests/NATS.Server.Monitoring.Tests/NATS.Server.Monitoring.Tests.csproj

@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NATS.Client.Core" />
+    <PackageReference Include="NSubstitute" />
+    <PackageReference Include="Shouldly" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+    <Using Include="Shouldly" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\NATS.Server\NATS.Server.csproj" />
+    <ProjectReference Include="..\NATS.Server.TestUtilities\NATS.Server.TestUtilities.csproj" />
+  </ItemGroup>
+
+</Project>

tests/NATS.Server.Monitoring.Tests/SubszTests.cs

@@ -3,8 +3,9 @@ using System.Net.Http.Json;
 using System.Net.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;
 using NATS.Server.Monitoring;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class SubszTests : IAsyncLifetime
 {
@@ -16,8 +17,8 @@ public class SubszTests : IAsyncLifetime
 
     public SubszTests()
     {
-        _natsPort = GetFreePort();
+        _natsPort = TestPortAllocator.GetFreePort();
-        _monitorPort = GetFreePort();
+        _monitorPort = TestPortAllocator.GetFreePort();
         _server = new NatsServer(
             new NatsOptions { Port = _natsPort, MonitorPort = _monitorPort },
             NullLoggerFactory.Instance);
@@ -128,10 +129,4 @@ public class SubszTests : IAsyncLifetime
         subz.Total.ShouldBeGreaterThanOrEqualTo(3);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        sock.Bind(new IPEndPoint(IPAddress.Loopback, 0));
-        return ((IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/SystemEventsTests.cs

@@ -2,8 +2,9 @@ using System.Text.Json;
 using NATS.Server;
 using NATS.Server.Events;
 using Microsoft.Extensions.Logging.Abstractions;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class SystemEventsTests
 {
@@ -117,17 +118,8 @@ public class SystemEventsTests
 
     private static NatsServer CreateTestServer()
     {
-        var port = GetFreePort();
+        var port = TestPortAllocator.GetFreePort();
         return new NatsServer(new NatsOptions { Port = port }, NullLoggerFactory.Instance);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new System.Net.Sockets.Socket(
-            System.Net.Sockets.AddressFamily.InterNetwork,
-            System.Net.Sockets.SocketType.Stream,
-            System.Net.Sockets.ProtocolType.Tcp);
-        sock.Bind(new System.Net.IPEndPoint(System.Net.IPAddress.Loopback, 0));
-        return ((System.Net.IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }

tests/NATS.Server.Monitoring.Tests/SystemRequestReplyTests.cs

@@ -3,8 +3,9 @@ using System.Text.Json;
 using NATS.Server;
 using NATS.Server.Events;
 using Microsoft.Extensions.Logging.Abstractions;
+using NATS.Server.TestUtilities;
 
-namespace NATS.Server.Tests;
+namespace NATS.Server.Monitoring.Tests;
 
 public class SystemRequestReplyTests
 {
@@ -154,17 +155,8 @@ public class SystemRequestReplyTests
 
     private static NatsServer CreateTestServer()
     {
-        var port = GetFreePort();
+        var port = TestPortAllocator.GetFreePort();
         return new NatsServer(new NatsOptions { Port = port }, NullLoggerFactory.Instance);
     }
 
-    private static int GetFreePort()
-    {
-        using var sock = new System.Net.Sockets.Socket(
-            System.Net.Sockets.AddressFamily.InterNetwork,
-            System.Net.Sockets.SocketType.Stream,
-            System.Net.Sockets.ProtocolType.Tcp);
-        sock.Bind(new System.Net.IPEndPoint(System.Net.IPAddress.Loopback, 0));
-        return ((System.Net.IPEndPoint)sock.LocalEndPoint!).Port;
-    }
 }