Upgrade to .NET 10, update all dependencies, add xUnit v3 tests, fix bugs

.github/workflows/dotnet.yml

@@ -15,14 +15,21 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup .NET
-      uses: actions/setup-dotnet@v3
+      uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 9.0.x
+        dotnet-version: 10.0.x
+    - name: Write test appsettings
+      env:
+        APPSETTINGS: ${{ secrets.APPSETTINGS }}
+      run: |
+        if [ -n "$APPSETTINGS" ]; then
+          echo "$APPSETTINGS" > HybridConnectionClientProxy.Tests/appsettings.Test.json
+        fi
     - name: Restore dependencies
-      run: dotnet restore
+      run: dotnet restore HybridConnectionClientProxy.slnx
     - name: Build
-      run: dotnet build --no-restore
+      run: dotnet build HybridConnectionClientProxy.slnx --no-restore
     - name: Test
-      run: dotnet test --no-build --verbosity normal
+      run: dotnet test HybridConnectionClientProxy.slnx --no-restore --verbosity normal

HybridConnectionClientProxy.Tests/HybridConnectionClientProxy.Tests.csproj

@@ -0,0 +1,34 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
+    <PackageReference Include="xunit.v3" Version="3.2.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="8.0.1">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\HybridConnectionClientProxy\HybridConnectionClientProxy.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Include="appsettings.Test.json" Condition="Exists('appsettings.Test.json')">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

HybridConnectionClientProxy.Tests/src/AzureIntegrationTests.cs

@@ -0,0 +1,158 @@
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Text.Json;
+
+using Xunit;
+
+namespace HybridConnectionClientProxy.Tests;
+
+/// <summary>
+/// Integration tests that run against a real Azure Hybrid Connection endpoint.
+///
+/// These tests require <c>appsettings.Test.json</c> to be present alongside the test
+/// assembly, containing valid Azure Relay credentials in the same format as
+/// <c>appsettings.json</c>.  When the file is absent (fork PRs, local runs without
+/// credentials) every test is skipped automatically.
+///
+/// The endpoint referenced by the first proxy in the config must have a listener
+/// registered and running for data-flow assertions to pass.
+/// </summary>
+public class AzureIntegrationTests
+{
+	private const int TimeoutMs = 30_000;
+
+	// -------------------------------------------------------------------------
+	// Tests
+	// -------------------------------------------------------------------------
+
+	[Fact]
+	public async Task AzureProxy_WhenClientConnects_ConnectionEstablishedWithoutError()
+	{
+		var connStr = GetConnectionString();
+		if( connStr is null ) Assert.Skip( "No Azure credentials in appsettings.Test.json" );
+
+		using var cts = new CancellationTokenSource( TimeoutMs );
+
+		var provider = new HybridConnectionClientProvider( connStr! );
+		var (proxyListener, proxyPort) = StartListener();
+		var proxyTask = ClientProxy.Create( provider, proxyListener, cts.Token );
+
+		using var client = new TcpClient();
+		await client.ConnectAsync( IPAddress.Loopback, proxyPort, cts.Token );
+
+		// Give the relay a moment to confirm the connection is live
+		await Task.Delay( 1_000, cts.Token );
+
+		await cts.CancelAsync();
+		proxyListener.Stop();
+		await proxyTask;
+	}
+
+	[Fact]
+	public async Task AzureProxy_WhenClientDisconnects_CleansUpPromptly()
+	{
+		var connStr = GetConnectionString();
+		if( connStr is null ) Assert.Skip( "No Azure credentials in appsettings.Test.json" );
+
+		using var cts = new CancellationTokenSource( TimeoutMs );
+
+		var provider = new HybridConnectionClientProvider( connStr! );
+		var (proxyListener, proxyPort) = StartListener();
+		var proxyTask = ClientProxy.Create( provider, proxyListener, cts.Token );
+
+		var client = new TcpClient();
+		await client.ConnectAsync( IPAddress.Loopback, proxyPort, cts.Token );
+		await Task.Delay( 500, cts.Token ); // let the relay connection settle
+
+		// Disconnect the client — this is the scenario that used to hang
+		client.Close();
+
+		// The proxy should clean up within a few seconds; if it hangs the test
+		// times out and fails, confirming the regression is present.
+		await Task.Delay( 3_000, cts.Token );
+
+		await cts.CancelAsync();
+		proxyListener.Stop();
+		await proxyTask;
+	}
+
+	[Fact]
+	public async Task AzureProxy_SmtpEhlo_ServerResponds250()
+	{
+		var connStr = GetConnectionString();
+		if( connStr is null ) Assert.Skip( "No Azure credentials in appsettings.Test.json" );
+
+		using var cts = new CancellationTokenSource( TimeoutMs );
+
+		var provider = new HybridConnectionClientProvider( connStr! );
+		var (proxyListener, proxyPort) = StartListener();
+		_ = ClientProxy.Create( provider, proxyListener, cts.Token );
+
+		using var client = new TcpClient();
+		await client.ConnectAsync( IPAddress.Loopback, proxyPort, cts.Token );
+		using var reader = new StreamReader( client.GetStream(), Encoding.ASCII, leaveOpen: true );
+		using var writer = new StreamWriter( client.GetStream(), Encoding.ASCII, leaveOpen: true ) { NewLine = "\r\n", AutoFlush = true };
+
+		// Server must send a 220 greeting
+		var greeting = await ReadSmtpResponseAsync( reader, cts.Token );
+		Assert.StartsWith( "220", greeting );
+
+		// Send EHLO and expect 250
+		await writer.WriteLineAsync( "EHLO test" );
+		var response = await ReadSmtpResponseAsync( reader, cts.Token );
+		Assert.StartsWith( "250", response );
+
+		// Quit cleanly
+		await writer.WriteLineAsync( "QUIT" );
+		await ReadSmtpResponseAsync( reader, cts.Token );
+
+		await cts.CancelAsync();
+		proxyListener.Stop();
+	}
+
+	// -------------------------------------------------------------------------
+	// Helpers
+	// -------------------------------------------------------------------------
+
+	private static string? GetConnectionString()
+	{
+		var path = Path.Combine( AppContext.BaseDirectory, "appsettings.Test.json" );
+		if( !File.Exists( path ) ) return null;
+
+		try
+		{
+			using var doc = JsonDocument.Parse( File.ReadAllText( path ) );
+			var proxies = doc.RootElement
+				.GetProperty( "AppSettings" )
+				.GetProperty( "Proxies" );
+			if( proxies.GetArrayLength() == 0 ) return null;
+			return proxies[0].GetProperty( "HybridConnectionString" ).GetString();
+		}
+		catch { return null; }
+	}
+
+	private static (TcpListener listener, int port) StartListener()
+	{
+		var listener = new TcpListener( IPAddress.Loopback, 0 );
+		listener.Start();
+		return (listener, ((IPEndPoint) listener.LocalEndpoint).Port);
+	}
+
+	/// <summary>
+	/// Reads a (possibly multi-line) SMTP response and returns the final line.
+	/// Multi-line responses use "NNN-text" for continuation lines and "NNN text" for the last.
+	/// </summary>
+	private static async Task<string> ReadSmtpResponseAsync( StreamReader reader, CancellationToken ct )
+	{
+		string? line;
+		do
+		{
+			line = await reader.ReadLineAsync( ct );
+			if( line is null ) throw new EndOfStreamException( "SMTP server closed the connection." );
+		}
+		while( line.Length >= 4 && line[3] == '-' ); // continuation line
+
+		return line;
+	}
+}