build: bootstrap solution and quality gates (#3)

Closes #3

.editorconfig

@@ -0,0 +1,26 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{cs,csproj,props,targets}]
+indent_style = space
+indent_size = 4
+
+[*.cs]
+dotnet_sort_system_directives_first = true
+csharp_new_line_before_open_brace = all
+csharp_style_namespace_declarations = file_scoped:warning
+csharp_style_var_for_built_in_types = false:suggestion
+csharp_style_var_when_type_is_apparent = true:suggestion
+csharp_style_var_elsewhere = false:suggestion
+
+[*.{json,yml,yaml}]
+indent_style = space
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false

.gitea/workflows/ci.yml

@@ -0,0 +1,34 @@
+name: quality-gate
+
+on:
+  push:
+    branches:
+      - main
+      - codex/**
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  quality:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Install .NET SDK
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 10.0.301
+
+      - name: Restore locked dependencies
+        run: dotnet restore Rendezvous.slnx --locked-mode
+
+      - name: Verify formatting and analyzers
+        run: dotnet format Rendezvous.slnx --verify-no-changes --no-restore
+
+      - name: Build
+        run: dotnet build Rendezvous.slnx --configuration Release --no-restore
+
+      - name: Test
+        run: dotnet test Rendezvous.slnx --configuration Release --no-build

.gitignore

@@ -0,0 +1,8 @@
+**/bin/
+**/obj/
+TestResults/
+.idea/
+.vs/
+*.suo
+*.user
+*.userosscache

Directory.Build.props

@@ -0,0 +1,15 @@
+<Project>
+  <PropertyGroup>
+    <AnalysisLevel>latest-recommended</AnalysisLevel>
+    <ContinuousIntegrationBuild Condition="'$(CI)' == 'true'">true</ContinuousIntegrationBuild>
+    <Deterministic>true</Deterministic>
+    <EnableNETAnalyzers>true</EnableNETAnalyzers>
+    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>latest</LangVersion>
+    <Nullable>enable</Nullable>
+    <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+    <RestoreLockedMode Condition="'$(CI)' == 'true'">true</RestoreLockedMode>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+</Project>

Directory.Packages.props

@@ -0,0 +1,12 @@
+<Project>
+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageVersion Include="LiteNetLib" Version="2.1.4" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.4.0" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
+  </ItemGroup>
+</Project>

NuGet.config

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
+  </packageSources>
+  <packageSourceMapping>
+    <packageSource key="nuget.org">
+      <package pattern="*" />
+    </packageSource>
+  </packageSourceMapping>
+</configuration>

README.md

@@ -79,3 +79,21 @@ Rendezvous is currently in its initial design and bootstrap stage. The first imp
 
 The ratified v1 boundaries, trust decisions, privacy rules, safety budgets, and
 threat model are indexed in [the architecture documentation](docs/architecture/README.md).
+
+## Development
+
+The repository pins .NET SDK 10.0.301. From a clean clone, run the same gates as
+CI from the repository root:
+
+```bash
+dotnet restore Rendezvous.slnx --locked-mode
+dotnet format Rendezvous.slnx --verify-no-changes --no-restore
+dotnet build Rendezvous.slnx --configuration Release --no-restore
+dotnet test Rendezvous.slnx --configuration Release --no-build
+```
+
+Run the bootstrap server with
+`dotnet run --project src/FinalFactory.Rendezvous.Server`. It serves HTTP health endpoints and binds
+the configured UDP mediator port; both stop through normal host cancellation.
+The project dependency rules and supported runtime choices are documented in
+[project and dependency boundaries](docs/architecture/project-boundaries.md).

Rendezvous.slnx

@@ -0,0 +1,11 @@
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/FinalFactory.Rendezvous.Client/FinalFactory.Rendezvous.Client.csproj" />
+    <Project Path="src/FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj" />
+    <Project Path="src/FinalFactory.Rendezvous.Server/FinalFactory.Rendezvous.Server.csproj" />
+    <Project Path="src/FinalFactory.Rendezvous.TestClient/FinalFactory.Rendezvous.TestClient.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/FinalFactory.Rendezvous.Tests/FinalFactory.Rendezvous.Tests.csproj" />
+  </Folder>
+</Solution>

docs/architecture/project-boundaries.md

@@ -0,0 +1,45 @@
+# Project and dependency boundaries
+
+Tracking: #3
+
+```text
+FinalFactory.Rendezvous.Contracts  <-  FinalFactory.Rendezvous.Client
+                ^                               ^
+                |                               |
+FinalFactory.Rendezvous.Server     FinalFactory.Rendezvous.TestClient
+```
+
+- `Contracts` targets `netstandard2.1` and contains only versioned,
+  transport-neutral IDs and wire contracts. It cannot reference Server,
+  LiteNetLib, or Godot.
+- `Client` targets `netstandard2.1`, references Contracts and the pinned
+  LiteNetLib package, and contains no Godot or Server dependency.
+- `Server` targets .NET 10 LTS, references Contracts and LiteNetLib, and owns
+  HTTP hosting, UDP mediation, application policy, and ephemeral state.
+- `TestClient` targets .NET 8, references only the public Client/Contracts seams
+  and LiteNetLib, and must never reach into Server internals.
+- `Tests` target .NET 10 and may reference every project solely to verify public
+  behavior and architecture boundaries.
+
+The dependency-boundary tests inspect compiled assembly references. A forbidden
+engine, transport, or server dependency therefore fails the normal test gate.
+
+## Supported toolchain
+
+- Build SDK: .NET SDK 10.0.301, pinned by `global.json`.
+- Server runtime: .NET 10 LTS.
+- Client/contracts compatibility target: .NET Standard 2.1, consumable by the
+  .NET 8-or-later runtime used by current Godot 4 C# projects.
+- TestClient runtime: .NET 8.
+- LiteNetLib: 2.1.4, pinned centrally and restored from the lock files.
+
+The repository uses central package versions, per-project lock files,
+deterministic compilation, nullable reference types, warnings as errors, current
+.NET analyzers, and formatting verification. CI restores in locked mode so a
+package graph change must be deliberate and committed.
+
+Primary compatibility references:
+
+- [.NET support policy](https://dotnet.microsoft.com/en-us/platform/support/policy)
+- [Godot stable C# prerequisites](https://docs.godotengine.org/en/stable/tutorials/scripting/c_sharp/c_sharp_basics.html)
+- [LiteNetLib 2.1.4 on NuGet](https://www.nuget.org/packages/LiteNetLib/2.1.4)

global.json

@@ -0,0 +1,7 @@
+{
+  "sdk": {
+    "version": "10.0.301",
+    "rollForward": "disable",
+    "allowPrerelease": false
+  }
+}

src/FinalFactory.Rendezvous.Client/FinalFactory.Rendezvous.Client.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.1</TargetFramework>
+    <AssemblyName>FinalFactory.Rendezvous.Client</AssemblyName>
+    <RootNamespace>FinalFactory.Rendezvous.Client</RootNamespace>
+    <IsPackable>true</IsPackable>
+    <PackageId>FinalFactory.Rendezvous.Client</PackageId>
+    <Description>Godot-independent client SDK for Final Factory Rendezvous.</Description>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj" />
+    <PackageReference Include="LiteNetLib" />
+  </ItemGroup>
+</Project>

src/FinalFactory.Rendezvous.Client/packages.lock.json

@@ -0,0 +1,16 @@
+{
+  "version": 2,
+  "dependencies": {
+    ".NETStandard,Version=v2.1": {
+      "LiteNetLib": {
+        "type": "Direct",
+        "requested": "[2.1.4, )",
+        "resolved": "2.1.4",
+        "contentHash": "KWlxvMw3Urpqj9joD96LRiK+LC62pQNs/zkXRJc+rHnxgkGp+vV703xzDrxRmv+V1YhCFfIGzs5nrVWtREIlyA=="
+      },
+      "finalfactory.rendezvous.contracts": {
+        "type": "Project"
+      }
+    }
+  }
+}

src/FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.1</TargetFramework>
+    <AssemblyName>FinalFactory.Rendezvous.Contracts</AssemblyName>
+    <RootNamespace>FinalFactory.Rendezvous.Contracts</RootNamespace>
+    <IsPackable>true</IsPackable>
+    <PackageId>FinalFactory.Rendezvous.Contracts</PackageId>
+    <Description>Versioned transport-neutral contracts for Final Factory Rendezvous.</Description>
+  </PropertyGroup>
+</Project>

src/FinalFactory.Rendezvous.Contracts/packages.lock.json

@@ -0,0 +1,6 @@
+{
+  "version": 2,
+  "dependencies": {
+    ".NETStandard,Version=v2.1": {}
+  }
+}

src/FinalFactory.Rendezvous.Server/FinalFactory.Rendezvous.Server.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <AssemblyName>FinalFactory.Rendezvous.Server</AssemblyName>
+    <RootNamespace>FinalFactory.Rendezvous.Server</RootNamespace>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj" />
+    <PackageReference Include="LiteNetLib" />
+  </ItemGroup>
+</Project>

src/FinalFactory.Rendezvous.Server/Program.cs

@@ -0,0 +1,31 @@
+using System.Net;
+using FinalFactory.Rendezvous.Server.Transport;
+
+WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
+
+builder.Services
+    .AddOptions<UdpMediatorOptions>()
+    .BindConfiguration(UdpMediatorOptions.SectionName)
+    .ValidateDataAnnotations()
+    .Validate(
+        options => IPAddress.TryParse(options.ListenAddress, out _),
+        $"{UdpMediatorOptions.SectionName}:ListenAddress must be an IP address.")
+    .ValidateOnStart();
+builder.Services.AddSingleton<UdpMediatorService>();
+builder.Services.AddHostedService(static services => services.GetRequiredService<UdpMediatorService>());
+
+WebApplication app = builder.Build();
+
+app.MapGet("/health/live", static () => Results.Ok(new { status = "live" }));
+app.MapGet(
+    "/health/ready",
+    static (UdpMediatorService mediator) => mediator.LocalEndpoint is null
+        ? Results.StatusCode(StatusCodes.Status503ServiceUnavailable)
+        : Results.Ok(new { status = "ready" }));
+
+await app.RunAsync();
+
+/// <summary>
+/// Entry point marker used by integration-test hosts.
+/// </summary>
+public partial class Program;

src/FinalFactory.Rendezvous.Server/Transport/UdpMediatorOptions.cs

@@ -0,0 +1,26 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace FinalFactory.Rendezvous.Server.Transport;
+
+/// <summary>
+/// Configures the UDP endpoint reserved for the Rendezvous mediator.
+/// </summary>
+public sealed class UdpMediatorOptions
+{
+    /// <summary>
+    /// Configuration section containing UDP mediator settings.
+    /// </summary>
+    public const string SectionName = "Rendezvous:Udp";
+
+    /// <summary>
+    /// Gets or sets the numeric IP address to bind.
+    /// </summary>
+    [Required]
+    public string ListenAddress { get; set; } = "0.0.0.0";
+
+    /// <summary>
+    /// Gets or sets the UDP port. Zero requests an ephemeral port for tests.
+    /// </summary>
+    [Range(0, 65_535)]
+    public int Port { get; set; } = 9050;
+}

src/FinalFactory.Rendezvous.Server/Transport/UdpMediatorService.cs

@@ -0,0 +1,116 @@
+using System.Net;
+using System.Net.Sockets;
+using Microsoft.Extensions.Options;
+
+namespace FinalFactory.Rendezvous.Server.Transport;
+
+/// <summary>
+/// Owns the cancellable UDP socket used by the future NAT mediator.
+/// </summary>
+public sealed partial class UdpMediatorService : BackgroundService
+{
+    private readonly ILogger<UdpMediatorService> _logger;
+    private readonly UdpMediatorOptions _options;
+    private UdpClient? _udpClient;
+
+    /// <summary>
+    /// Initializes a new UDP mediator service.
+    /// </summary>
+    public UdpMediatorService(
+        IOptions<UdpMediatorOptions> options,
+        ILogger<UdpMediatorService> logger)
+    {
+        _options = options.Value;
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Gets the bound endpoint after startup completes.
+    /// </summary>
+    public IPEndPoint? LocalEndpoint { get; private set; }
+
+    /// <inheritdoc />
+    public override Task StartAsync(CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+
+        if (_udpClient is not null)
+        {
+            throw new InvalidOperationException("The UDP mediator is already running.");
+        }
+
+        IPAddress listenAddress = IPAddress.Parse(_options.ListenAddress);
+        UdpClient udpClient = new(new IPEndPoint(listenAddress, _options.Port));
+        _udpClient = udpClient;
+        IPEndPoint localEndpoint =
+            (IPEndPoint?)udpClient.Client.LocalEndPoint
+            ?? throw new InvalidOperationException("The UDP socket did not expose its bound endpoint.");
+        LocalEndpoint = localEndpoint;
+
+        LogMediatorListening(_logger, localEndpoint.Address, localEndpoint.Port);
+
+        return base.StartAsync(cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public override async Task StopAsync(CancellationToken cancellationToken)
+    {
+        await base.StopAsync(cancellationToken).ConfigureAwait(false);
+        _udpClient?.Dispose();
+        _udpClient = null;
+        LocalEndpoint = null;
+        LogMediatorStopped(_logger);
+    }
+
+    /// <inheritdoc />
+    public override void Dispose()
+    {
+        _udpClient?.Dispose();
+        _udpClient = null;
+        LocalEndpoint = null;
+        base.Dispose();
+    }
+
+    /// <inheritdoc />
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        UdpClient udpClient = _udpClient
+            ?? throw new InvalidOperationException("The UDP mediator socket was not initialized.");
+
+        try
+        {
+            while (!stoppingToken.IsCancellationRequested)
+            {
+                _ = await udpClient.ReceiveAsync(stoppingToken).ConfigureAwait(false);
+                // Bootstrap deliberately emits no UDP response. Protocol handling lands in #11.
+            }
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            // Expected during normal shutdown.
+        }
+        catch (ObjectDisposedException) when (stoppingToken.IsCancellationRequested)
+        {
+            // Disposing the socket is the fallback that releases a blocked receive.
+        }
+        finally
+        {
+            LocalEndpoint = null;
+        }
+    }
+
+    [LoggerMessage(
+        EventId = 1,
+        Level = LogLevel.Information,
+        Message = "UDP mediator listening on {ListenAddress}:{ListenPort}")]
+    private static partial void LogMediatorListening(
+        ILogger logger,
+        IPAddress listenAddress,
+        int listenPort);
+
+    [LoggerMessage(
+        EventId = 2,
+        Level = LogLevel.Information,
+        Message = "UDP mediator stopped")]
+    private static partial void LogMediatorStopped(ILogger logger);
+}

src/FinalFactory.Rendezvous.Server/appsettings.json

@@ -0,0 +1,15 @@
+{
+  "Rendezvous": {
+    "Udp": {
+      "ListenAddress": "0.0.0.0",
+      "Port": 9050
+    }
+  },
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

src/FinalFactory.Rendezvous.Server/packages.lock.json

@@ -0,0 +1,16 @@
+{
+  "version": 2,
+  "dependencies": {
+    "net10.0": {
+      "LiteNetLib": {
+        "type": "Direct",
+        "requested": "[2.1.4, )",
+        "resolved": "2.1.4",
+        "contentHash": "KWlxvMw3Urpqj9joD96LRiK+LC62pQNs/zkXRJc+rHnxgkGp+vV703xzDrxRmv+V1YhCFfIGzs5nrVWtREIlyA=="
+      },
+      "finalfactory.rendezvous.contracts": {
+        "type": "Project"
+      }
+    }
+  }
+}

src/FinalFactory.Rendezvous.TestClient/FinalFactory.Rendezvous.TestClient.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <AssemblyName>FinalFactory.Rendezvous.TestClient</AssemblyName>
+    <RootNamespace>FinalFactory.Rendezvous.TestClient</RootNamespace>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../FinalFactory.Rendezvous.Client/FinalFactory.Rendezvous.Client.csproj" />
+    <ProjectReference Include="../FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj" />
+    <PackageReference Include="LiteNetLib" />
+  </ItemGroup>
+</Project>

src/FinalFactory.Rendezvous.TestClient/Program.cs

@@ -0,0 +1,16 @@
+namespace FinalFactory.Rendezvous.TestClient;
+
+/// <summary>
+/// Bootstrap entry point for the public-SDK-only diagnostic client.
+/// </summary>
+public static class Program
+{
+    /// <summary>
+    /// Runs the bootstrap diagnostic.
+    /// </summary>
+    public static int Main()
+    {
+        Console.WriteLine("Rendezvous TestClient bootstrap is ready.");
+        return 0;
+    }
+}

src/FinalFactory.Rendezvous.TestClient/packages.lock.json

@@ -0,0 +1,23 @@
+{
+  "version": 2,
+  "dependencies": {
+    "net8.0": {
+      "LiteNetLib": {
+        "type": "Direct",
+        "requested": "[2.1.4, )",
+        "resolved": "2.1.4",
+        "contentHash": "KWlxvMw3Urpqj9joD96LRiK+LC62pQNs/zkXRJc+rHnxgkGp+vV703xzDrxRmv+V1YhCFfIGzs5nrVWtREIlyA=="
+      },
+      "finalfactory.rendezvous.client": {
+        "type": "Project",
+        "dependencies": {
+          "FinalFactory.Rendezvous.Contracts": "[1.0.0, )",
+          "LiteNetLib": "[2.1.4, )"
+        }
+      },
+      "finalfactory.rendezvous.contracts": {
+        "type": "Project"
+      }
+    }
+  }
+}

tests/FinalFactory.Rendezvous.Tests/Architecture/DependencyBoundaryTests.cs

@@ -0,0 +1,113 @@
+using System.Reflection;
+using System.Xml.Linq;
+
+namespace FinalFactory.Rendezvous.Tests.Architecture;
+
+public sealed class DependencyBoundaryTests
+{
+    [Fact]
+    public void ContractsAreTransportAndEngineIndependent()
+    {
+        string[] references = GetReferences("FinalFactory.Rendezvous.Contracts");
+
+        Assert.DoesNotContain(references, IsGodotAssembly);
+        Assert.DoesNotContain(references, IsServerAssembly);
+        Assert.DoesNotContain(references, IsLiteNetLibAssembly);
+    }
+
+    [Fact]
+    public void ClientIsGodotAndServerIndependent()
+    {
+        string[] references = GetReferences("FinalFactory.Rendezvous.Client");
+
+        Assert.DoesNotContain(references, IsGodotAssembly);
+        Assert.DoesNotContain(references, IsServerAssembly);
+    }
+
+    [Fact]
+    public void TestClientUsesOnlyPublicRendezvousDependencies()
+    {
+        string[] references = GetReferences("FinalFactory.Rendezvous.TestClient");
+
+        Assert.DoesNotContain(references, IsGodotAssembly);
+        Assert.DoesNotContain(references, IsServerAssembly);
+    }
+
+    [Fact]
+    public void DeclaredDependencyGraphMatchesTheArchitecture()
+    {
+        AssertDeclaredDependencies(
+            "src/FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj",
+            [],
+            []);
+        AssertDeclaredDependencies(
+            "src/FinalFactory.Rendezvous.Client/FinalFactory.Rendezvous.Client.csproj",
+            ["FinalFactory.Rendezvous.Contracts"],
+            ["LiteNetLib"]);
+        AssertDeclaredDependencies(
+            "src/FinalFactory.Rendezvous.Server/FinalFactory.Rendezvous.Server.csproj",
+            ["FinalFactory.Rendezvous.Contracts"],
+            ["LiteNetLib"]);
+        AssertDeclaredDependencies(
+            "src/FinalFactory.Rendezvous.TestClient/FinalFactory.Rendezvous.TestClient.csproj",
+            ["FinalFactory.Rendezvous.Client", "FinalFactory.Rendezvous.Contracts"],
+            ["LiteNetLib"]);
+    }
+
+    private static void AssertDeclaredDependencies(
+        string projectPath,
+        string[] expectedProjects,
+        string[] expectedPackages)
+    {
+        XDocument project = XDocument.Load(Path.Combine(FindRepositoryRoot(), projectPath));
+        string[] projects = project
+            .Descendants("ProjectReference")
+            .Select(static element =>
+                Path.GetFileNameWithoutExtension(element.Attribute("Include")?.Value) ?? string.Empty)
+            .Order(StringComparer.Ordinal)
+            .ToArray();
+        string[] packages = project
+            .Descendants("PackageReference")
+            .Select(static element => element.Attribute("Include")?.Value ?? string.Empty)
+            .Order(StringComparer.Ordinal)
+            .ToArray();
+
+        Assert.Equal(expectedProjects.Order(StringComparer.Ordinal), projects);
+        Assert.Equal(expectedPackages.Order(StringComparer.Ordinal), packages);
+    }
+
+    private static string FindRepositoryRoot()
+    {
+        DirectoryInfo? directory = new(AppContext.BaseDirectory);
+
+        while (directory is not null)
+        {
+            if (File.Exists(Path.Combine(directory.FullName, "Rendezvous.slnx")))
+            {
+                return directory.FullName;
+            }
+
+            directory = directory.Parent;
+        }
+
+        throw new DirectoryNotFoundException("Could not locate the Rendezvous repository root.");
+    }
+
+    private static string[] GetReferences(string assemblyName) => Assembly
+        .Load(assemblyName)
+        .GetReferencedAssemblies()
+        .Select(static reference => reference.Name ?? string.Empty)
+        .ToArray();
+
+    private static bool IsGodotAssembly(string assemblyName) =>
+        assemblyName.StartsWith("Godot", StringComparison.OrdinalIgnoreCase);
+
+    private static bool IsLiteNetLibAssembly(string assemblyName) =>
+        string.Equals(assemblyName, "LiteNetLib", StringComparison.Ordinal);
+
+    private static bool IsServerAssembly(string assemblyName) =>
+        string.Equals(
+            assemblyName,
+            "FinalFactory.Rendezvous.Server",
+            StringComparison.Ordinal);
+}

tests/FinalFactory.Rendezvous.Tests/FinalFactory.Rendezvous.Tests.csproj

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <AssemblyName>FinalFactory.Rendezvous.Tests</AssemblyName>
+    <RootNamespace>FinalFactory.Rendezvous.Tests</RootNamespace>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio">
+      <PrivateAssets>all</PrivateAssets>
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+    </PackageReference>
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+    <ProjectReference Include="../../src/FinalFactory.Rendezvous.Contracts/FinalFactory.Rendezvous.Contracts.csproj" />
+    <ProjectReference Include="../../src/FinalFactory.Rendezvous.Server/FinalFactory.Rendezvous.Server.csproj" />
+    <ProjectReference Include="../../src/FinalFactory.Rendezvous.TestClient/FinalFactory.Rendezvous.TestClient.csproj" />
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tests/FinalFactory.Rendezvous.Tests/GlobalUsings.cs

@@ -0,0 +1 @@
+global using Xunit;

tests/FinalFactory.Rendezvous.Tests/Server/UdpMediatorServiceTests.cs

@@ -0,0 +1,34 @@
+using System.Net;
+using FinalFactory.Rendezvous.Server.Transport;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+
+namespace FinalFactory.Rendezvous.Tests.Server;
+
+public sealed class UdpMediatorServiceTests
+{
+    [Fact]
+    public async Task ServiceBindsAnEphemeralUdpPortAndStopsCleanly()
+    {
+        using CancellationTokenSource timeout = new(TimeSpan.FromSeconds(5));
+        UdpMediatorOptions options = new()
+        {
+            ListenAddress = IPAddress.Loopback.ToString(),
+            Port = 0,
+        };
+        using UdpMediatorService service = new(
+            Options.Create(options),
+            NullLogger<UdpMediatorService>.Instance);
+
+        await service.StartAsync(timeout.Token);
+
+        IPEndPoint? boundEndpoint = service.LocalEndpoint;
+        Assert.NotNull(boundEndpoint);
+        Assert.Equal(IPAddress.Loopback, boundEndpoint.Address);
+        Assert.InRange(boundEndpoint.Port, 1, 65_535);
+
+        await service.StopAsync(timeout.Token);
+
+        Assert.Null(service.LocalEndpoint);
+    }
+}

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