chore: import upstream snapshot with attribution

dotnet/tests/Microsoft.Agents.AI.Mcp.UnitTests/Skills/InMemoryMcpServer.cs

@@ -0,0 +1,76 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.IO.Pipelines;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using ModelContextProtocol.Client;
+using ModelContextProtocol.Protocol;
+using ModelContextProtocol.Server;
+
+namespace Microsoft.Agents.AI.Skills.Mcp.UnitTests;
+
+/// <summary>
+/// Spins up an in-memory MCP server hosting a configurable set of resources, and returns an
+/// <see cref="McpClient"/> connected to it. Disposes both ends together.
+/// </summary>
+[SuppressMessage("Performance", "CA1812:Avoid uninstantiated internal classes", Justification = "Instantiated by AgentMcpSkillsSourceTests which is temporarily excluded from compilation.")]
+internal sealed class InMemoryMcpServer : IAsyncDisposable
+{
+    private readonly Pipe _clientToServerPipe = new();
+    private readonly Pipe _serverToClientPipe = new();
+    private readonly CancellationTokenSource _cts = new();
+    private readonly ServiceProvider _serviceProvider;
+    private readonly Task _serverTask;
+
+    public InMemoryMcpServer(Action<IMcpServerBuilder> configure)
+    {
+        var services = new ServiceCollection();
+        services.AddLogging(builder => builder.AddProvider(NullLoggerProvider.Instance));
+
+        IMcpServerBuilder builder = services
+            .AddMcpServer()
+            .WithStreamServerTransport(
+                inputStream: this._clientToServerPipe.Reader.AsStream(),
+                outputStream: this._serverToClientPipe.Writer.AsStream());
+
+        configure(builder);
+
+        this._serviceProvider = services.BuildServiceProvider();
+        var server = this._serviceProvider.GetRequiredService<McpServer>();
+        this._serverTask = server.RunAsync(this._cts.Token);
+    }
+
+    public async Task<McpClient> CreateClientAsync(CancellationToken cancellationToken = default)
+    {
+        return await McpClient.CreateAsync(
+            new StreamClientTransport(
+                serverInput: this._clientToServerPipe.Writer.AsStream(),
+                serverOutput: this._serverToClientPipe.Reader.AsStream()),
+            cancellationToken: cancellationToken).ConfigureAwait(false);
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        await this._cts.CancelAsync().ConfigureAwait(false);
+
+        this._clientToServerPipe.Writer.Complete();
+        this._serverToClientPipe.Writer.Complete();
+
+        try
+        {
+            await this._serverTask.ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            // Expected when the server is cancelled during shutdown.
+        }
+
+        await this._serviceProvider.DisposeAsync().ConfigureAwait(false);
+        this._cts.Dispose();
+    }
+}