Add Conformance tests for the server (#983)

tests/ModelContextProtocol.ConformanceServer/Program.cs

@@ -0,0 +1,118 @@
+using ConformanceServer.Prompts;
+using ConformanceServer.Resources;
+using ConformanceServer.Tools;
+using Microsoft.Extensions.AI;
+using ModelContextProtocol.Protocol;
+using System.Collections.Concurrent;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
+
+namespace ModelContextProtocol.ConformanceServer;
+
+public class Program
+{
+    public static async Task MainAsync(string[] args, ILoggerProvider? loggerProvider = null, CancellationToken cancellationToken = default)
+    {
+        var builder = WebApplication.CreateBuilder(args);
+
+        if (loggerProvider != null)
+        {
+            builder.Logging.ClearProviders();
+            builder.Logging.AddProvider(loggerProvider);
+        }
+
+        // Dictionary of session IDs to a set of resource URIs they are subscribed to
+        // The value is a ConcurrentDictionary used as a thread-safe HashSet
+        // because .NET does not have a built-in concurrent HashSet
+        ConcurrentDictionary<string, ConcurrentDictionary<string, byte>> subscriptions = new();
+
+        builder.Services
+            .AddMcpServer()
+            .WithHttpTransport()
+            .WithTools<ConformanceTools>()
+            .WithPrompts<ConformancePrompts>()
+            .WithResources<ConformanceResources>()
+            .WithSubscribeToResourcesHandler(async (ctx, ct) =>
+            {
+                if (ctx.Server.SessionId == null)
+                {
+                    throw new McpException("Cannot add subscription for server with null SessionId");
+                }
+                if (ctx.Params?.Uri is { } uri)
+                {
+                    subscriptions[ctx.Server.SessionId].TryAdd(uri, 0);
+
+                    await ctx.Server.SampleAsync([
+                        new ChatMessage(ChatRole.System, "You are a helpful test server"),
+                        new ChatMessage(ChatRole.User, $"Resource {uri}, context: A new subscription was started"),
+                    ],
+                    options: new ChatOptions
+                    {
+                        MaxOutputTokens = 100,
+                        Temperature = 0.7f,
+                    },
+                    cancellationToken: ct);
+                }
+
+                return new EmptyResult();
+            })
+            .WithUnsubscribeFromResourcesHandler(async (ctx, ct) =>
+            {
+                if (ctx.Server.SessionId == null)
+                {
+                    throw new McpException("Cannot remove subscription for server with null SessionId");
+                }
+                if (ctx.Params?.Uri is { } uri)
+                {
+                    subscriptions[ctx.Server.SessionId].TryRemove(uri, out _);
+                }
+                return new EmptyResult();
+            })
+            .WithCompleteHandler(async (ctx, ct) =>
+            {
+                // Basic completion support - returns empty array for conformance
+                // Real implementations would provide contextual suggestions
+                return new CompleteResult
+                {
+                    Completion = new Completion
+                    {
+                        Values = [],
+                        HasMore = false,
+                        Total = 0
+                    }
+                };
+            })
+            .WithSetLoggingLevelHandler(async (ctx, ct) =>
+            {
+                if (ctx.Params?.Level is null)
+                {
+                    throw new McpProtocolException("Missing required argument 'level'", McpErrorCode.InvalidParams);
+                }
+
+                // The SDK updates the LoggingLevel field of the McpServer
+                // Send a log notification to confirm the level was set
+                await ctx.Server.SendNotificationAsync("notifications/message", new LoggingMessageNotificationParams
+                {
+                    Level = LoggingLevel.Info,
+                    Logger = "conformance-test-server",
+                    Data = JsonElement.Parse($"\"Log level set to: {ctx.Params.Level}\""),
+                }, cancellationToken: ct);
+
+                return new EmptyResult();
+            });
+
+        var app = builder.Build();
+
+        app.MapMcp();
+
+        app.MapGet("/health", () => TypedResults.Ok("Healthy"));
+
+        await app.RunAsync(cancellationToken);
+    }
+
+    public static async Task Main(string[] args)
+    {
+        await MainAsync(args);
+    }
+}