[.NET] Add happy path test for in-memory agent && Simplify HelloAgent…

… example && some clean-up in extension APIs (#4227)

* add happy path test

* remove unnecessary namespace

* fix build error

* Update AgentBaseTests.cs

* revert changes

---------

dotnet/samples/Hello/HelloAgent/HelloAgent.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>net8.0</TargetFramework>
@@ -8,7 +8,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Hosting" />
-    <PackageReference Include="Aspire.Hosting.AppHost" />
   </ItemGroup>
 
   <ItemGroup>

dotnet/src/Microsoft.AutoGen/Agents/App.cs

@@ -12,6 +12,7 @@ public static class AgentsApp
 {
     // need a variable to store the runtime instance
     public static WebApplication? Host { get; private set; }
+
     [MemberNotNull(nameof(Host))]
     public static async ValueTask<WebApplication> StartAsync(WebApplicationBuilder? builder = null, AgentTypes? agentTypes = null, bool local = false)
     {
@@ -58,7 +59,7 @@ public static async ValueTask ShutdownAsync()
         await Host.StopAsync();
     }
 
-    private static AgentApplicationBuilder AddAgents(this AgentApplicationBuilder builder, AgentTypes? agentTypes)
+    private static IHostApplicationBuilder AddAgents(this IHostApplicationBuilder builder, AgentTypes? agentTypes)
     {
         agentTypes ??= AgentTypes.GetAgentTypesFromAssembly()
                    ?? throw new InvalidOperationException("No agent types found in the assembly");

dotnet/src/Microsoft.AutoGen/Agents/Services/AgentWorkerHostingExtensions.cs

@@ -3,8 +3,6 @@
 
 using System.Diagnostics;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
@@ -13,25 +11,9 @@ namespace Microsoft.AutoGen.Agents;
 
 public static class AgentWorkerHostingExtensions
 {
-    public static WebApplicationBuilder AddAgentService(this WebApplicationBuilder builder, bool local = false, bool useGrpc = true)
+    public static IHostApplicationBuilder AddAgentService(this IHostApplicationBuilder builder, bool local = false, bool useGrpc = true)
     {
-        if (local)
-        {
-            //TODO: make configuration more flexible
-            builder.WebHost.ConfigureKestrel(serverOptions =>
-                        {
-                            serverOptions.ListenLocalhost(5001, listenOptions =>
-                            {
-                                listenOptions.Protocols = HttpProtocols.Http2;
-                                listenOptions.UseHttps();
-                            });
-                        });
-            builder.AddOrleans(local);
-        }
-        else
-        {
-            builder.AddOrleans();
-        }
+        builder.AddOrleans(local);
 
         builder.Services.TryAddSingleton(DistributedContextPropagator.Current);
 
@@ -45,10 +27,11 @@ public static WebApplicationBuilder AddAgentService(this WebApplicationBuilder b
         return builder;
     }
 
-    public static WebApplicationBuilder AddLocalAgentService(this WebApplicationBuilder builder, bool useGrpc = true)
+    public static IHostApplicationBuilder AddLocalAgentService(this IHostApplicationBuilder builder, bool useGrpc = true)
     {
         return builder.AddAgentService(local: true, useGrpc);
     }
+
     public static WebApplication MapAgentService(this WebApplication app, bool local = false, bool useGrpc = true)
     {
         if (useGrpc) { app.MapGrpcService<GrpcGatewayService>(); }

dotnet/src/Microsoft.AutoGen/Agents/Services/HostBuilderExtensions.cs

@@ -16,7 +16,23 @@ namespace Microsoft.AutoGen.Agents;
 public static class HostBuilderExtensions
 {
     private const string _defaultAgentServiceAddress = "https://localhost:5001";
-    public static AgentApplicationBuilder AddAgentWorker(this IHostApplicationBuilder builder, string agentServiceAddress = _defaultAgentServiceAddress, bool local = false)
+
+    public static IHostApplicationBuilder AddAgent<
+        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] TAgent>(this IHostApplicationBuilder builder, string typeName) where TAgent : AgentBase
+    {
+        builder.Services.AddKeyedSingleton("AgentTypes", (sp, key) => Tuple.Create(typeName, typeof(TAgent)));
+
+        return builder;
+    }
+
+    public static IHostApplicationBuilder AddAgent(this IHostApplicationBuilder builder, string typeName, Type agentType)
+    {
+        builder.Services.AddKeyedSingleton("AgentTypes", (sp, key) => Tuple.Create(typeName, agentType));
+
+        return builder;
+    }
+
+    public static IHostApplicationBuilder AddAgentWorker(this IHostApplicationBuilder builder, string agentServiceAddress = _defaultAgentServiceAddress, bool local = false)
     {
         builder.Services.TryAddSingleton(DistributedContextPropagator.Current);
 
@@ -98,7 +114,9 @@ public static AgentApplicationBuilder AddAgentWorker(this IHostApplicationBuilde
             return new EventTypes(typeRegistry, types, eventsMap);
         });
         builder.Services.AddSingleton<Client>();
-        return new AgentApplicationBuilder(builder);
+        builder.Services.AddSingleton(new AgentApplicationBuilder(builder));
+
+        return builder;
     }
 
     private static MessageDescriptor? GetMessageDescriptor(Type type)

dotnet/src/Microsoft.AutoGen/Agents/Services/Orleans/OrleansRuntimeHostingExtenions.cs

@@ -15,11 +15,17 @@ public static class OrleansRuntimeHostingExtenions
 {
     public static WebApplicationBuilder AddOrleans(this WebApplicationBuilder builder, bool local = false)
     {
+        return builder.AddOrleans(local);
+    }
 
+    public static IHostApplicationBuilder AddOrleans(this IHostApplicationBuilder builder, bool local = false)
+    {
         builder.Services.AddSerializer(serializer => serializer.AddProtobufSerializer());
+        builder.Services.AddSingleton<IRegistryGrain, RegistryGrain>();
+
         // Ensure Orleans is added before the hosted service to guarantee that it starts first.
         //TODO: make all of this configurable
-        builder.Host.UseOrleans(siloBuilder =>
+        builder.UseOrleans((siloBuilder) =>
         {
             // Development mode or local mode uses in-memory storage and streams
             if (builder.Environment.IsDevelopment() || local)
@@ -51,16 +57,16 @@ public static WebApplicationBuilder AddOrleans(this WebApplicationBuilder builde
                     options.SystemResponseTimeout = TimeSpan.FromMinutes(3);
                 });
                 siloBuilder.Configure<ClientMessagingOptions>(options =>
-               {
-                   options.ResponseTimeout = TimeSpan.FromMinutes(3);
-               });
+                {
+                    options.ResponseTimeout = TimeSpan.FromMinutes(3);
+                });
                 siloBuilder.UseCosmosClustering(o =>
-                    {
-                        o.ConfigureCosmosClient(cosmosDbconnectionString);
-                        o.ContainerName = "AutoGen";
-                        o.DatabaseName = "clustering";
-                        o.IsResourceCreationEnabled = true;
-                    });
+                {
+                    o.ConfigureCosmosClient(cosmosDbconnectionString);
+                    o.ContainerName = "AutoGen";
+                    o.DatabaseName = "clustering";
+                    o.IsResourceCreationEnabled = true;
+                });
 
                 siloBuilder.UseCosmosReminderService(o =>
                 {
@@ -84,7 +90,7 @@ public static WebApplicationBuilder AddOrleans(this WebApplicationBuilder builde
               .AddMemoryGrainStorage("PubSubStore");
             }
         });
-        builder.Services.AddSingleton<IRegistryGrain, RegistryGrain>();
+
         return builder;
     }
 }

dotnet/test/Microsoft.AutoGen.Agents.Tests/AgentBaseTests.cs

@@ -1,17 +1,24 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // AgentBaseTests.cs
 
+using System.Collections.Concurrent;
 using FluentAssertions;
 using Google.Protobuf.Reflection;
 using Microsoft.AutoGen.Abstractions;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Moq;
 using Xunit;
+using static Microsoft.AutoGen.Agents.Tests.AgentBaseTests;
 
 namespace Microsoft.AutoGen.Agents.Tests;
 
-public class AgentBaseTests
+[Collection(ClusterFixtureCollection.Name)]
+public class AgentBaseTests(InMemoryAgentRuntimeFixture fixture)
 {
+    private readonly InMemoryAgentRuntimeFixture _fixture = fixture;
+
     [Fact]
     public async Task ItInvokeRightHandlerTestAsync()
     {
@@ -26,12 +33,36 @@ public async Task ItInvokeRightHandlerTestAsync()
         agent.ReceivedItems[1].Should().Be(42);
     }
 
+    [Fact]
+    public async Task ItDelegateMessageToTestAgentAsync()
+    {
+        var client = _fixture.AppHost.Services.GetRequiredService<Client>();
+
+        await client.PublishMessageAsync(new TextMessage()
+        {
+            Source = nameof(ItDelegateMessageToTestAgentAsync),
+            TextMessage_ = "buffer"
+        }, token: CancellationToken.None);
+
+        // wait for 10 seconds
+        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        while (!TestAgent.ReceivedMessages.ContainsKey(nameof(ItDelegateMessageToTestAgentAsync)) && !cts.Token.IsCancellationRequested)
+        {
+            await Task.Delay(100);
+        }
+
+        TestAgent.ReceivedMessages[nameof(ItDelegateMessageToTestAgentAsync)].Should().NotBeNull();
+    }
+
     /// <summary>
     /// The test agent is a simple agent that is used for testing purposes.
     /// </summary>
-    public class TestAgent : AgentBase, IHandle<string>, IHandle<int>
+    public class TestAgent : AgentBase, IHandle<string>, IHandle<int>, IHandle<TextMessage>
     {
-        public TestAgent(IAgentRuntime context, EventTypes eventTypes, Logger<AgentBase> logger) : base(context, eventTypes, logger)
+        public TestAgent(
+            IAgentRuntime context,
+            [FromKeyedServices("EventTypes")] EventTypes eventTypes,
+            Logger<AgentBase>? logger = null) : base(context, eventTypes, logger)
         {
         }
 
@@ -47,6 +78,49 @@ public Task Handle(int item)
             return Task.CompletedTask;
         }
 
+        public Task Handle(TextMessage item)
+        {
+            ReceivedMessages[item.Source] = item.TextMessage_;
+            return Task.CompletedTask;
+        }
+
         public List<object> ReceivedItems { get; private set; } = [];
+
+        /// <summary>
+        /// Key: source
+        /// Value: message
+        /// </summary>
+        public static ConcurrentDictionary<string, object> ReceivedMessages { get; private set; } = new();
+    }
+}
+
+public sealed class InMemoryAgentRuntimeFixture : IDisposable
+{
+    public InMemoryAgentRuntimeFixture()
+    {
+        var builder = Microsoft.Extensions.Hosting.Host.CreateApplicationBuilder();
+
+        // step 1: create in-memory agent runtime
+        // step 2: register TestAgent to that agent runtime
+        builder
+            .AddAgentService(local: true, useGrpc: false)
+            .AddAgentWorker(local: true)
+            .AddAgent<TestAgent>(nameof(TestAgent));
+
+        AppHost = builder.Build();
+        AppHost.StartAsync().Wait();
+    }
+    public IHost AppHost { get; }
+
+    void IDisposable.Dispose()
+    {
+        AppHost.StopAsync().Wait();
+        AppHost.Dispose();
     }
 }
+
+[CollectionDefinition(Name)]
+public sealed class ClusterFixtureCollection : ICollectionFixture<InMemoryAgentRuntimeFixture>
+{
+    public const string Name = nameof(ClusterFixtureCollection);
+}

dotnet/test/Microsoft.AutoGen.Agents.Tests/Microsoft.AutoGen.Agents.Tests.csproj

@@ -9,6 +9,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.AutoGen\Agents\Microsoft.AutoGen.Agents.csproj" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
   </ItemGroup>
 
 </Project>

protos/agent_events.proto

@@ -3,7 +3,10 @@ syntax = "proto3";
 package agents;
 
 option csharp_namespace = "Microsoft.AutoGen.Abstractions";
-
+message TextMessage {
+    string textMessage = 1;
+    string source = 2;
+}
 message Input {
       string message = 1;
 }