address copilot initial feedback

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AServerServiceCollectionExtensionsTests.cs

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+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Moq.Protected;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Unit tests for the <see cref="A2AServerServiceCollectionExtensions"/> class.
+/// </summary>
+public sealed class A2AServerServiceCollectionExtensionsTests
+{
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent name registers a keyed A2AServer
+    /// that can be resolved from the service provider.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithAgentName_ResolvesKeyedA2AServerAsync()
+    {
+        // Arrange
+        const string AgentName = "test-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance registers a keyed A2AServer
+    /// that can be resolved from the service provider using the agent's name.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithAgentInstance_ResolvesKeyedA2AServerAsync()
+    {
+        // Arrange
+        const string AgentName = "instance-agent";
+        var agentMock = CreateAgentMock(AgentName);
+        var services = new ServiceCollection();
+
+        // Act
+        services.AddA2AServer(agentMock.Object);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when no ITaskStore or AgentSessionStore are registered,
+    /// AddA2AServer falls back to in-memory defaults and resolves successfully.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithNoCustomStores_FallsBackToInMemoryDefaultsAsync()
+    {
+        // Arrange
+        const string AgentName = "default-stores-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert - resolution succeeds without any stores registered
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom ITaskStore is registered, AddA2AServer uses it
+    /// instead of the default InMemoryTaskStore.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomTaskStore_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-taskstore-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockTaskStore = new Mock<ITaskStore>();
+        services.AddKeyedSingleton(AgentName, mockTaskStore.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom AgentSessionStore is registered, AddA2AServer uses it
+    /// instead of the default InMemoryAgentSessionStore.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomAgentSessionStore_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-sessionstore-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        services.AddKeyedSingleton(AgentName, mockSessionStore.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom IAgentHandler is registered, AddA2AServer uses it
+    /// instead of creating a default A2AAgentHandler.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomAgentHandler_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-handler-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockHandler = new Mock<IAgentHandler>();
+        services.AddKeyedSingleton(AgentName, mockHandler.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that the configureOptions callback is invoked when provided.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithConfigureOptions_InvokesCallbackAsync()
+    {
+        // Arrange
+        const string AgentName = "options-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        bool callbackInvoked = false;
+
+        // Act
+        services.AddA2AServer(AgentName, options =>
+        {
+            callbackInvoked = true;
+            options.AgentRunMode = AgentRunMode.AllowBackgroundIfSupported;
+        });
+
+        // Assert - callback is invoked during resolution
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+        Assert.True(callbackInvoked);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with a null configureOptions does not throw.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithNullConfigureOptions_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "null-options-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName, configureOptions: null);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the agent name is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => services.AddA2AServer(agentName: null!));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the agent name is whitespace.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithWhitespaceAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => services.AddA2AServer(agentName: "  "));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the services parameter is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullServices_ThrowsArgumentNullException()
+    {
+        // Arrange
+        IServiceCollection services = null!;
+
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => services.AddA2AServer("agent"));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance throws when the agent is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullAgent_ThrowsArgumentNullException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => services.AddA2AServer(agent: null!));
+    }
+
+    private static Mock<AIAgent> CreateAgentMock(string name)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns(name);
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Test response")]));
+
+        return agentMock;
+    }
+
+    private sealed class TestAgentSession : AgentSession;
+}