test

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AIntegrationTests.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Text.Json;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting.Server;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+public sealed class A2AIntegrationTests
+{
+    /// <summary>
+    /// Verifies that calling the A2A card endpoint with MapA2A returns an agent card with a URL populated.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WithAgentCard_CardEndpointReturnsCardWithUrlAsync()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.WebHost.UseTestServer();
+
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("test-agent", "Test instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication",
+            Version = "1.0"
+        };
+
+        // Map A2A with the agent card
+        app.MapA2A(agentBuilder, "/a2a/test-agent", agentCard);
+
+        await app.StartAsync();
+
+        try
+        {
+            // Get the test server client
+            TestServer testServer = app.Services.GetRequiredService<IServer>() as TestServer
+                ?? throw new InvalidOperationException("TestServer not found");
+            var httpClient = testServer.CreateClient();
+
+            // Act - Query the agent card endpoint
+            var requestUri = new Uri("/a2a/test-agent/v1/card", UriKind.Relative);
+            var response = await httpClient.GetAsync(requestUri);
+
+            // Assert
+            Assert.True(response.IsSuccessStatusCode, $"Expected successful response but got {response.StatusCode}");
+
+            var content = await response.Content.ReadAsStringAsync();
+            var jsonDoc = JsonDocument.Parse(content);
+            var root = jsonDoc.RootElement;
+
+            // Verify the card has expected properties
+            Assert.True(root.TryGetProperty("name", out var nameProperty));
+            Assert.Equal("Test Agent", nameProperty.GetString());
+
+            Assert.True(root.TryGetProperty("description", out var descProperty));
+            Assert.Equal("A test agent for A2A communication", descProperty.GetString());
+
+            // Verify the card has a URL property and it's not null/empty
+            Assert.True(root.TryGetProperty("url", out var urlProperty));
+            Assert.NotEqual(JsonValueKind.Null, urlProperty.ValueKind);
+
+            var url = urlProperty.GetString();
+            Assert.NotNull(url);
+            Assert.NotEmpty(url);
+            Assert.StartsWith("http", url, StringComparison.OrdinalIgnoreCase);
+
+            // agentCard's URL matches the agent endpoint
+            Assert.Equal($"{testServer.BaseAddress.ToString().TrimEnd('/')}/a2a/test-agent", url);
+        }
+        finally
+        {
+            await app.StopAsync();
+        }
+    }
+}

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

@@ -0,0 +1,218 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Extensions.AI;
+using Moq;
+using Moq.Protected;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Unit tests for the <see cref="AIAgentExtensions"/> class.
+/// </summary>
+public sealed class AIAgentExtensionsTests
+{
+    /// <summary>
+    /// Verifies that when messageSendParams.Metadata is null, the options passed to RunAsync are null.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenMetadataIsNull_PassesNullOptionsToRunAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
+
+        // Act
+        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
+            Metadata = null
+        });
+
+        // Assert
+        Assert.Null(capturedOptions);
+    }
+
+    /// <summary>
+    /// Verifies that when messageSendParams.Metadata has values, the options.AdditionalProperties contains the converted values.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenMetadataHasValues_PassesOptionsWithAdditionalPropertiesToRunAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
+
+        // Act
+        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
+            Metadata = new Dictionary<string, JsonElement>
+            {
+                ["key1"] = JsonSerializer.SerializeToElement("value1"),
+                ["key2"] = JsonSerializer.SerializeToElement(42)
+            }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.NotNull(capturedOptions.AdditionalProperties);
+        Assert.Equal(2, capturedOptions.AdditionalProperties.Count);
+        Assert.True(capturedOptions.AdditionalProperties.ContainsKey("key1"));
+        Assert.True(capturedOptions.AdditionalProperties.ContainsKey("key2"));
+    }
+
+    /// <summary>
+    /// Verifies that when messageSendParams.Metadata is an empty dictionary, the options passed to RunAsync is null
+    /// because the ToAdditionalProperties extension method returns null for empty dictionaries.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenMetadataIsEmptyDictionary_PassesNullOptionsToRunAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
+
+        // Act
+        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
+            Metadata = []
+        });
+
+        // Assert
+        Assert.Null(capturedOptions);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has AdditionalProperties, the returned AgentMessage.Metadata contains the converted values.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenResponseHasAdditionalProperties_ReturnsAgentMessageWithMetadataAsync()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProps = new()
+        {
+            ["responseKey1"] = "responseValue1",
+            ["responseKey2"] = 123
+        };
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = additionalProps
+        };
+        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
+
+        // Act
+        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
+        });
+
+        // Assert
+        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
+        Assert.NotNull(agentMessage.Metadata);
+        Assert.Equal(2, agentMessage.Metadata.Count);
+        Assert.True(agentMessage.Metadata.ContainsKey("responseKey1"));
+        Assert.True(agentMessage.Metadata.ContainsKey("responseKey2"));
+        Assert.Equal("responseValue1", agentMessage.Metadata["responseKey1"].GetString());
+        Assert.Equal(123, agentMessage.Metadata["responseKey2"].GetInt32());
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has null AdditionalProperties, the returned AgentMessage.Metadata is null.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenResponseHasNullAdditionalProperties_ReturnsAgentMessageWithNullMetadataAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = null
+        };
+        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
+
+        // Act
+        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
+        });
+
+        // Assert
+        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
+        Assert.Null(agentMessage.Metadata);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has empty AdditionalProperties, the returned AgentMessage.Metadata is null.
+    /// </summary>
+    [Fact]
+    public async Task MapA2A_WhenResponseHasEmptyAdditionalProperties_ReturnsAgentMessageWithNullMetadataAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = []
+        };
+        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
+
+        // Act
+        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
+        {
+            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
+        });
+
+        // Assert
+        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
+        Assert.Null(agentMessage.Metadata);
+    }
+
+    private static Mock<AIAgent> CreateAgentMock(Action<AgentRunOptions?> optionsCallback)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock.Setup(x => x.GetNewThreadAsync()).ReturnsAsync(new TestAgentThread());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentThread?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Callback<IEnumerable<ChatMessage>, AgentThread?, AgentRunOptions?, CancellationToken>(
+                (_, _, options, _) => optionsCallback(options))
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Test response")]));
+
+        return agentMock;
+    }
+
+    private static Mock<AIAgent> CreateAgentMockWithResponse(AgentResponse response)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock.Setup(x => x.GetNewThreadAsync()).ReturnsAsync(new TestAgentThread());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentThread?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(response);
+
+        return agentMock;
+    }
+
+    private static async Task<A2AResponse> InvokeOnMessageReceivedAsync(ITaskManager taskManager, MessageSendParams messageSendParams)
+    {
+        Func<MessageSendParams, CancellationToken, Task<A2AResponse>>? handler = taskManager.OnMessageReceived;
+        Assert.NotNull(handler);
+        return await handler.Invoke(messageSendParams, CancellationToken.None);
+    }
+
+    private sealed class TestAgentThread : AgentThread;
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/AdditionalPropertiesDictionaryExtensionsTests.cs

@@ -0,0 +1,187 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Generic;
+using System.Text.Json;
+using Microsoft.Agents.AI.Hosting.A2A.Converters;
+using Microsoft.Extensions.AI;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests.Converters;
+
+/// <summary>
+/// Unit tests for the <see cref="AdditionalPropertiesDictionaryExtensions"/> class.
+/// </summary>
+public sealed class AdditionalPropertiesDictionaryExtensionsTests
+{
+    [Fact]
+    public void ToA2AMetadata_WithNullAdditionalProperties_ReturnsNull()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary? additionalProperties = null;
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithEmptyAdditionalProperties_ReturnsNull()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = [];
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithStringValue_ReturnsMetadataWithJsonElement()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "stringKey", "stringValue" }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("stringKey"));
+        Assert.Equal("stringValue", result["stringKey"].GetString());
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithNumericValue_ReturnsMetadataWithJsonElement()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "numberKey", 42 }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("numberKey"));
+        Assert.Equal(42, result["numberKey"].GetInt32());
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithBooleanValue_ReturnsMetadataWithJsonElement()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "booleanKey", true }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("booleanKey"));
+        Assert.True(result["booleanKey"].GetBoolean());
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithMultipleProperties_ReturnsMetadataWithAllProperties()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "stringKey", "stringValue" },
+            { "numberKey", 42 },
+            { "booleanKey", true }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Equal(3, result.Count);
+
+        Assert.True(result.ContainsKey("stringKey"));
+        Assert.Equal("stringValue", result["stringKey"].GetString());
+
+        Assert.True(result.ContainsKey("numberKey"));
+        Assert.Equal(42, result["numberKey"].GetInt32());
+
+        Assert.True(result.ContainsKey("booleanKey"));
+        Assert.True(result["booleanKey"].GetBoolean());
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithArrayValue_ReturnsMetadataWithJsonElement()
+    {
+        // Arrange
+        int[] arrayValue = [1, 2, 3];
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "arrayKey", arrayValue }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("arrayKey"));
+        Assert.Equal(JsonValueKind.Array, result["arrayKey"].ValueKind);
+        Assert.Equal(3, result["arrayKey"].GetArrayLength());
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithNullValue_ReturnsMetadataWithNullJsonElement()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "nullKey", null! }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("nullKey"));
+        Assert.Equal(JsonValueKind.Null, result["nullKey"].ValueKind);
+    }
+
+    [Fact]
+    public void ToA2AMetadata_WithJsonElementValue_ReturnsMetadataWithJsonElement()
+    {
+        // Arrange
+        JsonElement jsonElement = JsonSerializer.SerializeToElement(new { name = "test", value = 123 });
+        AdditionalPropertiesDictionary additionalProperties = new()
+        {
+            { "jsonElementKey", jsonElement }
+        };
+
+        // Act
+        Dictionary<string, JsonElement>? result = additionalProperties.ToA2AMetadata();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Single(result);
+        Assert.True(result.ContainsKey("jsonElementKey"));
+        Assert.Equal(JsonValueKind.Object, result["jsonElementKey"].ValueKind);
+        Assert.Equal("test", result["jsonElementKey"].GetProperty("name").GetString());
+        Assert.Equal(123, result["jsonElementKey"].GetProperty("value").GetInt32());
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs

@@ -0,0 +1,85 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Linq;
+using A2A;
+using Microsoft.Agents.AI.Hosting.A2A.Converters;
+using Microsoft.Extensions.AI;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests.Converters;
+
+public class MessageConverterTests
+{
+    [Fact]
+    public void ToChatMessages_MessageSendParams_Null_ReturnsEmptyCollection()
+    {
+        MessageSendParams? messageSendParams = null;
+
+        var result = messageSendParams!.ToChatMessages();
+
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToChatMessages_MessageSendParams_WithNullMessage_ReturnsEmptyCollection()
+    {
+        var messageSendParams = new MessageSendParams
+        {
+            Message = null!
+        };
+
+        var result = messageSendParams.ToChatMessages();
+
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToChatMessages_MessageSendParams_WithMessageWithoutParts_ReturnsEmptyCollection()
+    {
+        var messageSendParams = new MessageSendParams
+        {
+            Message = new AgentMessage
+            {
+                MessageId = "test-id",
+                Role = MessageRole.User,
+                Parts = null!
+            }
+        };
+
+        var result = messageSendParams.ToChatMessages();
+
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToChatMessages_MessageSendParams_WithValidTextMessage_ReturnsCorrectChatMessage()
+    {
+        var messageSendParams = new MessageSendParams
+        {
+            Message = new AgentMessage
+            {
+                MessageId = "test-id",
+                Role = MessageRole.User,
+                Parts =
+                [
+                    new TextPart { Text = "Hello, world!" }
+                ]
+            }
+        };
+
+        var result = messageSendParams.ToChatMessages();
+
+        Assert.NotNull(result);
+        Assert.Single(result);
+
+        var chatMessage = result.First();
+        Assert.Equal("test-id", chatMessage.MessageId);
+        Assert.Equal(ChatRole.User, chatMessage.Role);
+        Assert.Single(chatMessage.Contents);
+
+        var textContent = Assert.IsType<TextContent>(chatMessage.Contents.First());
+        Assert.Equal("Hello, world!", textContent.Text);
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/EndpointRouteA2ABuilderExtensionsTests.cs

@@ -0,0 +1,479 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using A2A;
+using Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Tests for MicrosoftAgentAIHostingA2AEndpointRouteBuilderExtensions.MapA2A method.
+/// </summary>
+public sealed class EndpointRouteA2ABuilderExtensionsTests
+{
+    /// <summary>
+    /// Verifies that MapA2A throws ArgumentNullException for null endpoints.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2A(agentBuilder, "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A throws ArgumentNullException for null agentBuilder.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_NullAgentBuilder_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        IHostedAgentBuilder agentBuilder = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2A(agentBuilder, "/a2a"));
+
+        Assert.Equal("agentBuilder", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with IHostedAgentBuilder correctly maps the agent with default task manager configuration.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agentBuilder, "/a2a");
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with IHostedAgentBuilder and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_CustomTaskManagerConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agentBuilder, "/a2a", taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with IHostedAgentBuilder and agent card succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_WithAgentCard_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agentBuilder, "/a2a", agentCard);
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with IHostedAgentBuilder, agent card, and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_WithAgentCardAndCustomConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agentBuilder, "/a2a", agentCard, taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using string agent name.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentName_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2A("agent", "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with string agent name correctly maps the agent.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentName_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A("agent", "/a2a");
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with string agent name and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentName_CustomTaskManagerConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A("agent", "/a2a", taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with string agent name and agent card succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentName_WithAgentCard_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A("agent", "/a2a", agentCard);
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with string agent name, agent card, and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentName_WithAgentCardAndCustomConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A("agent", "/a2a", agentCard, taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using AIAgent.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAIAgent_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2A((AIAgent)null!, "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with AIAgent correctly maps the agent.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAIAgent_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agent, "/a2a");
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with AIAgent and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAIAgent_CustomTaskManagerConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agent, "/a2a", taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with AIAgent and agent card succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAIAgent_WithAgentCard_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agent, "/a2a", agentCard);
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A with AIAgent, agent card, and custom task manager configuration succeeds.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAIAgent_WithAgentCardAndCustomConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A test agent for A2A communication"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agent, "/a2a", agentCard, taskManager => { });
+        Assert.NotNull(result);
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using ITaskManager.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithTaskManager_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+        ITaskManager taskManager = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2A(taskManager, "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that multiple agents can be mapped to different paths.
+    /// </summary>
+    [Fact]
+    public void MapA2A_MultipleAgents_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agent1Builder = builder.AddAIAgent("agent1", "Instructions1", chatClientServiceKey: "chat-client");
+        IHostedAgentBuilder agent2Builder = builder.AddAIAgent("agent2", "Instructions2", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        app.MapA2A(agent1Builder, "/a2a/agent1");
+        app.MapA2A(agent2Builder, "/a2a/agent2");
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that custom paths can be specified for A2A endpoints.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithCustomPath_AcceptsValidPath()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        app.MapA2A(agentBuilder, "/custom/a2a/path");
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that task manager configuration callback is invoked correctly.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_TaskManagerConfigurationCallbackInvoked()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        bool configureCallbackInvoked = false;
+
+        // Act
+        app.MapA2A(agentBuilder, "/a2a", taskManager =>
+        {
+            configureCallbackInvoked = true;
+            Assert.NotNull(taskManager);
+        });
+
+        // Assert
+        Assert.True(configureCallbackInvoked);
+    }
+
+    /// <summary>
+    /// Verifies that agent card with all properties is accepted.
+    /// </summary>
+    [Fact]
+    public void MapA2A_WithAgentBuilder_FullAgentCard_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        var agentCard = new AgentCard
+        {
+            Name = "Test Agent",
+            Description = "A comprehensive test agent"
+        };
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2A(agentBuilder, "/a2a", agentCard);
+        Assert.NotNull(result);
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Internal/DummyChatClient.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.AI;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
+
+internal sealed class DummyChatClient : IChatClient
+{
+    public void Dispose()
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task<ChatResponse> GetResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default)
+    {
+        throw new NotImplementedException();
+    }
+
+    public object? GetService(Type serviceType, object? serviceKey = null) =>
+        serviceType.IsInstanceOfType(this) ? this : null;
+
+    public IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default)
+    {
+        throw new NotImplementedException();
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Microsoft.Agents.AI.Hosting.A2A.UnitTests.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.TestHost"  />
+  </ItemGroup>
+
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" />
+    <PackageReference Include="System.Linq.AsyncEnumerable" />
+  </ItemGroup>
+  
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Microsoft.Agents.AI.Hosting.A2A.AspNetCore\Microsoft.Agents.AI.Hosting.A2A.AspNetCore.csproj" />
+    <ProjectReference Include="..\..\src\Microsoft.Agents.AI.Hosting.A2A\Microsoft.Agents.AI.Hosting.A2A.csproj" />
+  </ItemGroup>
+
+</Project>