Add Google.GenAI ChatClient support with IChatClient polyfill

dotnet/Directory.Packages.props

@@ -35,6 +35,7 @@
     <PackageVersion Include="FastBertTokenizer" Version="1.0.28" />
     <PackageVersion Include="Google.Apis.Auth" Version="1.72.0" />
     <PackageVersion Include="Google.Apis.CustomSearchAPI.v1" Version="1.68.0.3520" />
+    <PackageVersion Include="Google.GenAI" Version="0.6.0" />
     <PackageVersion Include="Google.Protobuf" Version="3.32.1" />
     <PackageVersion Include="Grpc.AspNetCore" Version="2.71.0" />
     <PackageVersion Include="Grpc.AspNetCore.Server" Version="2.70.0" />

dotnet/src/Connectors/Connectors.Google.UnitTests/Connectors.Google.UnitTests.csproj

@@ -25,6 +25,7 @@
     </PackageReference>
     <PackageReference Include="System.Numerics.Tensors" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
+    <PackageReference Include="Google.GenAI" />
   </ItemGroup>
 
   <ItemGroup>

dotnet/src/Connectors/Connectors.Google.UnitTests/Extensions/GoogleAIServiceCollectionExtensionsTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using Google.GenAI;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.SemanticKernel;
@@ -113,4 +114,147 @@ public void GoogleAIEmbeddingGeneratorShouldBeRegisteredInServiceCollection()
         Assert.NotNull(embeddingsGenerationService);
         Assert.IsType<GoogleAIEmbeddingGenerator>(embeddingsGenerationService);
     }
+
+#if NET
+    [Fact]
+    public void GoogleGenAIChatClientShouldBeRegisteredInKernelServicesWithApiKey()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act
+        kernelBuilder.AddGoogleGenAIChatClient("modelId", "apiKey");
+        var kernel = kernelBuilder.Build();
+
+        // Assert
+        var chatClient = kernel.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GoogleGenAIChatClientShouldBeRegisteredInServiceCollectionWithApiKey()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act
+        services.AddGoogleGenAIChatClient("modelId", "apiKey");
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert
+        var chatClient = serviceProvider.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GoogleVertexAIChatClientShouldBeRegisteredInKernelServices()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act
+        kernelBuilder.AddGoogleVertexAIChatClient("modelId", project: "test-project", location: "us-central1");
+
+        // Assert - just verify no exception during registration
+        // Resolution requires real credentials, so skip that in unit tests
+        var kernel = kernelBuilder.Build();
+        Assert.NotNull(kernel.Services);
+    }
+
+    [Fact]
+    public void GoogleVertexAIChatClientShouldBeRegisteredInServiceCollection()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act
+        services.AddGoogleVertexAIChatClient("modelId", project: "test-project", location: "us-central1");
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert - just verify no exception during registration
+        // Resolution requires real credentials, so skip that in unit tests
+        Assert.NotNull(serviceProvider);
+    }
+
+    [Fact]
+    public void GoogleAIChatClientShouldBeRegisteredInKernelServicesWithClient()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+        using var googleClient = new Client(apiKey: "apiKey");
+
+        // Act
+        kernelBuilder.AddGoogleAIChatClient("modelId", googleClient);
+        var kernel = kernelBuilder.Build();
+
+        // Assert
+        var chatClient = kernel.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GoogleAIChatClientShouldBeRegisteredInServiceCollectionWithClient()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        using var googleClient = new Client(apiKey: "apiKey");
+
+        // Act
+        services.AddGoogleAIChatClient("modelId", googleClient);
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert
+        var chatClient = serviceProvider.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GoogleGenAIChatClientShouldBeRegisteredWithServiceId()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        const string serviceId = "test-service-id";
+
+        // Act
+        services.AddGoogleGenAIChatClient("modelId", "apiKey", serviceId: serviceId);
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert
+        var chatClient = serviceProvider.GetKeyedService<IChatClient>(serviceId);
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GoogleVertexAIChatClientShouldBeRegisteredWithServiceId()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        const string serviceId = "test-service-id";
+
+        // Act
+        services.AddGoogleVertexAIChatClient("modelId", project: "test-project", location: "us-central1", serviceId: serviceId);
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert - just verify no exception during registration
+        // Resolution requires real credentials, so skip that in unit tests
+        Assert.NotNull(serviceProvider);
+    }
+
+    [Fact]
+    public void GoogleAIChatClientShouldResolveFromServiceProviderWhenClientNotProvided()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        using var googleClient = new Client(apiKey: "apiKey");
+        services.AddSingleton(googleClient);
+
+        // Act
+        services.AddGoogleAIChatClient("modelId");
+        var serviceProvider = services.BuildServiceProvider();
+
+        // Assert
+        var chatClient = serviceProvider.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+#endif
 }

dotnet/src/Connectors/Connectors.Google.UnitTests/Services/GoogleGeminiChatClientTests.cs

@@ -0,0 +1,161 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+#if NET
+
+using System;
+using Google.GenAI;
+using Microsoft.Extensions.AI;
+using Microsoft.SemanticKernel;
+using Xunit;
+
+namespace SemanticKernel.Connectors.Google.UnitTests.Services;
+
+public sealed class GoogleGeminiChatClientTests
+{
+    [Fact]
+    public void GenAIChatClientShouldBeCreatedWithApiKey()
+    {
+        // Arrange
+        string modelId = "gemini-1.5-pro";
+        string apiKey = "test-api-key";
+
+        // Act
+        var kernelBuilder = Kernel.CreateBuilder();
+        kernelBuilder.AddGoogleGenAIChatClient(modelId, apiKey);
+        var kernel = kernelBuilder.Build();
+
+        // Assert
+        var chatClient = kernel.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void VertexAIChatClientShouldBeCreated()
+    {
+        // Arrange
+        string modelId = "gemini-1.5-pro";
+
+        // Act
+        var kernelBuilder = Kernel.CreateBuilder();
+        kernelBuilder.AddGoogleVertexAIChatClient(modelId, project: "test-project", location: "us-central1");
+        var kernel = kernelBuilder.Build();
+
+        // Assert - just verify no exception during registration
+        // Resolution requires real credentials, so skip that in unit tests
+        Assert.NotNull(kernel.Services);
+    }
+
+    [Fact]
+    public void ChatClientShouldBeCreatedWithGoogleClient()
+    {
+        // Arrange
+        string modelId = "gemini-1.5-pro";
+        using var googleClient = new Client(apiKey: "test-api-key");
+
+        // Act
+        var kernelBuilder = Kernel.CreateBuilder();
+        kernelBuilder.AddGoogleAIChatClient(modelId, googleClient);
+        var kernel = kernelBuilder.Build();
+
+        // Assert
+        var chatClient = kernel.GetRequiredService<IChatClient>();
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void GenAIChatClientShouldBeCreatedWithServiceId()
+    {
+        // Arrange
+        string modelId = "gemini-1.5-pro";
+        string apiKey = "test-api-key";
+        string serviceId = "test-service";
+
+        // Act
+        var kernelBuilder = Kernel.CreateBuilder();
+        kernelBuilder.AddGoogleGenAIChatClient(modelId, apiKey, serviceId: serviceId);
+        var kernel = kernelBuilder.Build();
+
+        // Assert
+        var chatClient = kernel.GetRequiredService<IChatClient>(serviceId);
+        Assert.NotNull(chatClient);
+    }
+
+    [Fact]
+    public void VertexAIChatClientShouldBeCreatedWithServiceId()
+    {
+        // Arrange
+        string modelId = "gemini-1.5-pro";
+        string serviceId = "test-service";
+
+        // Act
+        var kernelBuilder = Kernel.CreateBuilder();
+        kernelBuilder.AddGoogleVertexAIChatClient(modelId, project: "test-project", location: "us-central1", serviceId: serviceId);
+        var kernel = kernelBuilder.Build();
+
+        // Assert - just verify no exception during registration
+        // Resolution requires real credentials, so skip that in unit tests
+        Assert.NotNull(kernel.Services);
+    }
+
+    [Fact]
+    public void GenAIChatClientThrowsForNullModelId()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleGenAIChatClient(null!, "apiKey"));
+    }
+
+    [Fact]
+    public void GenAIChatClientThrowsForEmptyModelId()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleGenAIChatClient("", "apiKey"));
+    }
+
+    [Fact]
+    public void GenAIChatClientThrowsForNullApiKey()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleGenAIChatClient("modelId", null!));
+    }
+
+    [Fact]
+    public void GenAIChatClientThrowsForEmptyApiKey()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleGenAIChatClient("modelId", ""));
+    }
+
+    [Fact]
+    public void VertexAIChatClientThrowsForNullModelId()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleVertexAIChatClient(null!, project: "test-project", location: "us-central1"));
+    }
+
+    [Fact]
+    public void VertexAIChatClientThrowsForEmptyModelId()
+    {
+        // Arrange
+        var kernelBuilder = Kernel.CreateBuilder();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => kernelBuilder.AddGoogleVertexAIChatClient("", project: "test-project", location: "us-central1"));
+    }
+}
+
+#endif

dotnet/src/Connectors/Connectors.Google/Connectors.Google.csproj

@@ -24,6 +24,11 @@
     <ProjectReference Include="..\..\SemanticKernel.Core\SemanticKernel.Core.csproj" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0' or '$(TargetFramework)' == 'net9.0' or '$(TargetFramework)' == 'net10.0'">
+    <PackageReference Include="Google.GenAI" />
+    <PackageReference Include="Google.Apis.Auth" />
+  </ItemGroup>
+
   <ItemGroup>
     <InternalsVisibleTo Include="SemanticKernel.Connectors.GoogleVertexAI.UnitTests" />
     <InternalsVisibleTo Include="DynamicProxyGenAssembly2" />