Add AddOllamaChatClient extensions for IChatClient interface

[rogerbarreto]

Summary

Implements missing AddOllamaChatClient extension methods for the Ollama Connector targeting the IChatClient interface, following the same patterns as existing IChatCompletionService extensions.

Changes

🔧 Extension Methods Added

IServiceCollection Extensions (in OllamaServiceCollectionExtensions.DependencyInjection.cs):

• AddOllamaChatClient(modelId, endpoint, serviceId) - Using URI endpoint
• AddOllamaChatClient(modelId, httpClient, serviceId) - Using HttpClient
• AddOllamaChatClient(ollamaClient, serviceId) - Using existing OllamaApiClient

IKernelBuilder Extensions (in OllamaKernelBuilderExtensions.cs):

• AddOllamaChatClient(modelId, endpoint, serviceId) - Using URI endpoint
• AddOllamaChatClient(modelId, httpClient, serviceId) - Using HttpClient
• AddOllamaChatClient(ollamaClient, serviceId) - Using existing OllamaApiClient

🧪 Comprehensive Testing

Unit Tests Created:

• OllamaServiceCollectionExtensionsChatClientTests.cs - 7 tests for service collection extensions
• OllamaKernelBuilderExtensionsChatClientTests.cs - 6 tests for kernel builder extensions
• OllamaChatClientTests.cs - 12 tests for IChatClient functionality

Integration Tests Created:

• OllamaChatClientIntegrationTests.cs - 7 integration tests

🎯 Key Features

• Same Signature Patterns: All extensions follow the exact same parameter signatures as existing IChatCompletionService extensions
• IChatClient Target: Returns IChatClient instead of IChatCompletionService
• Function Calling Support: Includes UseKernelFunctionInvocation() for function calling capabilities
• No Experimental Attributes: Correctly inherits experimental nature from assembly-level [assembly: Experimental("SKEXP0070")]
• Performance Optimized: All analyzer warnings resolved
• Code Formatted: All files properly formatted with dotnet format

Test Results

• ✅ 101 Tests Passing
• ⏭️ 1 Test Skipped (expected - AutoFunctionInvocationFilter not supported)
• ❌ 0 Tests Failed
• ⚠️ 0 Warnings
• 🏗️ Clean Build

Usage Examples

// Service Collection
services.AddOllamaChatClient("llama3.2", new Uri("http://localhost:11434"), "my-ollama");

// Kernel Builder
var kernel = Kernel.CreateBuilder()
    .AddOllamaChatClient("llama3.2", new Uri("http://localhost:11434"))
    .Build();

// Direct Usage
var chatClient = kernel.GetRequiredService<IChatClient>();
var response = await chatClient.GetResponseAsync(messages);

Files Modified/Created

Modified:

• dotnet/src/Connectors/Connectors.Ollama/Extensions/OllamaServiceCollectionExtensions.DependencyInjection.cs
• dotnet/src/Connectors/Connectors.Ollama/Extensions/OllamaKernelBuilderExtensions.cs

Created:

• dotnet/src/Connectors/Connectors.Ollama.UnitTests/Extensions/OllamaServiceCollectionExtensionsChatClientTests.cs
• dotnet/src/Connectors/Connectors.Ollama.UnitTests/Extensions/OllamaKernelBuilderExtensionsChatClientTests.cs
• dotnet/src/Connectors/Connectors.Ollama.UnitTests/Services/OllamaChatClientTests.cs
• dotnet/src/IntegrationTests/Connectors/Ollama/OllamaChatClientIntegrationTests.cs

The implementation is production-ready, follows all established patterns, includes comprehensive testing, and provides the same functionality as existing IChatCompletionService extensions but targeting the IChatClient interface instead.

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Pull Request opened by Augment Code with guidance from the PR author