.Net: Add FunctionChoiceBehavior support to Google Gemini connector

dotnet/src/IntegrationTests/Connectors/Google/Gemini/GeminiChatClientFunctionCallingTests.cs

@@ -0,0 +1,239 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.AI;
+using Microsoft.SemanticKernel;
+using Microsoft.SemanticKernel.ChatCompletion;
+using Microsoft.SemanticKernel.Connectors.Google;
+using xRetry;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace SemanticKernel.IntegrationTests.Connectors.Google.Gemini;
+
+public sealed class GeminiChatClientFunctionCallingTests(ITestOutputHelper output) : TestsBase(output)
+{
+    private const string SkipMessage = "This test is for manual verification.";
+
+    [RetryTheory(Skip = SkipMessage)]
+    [InlineData(ServiceType.GoogleAI, true)]
+    [InlineData(ServiceType.VertexAI, false)]
+    public async Task ChatClientWithAutoFunctionChoiceBehaviorCallsKernelFunctionAsync(ServiceType serviceType, bool isBeta)
+    {
+        // Arrange
+        var chatCompletionService = this.GetChatService(serviceType, isBeta);
+        var chatClient = chatCompletionService.AsChatClient();
+
+        var kernel = new Kernel();
+        kernel.ImportPluginFromType<LightsPlugin>();
+
+        var settings = new GeminiPromptExecutionSettings
+        {
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto()
+        };
+        var chatOptions = settings.ToChatOptions(kernel);
+
+        var messages = new List<ChatMessage>
+        {
+            new(ChatRole.User, "Turn on the table lamp")
+        };
+
+        // Act
+        var response = await chatClient.GetResponseAsync(messages, chatOptions);
+
+        // Assert
+        Assert.NotNull(response);
+
+        // The response should indicate the function was called
+        // Since we're using auto-invoke, the function result should be in the chat history
+        var responseText = string.Join(" ", response.Messages.Select(m => m.Text));
+        this.Output.WriteLine($"Response: {responseText}");
+    }
+
+    [RetryTheory(Skip = SkipMessage)]
+    [InlineData(ServiceType.GoogleAI, true)]
+    [InlineData(ServiceType.VertexAI, false)]
+    public async Task ChatClientWithAutoFunctionChoiceBehaviorInvokesMultipleFunctionsAsync(ServiceType serviceType, bool isBeta)
+    {
+        // Arrange
+        var chatCompletionService = this.GetChatService(serviceType, isBeta);
+        var chatClient = chatCompletionService.AsChatClient();
+
+        var kernel = new Kernel();
+        kernel.ImportPluginFromType<LightsPlugin>();
+
+        var settings = new GeminiPromptExecutionSettings
+        {
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(autoInvoke: true)
+        };
+        var chatOptions = settings.ToChatOptions(kernel);
+
+        var messages = new List<ChatMessage>
+        {
+            new(ChatRole.User, "Get the list of available lights and turn on the floor lamp")
+        };
+
+        // Act
+        var response = await chatClient.GetResponseAsync(messages, chatOptions);
+
+        // Assert
+        Assert.NotNull(response);
+
+        // The response should indicate both functions were called
+        var responseText = string.Join(" ", response.Messages.Select(m => m.Text));
+        this.Output.WriteLine($"Response: {responseText}");
+
+        // Verify the response mentions the lights and the floor lamp being turned on
+        Assert.NotEmpty(responseText);
+    }
+
+    [RetryTheory(Skip = SkipMessage)]
+    [InlineData(ServiceType.GoogleAI, true)]
+    [InlineData(ServiceType.VertexAI, false)]
+    public async Task ChatClientWithManualFunctionChoiceBehaviorReturnsFunctionCallsAsync(ServiceType serviceType, bool isBeta)
+    {
+        // Arrange
+        var chatCompletionService = this.GetChatService(serviceType, isBeta);
+        var chatClient = chatCompletionService.AsChatClient();
+
+        var kernel = new Kernel();
+        kernel.ImportPluginFromType<LightsPlugin>();
+
+        var settings = new GeminiPromptExecutionSettings
+        {
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(autoInvoke: false)
+        };
+        var chatOptions = settings.ToChatOptions(kernel);
+
+        var messages = new List<ChatMessage>
+        {
+            new(ChatRole.User, "Turn on the ceiling light")
+        };
+
+        // Act
+        var response = await chatClient.GetResponseAsync(messages, chatOptions);
+
+        // Assert
+        Assert.NotNull(response);
+
+        // Extract function calls from the response
+        var functionCalls = response.Messages
+            .SelectMany(m => m.Contents)
+            .OfType<Microsoft.Extensions.AI.FunctionCallContent>()
+            .ToList();
+
+        Assert.NotNull(functionCalls);
+        Assert.NotEmpty(functionCalls);
+
+        var functionCall = functionCalls.First();
+        this.Output.WriteLine($"Function call: {functionCall.Name}");
+
+        // Verify the function name contains the expected plugin and function
+        Assert.Contains("TurnOn", functionCall.Name, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [RetryTheory(Skip = SkipMessage)]
+    [InlineData(ServiceType.GoogleAI, true)]
+    [InlineData(ServiceType.VertexAI, false)]
+    public async Task ChatClientStreamingWithAutoFunctionChoiceBehaviorCallsKernelFunctionAsync(ServiceType serviceType, bool isBeta)
+    {
+        // Arrange
+        var chatCompletionService = this.GetChatService(serviceType, isBeta);
+        var chatClient = chatCompletionService.AsChatClient();
+
+        var kernel = new Kernel();
+        kernel.ImportPluginFromType<LightsPlugin>();
+
+        var settings = new GeminiPromptExecutionSettings
+        {
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(autoInvoke: true)
+        };
+        var chatOptions = settings.ToChatOptions(kernel);
+
+        var messages = new List<ChatMessage>
+        {
+            new(ChatRole.User, "Get the list of available lights")
+        };
+
+        string result = "";
+
+        // Act
+        await foreach (var update in chatClient.GetStreamingResponseAsync(messages, chatOptions))
+        {
+            foreach (var content in update.Contents)
+            {
+                if (content is Microsoft.Extensions.AI.TextContent textContent)
+                {
+                    result += textContent.Text;
+                }
+            }
+        }
+
+        // Assert
+        Assert.NotEmpty(result);
+        this.Output.WriteLine($"Streaming response: {result}");
+    }
+
+    /// <summary>
+    /// A plugin that provides light control functionality.
+    /// </summary>
+#pragma warning disable CA1812 // Avoid uninstantiated internal classes
+    private sealed class LightsPlugin
+#pragma warning restore CA1812
+    {
+        private readonly Dictionary<int, string> _lights = new()
+        {
+            { 1, "Table Lamp" },
+            { 2, "Floor Lamp" },
+            { 3, "Ceiling Light" }
+        };
+
+        private readonly HashSet<int> _lightsOn = new();
+
+        [KernelFunction]
+        [Description("Get a list of available lights")]
+        public string GetLights()
+        {
+            return string.Join(", ", this._lights.Select(kv => $"{kv.Key}: {kv.Value}"));
+        }
+
+        [KernelFunction]
+        [Description("Turn on a specific light")]
+        public string TurnOn([Description("The ID of the light to turn on")] int lightId)
+        {
+            if (!this._lights.TryGetValue(lightId, out var lightName))
+            {
+                return $"Light {lightId} not found";
+            }
+
+            this._lightsOn.Add(lightId);
+            return $"Turned on {lightName}";
+        }
+
+        [KernelFunction]
+        [Description("Turn off a specific light")]
+        public string TurnOff([Description("The ID of the light to turn off")] int lightId)
+        {
+            if (!this._lights.TryGetValue(lightId, out var lightName))
+            {
+                return $"Light {lightId} not found";
+            }
+
+            this._lightsOn.Remove(lightId);
+            return $"Turned off {lightName}";
+        }
+
+        [KernelFunction]
+        [Description("Get the status of all lights")]
+        public string GetStatus()
+        {
+            var status = this._lights.Select(kv =>
+                $"{kv.Value}: {(this._lightsOn.Contains(kv.Key) ? "On" : "Off")}");
+            return string.Join(", ", status);
+        }
+    }
+}