.Net: Gemini added support of system messages and removed messages order limitation

dotnet/samples/Concepts/ChatCompletion/Google_GeminiChatCompletion.cs

@@ -89,7 +89,7 @@ private async Task SimpleChatAsync(Kernel kernel)
     {
         Console.WriteLine("======== Simple Chat ========");
 
-        var chatHistory = new ChatHistory();
+        var chatHistory = new ChatHistory("You are an expert in the tool shop.");
         var chat = kernel.GetRequiredService<IChatCompletionService>();
 
         // First user message

dotnet/samples/Concepts/ChatCompletion/Google_GeminiChatCompletionStreaming.cs

@@ -90,7 +90,7 @@ private async Task StreamingChatAsync(Kernel kernel)
     {
         Console.WriteLine("======== Streaming Chat ========");
 
-        var chatHistory = new ChatHistory();
+        var chatHistory = new ChatHistory("You are an expert in the tool shop.");
         var chat = kernel.GetRequiredService<IChatCompletionService>();
 
         // First user message

dotnet/samples/Concepts/ChatCompletion/Google_GeminiVision.cs

@@ -14,7 +14,7 @@ public async Task GoogleAIAsync()
         Console.WriteLine("============= Google AI - Gemini Chat Completion with vision =============");
 
         string geminiApiKey = TestConfiguration.GoogleAI.ApiKey;
-        string geminiModelId = "gemini-pro-vision";
+        string geminiModelId = TestConfiguration.GoogleAI.Gemini.ModelId;
 
         if (geminiApiKey is null)
         {
@@ -28,7 +28,7 @@ public async Task GoogleAIAsync()
                 apiKey: geminiApiKey)
             .Build();
 
-        var chatHistory = new ChatHistory();
+        var chatHistory = new ChatHistory("Your job is describing images.");
         var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();
 
         // Load the image from the resources
@@ -55,7 +55,7 @@ public async Task VertexAIAsync()
         Console.WriteLine("============= Vertex AI - Gemini Chat Completion with vision =============");
 
         string geminiBearerKey = TestConfiguration.VertexAI.BearerKey;
-        string geminiModelId = "gemini-pro-vision";
+        string geminiModelId = TestConfiguration.VertexAI.Gemini.ModelId;
         string geminiLocation = TestConfiguration.VertexAI.Location;
         string geminiProject = TestConfiguration.VertexAI.ProjectId;
 
@@ -96,7 +96,7 @@ public async Task VertexAIAsync()
         //         location: TestConfiguration.VertexAI.Location,
         //         projectId: TestConfiguration.VertexAI.ProjectId);
 
-        var chatHistory = new ChatHistory();
+        var chatHistory = new ChatHistory("Your job is describing images.");
         var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();
 
         // Load the image from the resources

dotnet/src/Connectors/Connectors.Google.UnitTests/Core/Gemini/Clients/GeminiChatGenerationTests.cs

@@ -259,21 +259,7 @@ await Assert.ThrowsAsync<InvalidOperationException>(
     }
 
     [Fact]
-    public async Task ShouldThrowInvalidOperationExceptionIfChatHistoryContainsMoreThanOneSystemMessageAsync()
-    {
-        var client = this.CreateChatCompletionClient();
-        var chatHistory = new ChatHistory("System message");
-        chatHistory.AddSystemMessage("System message 2");
-        chatHistory.AddSystemMessage("System message 3");
-        chatHistory.AddUserMessage("hello");
-
-        // Act & Assert
-        await Assert.ThrowsAsync<InvalidOperationException>(
-            () => client.GenerateChatMessageAsync(chatHistory));
-    }
-
-    [Fact]
-    public async Task ShouldPassConvertedSystemMessageToUserMessageToRequestAsync()
+    public async Task ShouldPassSystemMessageToRequestAsync()
     {
         // Arrange
         var client = this.CreateChatCompletionClient();
@@ -287,40 +273,35 @@ public async Task ShouldPassConvertedSystemMessageToUserMessageToRequestAsync()
         // Assert
         GeminiRequest? request = JsonSerializer.Deserialize<GeminiRequest>(this._messageHandlerStub.RequestContent);
         Assert.NotNull(request);
-        var systemMessage = request.Contents[0].Parts![0].Text;
-        var messageRole = request.Contents[0].Role;
-        Assert.Equal(AuthorRole.User, messageRole);
+        Assert.NotNull(request.SystemInstruction);
+        var systemMessage = request.SystemInstruction.Parts![0].Text;
+        Assert.Null(request.SystemInstruction.Role);
         Assert.Equal(message, systemMessage);
     }
 
     [Fact]
-    public async Task ShouldThrowNotSupportedIfChatHistoryHaveIncorrectOrderAsync()
+    public async Task ShouldPassMultipleSystemMessagesToRequestAsync()
     {
         // Arrange
+        string[] messages = ["System message 1", "System message 2", "System message 3"];
         var client = this.CreateChatCompletionClient();
-        var chatHistory = new ChatHistory();
+        var chatHistory = new ChatHistory(messages[0]);
+        chatHistory.AddSystemMessage(messages[1]);
+        chatHistory.AddSystemMessage(messages[2]);
         chatHistory.AddUserMessage("Hello");
-        chatHistory.AddAssistantMessage("Hi");
-        chatHistory.AddAssistantMessage("Hi me again");
-        chatHistory.AddUserMessage("How are you?");
 
-        // Act & Assert
-        await Assert.ThrowsAsync<NotSupportedException>(
-            () => client.GenerateChatMessageAsync(chatHistory));
-    }
-
-    [Fact]
-    public async Task ShouldThrowNotSupportedIfChatHistoryNotEndWithUserMessageAsync()
-    {
-        // Arrange
-        var client = this.CreateChatCompletionClient();
-        var chatHistory = new ChatHistory();
-        chatHistory.AddUserMessage("Hello");
-        chatHistory.AddAssistantMessage("Hi");
+        // Act
+        await client.GenerateChatMessageAsync(chatHistory);
 
-        // Act & Assert
-        await Assert.ThrowsAsync<NotSupportedException>(
-            () => client.GenerateChatMessageAsync(chatHistory));
+        // Assert
+        GeminiRequest? request = JsonSerializer.Deserialize<GeminiRequest>(this._messageHandlerStub.RequestContent);
+        Assert.NotNull(request);
+        Assert.NotNull(request.SystemInstruction);
+        Assert.Null(request.SystemInstruction.Role);
+        Assert.Collection(request.SystemInstruction.Parts!,
+            item => Assert.Equal(messages[0], item.Text),
+            item => Assert.Equal(messages[1], item.Text),
+            item => Assert.Equal(messages[2], item.Text));
     }
 
     [Fact]

dotnet/src/Connectors/Connectors.Google.UnitTests/Core/Gemini/Clients/GeminiChatStreamingTests.cs

@@ -248,7 +248,7 @@ public async Task ShouldUsePromptExecutionSettingsAsync()
     }
 
     [Fact]
-    public async Task ShouldPassConvertedSystemMessageToUserMessageToRequestAsync()
+    public async Task ShouldPassSystemMessageToRequestAsync()
     {
         // Arrange
         var client = this.CreateChatCompletionClient();
@@ -262,12 +262,37 @@ public async Task ShouldPassConvertedSystemMessageToUserMessageToRequestAsync()
         // Assert
         GeminiRequest? request = JsonSerializer.Deserialize<GeminiRequest>(this._messageHandlerStub.RequestContent);
         Assert.NotNull(request);
-        var systemMessage = request.Contents[0].Parts![0].Text;
-        var messageRole = request.Contents[0].Role;
-        Assert.Equal(AuthorRole.User, messageRole);
+        Assert.NotNull(request.SystemInstruction);
+        var systemMessage = request.SystemInstruction.Parts![0].Text;
+        Assert.Null(request.SystemInstruction.Role);
         Assert.Equal(message, systemMessage);
     }
 
+    [Fact]
+    public async Task ShouldPassMultipleSystemMessagesToRequestAsync()
+    {
+        // Arrange
+        string[] messages = ["System message 1", "System message 2", "System message 3"];
+        var client = this.CreateChatCompletionClient();
+        var chatHistory = new ChatHistory(messages[0]);
+        chatHistory.AddSystemMessage(messages[1]);
+        chatHistory.AddSystemMessage(messages[2]);
+        chatHistory.AddUserMessage("Hello");
+
+        // Act
+        await client.StreamGenerateChatMessageAsync(chatHistory).ToListAsync();
+
+        // Assert
+        GeminiRequest? request = JsonSerializer.Deserialize<GeminiRequest>(this._messageHandlerStub.RequestContent);
+        Assert.NotNull(request);
+        Assert.NotNull(request.SystemInstruction);
+        Assert.Null(request.SystemInstruction.Role);
+        Assert.Collection(request.SystemInstruction.Parts!,
+            item => Assert.Equal(messages[0], item.Text),
+            item => Assert.Equal(messages[1], item.Text),
+            item => Assert.Equal(messages[2], item.Text));
+    }
+
     [Theory]
     [InlineData(0)]
     [InlineData(-15)]

dotnet/src/Connectors/Connectors.Google.UnitTests/Core/Gemini/GeminiRequestTests.cs

@@ -15,7 +15,7 @@ namespace SemanticKernel.Connectors.Google.UnitTests.Core.Gemini;
 public sealed class GeminiRequestTests
 {
     [Fact]
-    public void FromPromptItReturnsGeminiRequestWithConfiguration()
+    public void FromPromptItReturnsWithConfiguration()
     {
         // Arrange
         var prompt = "prompt-example";
@@ -37,7 +37,7 @@ public void FromPromptItReturnsGeminiRequestWithConfiguration()
     }
 
     [Fact]
-    public void FromPromptItReturnsGeminiRequestWithSafetySettings()
+    public void FromPromptItReturnsWithSafetySettings()
     {
         // Arrange
         var prompt = "prompt-example";
@@ -59,7 +59,7 @@ public void FromPromptItReturnsGeminiRequestWithSafetySettings()
     }
 
     [Fact]
-    public void FromPromptItReturnsGeminiRequestWithPrompt()
+    public void FromPromptItReturnsWithPrompt()
     {
         // Arrange
         var prompt = "prompt-example";
@@ -73,7 +73,7 @@ public void FromPromptItReturnsGeminiRequestWithPrompt()
     }
 
     [Fact]
-    public void FromChatHistoryItReturnsGeminiRequestWithConfiguration()
+    public void FromChatHistoryItReturnsWithConfiguration()
     {
         // Arrange
         ChatHistory chatHistory = [];
@@ -98,7 +98,7 @@ public void FromChatHistoryItReturnsGeminiRequestWithConfiguration()
     }
 
     [Fact]
-    public void FromChatHistoryItReturnsGeminiRequestWithSafetySettings()
+    public void FromChatHistoryItReturnsWithSafetySettings()
     {
         // Arrange
         ChatHistory chatHistory = [];
@@ -123,10 +123,11 @@ public void FromChatHistoryItReturnsGeminiRequestWithSafetySettings()
     }
 
     [Fact]
-    public void FromChatHistoryItReturnsGeminiRequestWithChatHistory()
+    public void FromChatHistoryItReturnsWithChatHistory()
     {
         // Arrange
-        ChatHistory chatHistory = [];
+        string systemMessage = "system-message";
+        var chatHistory = new ChatHistory(systemMessage);
         chatHistory.AddUserMessage("user-message");
         chatHistory.AddAssistantMessage("assist-message");
         chatHistory.AddUserMessage("user-message2");
@@ -136,18 +137,41 @@ public void FromChatHistoryItReturnsGeminiRequestWithChatHistory()
         var request = GeminiRequest.FromChatHistoryAndExecutionSettings(chatHistory, executionSettings);
 
         // Assert
+        Assert.NotNull(request.SystemInstruction?.Parts);
+        Assert.Single(request.SystemInstruction.Parts);
+        Assert.Equal(request.SystemInstruction.Parts[0].Text, systemMessage);
         Assert.Collection(request.Contents,
-            c => Assert.Equal(chatHistory[0].Content, c.Parts![0].Text),
             c => Assert.Equal(chatHistory[1].Content, c.Parts![0].Text),
-            c => Assert.Equal(chatHistory[2].Content, c.Parts![0].Text));
+            c => Assert.Equal(chatHistory[2].Content, c.Parts![0].Text),
+            c => Assert.Equal(chatHistory[3].Content, c.Parts![0].Text));
         Assert.Collection(request.Contents,
-            c => Assert.Equal(chatHistory[0].Role, c.Role),
             c => Assert.Equal(chatHistory[1].Role, c.Role),
-            c => Assert.Equal(chatHistory[2].Role, c.Role));
+            c => Assert.Equal(chatHistory[2].Role, c.Role),
+            c => Assert.Equal(chatHistory[3].Role, c.Role));
+    }
+
+    [Fact]
+    public void FromChatHistoryMultipleSystemMessagesItReturnsWithSystemMessages()
+    {
+        // Arrange
+        string[] systemMessages = ["system-message", "system-message2", "system-message3", "system-message4"];
+        var chatHistory = new ChatHistory(systemMessages[0]);
+        chatHistory.AddUserMessage("user-message");
+        chatHistory.AddSystemMessage(systemMessages[1]);
+        chatHistory.AddMessage(AuthorRole.System,
+            [new TextContent(systemMessages[2]), new TextContent(systemMessages[3])]);
+        var executionSettings = new GeminiPromptExecutionSettings();
+
+        // Act
+        var request = GeminiRequest.FromChatHistoryAndExecutionSettings(chatHistory, executionSettings);
+
+        // Assert
+        Assert.NotNull(request.SystemInstruction?.Parts);
+        Assert.All(systemMessages, msg => Assert.Contains(request.SystemInstruction.Parts, p => p.Text == msg));
     }
 
     [Fact]
-    public void FromChatHistoryTextAsTextContentItReturnsGeminiRequestWithChatHistory()
+    public void FromChatHistoryTextAsTextContentItReturnsWithChatHistory()
     {
         // Arrange
         ChatHistory chatHistory = [];
@@ -163,11 +187,11 @@ public void FromChatHistoryTextAsTextContentItReturnsGeminiRequestWithChatHistor
         Assert.Collection(request.Contents,
             c => Assert.Equal(chatHistory[0].Content, c.Parts![0].Text),
             c => Assert.Equal(chatHistory[1].Content, c.Parts![0].Text),
-            c => Assert.Equal(chatHistory[2].Items!.Cast<TextContent>().Single().Text, c.Parts![0].Text));
+            c => Assert.Equal(chatHistory[2].Items.Cast<TextContent>().Single().Text, c.Parts![0].Text));
     }
 
     [Fact]
-    public void FromChatHistoryImageAsImageContentItReturnsGeminiRequestWithChatHistory()
+    public void FromChatHistoryImageAsImageContentItReturnsWithChatHistory()
     {
         // Arrange
         ReadOnlyMemory<byte> imageAsBytes = new byte[] { 0x00, 0x01, 0x02, 0x03 };
@@ -187,7 +211,7 @@ public void FromChatHistoryImageAsImageContentItReturnsGeminiRequestWithChatHist
         Assert.Collection(request.Contents,
             c => Assert.Equal(chatHistory[0].Content, c.Parts![0].Text),
             c => Assert.Equal(chatHistory[1].Content, c.Parts![0].Text),
-            c => Assert.Equal(chatHistory[2].Items!.Cast<ImageContent>().Single().Uri,
+            c => Assert.Equal(chatHistory[2].Items.Cast<ImageContent>().Single().Uri,
                 c.Parts![0].FileData!.FileUri),
             c => Assert.True(imageAsBytes.ToArray()
                 .SequenceEqual(Convert.FromBase64String(c.Parts![0].InlineData!.InlineData))));
@@ -272,7 +296,7 @@ public void FromChatHistoryToolCallsNotNullAddsFunctionCalls()
     }
 
     [Fact]
-    public void AddFunctionItAddsFunctionToGeminiRequest()
+    public void AddFunctionToGeminiRequest()
     {
         // Arrange
         var request = new GeminiRequest();
@@ -287,7 +311,7 @@ public void AddFunctionItAddsFunctionToGeminiRequest()
     }
 
     [Fact]
-    public void AddMultipleFunctionsItAddsFunctionsToGeminiRequest()
+    public void AddMultipleFunctionsToGeminiRequest()
     {
         // Arrange
         var request = new GeminiRequest();
@@ -308,7 +332,7 @@ public void AddMultipleFunctionsItAddsFunctionsToGeminiRequest()
     }
 
     [Fact]
-    public void AddChatMessageToRequestItAddsChatMessageToGeminiRequest()
+    public void AddChatMessageToRequest()
     {
         // Arrange
         ChatHistory chat = [];