.Net: Fix 5796 function calling enum params (#5998)

### Motivation and Context

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Fixes #5796

### Description

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

Type for enum wasn't correctly set in JsonSchemaMapper, it didn't matter
for OpenAI but gemini was throwing exception if type isn't specified.
Fixed that with `string` type.
Added new unit tests for Gemini and OpenAI. Both passed.

@RogerBarreto 
@SergeyMenshykh

DataHelper and BertOnyx was updated automatically by formatter.

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

---------

Co-authored-by: Roger Barreto <[email protected]>

dotnet/samples/GettingStarted/Step7_Observability.cs

@@ -77,7 +77,7 @@ void MyInvokedHandler(object? sender, FunctionInvokedEventArgs e)
  {
  if (e.Result.Metadata is not null && e.Result.Metadata.ContainsKey("Usage"))
  {
- Console.WriteLine($"Token usage: {e.Result.Metadata?["Usage"]?.AsJson()}");
+ Console.WriteLine("Token usage: {0}", e.Result.Metadata?["Usage"]?.AsJson());
  }
  }
 

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

@@ -200,7 +200,7 @@ public void ItCanCreateValidGeminiFunctionManualForPlugin()
  // Assert
  Assert.NotNull(result);
  Assert.Equal(
- """{"type":"object","required":["parameter1","parameter2","parameter3"],"properties":{"parameter1":{"type":"string","description":"String parameter"},"parameter2":{"enum":["Value1","Value2"],"description":"Enum parameter"},"parameter3":{"type":"string","format":"date-time","description":"DateTime parameter"}}}""",
+ """{"type":"object","required":["parameter1","parameter2","parameter3"],"properties":{"parameter1":{"type":"string","description":"String parameter"},"parameter2":{"type":"string","enum":["Value1","Value2"],"description":"Enum parameter"},"parameter3":{"type":"string","format":"date-time","description":"DateTime parameter"}}}""",
  JsonSerializer.Serialize(result.Parameters)
  );
  }

dotnet/src/Connectors/Connectors.UnitTests/OpenAI/FunctionCalling/KernelFunctionMetadataExtensionsTests.cs

@@ -196,7 +196,7 @@ public void ItCanCreateValidOpenAIFunctionManualForPlugin()
  // Assert
  Assert.NotNull(result);
  Assert.Equal(
- """{"type":"object","required":["parameter1","parameter2","parameter3"],"properties":{"parameter1":{"type":"string","description":"String parameter"},"parameter2":{"enum":["Value1","Value2"],"description":"Enum parameter"},"parameter3":{"type":"string","format":"date-time","description":"DateTime parameter"}}}""",
+ """{"type":"object","required":["parameter1","parameter2","parameter3"],"properties":{"parameter1":{"type":"string","description":"String parameter"},"parameter2":{"type":"string","enum":["Value1","Value2"],"description":"Enum parameter"},"parameter3":{"type":"string","format":"date-time","description":"DateTime parameter"}}}""",
  result.Parameters.ToString()
  );
  }

dotnet/src/IntegrationTests/Connectors/GoogleVertexAI/EmbeddingGenerationTests.cs → dotnet/src/IntegrationTests/Connectors/Google/EmbeddingGenerationTests.cs

@@ -6,7 +6,7 @@
 using Xunit;
 using Xunit.Abstractions;
 
-namespace SemanticKernel.IntegrationTests.Connectors.GoogleVertexAI;
+namespace SemanticKernel.IntegrationTests.Connectors.Google;
 
 public sealed class EmbeddingGenerationTests(ITestOutputHelper output) : TestsBase(output)
 {

dotnet/src/IntegrationTests/Connectors/GoogleVertexAI/Gemini/GeminiChatCompletionTests.cs → dotnet/src/IntegrationTests/Connectors/Google/Gemini/GeminiChatCompletionTests.cs

@@ -12,7 +12,7 @@
 using Xunit;
 using Xunit.Abstractions;
 
-namespace SemanticKernel.IntegrationTests.Connectors.GoogleVertexAI.Gemini;
+namespace SemanticKernel.IntegrationTests.Connectors.Google.Gemini;
 
 public sealed class GeminiChatCompletionTests(ITestOutputHelper output) : TestsBase(output)
 {

dotnet/src/IntegrationTests/Connectors/GoogleVertexAI/Gemini/GeminiFunctionCallingTests.cs → dotnet/src/IntegrationTests/Connectors/Google/Gemini/GeminiFunctionCallingTests.cs

@@ -4,14 +4,15 @@
 using System.ComponentModel;
 using System.Linq;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Time.Testing;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.ChatCompletion;
 using Microsoft.SemanticKernel.Connectors.Google;
 using xRetry;
 using Xunit;
 using Xunit.Abstractions;
 
-namespace SemanticKernel.IntegrationTests.Connectors.GoogleVertexAI.Gemini;
+namespace SemanticKernel.IntegrationTests.Connectors.Google.Gemini;
 
 public sealed class GeminiFunctionCallingTests(ITestOutputHelper output) : TestsBase(output)
 {
@@ -291,6 +292,64 @@ public async Task ChatStreamingAutoInvokeTwoPluginsShouldGetDateAndReturnTasksBy
  Assert.Contains("5", content, StringComparison.OrdinalIgnoreCase);
  }
 
+ [RetryTheory]
+ [InlineData(ServiceType.GoogleAI, Skip = "This test is for manual verification.")]
+ [InlineData(ServiceType.VertexAI, Skip = "This test is for manual verification.")]
+ public async Task ChatGenerationAutoInvokeShouldCallFunctionWithEnumParameterAndReturnResponseAsync(ServiceType serviceType)
+ {
+ // Arrange
+ var kernel = new Kernel();
+ var timeProvider = new FakeTimeProvider();
+ timeProvider.SetUtcNow(new DateTimeOffset(new DateTime(2024, 4, 24))); // Wednesday
+ var timePlugin = new TimePlugin(timeProvider);
+ kernel.ImportPluginFromObject(timePlugin, nameof(TimePlugin));
+ var sut = this.GetChatService(serviceType);
+ var chatHistory = new ChatHistory();
+ chatHistory.AddUserMessage("When was last friday? Show the date in format DD.MM.YYYY for example: 15.07.2019");
+ var executionSettings = new GeminiPromptExecutionSettings()
+ {
+ MaxTokens = 2000,
+ ToolCallBehavior = GeminiToolCallBehavior.AutoInvokeKernelFunctions,
+ };
+
+ // Act
+ var response = await sut.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
+
+ // Assert
+ this.Output.WriteLine(response.Content);
+ Assert.Contains("19.04.2024", response.Content, StringComparison.OrdinalIgnoreCase);
+ }
+
+ [RetryTheory]
+ [InlineData(ServiceType.GoogleAI, Skip = "This test is for manual verification.")]
+ [InlineData(ServiceType.VertexAI, Skip = "This test is for manual verification.")]
+ public async Task ChatStreamingAutoInvokeShouldCallFunctionWithEnumParameterAndReturnResponseAsync(ServiceType serviceType)
+ {
+ // Arrange
+ var kernel = new Kernel();
+ var timeProvider = new FakeTimeProvider();
+ timeProvider.SetUtcNow(new DateTimeOffset(new DateTime(2024, 4, 24))); // Wednesday
+ var timePlugin = new TimePlugin(timeProvider);
+ kernel.ImportPluginFromObject(timePlugin, nameof(TimePlugin));
+ var sut = this.GetChatService(serviceType);
+ var chatHistory = new ChatHistory();
+ chatHistory.AddUserMessage("When was last friday? Show the date in format DD.MM.YYYY for example: 15.07.2019");
+ var executionSettings = new GeminiPromptExecutionSettings()
+ {
+ MaxTokens = 2000,
+ ToolCallBehavior = GeminiToolCallBehavior.AutoInvokeKernelFunctions,
+ };
+
+ // Act
+ var responses = await sut.GetStreamingChatMessageContentsAsync(chatHistory, executionSettings, kernel)
+ .ToListAsync();
+
+ // Assert
+ string content = string.Concat(responses.Select(c => c.Content));
+ this.Output.WriteLine(content);
+ Assert.Contains("19.04.2024", content, StringComparison.OrdinalIgnoreCase);
+ }
+
  public sealed class CustomerPlugin
  {
  [KernelFunction(nameof(GetCustomers))]
@@ -343,6 +402,37 @@ public DateTime GetDate()
  }
  }
 
+ public sealed class TimePlugin
+ {
+ private readonly TimeProvider _timeProvider;
+
+ public TimePlugin(TimeProvider timeProvider)
+ {
+ this._timeProvider = timeProvider;
+ }
+
+ [KernelFunction]
+ [Description("Get the date of the last day matching the supplied week day name in English. Example: Che giorno era 'Martedi' scorso -> dateMatchingLastDayName 'Tuesday' => Tuesday, 16 May, 2023")]
+ public string DateMatchingLastDayName(
+ [Description("The day name to match")] DayOfWeek input,
+ IFormatProvider? formatProvider = null)
+ {
+ DateTimeOffset dateTime = this._timeProvider.GetUtcNow();
+
+ // Walk backwards from the previous day for up to a week to find the matching day
+ for (int i = 1; i <= 7; ++i)
+ {
+ dateTime = dateTime.AddDays(-1);
+ if (dateTime.DayOfWeek == input)
+ {
+ break;
+ }
+ }
+
+ return dateTime.ToString("D", formatProvider);
+ }
+ }
+
  public sealed class MathPlugin
  {
  [KernelFunction(nameof(Sum))]

dotnet/src/IntegrationTests/Connectors/GoogleVertexAI/TestsBase.cs → dotnet/src/IntegrationTests/Connectors/Google/TestsBase.cs

@@ -7,7 +7,7 @@
 using Microsoft.SemanticKernel.Embeddings;
 using Xunit.Abstractions;
 
-namespace SemanticKernel.IntegrationTests.Connectors.GoogleVertexAI;
+namespace SemanticKernel.IntegrationTests.Connectors.Google;
 
 public abstract class TestsBase(ITestOutputHelper output)
 {

dotnet/src/IntegrationTests/Connectors/OpenAI/OpenAIToolsTests.cs

@@ -9,6 +9,7 @@
 using System.Threading.Tasks;
 using Azure.AI.OpenAI;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Time.Testing;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.ChatCompletion;
 using Microsoft.SemanticKernel.Connectors.OpenAI;
@@ -112,6 +113,27 @@ public async Task CanAutoInvokeKernelFunctionsWithPrimitiveTypeParametersAsync()
  Assert.Contains("10", result.GetValue<string>(), StringComparison.InvariantCulture);
  }
 
+ [Fact(Skip = "OpenAI is throttling requests. Switch this test to use Azure OpenAI.")]
+ public async Task CanAutoInvokeKernelFunctionsWithEnumTypeParametersAsync()
+ {
+ // Arrange
+ Kernel kernel = this.InitializeKernel();
+ var timeProvider = new FakeTimeProvider();
+ timeProvider.SetUtcNow(new DateTimeOffset(new DateTime(2024, 4, 24))); // Wednesday
+ var timePlugin = new TimePlugin(timeProvider);
+ kernel.ImportPluginFromObject(timePlugin, nameof(TimePlugin));
+
+ // Act
+ OpenAIPromptExecutionSettings settings = new() { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+ var result = await kernel.InvokePromptAsync(
+ "When was last friday? Show the date in format DD.MM.YYYY for example: 15.07.2019",
+ new(settings));
+
+ // Assert
+ Assert.NotNull(result);
+ Assert.Contains("19.04.2024", result.GetValue<string>(), StringComparison.OrdinalIgnoreCase);
+ }
+
  [Fact]
  public async Task CanAutoInvokeKernelFunctionFromPromptAsync()
  {
@@ -550,4 +572,35 @@ private sealed class FakeFunctionFilter : IFunctionInvocationFilter
  }
 
  #endregion
+
+ public sealed class TimePlugin
+ {
+ private readonly TimeProvider _timeProvider;
+
+ public TimePlugin(TimeProvider timeProvider)
+ {
+ this._timeProvider = timeProvider;
+ }
+
+ [KernelFunction]
+ [Description("Get the date of the last day matching the supplied week day name in English. Example: Che giorno era 'Martedi' scorso -> dateMatchingLastDayName 'Tuesday' => Tuesday, 16 May, 2023")]
+ public string DateMatchingLastDayName(
+ [Description("The day name to match")] DayOfWeek input,
+ IFormatProvider? formatProvider = null)
+ {
+ DateTimeOffset dateTime = this._timeProvider.GetUtcNow();
+
+ // Walk backwards from the previous day for up to a week to find the matching day
+ for (int i = 1; i <= 7; ++i)
+ {
+ dateTime = dateTime.AddDays(-1);
+ if (dateTime.DayOfWeek == input)
+ {
+ break;
+ }
+ }
+
+ return dateTime.ToString("D", formatProvider);
+ }
+ }
 }

dotnet/src/IntegrationTests/IntegrationTests.csproj

@@ -32,6 +32,7 @@
  <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" />
  <PackageReference Include="Microsoft.Extensions.Http" />
  <PackageReference Include="Microsoft.Extensions.Http.Resilience" />
+ <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" />
  <PackageReference Include="Microsoft.NET.Test.Sdk" />
  <PackageReference Include="System.Linq.Async" />
  <PackageReference Include="xRetry" />

dotnet/src/InternalUtilities/src/Schema/JsonSchemaMapper.cs

@@ -173,6 +173,7 @@ public static string ToJsonString(this JsonNode? node, bool writeIndented = fals
  string? title = null,
  string? description = null,
  bool isNullableReferenceType = false,
+ bool isNullableOfTElement = false,
  JsonConverter? customConverter = null,
  bool hasDefaultValue = false,
  JsonNode? defaultValue = null,
@@ -186,7 +187,7 @@ public static string ToJsonString(this JsonNode? node, bool writeIndented = fals
  JsonConverter effectiveConverter = customConverter ?? typeInfo.Converter;
  JsonNumberHandling? effectiveNumberHandling = customNumberHandling ?? typeInfo.NumberHandling;
  bool emitsTypeDiscriminator = derivedTypeDiscriminator?.Value is not null;
- bool isCacheable = !emitsTypeDiscriminator && description is null && !hasDefaultValue;
+ bool isCacheable = !emitsTypeDiscriminator && description is null && !hasDefaultValue && !isNullableOfTElement;
 
  if (!IsBuiltInConverter(effectiveConverter))
  {
@@ -220,7 +221,8 @@ public static string ToJsonString(this JsonNode? node, bool writeIndented = fals
  defaultValue: defaultValue,
  customNumberHandling: customNumberHandling,
  customConverter: customConverter,
- parentNullableOfT: type);
+ parentNullableOfT: type,
+ isNullableOfTElement: true);
  }
 
  if (isCacheable && typeInfo.Kind != JsonTypeInfoKind.None)
@@ -319,23 +321,15 @@ public static string ToJsonString(this JsonNode? node, bool writeIndented = fals
  }
  else if (type.IsEnum)
  {
- if (TryGetStringEnumConverterValues(typeInfo, effectiveConverter, out JsonArray? values))
+ if (TryGetStringEnumConverterValues(typeInfo, effectiveConverter, out enumValues))
  {
- if (values is null)
- {
- // enum declared with the flags attribute -- do not surface enum values in the JSON schema.
- schemaType = JsonSchemaType.String;
- }
- else
+ schemaType = JsonSchemaType.String;
+
+ if (enumValues != null && isNullableOfTElement)
  {
- if (parentNullableOfT is not null)
- {
- // We're generating the schema for a nullable
- // enum type. Append null to the "enum" array.
- values.Add(null);
- }
-
- enumValues = values;
+ // We're generating the schema for a nullable
+ // enum type. Append null to the "enum" array.
+ enumValues.Add(null);
  }
  }
  else
@@ -417,15 +411,15 @@ public static string ToJsonString(this JsonNode? node, bool writeIndented = fals
 
  state.Push(property.Name);
  JsonObject propertySchema = MapJsonSchemaCore(
- propertyTypeInfo,
- ref state,
+ typeInfo: propertyTypeInfo,
+ state: ref state,
  title: null,
- propertyDescription,
- isPropertyNullableReferenceType,
- property.CustomConverter,
- propertyHasDefaultValue,
- propertyDefaultValue,
- propertyNumberHandling);
+ description: propertyDescription,
+ isNullableReferenceType: isPropertyNullableReferenceType,
+ customConverter: property.CustomConverter,
+ hasDefaultValue: propertyHasDefaultValue,
+ defaultValue: propertyDefaultValue,
+ customNumberHandling: propertyNumberHandling);
 
  state.Pop();