.Net: During OpenAPI import use payload parameter if specified (#5874)

### Motivation and Context

Closes #5870 

### Description

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

### Contribution Checklist

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

- [ ] The code builds clean without any errors or warnings
- [ ] 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
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

dotnet/src/Functions/Functions.OpenApi/Extensions/RestApiOperationExtensions.cs

@@ -2,7 +2,6 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using System.Net.Http;
 using System.Text.RegularExpressions;
 
 namespace Microsoft.SemanticKernel.Plugins.OpenApi;
@@ -34,7 +33,7 @@ internal static class RestApiOperationExtensions
         var parameters = new List<RestApiOperationParameter>(operation.Parameters);
 
         // Add payload parameters
-        if (operation.Method == HttpMethod.Put || operation.Method == HttpMethod.Post)
+        if (operation.Payload is not null)
         {
             parameters.AddRange(GetPayloadParameters(operation, addPayloadParamsFromMetadata, enablePayloadNamespacing));
         }

dotnet/src/Functions/Functions.OpenApi/RestApiOperationRunner.cs

@@ -226,7 +226,7 @@ private static async Task<RestApiOperationResponse> SerializeResponseContentAsyn
     /// <returns>The HttpContent representing the payload.</returns>
     private HttpContent? BuildOperationPayload(RestApiOperation operation, IDictionary<string, object?> arguments)
     {
-        if (operation?.Method != HttpMethod.Put && operation?.Method != HttpMethod.Post)
+        if (operation.Payload is null && !arguments.ContainsKey(RestApiOperation.PayloadArgumentName))
         {
             return null;
         }

dotnet/src/Functions/Functions.UnitTests/Functions.UnitTests.csproj

@@ -26,6 +26,7 @@
     <EmbeddedResource Include="OpenApi\TestPlugins\nonCompliant_documentV3_0.json" />
     <EmbeddedResource Include="OpenApi\TestPlugins\documentV3_1.yaml" />
     <EmbeddedResource Include="OpenApi\TestPlugins\documentV3_0.json" />
+    <EmbeddedResource Include="OpenApi\TestPlugins\repair-service.json" />
     <EmbeddedResource Include="OpenApi\TestResponses\ObjectResponseSchema.json" />
     <EmbeddedResource Include="OpenApi\TestResponses\ProductResponseSchema.json" />
     <EmbeddedResource Include="OpenApi\TestResponses\ValidProductContent.json" />

dotnet/src/Functions/Functions.UnitTests/OpenApi/Extensions/KernelOpenApiPluginExtensionsTests.cs

@@ -243,13 +243,39 @@ public async Task ItShouldSanitizeOperationNameAsync()
         Assert.True(plugin.TryGetFunction("IssuesCreatemilestone", out var _));
     }
 
+    [Fact]
+    public async Task ItCanIncludeOpenApiDeleteAndPatchOperationsAsync()
+    {
+        // Arrange
+        var openApiDocument = ResourcePluginsProvider.LoadFromResource("repair-service.json");
+
+        // Act
+        var plugin = await this._kernel.ImportPluginFromOpenApiAsync("repairServicePlugin", openApiDocument, this._executionParameters);
+
+        // Assert
+        Assert.NotNull(plugin);
+        var functionsMetadata = plugin.GetFunctionsMetadata();
+        Assert.Equal(4, functionsMetadata.Count);
+        AssertPayloadParameters(plugin, "updateRepair");
+        AssertPayloadParameters(plugin, "deleteRepair");
+    }
+
     public void Dispose()
     {
         this._openApiDocument.Dispose();
     }
 
     #region private ================================================================================
 
+    private static void AssertPayloadParameters(KernelPlugin plugin, string functionName)
+    {
+        Assert.True(plugin.TryGetFunction(functionName, out var function));
+        Assert.NotNull(function.Metadata.Parameters);
+        Assert.Equal(2, function.Metadata.Parameters.Count);
+        Assert.Equal("payload", function.Metadata.Parameters[0].Name);
+        Assert.Equal("content_type", function.Metadata.Parameters[1].Name);
+    }
+
     private KernelArguments GetFakeFunctionArguments()
     {
         return new KernelArguments

dotnet/src/Functions/Functions.UnitTests/OpenApi/Extensions/RestApiOperationExtensionsTests.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Linq;
 using System.Net.Http;
-using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.Plugins.OpenApi;
 using Xunit;
 
@@ -225,18 +224,6 @@ public void ItShouldAddNamespaceToParametersDeclaredInPayloadMetadata(string met
         Assert.Null(hasMagicWards.Description);
     }
 
-    [Theory]
-    [InlineData("PUT")]
-    [InlineData("POST")]
-    public void ItShouldThrowExceptionIfPayloadMetadataDescribingParametersIsMissing(string method)
-    {
-        //Arrange
-        var operation = CreateTestOperation(method, null);
-
-        //Act
-        Assert.Throws<KernelException>(() => operation.GetParameters(addPayloadParamsFromMetadata: true, enablePayloadNamespacing: true));
-    }
-
     [Theory]
     [InlineData("PUT")]
     [InlineData("POST")]

dotnet/src/Functions/Functions.UnitTests/OpenApi/RestApiOperationRunnerTests.cs

@@ -51,17 +51,24 @@ public RestApiOperationRunnerTests()
         this._httpClient = new HttpClient(this._httpMessageHandlerStub);
     }
 
-    [Fact]
-    public async Task ItCanRunCreateAndUpdateOperationsWithJsonPayloadSuccessfullyAsync()
+    [Theory]
+    [InlineData("POST")]
+    [InlineData("PUT")]
+    [InlineData("PATCH")]
+    [InlineData("DELETE")]
+    [InlineData("GET")]
+    public async Task ItCanRunCreateAndUpdateOperationsWithJsonPayloadSuccessfullyAsync(string method)
     {
         // Arrange
         this._httpMessageHandlerStub.ResponseToReturn.Content = new StringContent("fake-content", Encoding.UTF8, MediaTypeNames.Application.Json);
 
+        var httpMethod = new HttpMethod(method);
+
         var operation = new RestApiOperation(
             "fake-id",
             new Uri("https://fake-random-test-host"),
             "fake-path",
-            HttpMethod.Post,
+            httpMethod,
             "fake-description",
             [],
             payload: null
@@ -91,7 +98,7 @@ public async Task ItCanRunCreateAndUpdateOperationsWithJsonPayloadSuccessfullyAs
         Assert.NotNull(this._httpMessageHandlerStub.RequestUri);
         Assert.Equal("https://fake-random-test-host/fake-path", this._httpMessageHandlerStub.RequestUri.AbsoluteUri);
 
-        Assert.Equal(HttpMethod.Post, this._httpMessageHandlerStub.Method);
+        Assert.Equal(httpMethod, this._httpMessageHandlerStub.Method);
 
         Assert.NotNull(this._httpMessageHandlerStub.ContentHeaders);
         Assert.Contains(this._httpMessageHandlerStub.ContentHeaders, h => h.Key == "Content-Type" && h.Value.Contains("application/json; charset=utf-8"));
@@ -122,17 +129,24 @@ public async Task ItCanRunCreateAndUpdateOperationsWithJsonPayloadSuccessfullyAs
         this._authenticationHandlerMock.Verify(x => x(It.IsAny<HttpRequestMessage>(), It.IsAny<CancellationToken>()), Times.Once);
     }
 
-    [Fact]
-    public async Task ItCanRunCreateAndUpdateOperationsWithPlainTextPayloadSuccessfullyAsync()
+    [Theory]
+    [InlineData("POST")]
+    [InlineData("PUT")]
+    [InlineData("PATCH")]
+    [InlineData("DELETE")]
+    [InlineData("GET")]
+    public async Task ItCanRunCreateAndUpdateOperationsWithPlainTextPayloadSuccessfullyAsync(string method)
     {
         // Arrange
         this._httpMessageHandlerStub.ResponseToReturn.Content = new StringContent("fake-content", Encoding.UTF8, MediaTypeNames.Text.Plain);
 
+        var httpMethod = new HttpMethod(method);
+
         var operation = new RestApiOperation(
             "fake-id",
             new Uri("https://fake-random-test-host"),
             "fake-path",
-            HttpMethod.Post,
+            httpMethod,
             "fake-description",
             [],
             payload: null
@@ -153,7 +167,7 @@ public async Task ItCanRunCreateAndUpdateOperationsWithPlainTextPayloadSuccessfu
         Assert.NotNull(this._httpMessageHandlerStub.RequestUri);
         Assert.Equal("https://fake-random-test-host/fake-path", this._httpMessageHandlerStub.RequestUri.AbsoluteUri);
 
-        Assert.Equal(HttpMethod.Post, this._httpMessageHandlerStub.Method);
+        Assert.Equal(httpMethod, this._httpMessageHandlerStub.Method);
 
         Assert.NotNull(this._httpMessageHandlerStub.ContentHeaders);
         Assert.Contains(this._httpMessageHandlerStub.ContentHeaders, h => h.Key == "Content-Type" && h.Value.Contains("text/plain; charset=utf-8"));
@@ -537,7 +551,7 @@ public async Task ItShouldThrowExceptionIfPayloadMetadataDoesNotHaveContentTypeA
             payload: null
         );
 
-        var arguments = new KernelArguments();
+        KernelArguments arguments = new() { { RestApiOperation.PayloadArgumentName, "fake-content" } };
 
         var sut = new RestApiOperationRunner(
             this._httpClient,
@@ -564,7 +578,7 @@ public async Task ItShouldThrowExceptionIfContentTypeArgumentIsNotProvidedAsync(
             payload: null
         );
 
-        var arguments = new KernelArguments();
+        KernelArguments arguments = new() { { RestApiOperation.PayloadArgumentName, "fake-content" } };
 
         var sut = new RestApiOperationRunner(
             this._httpClient,