Move transformer

Add type-based transformer for operations to its own class.

Author: martincostello

src/OpenApi/src/Services/OpenApiOptions.cs

@@ -104,7 +104,7 @@ public OpenApiOptions AddDocumentTransformer(Func<OpenApiDocument, OpenApiDocume
     public OpenApiOptions AddOperationTransformer<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] TTransformerType>()
         where TTransformerType : IOpenApiOperationTransformer
     {
-        OperationTransformers.Add(new TypeBasedOpenApiDocumentTransformer(typeof(TTransformerType)));
+        OperationTransformers.Add(new TypeBasedOpenApiOperationTransformer(typeof(TTransformerType)));
         return this;
     }
 

src/OpenApi/src/Transformers/TypeBasedOpenApiDocumentTransformer.cs

@@ -8,7 +8,7 @@
 
 namespace Microsoft.AspNetCore.OpenApi;
 
-internal sealed class TypeBasedOpenApiDocumentTransformer : IOpenApiDocumentTransformer, IOpenApiOperationTransformer
+internal sealed class TypeBasedOpenApiDocumentTransformer : IOpenApiDocumentTransformer
 {
     [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
     private readonly Type _transformerType;
@@ -40,26 +40,4 @@ public async Task TransformAsync(OpenApiDocument document, OpenApiDocumentTransf
             }
         }
     }
-
-    public async Task TransformAsync(OpenApiOperation operation, OpenApiOperationTransformerContext context, CancellationToken cancellationToken)
-    {
-        var transformer = _transformerFactory.Invoke(context.ApplicationServices, []) as IOpenApiOperationTransformer;
-        Debug.Assert(transformer is not null, $"The type {_transformerType} does not implement {nameof(IOpenApiOperationTransformer)}.");
-
-        try
-        {
-            await transformer.TransformAsync(operation, context, cancellationToken);
-        }
-        finally
-        {
-            if (transformer is IAsyncDisposable asyncDisposable)
-            {
-                await asyncDisposable.DisposeAsync();
-            }
-            else if (transformer is IDisposable disposable)
-            {
-                disposable.Dispose();
-            }
-        }
-    }
 }

src/OpenApi/src/Transformers/TypeBasedOpenApiOperationTransformer.cs

@@ -0,0 +1,44 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.OpenApi.Models;
+
+namespace Microsoft.AspNetCore.OpenApi;
+
+internal sealed class TypeBasedOpenApiOperationTransformer : IOpenApiOperationTransformer
+{
+    [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
+    private readonly Type _transformerType;
+    private readonly ObjectFactory _transformerFactory;
+
+    internal TypeBasedOpenApiOperationTransformer([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] Type transformerType)
+    {
+        _transformerType = transformerType;
+        _transformerFactory = ActivatorUtilities.CreateFactory(_transformerType, []);
+    }
+
+    public async Task TransformAsync(OpenApiOperation operation, OpenApiOperationTransformerContext context, CancellationToken cancellationToken)
+    {
+        var transformer = _transformerFactory.Invoke(context.ApplicationServices, []) as IOpenApiOperationTransformer;
+        Debug.Assert(transformer is not null, $"The type {_transformerType} does not implement {nameof(IOpenApiOperationTransformer)}.");
+
+        try
+        {
+            await transformer.TransformAsync(operation, context, cancellationToken);
+        }
+        finally
+        {
+            if (transformer is IAsyncDisposable asyncDisposable)
+            {
+                await asyncDisposable.DisposeAsync();
+            }
+            else if (transformer is IDisposable disposable)
+            {
+                disposable.Dispose();
+            }
+        }
+    }
+}

src/OpenApi/test/Transformers/OpenApiOptionsTests.cs

@@ -114,7 +114,7 @@ public void AddOperationTransformer_WithOperationTransformerType()
 
         // Assert
         var insertedTransformer = Assert.Single(options.OperationTransformers);
-        Assert.IsType<TypeBasedOpenApiDocumentTransformer>(insertedTransformer);
+        Assert.IsType<TypeBasedOpenApiOperationTransformer>(insertedTransformer);
         Assert.IsType<OpenApiOptions>(result);
         Assert.Empty(options.DocumentTransformers);
         Assert.Empty(options.SchemaTransformers);