Add generic variants of MVC attributes (#47075)

* Add generic variants of MVC attributes

* Throw descriptive exception if multiple attributes applied

* Add constraint to ModelBinderAttribute

Author: captainsafia

src/Mvc/Mvc.ApiExplorer/test/DefaultApiDescriptionProviderTest.cs

@@ -2456,7 +2456,7 @@ private void AcceptsProduct_Default([ModelBinder] Product product)
     }
 
     // This will show up as source = unknown
-    private void AcceptsProduct_Custom([ModelBinder(BinderType = typeof(BodyModelBinder))] Product product)
+    private void AcceptsProduct_Custom([ModelBinder<BodyModelBinder>] Product product)
     {
     }
 
@@ -2556,7 +2556,7 @@ private void FromModelBinding(int id)
     {
     }
 
-    private void FromCustom([ModelBinder(typeof(BodyModelBinder))] int id)
+    private void FromCustom([ModelBinder<BodyModelBinder>] int id)
     {
     }
 

src/Mvc/Mvc.Core/src/Filters/MiddlewareFilterOfTAttribute.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="T">A type which configures a middleware pipeline.</typeparam>
+public class MiddlewareFilterAttribute<T> : MiddlewareFilterAttribute
+{
+    /// <summary>
+    /// Instantiates a new instance of <see cref="MiddlewareFilterAttribute"/>.
+    /// </summary>
+    public MiddlewareFilterAttribute() : base(typeof(T)) { }
+}

src/Mvc/Mvc.Core/src/ModelBinderOfTAttribute.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="TBinder">A <see cref="Type"/> which implements <see cref="IModelBinder"/>.</typeparam>
+/// <remarks>
+/// This is a derived generic variant of the <see cref="ModelBinderAttribute"/>.
+/// Ensure that only one instance of either attribute is provided on the target.
+/// </remarks>
+public class ModelBinderAttribute<TBinder> : ModelBinderAttribute where TBinder : IModelBinder
+{
+    /// <summary>
+    /// Initializes a new instance of <see cref="ModelBinderAttribute"/>.
+    /// </summary>
+    /// <remarks>
+    /// Subclass this attribute and set <see cref="BindingSource"/> if <see cref="BindingSource.Custom"/> is not
+    /// correct for the specified type parameter.
+    /// </remarks>
+    public ModelBinderAttribute() : base(typeof(TBinder)) { }
+}

src/Mvc/Mvc.Core/src/ModelBinding/Metadata/ModelAttributes.cs

@@ -214,6 +214,25 @@ public static ModelAttributes GetAttributesForParameter(ParameterInfo parameterI
 
     private static Type? GetMetadataType(Type type)
     {
-        return type.GetCustomAttribute<ModelMetadataTypeAttribute>()?.MetadataType;
+        // GetCustomAttribute will examine the members inheritance chain
+        // for attributes of a particular type by default. Meaning that
+        // in the following scenario, the `ModelMetadataType` attribute on
+        // both the derived _and_ base class will be returned.
+        // [ModelMetadataType<BaseModel>]
+        // private class BaseViewModel { }
+        // [ModelMetadataType<DerivedModel>]
+        // private class DerivedViewModel : BaseViewModel { }
+        // To avoid this, we call `GetCustomAttributes` directly
+        // to avoid examining the inheritance hierarchy.
+        // See https://source.dot.net/#System.Private.CoreLib/src/System/Attribute.CoreCLR.cs,677
+        var modelMetadataTypeAttributes = type.GetCustomAttributes<ModelMetadataTypeAttribute>(inherit: false);
+        try
+        {
+            return modelMetadataTypeAttributes?.SingleOrDefault()?.MetadataType;
+        }
+        catch (InvalidOperationException e)
+        {
+            throw new InvalidOperationException("Only one ModelMetadataType attribute is permitted per type.", e);
+        }
     }
 }

src/Mvc/Mvc.Core/src/ModelMetadataTypeOfTAttribute.cs

@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="T">The type of metadata class that is associated with a data model class.</typeparam>
+/// <remarks>
+/// This is a derived generic variant of the <see cref="ModelMetadataTypeAttribute"/>
+/// which does not allow multiple instances on a single target.
+/// Ensure that only one instance of either attribute is provided on the target.
+/// </remarks>
+public class ModelMetadataTypeAttribute<T> : ModelMetadataTypeAttribute
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ModelMetadataTypeAttribute" /> class.
+    /// </summary>
+    public ModelMetadataTypeAttribute() : base(typeof(T)) { }
+}

src/Mvc/Mvc.Core/src/ProducesOfTAttribute.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="T">The <see cref="Type"/> of object that is going to be written in the response.</typeparam>
+/// <remarks>
+/// This is a derived generic variant of the <see cref="ProducesAttribute"/>.
+/// Ensure that only one instance of either attribute is provided on the target.
+/// </remarks>
+public class ProducesAttribute<T> : ProducesAttribute
+{
+    /// <summary>
+    /// Initializes an instance of <see cref="ProducesAttribute"/>.
+    /// </summary>
+    public ProducesAttribute() : base(typeof(T)) { }
+}

src/Mvc/Mvc.Core/src/ProducesResponseTypeOfTAttribute.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="T">The <see cref="Type"/> of object that is going to be written in the response.</typeparam>
+public class ProducesResponseTypeAttribute<T> : ProducesResponseTypeAttribute
+{
+    /// <summary>
+    /// Initializes an instance of <see cref="ProducesResponseTypeAttribute"/>.
+    /// </summary>
+    /// <param name="statusCode">The HTTP response status code.</param>
+    public ProducesResponseTypeAttribute(int statusCode) : base(typeof(T), statusCode) { }
+
+    /// <summary>
+    /// Initializes an instance of <see cref="ProducesResponseTypeAttribute"/>.
+    /// </summary>
+    /// <param name="statusCode">The HTTP response status code.</param>
+    /// <param name="contentType">The content type associated with the response.</param>
+    /// <param name="additionalContentTypes">Additional content types supported by the response.</param>
+    public ProducesResponseTypeAttribute(int statusCode, string contentType, params string[] additionalContentTypes)
+            : base(typeof(T), statusCode, contentType, additionalContentTypes) { }
+}

src/Mvc/Mvc.Core/src/PublicAPI.Unshipped.txt

@@ -1,5 +1,20 @@
 #nullable enable
 *REMOVED*static Microsoft.AspNetCore.Routing.ControllerLinkGeneratorExtensions.GetUriByAction(this Microsoft.AspNetCore.Routing.LinkGenerator! generator, string! action, string! controller, object? values, string? scheme, Microsoft.AspNetCore.Http.HostString host, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null) -> string?
+Microsoft.AspNetCore.Mvc.MiddlewareFilterAttribute<T>
+Microsoft.AspNetCore.Mvc.MiddlewareFilterAttribute<T>.MiddlewareFilterAttribute() -> void
+Microsoft.AspNetCore.Mvc.ModelBinderAttribute<TBinder>
+Microsoft.AspNetCore.Mvc.ModelBinderAttribute<TBinder>.ModelBinderAttribute() -> void
+Microsoft.AspNetCore.Mvc.ModelMetadataTypeAttribute<T>
+Microsoft.AspNetCore.Mvc.ModelMetadataTypeAttribute<T>.ModelMetadataTypeAttribute() -> void
+Microsoft.AspNetCore.Mvc.ProducesAttribute<T>
+Microsoft.AspNetCore.Mvc.ProducesAttribute<T>.ProducesAttribute() -> void
+Microsoft.AspNetCore.Mvc.ProducesResponseTypeAttribute<T>
+Microsoft.AspNetCore.Mvc.ProducesResponseTypeAttribute<T>.ProducesResponseTypeAttribute(int statusCode) -> void
+Microsoft.AspNetCore.Mvc.ProducesResponseTypeAttribute<T>.ProducesResponseTypeAttribute(int statusCode, string! contentType, params string![]! additionalContentTypes) -> void
+Microsoft.AspNetCore.Mvc.ServiceFilterAttribute<TFilter>
+Microsoft.AspNetCore.Mvc.ServiceFilterAttribute<TFilter>.ServiceFilterAttribute() -> void
+Microsoft.AspNetCore.Mvc.TypeFilterAttribute<TFilter>
+Microsoft.AspNetCore.Mvc.TypeFilterAttribute<TFilter>.TypeFilterAttribute() -> void
 Microsoft.AspNetCore.Mvc.ValidationProblemDetails.Errors.set -> void
 static Microsoft.AspNetCore.Routing.ControllerLinkGeneratorExtensions.GetUriByAction(this Microsoft.AspNetCore.Routing.LinkGenerator! generator, string! action, string! controller, object? values, string! scheme, Microsoft.AspNetCore.Http.HostString host, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null) -> string?
 Microsoft.AspNetCore.Mvc.CreatedResult.CreatedResult() -> void

src/Mvc/Mvc.Core/src/ServiceFilterOfTAttribute.cs

@@ -0,0 +1,18 @@
+// 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 Microsoft.AspNetCore.Mvc.Filters;
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="TFilter">The <see cref="Type"/> of filter to find.</typeparam>
+[DebuggerDisplay("ServiceFilter: Type={ServiceType} Order={Order}")]
+public class ServiceFilterAttribute<TFilter> : ServiceFilterAttribute where TFilter : IFilterMetadata
+{
+    /// <summary>
+    /// Instantiates a new <see cref="ServiceFilterAttribute"/> instance.
+    /// </summary>
+    public ServiceFilterAttribute() : base(typeof(TFilter)) { }
+}

src/Mvc/Mvc.Core/src/TypeFilterOfTAttribute.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Mvc.Filters;
+
+namespace Microsoft.AspNetCore.Mvc;
+
+/// <inheritdoc />
+/// <typeparam name="TFilter">The <see cref="Type"/> of filter to create.</typeparam>
+public class TypeFilterAttribute<TFilter> : TypeFilterAttribute where TFilter : IFilterMetadata
+{
+    /// <summary>
+    /// Instantiates a new <see cref="TypeFilterAttribute"/> instance.
+    /// </summary>
+    public TypeFilterAttribute() : base(typeof(TFilter)) { }
+}