Use the declared type to infer NullableContextOptions (#15134)

* Use the declared type to infer NullableContextOptions

Prior to this change MVC used the runtime type rather than the declared type to
determine the nullability of a property based on state. In the case of inheritance,
this can be erroneous since the declared type may have a different nullability context
than the model type.

This change addresses this by adding content to `ModelIdentity` that allows inspecting the
declared type.

* Add an overload to `ModelMetadataIdentity` that allows flowing `PropertyInfo`
* Use the declared type in `DataAnnotationsMetadataProvider` to determine nullability based on context.

Fixes #14812

Author: pranavkm

src/Mvc/Mvc.Abstractions/ref/Microsoft.AspNetCore.Mvc.Abstractions.netcoreapp.cs

@@ -883,10 +883,13 @@ protected ModelBindingMessageProvider() { }
         public System.Type ModelType { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
         public string Name { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
         public System.Reflection.ParameterInfo ParameterInfo { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        public System.Reflection.PropertyInfo PropertyInfo { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
         public bool Equals(Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity other) { throw null; }
         public override bool Equals(object obj) { throw null; }
         public static Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity ForParameter(System.Reflection.ParameterInfo parameter) { throw null; }
         public static Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity ForParameter(System.Reflection.ParameterInfo parameter, System.Type modelType) { throw null; }
+        public static Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity ForProperty(System.Reflection.PropertyInfo propertyInfo, System.Type modelType, System.Type containerType) { throw null; }
+        [System.ObsoleteAttribute("This API is obsolete and may be removed in a future release.")]
         public static Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity ForProperty(System.Type modelType, string name, System.Type containerType) { throw null; }
         public static Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.ModelMetadataIdentity ForType(System.Type modelType) { throw null; }
         public override int GetHashCode() { throw null; }

src/Mvc/Mvc.Abstractions/src/ModelBinding/Metadata/ModelMetadataIdentity.cs

@@ -17,12 +17,14 @@ private ModelMetadataIdentity(
             Type modelType,
             string name = null,
             Type containerType = null,
-            ParameterInfo parameterInfo = null)
+            ParameterInfo parameterInfo = null,
+            PropertyInfo propertyInfo = null)
         {
             ModelType = modelType;
             Name = name;
             ContainerType = containerType;
             ParameterInfo = parameterInfo;
+            PropertyInfo = propertyInfo;
         }
 
         /// <summary>
@@ -47,6 +49,7 @@ public static ModelMetadataIdentity ForType(Type modelType)
         /// <param name="name">The name of the property.</param>
         /// <param name="containerType">The container type of the model property.</param>
         /// <returns>A <see cref="ModelMetadataIdentity"/>.</returns>
+        [Obsolete("This API is obsolete and may be removed in a future release.")]
         public static ModelMetadataIdentity ForProperty(
             Type modelType,
             string name,
@@ -70,6 +73,36 @@ public static ModelMetadataIdentity ForProperty(
             return new ModelMetadataIdentity(modelType, name, containerType);
         }
 
+        /// <summary>
+        /// Creates a <see cref="ModelMetadataIdentity"/> for the provided property.
+        /// </summary>
+        /// <param name="modelType">The model type.</param>
+        /// <param name="propertyInfo">The property.</param>
+        /// <param name="containerType">The container type of the model property.</param>
+        /// <returns>A <see cref="ModelMetadataIdentity"/>.</returns>
+        public static ModelMetadataIdentity ForProperty(
+            PropertyInfo propertyInfo,
+            Type modelType,
+            Type containerType)
+        {
+            if (propertyInfo == null)
+            {
+                throw new ArgumentNullException(nameof(propertyInfo));
+            }
+
+            if (modelType == null)
+            {
+                throw new ArgumentNullException(nameof(modelType));
+            }
+
+            if (containerType == null)
+            {
+                throw new ArgumentNullException(nameof(containerType));
+            }
+
+            return new ModelMetadataIdentity(modelType, propertyInfo.Name, containerType, propertyInfo: propertyInfo);
+        }
+
         /// <summary>
         /// Creates a <see cref="ModelMetadataIdentity"/> for the provided parameter.
         /// </summary>
@@ -145,14 +178,21 @@ public ModelMetadataKind MetadataKind
         /// </summary>
         public ParameterInfo ParameterInfo { get; }
 
+        /// <summary>
+        /// Gets a descriptor for the property, or <c>null</c> if this instance
+        /// does not represent a property.
+        /// </summary>
+        public PropertyInfo PropertyInfo { get; }
+
         /// <inheritdoc />
         public bool Equals(ModelMetadataIdentity other)
         {
             return
                 ContainerType == other.ContainerType &&
                 ModelType == other.ModelType &&
                 Name == other.Name &&
-                ParameterInfo == other.ParameterInfo;
+                ParameterInfo == other.ParameterInfo && 
+                PropertyInfo == other.PropertyInfo;
         }
 
         /// <inheritdoc />
@@ -170,6 +210,7 @@ public override int GetHashCode()
             hash.Add(ModelType);
             hash.Add(Name, StringComparer.Ordinal);
             hash.Add(ParameterInfo);
+            hash.Add(PropertyInfo);
             return hash;
         }
     }

src/Mvc/Mvc.Abstractions/test/ModelBinding/ModelMetadataTest.cs

@@ -270,7 +270,8 @@ public void ContainerType_IsNull_ForParameter()
         public void ContainerType_ReturnExpectedMetadata_ForProperty()
         {
             // Arrange & Act
-            var metadata = new TestModelMetadata(typeof(int), nameof(string.Length), typeof(string));
+            var property = typeof(string).GetProperty(nameof(string.Length));
+            var metadata = new TestModelMetadata(property, typeof(int), typeof(string));
 
             // Assert
             Assert.Equal(typeof(string), metadata.ContainerType);
@@ -308,7 +309,8 @@ public void Names_ReturnExpectedMetadata_ForParameter()
         public void Names_ReturnExpectedMetadata_ForProperty()
         {
             // Arrange & Act
-            var metadata = new TestModelMetadata(typeof(int), nameof(string.Length), typeof(string));
+            var property = typeof(string).GetProperty(nameof(string.Length));
+            var metadata = new TestModelMetadata(property, typeof(int), typeof(string));
 
             // Assert
             Assert.Equal(nameof(string.Length), metadata.Name);
@@ -322,7 +324,8 @@ public void Names_ReturnExpectedMetadata_ForProperty()
         public void GetDisplayName_ReturnsDisplayName_IfSet()
         {
             // Arrange
-            var metadata = new TestModelMetadata(typeof(int), "Length", typeof(string));
+            var property = typeof(string).GetProperty(nameof(string.Length));
+            var metadata = new TestModelMetadata(property, typeof(int), typeof(string));
             metadata.SetDisplayName("displayName");
 
             // Act
@@ -351,7 +354,8 @@ public void GetDisplayName_ReturnsParameterName_WhenSetAndDisplayNameIsNull()
         public void GetDisplayName_ReturnsPropertyName_WhenSetAndDisplayNameIsNull()
         {
             // Arrange
-            var metadata = new TestModelMetadata(typeof(int), "Length", typeof(string));
+            var property = typeof(string).GetProperty(nameof(string.Length));
+            var metadata = new TestModelMetadata(property, typeof(int), typeof(string));
 
             // Act
             var result = metadata.GetDisplayName();
@@ -419,8 +423,8 @@ public TestModelMetadata(ParameterInfo parameter)
             {
             }
 
-            public TestModelMetadata(Type modelType, string propertyName, Type containerType)
-                : base(ModelMetadataIdentity.ForProperty(modelType, propertyName, containerType))
+            public TestModelMetadata(PropertyInfo propertyInfo, Type modelType, Type containerType)
+                : base(ModelMetadataIdentity.ForProperty(propertyInfo, modelType, containerType))
             {
             }
 

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

@@ -190,7 +190,7 @@ private ModelMetadataCacheEntry GetCacheEntry(ParameterInfo parameter, Type mode
         private ModelMetadataCacheEntry GetCacheEntry(PropertyInfo property, Type modelType)
         {
             return _typeCache.GetOrAdd(
-                ModelMetadataIdentity.ForProperty(modelType, property.Name, property.DeclaringType),
+                ModelMetadataIdentity.ForProperty(property, modelType, property.DeclaringType),
                 _cacheEntryFactory);
         }
 
@@ -275,8 +275,8 @@ protected virtual DefaultMetadataDetails[] CreatePropertyDetails(ModelMetadataId
                 var propertyHelper = propertyHelpers[i];
 
                 var propertyKey = ModelMetadataIdentity.ForProperty(
+                    propertyHelper.Property,
                     propertyHelper.Property.PropertyType,
-                    propertyHelper.Name,
                     key.ModelType);
 
                 var propertyEntry = CreateSinglePropertyDetails(propertyKey, propertyHelper);

src/Mvc/Mvc.Core/test/BindAttributeTest.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
 using Moq;
 using Xunit;
@@ -27,7 +25,9 @@ public void BindAttribute_Include(string property, bool isIncluded)
 
             var context = new DefaultModelBindingContext();
 
+#pragma warning disable CS0618 // Type or member is obsolete
             var identity = ModelMetadataIdentity.ForProperty(typeof(int), property, typeof(string));
+#pragma warning restore CS0618 // Type or member is obsolete
             context.ModelMetadata = new Mock<ModelMetadata>(identity).Object;
 
             // Act

src/Mvc/Mvc.Core/test/ModelBinding/Metadata/DefaultBindingMetadataProviderTest.cs

@@ -161,7 +161,7 @@ public void CreateBindingDetails_FindsBindingBehaviorNever_OnProperty()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -184,7 +184,7 @@ public void CreateBindingDetails_FindsBindNever_OnProperty()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -207,7 +207,7 @@ public void CreateBindingDetails_FindsBindingBehaviorOptional_OnProperty()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -230,7 +230,7 @@ public void CreateBindingDetails_FindsBindingBehaviorRequired_OnProperty()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -253,7 +253,7 @@ public void CreateBindingDetails_FindsBindRequired_OnProperty()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -420,7 +420,7 @@ public void CreateBindingDetails_UsesFirstAttribute()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -438,7 +438,7 @@ public void CreateBindingDetails_FindsBindRequired_OnContainerClass()
         {
             // Arrange
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindRequiredOnClass).GetProperty(nameof(BindRequiredOnClass.Property)), typeof(int), typeof(BindRequiredOnClass)),
                 new ModelAttributes(new object[0], new object[0], null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -456,7 +456,7 @@ public void CreateBindingDetails_FindsBindNever_OnContainerClass()
         {
             // Arrange
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindNeverOnClass).GetProperty(nameof(BindNeverOnClass.Property)), typeof(int), typeof(BindNeverOnClass)),
                 new ModelAttributes(new object[0], new object[0], null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -474,7 +474,7 @@ public void CreateBindingDetails_FindsBindNever_OnBaseClass()
         {
             // Arrange
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindNeverOnClass).GetProperty(nameof(BindNeverOnClass.Property)), typeof(int), typeof(BindNeverOnClass)),
                 new ModelAttributes(new object[0], new object[0], null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -497,7 +497,7 @@ public void CreateBindingDetails_OverrideBehaviorOnClass_OverrideWithOptional()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindNeverOnClass).GetProperty(nameof(BindNeverOnClass.Property)), typeof(int), typeof(BindNeverOnClass)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -520,7 +520,7 @@ public void CreateBindingDetails_OverrideBehaviorOnClass_OverrideWithRequired()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindNeverOnClass).GetProperty(nameof(BindNeverOnClass.Property)), typeof(int), typeof(BindNeverOnClass)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -543,7 +543,7 @@ public void CreateBindingDetails_OverrideInheritedBehaviorOnClass_OverrideWithRe
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(InheritedBindNeverOnClass).GetProperty(nameof(InheritedBindNeverOnClass.Property)), typeof(int), typeof(InheritedBindNeverOnClass)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -566,7 +566,7 @@ public void CreateBindingDetails_OverrideBehaviorOnClass_OverrideWithNever()
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
+                ModelMetadataIdentity.ForProperty(typeof(BindRequiredOnClass).GetProperty(nameof(BindRequiredOnClass.Property)), typeof(int), typeof(BindRequiredOnClass)),
                 new ModelAttributes(new object[0], propertyAttributes, null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -585,7 +585,7 @@ public void CreateBindingDetails_OverrideBehaviorOnBaseClass_OverrideWithRequire
         {
             // Arrange
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOverridesInheritedBindNever)),
+                ModelMetadataIdentity.ForProperty(typeof(BindRequiredOverridesInheritedBindNever).GetProperty(nameof(BindRequiredOverridesInheritedBindNever.Property)), typeof(int), typeof(BindRequiredOverridesInheritedBindNever)),
                 new ModelAttributes(new object[0], new object[0], null));
 
             var provider = new DefaultBindingMetadataProvider();
@@ -641,7 +641,7 @@ public void CreateBindingDetails_BindingBehaviorLeftAlone_ForAttributeOnProperty
             };
 
             var context = new BindingMetadataProviderContext(
-                ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
+                ModelMetadataIdentity.ForProperty(typeof(string).GetProperty(nameof(string.Length)), typeof(int), typeof(string)),
                 new ModelAttributes(typeAttributes, new object[0], null));
 
             // These values shouldn't be changed since this is a Type-Metadata