Add validation for MetadataType attribute - Issue #46678 (#51772)

* MetadataType attribute class properties are now validated.

Fix #46678

* Clean up PR #51772

Co-authored-by: Brice Lambson <brice@bricelam.net>

src/libraries/System.ComponentModel.Annotations/src/System/ComponentModel/DataAnnotations/ValidationAttributeStore.cs

@@ -124,8 +124,7 @@ private TypeStoreItem GetTypeStoreItem([DynamicallyAccessedMembers(TypeStoreItem
             {
                 if (!_typeStoreItems.TryGetValue(type, out TypeStoreItem? item))
                 {
-                    // use CustomAttributeExtensions.GetCustomAttributes() to get inherited attributes as well as direct ones
-                    var attributes = CustomAttributeExtensions.GetCustomAttributes(type, true);
+                    var attributes = TypeDescriptor.GetAttributes(type).Cast<Attribute>();
                     item = new TypeStoreItem(type, attributes);
                     _typeStoreItems[type] = item;
                 }
@@ -170,7 +169,7 @@ internal StoreItem(IEnumerable<Attribute> attributes)
         /// </summary>
         private sealed class TypeStoreItem : StoreItem
         {
-            internal const DynamicallyAccessedMemberTypes DynamicallyAccessedTypes = DynamicallyAccessedMemberTypes.PublicProperties | DynamicallyAccessedMemberTypes.NonPublicProperties;
+            internal const DynamicallyAccessedMemberTypes DynamicallyAccessedTypes = DynamicallyAccessedMemberTypes.All;
 
             private readonly object _syncRoot = new object();
             [DynamicallyAccessedMembers(DynamicallyAccessedTypes)]
@@ -183,6 +182,7 @@ internal TypeStoreItem([DynamicallyAccessedMembers(DynamicallyAccessedTypes)] Ty
                 _type = type;
             }
 
+            [RequiresUnreferencedCode("The Types of _type's properties cannot be statically discovered.")]
             internal PropertyStoreItem GetPropertyStoreItem(string propertyName)
             {
                 if (!TryGetPropertyStoreItem(propertyName, out PropertyStoreItem? item))
@@ -194,6 +194,7 @@ internal PropertyStoreItem GetPropertyStoreItem(string propertyName)
                 return item;
             }
 
+            [RequiresUnreferencedCode("The Types of _type's properties cannot be statically discovered.")]
             internal bool TryGetPropertyStoreItem(string propertyName, [NotNullWhen(true)] out PropertyStoreItem? item)
             {
                 if (string.IsNullOrEmpty(propertyName))
@@ -215,23 +216,51 @@ internal bool TryGetPropertyStoreItem(string propertyName, [NotNullWhen(true)] o
                 return _propertyStoreItems.TryGetValue(propertyName, out item);
             }
 
+            [RequiresUnreferencedCode("The Types of _type's properties cannot be statically discovered.")]
             private Dictionary<string, PropertyStoreItem> CreatePropertyStoreItems()
             {
                 var propertyStoreItems = new Dictionary<string, PropertyStoreItem>();
 
-                // exclude index properties to match old TypeDescriptor functionality
-                var properties = _type.GetRuntimeProperties()
-                    .Where(prop => IsPublic(prop) && !prop.GetIndexParameters().Any());
-                foreach (PropertyInfo property in properties)
+                var properties = TypeDescriptor.GetProperties(_type);
+                foreach (PropertyDescriptor property in properties)
                 {
-                    // use CustomAttributeExtensions.GetCustomAttributes() to get inherited attributes as well as direct ones
-                    var item = new PropertyStoreItem(property.PropertyType,
-                        CustomAttributeExtensions.GetCustomAttributes(property, true));
+                    var item = new PropertyStoreItem(property.PropertyType, GetExplicitAttributes(property).Cast<Attribute>());
                     propertyStoreItems[property.Name] = item;
                 }
 
                 return propertyStoreItems;
             }
+
+            /// <summary>
+            ///     Method to extract only the explicitly specified attributes from a <see cref="PropertyDescriptor"/>
+            /// </summary>
+            /// <remarks>
+            ///     Normal TypeDescriptor semantics are to inherit the attributes of a property's type.  This method
+            ///     exists to suppress those inherited attributes.
+            /// </remarks>
+            /// <param name="propertyDescriptor">The property descriptor whose attributes are needed.</param>
+            /// <returns>A new <see cref="AttributeCollection"/> stripped of any attributes from the property's type.</returns>
+            [RequiresUnreferencedCode("The Type of propertyDescriptor.PropertyType cannot be statically discovered.")]
+            private AttributeCollection GetExplicitAttributes(PropertyDescriptor propertyDescriptor)
+            {
+                List<Attribute> attributes = new List<Attribute>(propertyDescriptor.Attributes.Cast<Attribute>());
+                IEnumerable<Attribute> typeAttributes = TypeDescriptor.GetAttributes(propertyDescriptor.PropertyType).Cast<Attribute>();
+                bool removedAttribute = false;
+                foreach (Attribute attr in typeAttributes)
+                {
+                    for (int i = attributes.Count - 1; i >= 0; --i)
+                    {
+                        // We must use ReferenceEquals since attributes could Match if they are the same.
+                        // Only ReferenceEquals will catch actual duplications.
+                        if (object.ReferenceEquals(attr, attributes[i]))
+                        {
+                            attributes.RemoveAt(i);
+                            removedAttribute = true;
+                        }
+                    }
+                }
+                return removedAttribute ? new AttributeCollection(attributes.ToArray()) : propertyDescriptor.Attributes;
+            }
         }
 
         /// <summary>

src/libraries/System.ComponentModel.Annotations/src/System/ComponentModel/DataAnnotations/Validator.cs

@@ -514,17 +514,16 @@ private static IEnumerable<ValidationError> GetObjectPropertyValidationErrors(ob
         private static ICollection<KeyValuePair<ValidationContext, object?>> GetPropertyValues(object instance,
             ValidationContext validationContext)
         {
-            var properties = instance.GetType().GetRuntimeProperties()
-                                .Where(p => ValidationAttributeStore.IsPublic(p) && !p.GetIndexParameters().Any());
-            var items = new List<KeyValuePair<ValidationContext, object?>>(properties.Count());
-            foreach (var property in properties)
+            var properties = TypeDescriptor.GetProperties(instance);
+            var items = new List<KeyValuePair<ValidationContext, object?>>(properties.Count);
+            foreach (PropertyDescriptor property in properties)
             {
                 var context = CreateValidationContext(instance, validationContext);
                 context.MemberName = property.Name;
 
                 if (_store.GetPropertyValidationAttributes(context).Any())
                 {
-                    items.Add(new KeyValuePair<ValidationContext, object?>(context, property.GetValue(instance, null)));
+                    items.Add(new KeyValuePair<ValidationContext, object?>(context, property.GetValue(instance)));
                 }
             }