Add `IsReferenceOrNullableType` and `UnderlyingOrModelType` to `ModelMetadata`

- #2992
- use new properties to replace common helper methods
- still a few `Nullable.GetUnderlyingType()` calls
  - creating `ModelMetadata` or sites lacking `ModelMetadata` access e.g. `ModelBindingHelper.ConvertTo()`

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/ModelMetadata.cs

@@ -5,9 +5,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
-#if DNXCORE50
 using System.Reflection;
-#endif
 using Microsoft.AspNet.Mvc.ModelBinding.Metadata;
 using Microsoft.Framework.Internal;
 
@@ -139,8 +137,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public abstract ModelMetadata ElementMetadata { get; }
 
         /// <summary>
-        /// Gets the ordered display names and values of all <see cref="Enum"/> values in <see cref="ModelType"/> or
+        /// Gets the ordered display names and values of all <see cref="Enum"/> values in
-        /// <c>Nullable.GetUnderlyingType(ModelType)</c>.
+        /// <see cref="UnderlyingOrModelType"/>.
         /// </summary>
         /// <value>
         /// An <see cref="IEnumerable{KeyValuePair{string, string}}"/> of mappings between <see cref="Enum"/> field names
@@ -149,8 +147,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public abstract IEnumerable<KeyValuePair<string, string>> EnumDisplayNamesAndValues { get; }
 
         /// <summary>
-        /// Gets the names and values of all <see cref="Enum"/> values in <see cref="ModelType"/> or
+        /// Gets the names and values of all <see cref="Enum"/> values in <see cref="UnderlyingOrModelType"/>.
-        /// <c>Nullable.GetUnderlyingType(ModelType)</c>.
         /// </summary>
         /// <value>
         /// An <see cref="IReadOnlyDictionary{string, string}"/> of mappings between <see cref="Enum"/> field names
@@ -204,23 +201,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         public abstract bool IsBindingRequired { get; }
 
         /// <summary>
-        /// Gets a value indicating whether <see cref="ModelType"/> or <c>Nullable.GetUnderlyingType(ModelType)</c> is
+        /// Gets a value indicating whether <see cref="UnderlyingOrModelType"/> is for an <see cref="Enum"/>.
-        /// for an <see cref="Enum"/>.
         /// </summary>
         /// <value>
         /// <c>true</c> if <c>type.IsEnum</c> (<c>type.GetTypeInfo().IsEnum</c> for DNX Core 5.0) is <c>true</c> for
-        /// <see cref="ModelType"/> or <c>Nullable.GetUnderlyingType(ModelType)</c>; <c>false</c> otherwise.
+        /// <see cref="UnderlyingOrModelType"/>; <c>false</c> otherwise.
         /// </value>
         public abstract bool IsEnum { get; }
 
         /// <summary>
-        /// Gets a value indicating whether <see cref="ModelType"/> or <c>Nullable.GetUnderlyingType(ModelType)</c> is
+        /// Gets a value indicating whether <see cref="UnderlyingOrModelType"/> is for an <see cref="Enum"/> with an
-        /// for an <see cref="Enum"/> with an associated <see cref="FlagsAttribute"/>.
+        /// associated <see cref="FlagsAttribute"/>.
         /// </summary>
         /// <value>
-        /// <c>true</c> if <see cref="IsEnum"/> is <c>true</c> and <see cref="ModelType"/> or
+        /// <c>true</c> if <see cref="IsEnum"/> is <c>true</c> and <see cref="UnderlyingOrModelType"/> has an
-        /// <c>Nullable.GetUnderlyingType(ModelType)</c> has an associated <see cref="FlagsAttribute"/>; <c>false</c>
+        /// associated <see cref="FlagsAttribute"/>; <c>false</c> otherwise.
-        /// otherwise.
         /// </value>
         public abstract bool IsFlagsEnum { get; }
 
@@ -346,6 +341,32 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             }
         }
 
+        /// <summary>
+        /// Gets a value indicating whether or not <see cref="ModelType"/> allows <c>null</c> values.
+        /// </summary>
+        public bool IsReferenceOrNullableType
+        {
+            get
+            {
+                return !ModelType.GetTypeInfo().IsValueType || IsNullableValueType;
+            }
+        }
+
+        /// <summary>
+        /// Gets the underlying type argument if <see cref="ModelType"/> inherits from <see cref="Nullable{T}"/>.
+        /// Otherwise gets <see cref="ModelType"/>.
+        /// </summary>
+        /// <remarks>
+        /// Identical to <see cref="ModelType"/> unless <see cref="IsNullableValueType"/> is <c>true</c>.
+        /// </remarks>
+        public Type UnderlyingOrModelType
+        {
+            get
+            {
+                return Nullable.GetUnderlyingType(ModelType) ?? ModelType;
+            }
+        }
+
         /// <summary>
         /// Gets a property getter delegate to get the property value from a model object.
         /// </summary>

src/Microsoft.AspNet.Mvc.Core/DefaultControllerActionArgumentBinder.cs

@@ -127,8 +127,11 @@ namespace Microsoft.AspNet.Mvc
                 var source = property.Value;
                 if (propertyHelper.Property.CanWrite && propertyHelper.Property.SetMethod?.IsPublic == true)
                 {
-                    // Handle settable property. Do not set the property if the type is a non-nullable type.
+                    // Handle settable property.
-                    if (source != null || AllowsNullValue(propertyType))
+                    var metadata = _modelMetadataProvider.GetMetadataForType(propertyType);
+
+                    // Do not set the property to null if the type is a non-nullable type.
+                    if (source != null || metadata.IsReferenceOrNullableType)
                     {
                         propertyHelper.SetValue(controller, source);
                     }
@@ -218,10 +221,5 @@ namespace Microsoft.AspNet.Mvc
                 ValueProvider = bindingContext.ValueProvider,
             };
         }
-
-        private static bool AllowsNullValue([NotNull] Type type)
-        {
-            return !type.GetTypeInfo().IsValueType || Nullable.GetUnderlyingType(type) != null;
-        }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/DefaultModelMetadata.cs

@@ -7,7 +7,9 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
 using System.Linq;
+#if DNXCORE50
 using System.Reflection;
+#endif
 using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
@@ -407,8 +409,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                     }
                     else
                     {
-                        // Default to IsRequired = true for value types.
+                        // Default to IsRequired = true for non-Nullable<T> value types.
-                        _isRequired = !AllowsNullValue(ModelType);
+                        _isRequired = !IsReferenceOrNullableType;
                     }
                 }
 
@@ -526,10 +528,5 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 return _details.PropertySetter;
             }
         }
-
-        private static bool AllowsNullValue([NotNull] Type type)
-        {
-            return !type.GetTypeInfo().IsValueType || Nullable.GetUnderlyingType(type) != null;
-        }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/DisplayMetadata.cs

@@ -58,14 +58,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
 
         /// <summary>
         /// Gets the ordered display names and values of all <see cref="System.Enum"/> values in
-        /// <see cref="ModelMetadata.ModelType"/> or <c>Nullable.GetUnderlyingType(ModelType)</c>. See
+        /// <see cref="ModelMetadata.UnderlyingOrModelType"/>. See
         /// <see cref="ModelMetadata.EnumDisplayNamesAndValues"/>.
         /// </summary>
         public IEnumerable<KeyValuePair<string, string>> EnumDisplayNamesAndValues { get; set; }
 
         /// <summary>
-        /// Gets the names and values of all <see cref="System.Enum"/> values in <see cref="ModelMetadata.ModelType"/>
+        /// Gets the names and values of all <see cref="System.Enum"/> values in
-        /// or <c>Nullable.GetUnderlyingType(ModelType)</c>. See <see cref="ModelMetadata.EnumNamesAndValues"/>.
+        /// <see cref="ModelMetadata.UnderlyingOrModelType"/>. See <see cref="ModelMetadata.EnumNamesAndValues"/>.
         /// </summary>
         // This could be implemented in DefaultModelMetadata. But value should be cached.
         public IReadOnlyDictionary<string, string> EnumNamesAndValues { get; set; }
@@ -89,17 +89,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
         public bool HtmlEncode { get; set; } = true;
 
         /// <summary>
-        /// Gets a value indicating whether <see cref="ModelMetadata.ModelType"/> or
+        /// Gets a value indicating whether <see cref="ModelMetadata.UnderlyingOrModelType"/> is for an
-        /// <c>Nullable.GetUnderlyingType(ModelType)</c> is for an <see cref="System.Enum"/>. See
+        /// <see cref="System.Enum"/>. See <see cref="ModelMetadata.IsEnum"/>.
-        /// <see cref="ModelMetadata.IsEnum"/>.
         /// </summary>
         // This could be implemented in DefaultModelMetadata. But value is needed in the details provider.
         public bool IsEnum { get; set; }
 
         /// <summary>
-        /// Gets a value indicating whether <see cref="ModelMetadata.ModelType"/> or
+        /// Gets a value indicating whether <see cref="ModelMetadata.UnderlyingOrModelType"/> is for an
-        /// <c>Nullable.GetUnderlyingType(ModelType)</c> is for an <see cref="System.Enum"/> with an associated
+        /// <see cref="System.Enum"/> with an associated <see cref="System.FlagsAttribute"/>. See
-        /// <see cref="System.FlagsAttribute"/>. See <see cref="ModelMetadata.IsFlagsEnum"/>.
+        /// <see cref="ModelMetadata.IsFlagsEnum"/>.
         /// </summary>
         // This could be implemented in DefaultModelMetadata. But value is needed in the details provider.
         public bool IsFlagsEnum { get; set; }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/SimpleTypeModelBinder.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Core;
 
@@ -51,7 +50,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 // When converting newModel a null value may indicate a failed conversion for an otherwise required
                 // model (can't set a ValueType to null). This detects if a null model value is acceptable given the
                 // current bindingContext. If not, an error is logged.
-                if (model == null && !AllowsNullValue(bindingContext.ModelType))
+                if (model == null && !bindingContext.ModelMetadata.IsReferenceOrNullableType)
                 {
                     bindingContext.ModelState.TryAddModelError(
                         bindingContext.ModelName,
@@ -83,10 +82,5 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 key: bindingContext.ModelName,
                 isModelSet: false);
         }
-
-        private static bool AllowsNullValue(Type type)
-        {
-            return !type.GetTypeInfo().IsValueType || Nullable.GetUnderlyingType(type) != null;
-        }
     }
 }

src/Microsoft.AspNet.Mvc.DataAnnotations/NumericClientModelValidatorProvider.cs

@@ -1,9 +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 System.Collections.Generic;
-
 namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
 {
     /// <summary>
@@ -15,8 +12,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         /// <inheritdoc />
         public void GetValidators(ClientValidatorProviderContext context)
         {
-            var type = context.ModelMetadata.ModelType;
+            var typeToValidate = context.ModelMetadata.UnderlyingOrModelType;
-            var typeToValidate = Nullable.GetUnderlyingType(type) ?? type;
 
             // Check only the numeric types for which we set type='text'.
             if (typeToValidate == typeof(float) ||

src/Microsoft.AspNet.Mvc.TagHelpers/InputTagHelper.cs

@@ -386,11 +386,7 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
             var fieldType = modelExplorer.ModelType;
             if (typeof(bool?) != fieldType)
             {
-                var underlyingType = Nullable.GetUnderlyingType(fieldType);
+                fieldType = modelExplorer.Metadata.UnderlyingOrModelType;
-                if (underlyingType != null)
-                {
-                    fieldType = underlyingType;
-                }
             }
 
             foreach (string typeName in TemplateRenderer.GetTypeNames(modelExplorer.Metadata, fieldType))

src/Microsoft.AspNet.Mvc.ViewFeatures/Rendering/Html/DefaultHtmlGenerator.cs

@@ -8,7 +8,6 @@ using System.Diagnostics;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
-using System.Text;
 using Microsoft.AspNet.Antiforgery;
 using Microsoft.AspNet.Html.Abstractions;
 using Microsoft.AspNet.Mvc.ModelBinding;
@@ -838,7 +837,7 @@ namespace Microsoft.AspNet.Mvc.Rendering
             // Logic below assumes isTargetEnum and enumNames are consistent. Confirm that expectation is met.
             Debug.Assert(isTargetEnum ^ enumNames == null);
 
-            var innerType = Nullable.GetUnderlyingType(metadata.ModelType) ?? metadata.ModelType;
+            var innerType = metadata.UnderlyingOrModelType;
 
             // Convert raw value collection to strings.
             var currentValues = new HashSet<string>(StringComparer.OrdinalIgnoreCase);

src/Microsoft.AspNet.Mvc.ViewFeatures/Rendering/Internal/TemplateRenderer.cs

@@ -146,10 +146,8 @@ namespace Microsoft.AspNet.Mvc.Rendering.Internal
 
             // We don't want to search for Nullable<T>, we want to search for T (which should handle both T and
             // Nullable<T>).
-            var modelType = _viewData.ModelExplorer.ModelType;
+            var fieldType = metadata.UnderlyingOrModelType;
-            var fieldType = Nullable.GetUnderlyingType(modelType) ?? modelType;
+            foreach (var typeName in GetTypeNames(metadata, fieldType))
-
-            foreach (var typeName in GetTypeNames(_viewData.ModelExplorer.Metadata, fieldType))
             {
                 yield return typeName;
             }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewDataDictionary.cs

@@ -5,7 +5,9 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Globalization;
+#if DNXCORE50
 using System.Reflection;
+#endif
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering.Expressions;
 using Microsoft.AspNet.Mvc.ViewFeatures;
@@ -186,8 +188,7 @@ namespace Microsoft.AspNet.Mvc
         {
             // This is the core constructor called when Model is known.
             var modelType = GetModelType(model);
-            var metadataModelType =
+            var metadataModelType = source.ModelMetadata.UnderlyingOrModelType;
-                Nullable.GetUnderlyingType(source.ModelMetadata.ModelType) ?? source.ModelMetadata.ModelType;
             if (modelType == metadataModelType && model == source.ModelExplorer.Model)
             {
                 // Preserve any customizations made to source.ModelExplorer.ModelMetadata if the Type
@@ -260,7 +261,7 @@ namespace Microsoft.AspNet.Mvc
 
         public TemplateInfo TemplateInfo { get; }
 
-        #region IDictionary properties
+#region IDictionary properties
         // Do not just pass through to _data: Indexer should not throw a KeyNotFoundException.
         public object this[string index]
         {
@@ -295,7 +296,7 @@ namespace Microsoft.AspNet.Mvc
         {
             get { return _data.Values; }
         }
-        #endregion
+#endregion
 
         // for unit testing
         internal IDictionary<string, object> Data
@@ -383,13 +384,13 @@ namespace Microsoft.AspNet.Mvc
             EnsureCompatible(value);
 
             // Reset or override ModelMetadata based on runtime value type. Fall back to declared type if value is
-            // null. When called from the Model setter, ModelMetadata will (temporarily) be null. When called from
+            // null. When called from a constructor, current ModelExplorer may already be set to preserve
-            // a constructor, current ModelMetadata may already be set to preserve customizations made in parent scope.
+            // customizations made in parent scope. But ModelExplorer is never null after instance is initialized.
             var modelType = GetModelType(value);
             Type metadataModelType = null;
             if (ModelExplorer != null)
             {
-                metadataModelType = Nullable.GetUnderlyingType(ModelMetadata.ModelType) ?? ModelMetadata.ModelType;
+                metadataModelType = ModelMetadata.UnderlyingOrModelType;
             }
 
             if (metadataModelType != modelType)
@@ -413,7 +414,7 @@ namespace Microsoft.AspNet.Mvc
         {
             // IsCompatibleObject verifies if the value is either an instance of _declaredModelType or (if value is
             // null) that _declaredModelType is a nullable type.
-            var castWillSucceed = IsCompatibleWith(_declaredModelType, value);
+            var castWillSucceed = IsCompatibleWithDeclaredType(value);
             if (!castWillSucceed)
             {
                 string message;
@@ -435,19 +436,20 @@ namespace Microsoft.AspNet.Mvc
             return (value == null) ? _declaredModelType : value.GetType();
         }
 
-        private static bool IsCompatibleWith([NotNull] Type type, object value)
+        private bool IsCompatibleWithDeclaredType(object value)
         {
             if (value == null)
             {
-                return !type.GetTypeInfo().IsValueType || Nullable.GetUnderlyingType(type) != null;
+                // In this case ModelMetadata.ModelType matches _declaredModelType.
+                return ModelMetadata.IsReferenceOrNullableType;
             }
             else
             {
-                return type.GetTypeInfo().IsAssignableFrom(value.GetType().GetTypeInfo());
+                return _declaredModelType.IsAssignableFrom(value.GetType());
             }
         }
 
-        #region IDictionary methods
+#region IDictionary methods
         public void Add([NotNull] string key, object value)
         {
             _data.Add(key, value);
@@ -502,6 +504,6 @@ namespace Microsoft.AspNet.Mvc
         {
             return _data.GetEnumerator();
         }
-        #endregion
+#endregion
     }
 }

test/Microsoft.AspNet.Mvc.Abstractions.Test/ModelBinding/ModelMetadataTest.cs

@@ -21,7 +21,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         [InlineData(typeof(string))]
         [InlineData(typeof(Nullable<int>))]
         [InlineData(typeof(int))]
-        public void IsComplexTypeTestsReturnsFalseForSimpleTypes(Type type)
+        public void IsComplexType_ReturnsFalseForSimpleTypes(Type type)
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();
@@ -38,7 +38,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         [InlineData(typeof(IDisposable))]
         [InlineData(typeof(IsComplexTypeModel))]
         [InlineData(typeof(Nullable<IsComplexTypeModel>))]
-        public void IsComplexTypeTestsReturnsTrueForComplexTypes(Type type)
+        public void IsComplexType_ReturnsTrueForComplexTypes(Type type)
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();
@@ -50,12 +50,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             Assert.True(modelMetadata.IsComplexType);
         }
 
+        // IsCollectionType
+        private class NonCollectionType
+        {
+        }
+
+        private class DerivedList : List<int>
+        {
+        }
+
         [Theory]
         [InlineData(typeof(object))]
         [InlineData(typeof(int))]
         [InlineData(typeof(NonCollectionType))]
         [InlineData(typeof(string))]
-        public void IsCollectionType_NonCollectionTypes(Type type)
+        public void IsCollectionType_ReturnsFalseForNonCollectionTypes(Type type)
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();
@@ -75,7 +84,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         [InlineData(typeof(IEnumerable<string>))]
         [InlineData(typeof(Collection<int>))]
         [InlineData(typeof(Dictionary<object, object>))]
-        public void IsCollectionType_CollectionTypes(Type type)
+        public void IsCollectionType_ReturnsTrueForCollectionTypes(Type type)
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();
@@ -87,14 +96,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             Assert.True(modelMetadata.IsCollectionType);
         }
 
-        private class NonCollectionType
-        {
-        }
-
-        private class DerivedList : List<int>
-        {
-        }
-
         // IsNullableValueType
 
         [Theory]
@@ -102,7 +103,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         [InlineData(typeof(IDisposable), false)]
         [InlineData(typeof(Nullable<int>), true)]
         [InlineData(typeof(int), false)]
-        public void IsNullableValueTypeTests(Type modelType, bool expected)
+        [InlineData(typeof(DerivedList), false)]
+        [InlineData(typeof(IsComplexTypeModel), false)]
+        [InlineData(typeof(Nullable<IsComplexTypeModel>), true)]
+        public void IsNullableValueType_ReturnsExpectedValue(Type modelType, bool expected)
         {
             // Arrange
             var modelMetadata = new TestModelMetadata(modelType);
@@ -111,18 +115,42 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             Assert.Equal(expected, modelMetadata.IsNullableValueType);
         }
 
-        private class Class1
+        // IsReferenceOrNullableType
+
+        [Theory]
+        [InlineData(typeof(string), true)]
+        [InlineData(typeof(IDisposable), true)]
+        [InlineData(typeof(Nullable<int>), true)]
+        [InlineData(typeof(int), false)]
+        [InlineData(typeof(DerivedList), true)]
+        [InlineData(typeof(IsComplexTypeModel), false)]
+        [InlineData(typeof(Nullable<IsComplexTypeModel>), true)]
+        public void IsReferenceOrNullableType_ReturnsExpectedValue(Type modelType, bool expected)
         {
-            public string Prop1 { get; set; }
+            // Arrange
-            public override string ToString()
+            var modelMetadata = new TestModelMetadata(modelType);
-            {
+
-                return "Class1";
+            // Act & Assert
-            }
+            Assert.Equal(expected, modelMetadata.IsReferenceOrNullableType);
         }
 
-        private class Class2
+        // UnderlyingOrModelType
+
+        [Theory]
+        [InlineData(typeof(string), typeof(string))]
+        [InlineData(typeof(IDisposable), typeof(IDisposable))]
+        [InlineData(typeof(Nullable<int>), typeof(int))]
+        [InlineData(typeof(int), typeof(int))]
+        [InlineData(typeof(DerivedList), typeof(DerivedList))]
+        [InlineData(typeof(IsComplexTypeModel), typeof(IsComplexTypeModel))]
+        [InlineData(typeof(Nullable<IsComplexTypeModel>), typeof(IsComplexTypeModel))]
+        public void UnderlyingOrModelType_ReturnsExpectedValue(Type modelType, Type expected)
         {
-            public int Prop2 { get; set; }
+            // Arrange
+            var modelMetadata = new TestModelMetadata(modelType);
+
+            // Act & Assert
+            Assert.Equal(expected, modelMetadata.UnderlyingOrModelType);
         }
 
         // GetDisplayName()
@@ -143,7 +171,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         }
 
         [Fact]
-        public void ReturnsPropertyNameWhenSetAndDisplayNameIsNull()
+        public void GetDisplayName_ReturnsPropertyName_WhenSetAndDisplayNameIsNull()
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();
@@ -157,7 +185,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         }
 
         [Fact]
-        public void ReturnsTypeNameWhenPropertyNameAndDisplayNameAreNull()
+        public void GetDisplayName_ReturnsTypeName_WhenPropertyNameAndDisplayNameAreNull()
         {
             // Arrange
             var provider = new EmptyModelMetadataProvider();