Make ModelBindingContext.Result non-nullable

This change simplifies a bunch of code and fits more in line with the
current design of model binding.

Now, a model binder only has to do anything if it was successful.
'return' is enough to indicate failure.

src/Microsoft.AspNetCore.Mvc.Abstractions/ModelBinding/ModelBindingContext.cs

@@ -106,18 +106,15 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 
         /// <summary>
         /// <para>
-        /// On completion returns a <see cref="ModelBindingResult"/> which
+        /// Gets or sets a <see cref="ModelBindingResult"/> which represents the result of the model binding process.
-        /// represents the result of the model binding process.
         /// </para>
         /// <para>
-        /// If model binding was successful, the <see cref="ModelBindingResult"/> should be a value created
+        /// Before an <see cref="IModelBinder"/> is called, <see cref="Result"/> will be set to a value indicating
-        /// with <see cref="ModelBindingResult.Success"/>. If model binding failed, the
+        /// failure. The binder should set <see cref="Result"/> to a value created with
-        /// <see cref="ModelBindingResult"/> should be a value created with <see cref="ModelBindingResult.Failed"/>.
+        /// <see cref="ModelBindingResult.Success"/> if model binding succeeded.
-        /// If there was no data, or this model binder cannot handle the operation, the
-        /// <see cref="ModelBindingResult"/> should be null.
         /// </para>
         /// </summary>
-        public abstract ModelBindingResult? Result { get; set; }
+        public abstract ModelBindingResult Result { get; set; }
 
         /// <summary>
         /// Pushes a layer of state onto this context. Model binders will call this as part of recursion when binding properties

src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerArgumentBinder.cs

@@ -85,9 +85,9 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 var parameter = parameters[i];
 
                 var result = await BindModelAsync(parameter, controllerContext, valueProvider);
-                if (result != null && result.Value.IsModelSet)
+                if (result.IsModelSet)
                 {
-                    arguments[parameter.Name] = result.Value.Model;
+                    arguments[parameter.Name] = result.Model;
                 }
             }
 
@@ -105,18 +105,18 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 var property = properties[i];
 
                 var result = await BindModelAsync(property, controllerContext, valueProvider);
-                if (result != null && result.Value.IsModelSet)
+                if (result.IsModelSet)
                 {
                     var propertyHelper = FindPropertyHelper(propertyHelpers, property);
                     if (propertyHelper != null)
                     {
-                        ActivateProperty(property, propertyHelper, controller, result.Value.Model);
+                        ActivateProperty(property, propertyHelper, controller, result.Model);
                     }
                 }
             }
         }
 
-        public async Task<ModelBindingResult?> BindModelAsync(
+        public async Task<ModelBindingResult> BindModelAsync(
             ParameterDescriptor parameter,
             ControllerContext controllerContext)
         {
@@ -135,7 +135,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             return await BindModelAsync(parameter, controllerContext, valueProvider);
         }
 
-        public async Task<ModelBindingResult?> BindModelAsync(
+        public async Task<ModelBindingResult> BindModelAsync(
             ParameterDescriptor parameter,
             ControllerContext controllerContext,
             IValueProvider valueProvider)
@@ -189,13 +189,13 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             await binder.BindModelAsync(modelBindingContext);
 
             var modelBindingResult = modelBindingContext.Result;
-            if (modelBindingResult != null && modelBindingResult.Value.IsModelSet)
+            if (modelBindingResult.IsModelSet)
             {
                 _validator.Validate(
                     controllerContext,
                     modelBindingContext.ValidationState,
                     modelBindingContext.ModelName,
-                    modelBindingResult.Value.Model);
+                    modelBindingResult.Model);
             }
 
             return modelBindingResult;

src/Microsoft.AspNetCore.Mvc.Core/Internal/DefaultModelBindingContext.cs

@@ -177,7 +177,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
         }
 
         /// <inheritdoc />
-        public override ModelBindingResult? Result
+        public override ModelBindingResult Result
         {
             get
             {
@@ -303,7 +303,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
         {
             _stack.Push(_state);
 
-            Result = null;
+            Result = default(ModelBindingResult);
 
             return new NestedScope(this);
         }
@@ -344,7 +344,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             public BindingSource BindingSource;
             public bool IsTopLevelObject;
 
-            public ModelBindingResult? Result;
+            public ModelBindingResult Result;
         };
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/Internal/NoOpBinder.cs

@@ -12,7 +12,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 
         public Task BindModelAsync(ModelBindingContext bindingContext)
         {
-            bindingContext.Result = ModelBindingResult.Failed();
             return TaskCache.CompletedTask;
         }
     }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/BinderTypeModelBinder.cs

@@ -52,11 +52,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = (IModelBinder)_factory(requestServices, arguments: null);
 
             await binder.BindModelAsync(bindingContext);
-
-            if (bindingContext.Result == null)
-            {
-                bindingContext.Result = ModelBindingResult.Failed();
-            }
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/BodyModelBinder.cs

@@ -91,11 +91,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 
                 var exception = new UnsupportedContentTypeException(message);
                 bindingContext.ModelState.AddModelError(modelBindingKey, exception, bindingContext.ModelMetadata);
-
-                // This model binder is the only handler for the Body binding source and it cannot run twice. Always
-                // tell the model binding system to skip other model binders and never to fall back i.e. indicate a
-                // fatal error.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return;
             }
 
@@ -107,9 +102,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 
                 if (result.HasError)
                 {
-                    // Formatter encountered an error. Do not use the model it returned. As above, tell the model
+                    // Formatter encountered an error. Do not use the model it returned.
-                    // binding system to skip other model binders and never to fall back.
-                    bindingContext.Result = ModelBindingResult.Failed();
                     return;
                 }
 
@@ -119,11 +112,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             catch (Exception ex)
             {
                 bindingContext.ModelState.AddModelError(modelBindingKey, ex, bindingContext.ModelMetadata);
-
-                // This model binder is the only handler for the Body binding source and it cannot run twice. Always
-                // tell the model binding system to skip other model binders and never to fall back i.e. indicate a
-                // fatal error.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return;
             }
         }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/ByteArrayModelBinder.cs

@@ -24,7 +24,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
             if (valueProviderResult == ValueProviderResult.None)
             {
-                bindingContext.Result = ModelBindingResult.Failed();
                 return TaskCache.CompletedTask;
             }
 
@@ -34,7 +33,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var value = valueProviderResult.FirstValue;
             if (string.IsNullOrEmpty(value))
             {
-                bindingContext.Result = ModelBindingResult.Failed();
                 return TaskCache.CompletedTask;
             }
 
@@ -50,12 +48,8 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     bindingContext.ModelName,
                     exception,
                     bindingContext.ModelMetadata);
+                return TaskCache.CompletedTask;
             }
-
-            // Matched the type (byte[]) only this binder supports. As in missing data cases, always tell the model
-            // binding system to skip other model binders i.e. return non-null.
-            bindingContext.Result = ModelBindingResult.Failed();
-            return TaskCache.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/CollectionModelBinder.cs

@@ -192,9 +192,9 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 {
                     await ElementBinder.BindModelAsync(bindingContext);
 
-                    if (bindingContext.Result != null && bindingContext.Result.Value.IsModelSet)
+                    if (bindingContext.Result.IsModelSet)
                     {
-                        boundValue = bindingContext.Result.Value.Model;
+                        boundValue = bindingContext.Result.Model;
                         boundCollection.Add(ModelBindingHelper.CastOrDefault<TElement>(boundValue));
                     }
                 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/ComplexTypeModelBinder.cs

@@ -90,7 +90,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     model: propertyModel))
                 {
                     await BindProperty(bindingContext);
-                    result = bindingContext.Result ?? ModelBindingResult.Failed();
+                    result = bindingContext.Result;
                 }
 
                 if (result.IsModelSet)

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/DictionaryModelBinder.cs

@@ -49,13 +49,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             }
 
             await base.BindModelAsync(bindingContext);
-            if (bindingContext.Result == null || !bindingContext.Result.Value.IsModelSet)
+            if (!bindingContext.Result.IsModelSet)
             {
                 // No match for the prefix at all.
                 return;
             }
 
-            var result = bindingContext.Result.Value;
+            var result = bindingContext.Result;
 
             Debug.Assert(result.Model != null);
             var model = (IDictionary<TKey, TValue>)result.Model;
@@ -103,7 +103,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     var valueResult = bindingContext.Result;
 
                     // Always add an entry to the dictionary but validate only if binding was successful.
-                    model[convertedKey] = ModelBindingHelper.CastOrDefault<TValue>(valueResult.Value.Model);
+                    model[convertedKey] = ModelBindingHelper.CastOrDefault<TValue>(valueResult.Model);
                     keyMappings.Add(kvp.Key, convertedKey);
                 }
             }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/FormFileModelBinder.cs

@@ -34,9 +34,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 !bindingContext.ModelMetadata.IsReadOnly;
             if (!createFileCollection && !ModelBindingHelper.CanGetCompatibleCollection<IFormFile>(bindingContext))
             {
-                // Silently fail and stop other model binders running if unable to create an instance or use the
+                // Silently fail if unable to create an instance or use the current instance.
-                // current instance.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return;
             }
 
@@ -65,7 +63,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 if (postedFiles.Count == 0)
                 {
                     // Silently fail if the named file does not exist in the request.
-                    bindingContext.Result = ModelBindingResult.Failed();
                     return;
                 }
 
@@ -77,7 +74,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 {
                     // Silently fail if no files match. Will bind to an empty collection (treat empty as a success
                     // case and not reach here) if binding to a top-level object.
-                    bindingContext.Result = ModelBindingResult.Failed();
                     return;
                 }
 

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/KeyValuePairModelBinder.cs

@@ -68,10 +68,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 bindingContext.ModelState.TryAddModelError(
                     keyModelName,
                     bindingContext.ModelMetadata.ModelBindingMessageProvider.MissingKeyOrValueAccessor());
-
-                // Were able to get some data for this model.
-                // Always tell the model binding system to skip other model binders.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return;
             }
 
@@ -80,10 +76,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 bindingContext.ModelState.TryAddModelError(
                     valueModelName,
                     bindingContext.ModelMetadata.ModelBindingMessageProvider.MissingKeyOrValueAccessor());
-
-                // Were able to get some data for this model.
-                // Always tell the model binding system to skip other model binders.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return;
             }
 
@@ -112,15 +104,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             {
                 await binder.BindModelAsync(bindingContext);
 
-                var result = bindingContext.Result;
+                return bindingContext.Result;
-                if (result != null && result.Value.IsModelSet)
-                {
-                    return result.Value;
-                }
-                else
-                {
-                    return ModelBindingResult.Failed();
-                }
             }
         }
     }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/SimpleTypeModelBinder.cs

@@ -38,7 +38,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             if (valueProviderResult == ValueProviderResult.None)
             {
                 // no entry
-                bindingContext.Result = ModelBindingResult.Failed();
                 return TaskCache.CompletedTask;
             }
 
@@ -76,8 +75,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                         bindingContext.ModelName,
                         bindingContext.ModelMetadata.ModelBindingMessageProvider.ValueMustNotBeNullAccessor(
                             valueProviderResult.ToString()));
-
+                    
-                    bindingContext.Result = ModelBindingResult.Failed();
                     return TaskCache.CompletedTask;
                 }
                 else
@@ -102,8 +100,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     bindingContext.ModelMetadata);
 
                 // Were able to find a converter for the type but conversion failed.
-                // Tell the model binding system to skip other model binders.
-                bindingContext.Result = ModelBindingResult.Failed();
                 return TaskCache.CompletedTask;
             }
         }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Internal/ModelBindingHelper.cs

@@ -450,13 +450,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Internal
 
             await binder.BindModelAsync(modelBindingContext);
             var modelBindingResult = modelBindingContext.Result;
-            if (modelBindingResult != null && modelBindingResult.Value.IsModelSet)
+            if (modelBindingResult.IsModelSet)
             {
                 objectModelValidator.Validate(
                     actionContext,
                     modelBindingContext.ValidationState,
                     modelBindingContext.ModelName,
-                    modelBindingResult.Value.Model);
+                    modelBindingResult.Model);
 
                 return modelState.IsValid;
             }

test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/ModelBinderExtensions.cs

@@ -1,18 +0,0 @@
-// 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.Threading.Tasks;
-
-namespace Microsoft.AspNetCore.Mvc.ModelBinding
-{
-    public static class ModelBinderExtensions
-    {
-        public static async Task<ModelBindingResult> BindModelResultAsync(
-            this IModelBinder binder, 
-            ModelBindingContext context)
-        {
-            await binder.BindModelAsync(context);
-            return context.Result ?? default(ModelBindingResult);
-        }
-    }
-}

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/ArrayModelBinderTest.cs

@@ -29,12 +29,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ArrayModelBinder<int>(new SimpleTypeModelBinder(typeof(int)));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var array = Assert.IsType<int[]>(result.Model);
+            var array = Assert.IsType<int[]>(bindingContext.Result.Model);
             Assert.Equal(new[] { 42, 84 }, array);
         }
 
@@ -44,23 +44,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             // Arrange
             var binder = new ArrayModelBinder<string>(new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.IsTopLevelObject = true;
+            bindingContext.IsTopLevelObject = true;
 
             // Lack of prefix and non-empty model name both ignored.
-            context.ModelName = "modelName";
+            bindingContext.ModelName = "modelName";
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(string[]));
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(string[]));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Empty(Assert.IsType<string[]>(result.Model));
+            Assert.Empty(Assert.IsType<string[]>(bindingContext.Result.Model));
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
         }
 
         [Theory]
@@ -71,21 +71,21 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             // Arrange
             var binder = new ArrayModelBinder<string>(new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = ModelNames.CreatePropertyModelName(prefix, "ArrayProperty");
+            bindingContext.ModelName = ModelNames.CreatePropertyModelName(prefix, "ArrayProperty");
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithArrayProperty),
                 nameof(ModelWithArrayProperty.ArrayProperty));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(default(ModelBindingResult), result);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         public static TheoryData<int[]> ArrayModelData
@@ -128,11 +128,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ArrayModelBinder<int>(new SimpleTypeModelBinder(typeof(int)));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Same(model, result.Model);
+            Assert.Same(model, bindingContext.Result.Model);
 
             for (var i = 0; i < arrayLength; i++)
             {
@@ -151,7 +151,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     var model = value.ConvertTo(mbc.ModelType);
                     return ModelBindingResult.Success(model);
                 }
-                return null;
+                return ModelBindingResult.Failed();
             });
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/BinderTypeModelBinderTest.cs

@@ -23,10 +23,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new BinderTypeModelBinder(typeof(NullModelBinder));
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(binderResult.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         [Fact]
@@ -45,12 +45,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new BinderTypeModelBinder(typeof(NotNullModelBinder));
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            var p = (Person)binderResult.Model;
+            var person = (Person)bindingContext.Result.Model;
-            Assert.Equal(model.Age, p.Age);
+            Assert.Equal(model.Age, person.Age);
-            Assert.Equal(model.Name, p.Name);
+            Assert.Equal(model.Name, person.Name);
         }
 
         [Fact]

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/BodyModelBinderTests.cs

@@ -40,13 +40,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new[] { inputFormatter });
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
             mockInputFormatter.Verify(v => v.CanRead(It.IsAny<InputFormatterContext>()), Times.Once);
             mockInputFormatter.Verify(v => v.ReadAsync(It.IsAny<InputFormatterContext>()), Times.Once);
-            Assert.NotNull(binderResult);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.True(binderResult.IsModelSet);
         }
 
         [Fact]
@@ -61,14 +60,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new List<IInputFormatter>());
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-
+            Assert.False(bindingContext.Result.IsModelSet);
-            // Returns non-null because it understands the metadata type.
+            Assert.Null(bindingContext.Result.Model);
-            Assert.NotNull(binderResult);
-            Assert.False(binderResult.IsModelSet);
-            Assert.Null(binderResult.Model);
 
             // Key is the empty string because this was a top-level binding.
             var entry = Assert.Single(bindingContext.ModelState);
@@ -89,14 +85,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new List<IInputFormatter>());
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-
+            Assert.False(bindingContext.Result.IsModelSet);
-            // Returns non-null because it understands the metadata type.
+            Assert.Null(bindingContext.Result.Model);
-            Assert.NotNull(binderResult);
-            Assert.False(binderResult.IsModelSet);
-            Assert.Null(binderResult.Model);
 
             // Key is the bindermodelname because this was a top-level binding.
             var entry = Assert.Single(bindingContext.ModelState);
@@ -116,11 +109,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new List<IInputFormatter>());
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(binderResult);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.False(binderResult.IsModelSet);
         }
 
         [Fact]
@@ -142,14 +134,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new[] { new XyzFormatter() });
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-
+            Assert.False(bindingContext.Result.IsModelSet);
-            // Returns non-null because it understands the metadata type.
+            Assert.Null(bindingContext.Result.Model);
-            Assert.NotNull(binderResult);
-            Assert.False(binderResult.IsModelSet);
-            Assert.Null(binderResult.Model);
 
             // Key is the empty string because this was a top-level binding.
             var entry = Assert.Single(bindingContext.ModelState);
@@ -176,14 +165,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(new List<IInputFormatter>());
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-
+            Assert.False(bindingContext.Result.IsModelSet);
-            // Returns non-null result because it understands the metadata type.
+            Assert.Null(bindingContext.Result.Model);
-            Assert.NotNull(binderResult);
-            Assert.False(binderResult.IsModelSet);
-            Assert.Null(binderResult.Model);
 
             // Key is the empty string because this was a top-level binding.
             var entry = Assert.Single(bindingContext.ModelState);
@@ -213,11 +199,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = CreateBinder(inputFormatters);
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(binderResult.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Same(canReadFormatter1, binderResult.Model);
+            Assert.Same(canReadFormatter1, bindingContext.Result.Model);
         }
 
         private static DefaultModelBindingContext GetBindingContext(

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/ByteArrayModelBinderTests.cs

@@ -24,12 +24,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ByteArrayModelBinder();
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(binderResult);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.False(binderResult.IsModelSet);
+            Assert.Null(bindingContext.Result.Model);
-            Assert.Null(binderResult.Model);
 
             var modelState = Assert.Single(bindingContext.ModelState);
             Assert.Equal("foo", modelState.Key);
@@ -49,11 +48,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ByteArrayModelBinder();
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(binderResult);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var bytes = Assert.IsType<byte[]>(binderResult.Model);
+            var bytes = Assert.IsType<byte[]>(bindingContext.Result.Model);
             Assert.Equal(new byte[] { 23, 43, 53 }, bytes);
         }
 
@@ -72,10 +71,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ByteArrayModelBinder();
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(binderResult);
+            Assert.False(bindingContext.Result.IsModelSet);
             Assert.False(bindingContext.ModelState.IsValid);
             var error = Assert.Single(bindingContext.ModelState["foo"].Errors);
             Assert.Equal(expected, error.ErrorMessage);
@@ -94,12 +93,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new ByteArrayModelBinder();
 
             // Act
-            var binderResult = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(binderResult);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.False(binderResult.IsModelSet);
+            Assert.Null(bindingContext.Result.Model);
-            Assert.Null(binderResult.Model);
 
             Assert.Empty(bindingContext.ModelState); // No submitted data for "foo".
         }

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/CancellationTokenModelBinderTests.cs

@@ -20,11 +20,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new CancellationTokenModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(bindingContext.HttpContext.RequestAborted, result.Model);
+            Assert.Equal(bindingContext.HttpContext.RequestAborted, bindingContext.Result.Model);
         }
 
         private static DefaultModelBindingContext GetBindingContext(Type modelType)

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/CollectionModelBinderTest.cs

@@ -81,12 +81,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new CollectionModelBinder<int>(CreateIntBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var list = Assert.IsAssignableFrom<IList<int>>(result.Model);
+            var list = Assert.IsAssignableFrom<IList<int>>(bindingContext.Result.Model);
             Assert.Equal(new[] { 42, 100, 200 }, list.ToArray());
 
             Assert.True(modelState.IsValid);
@@ -112,12 +112,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new CollectionModelBinder<int>(CreateIntBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            Assert.Same(list, result.Model);
+            Assert.Same(list, bindingContext.Result.Model);
             Assert.Equal(new[] { 42, 100, 200 }, list.ToArray());
 
             Assert.True(modelState.IsValid);
@@ -138,12 +138,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new CollectionModelBinder<int>(CreateIntBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var list = Assert.IsAssignableFrom<IList<int>>(result.Model);
+            var list = Assert.IsAssignableFrom<IList<int>>(bindingContext.Result.Model);
             Assert.Equal(new[] { 42, 100, 200 }, list.ToArray());
         }
 
@@ -164,12 +164,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new CollectionModelBinder<int>(CreateIntBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            Assert.Same(list, result.Model);
+            Assert.Same(list, bindingContext.Result.Model);
             Assert.Equal(new[] { 42, 100, 200 }, list.ToArray());
         }
 
@@ -185,13 +185,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var bindingContext = GetModelBindingContext(valueProvider, isReadOnly: false);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.NotNull(result.Model);
 
-            var model = Assert.IsType<List<int>>(result.Model);
+            var model = Assert.IsType<List<int>>(bindingContext.Result.Model);
             Assert.Empty(model);
         }
 
@@ -214,25 +213,25 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
         public async Task CollectionModelBinder_CreatesEmptyCollection_IfIsTopLevelObject()
         {
             // Arrange
-            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: null));
+            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: ModelBindingResult.Failed()));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.IsTopLevelObject = true;
+            bindingContext.IsTopLevelObject = true;
 
             // Lack of prefix and non-empty model name both ignored.
-            context.ModelName = "modelName";
+            bindingContext.ModelName = "modelName";
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(List<string>));
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(List<string>));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Empty(Assert.IsType<List<string>>(result.Model));
+            Assert.Empty(Assert.IsType<List<string>>(bindingContext.Result.Model));
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
         }
 
         // Setup like CollectionModelBinder_CreatesEmptyCollection_IfIsTopLevelObject  except
@@ -241,29 +240,29 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
         public async Task CollectionModelBinder_DoesNotCreateEmptyCollection_IfModelNonNull()
         {
             // Arrange
-            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: null));
+            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: ModelBindingResult.Failed()));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.IsTopLevelObject = true;
+            bindingContext.IsTopLevelObject = true;
 
             var list = new List<string>();
-            context.Model = list;
+            bindingContext.Model = list;
 
             // Lack of prefix and non-empty model name both ignored.
-            context.ModelName = "modelName";
+            bindingContext.ModelName = "modelName";
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(List<string>));
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(List<string>));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Same(list, result.Model);
+            Assert.Same(list, bindingContext.Result.Model);
             Assert.Empty(list);
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
         }
 
         [Theory]
@@ -272,23 +271,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
         public async Task CollectionModelBinder_DoesNotCreateCollection_IfNotIsTopLevelObject(string prefix)
         {
             // Arrange
-            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: null));
+            var binder = new CollectionModelBinder<string>(new StubModelBinder(result: ModelBindingResult.Failed()));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = ModelNames.CreatePropertyModelName(prefix, "ListProperty");
+            bindingContext.ModelName = ModelNames.CreatePropertyModelName(prefix, "ListProperty");
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithListProperty),
                 nameof(ModelWithListProperty.ListProperty));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(default(ModelBindingResult), result);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         // Model type -> can create instance.
@@ -378,7 +377,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 var value = mbc.ValueProvider.GetValue(mbc.ModelName);
                 if (value == ValueProviderResult.None)
                 {
-                    return null;
+                    return ModelBindingResult.Failed();
                 }
 
                 var model = value.ConvertTo(mbc.ModelType);

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/ComplexTypeModelBinderTest.cs

@@ -283,12 +283,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 .Returns(false);
 
             // Act
-            var result = await testableBinder.Object.BindModelResultAsync(bindingContext);
+            await testableBinder.Object.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.NotNull(result);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.True(result.IsModelSet);
+            var returnedPerson = Assert.IsType<Person>(bindingContext.Result.Model);
-            var returnedPerson = Assert.IsType<Person>(result.Model);
             Assert.Same(model, returnedPerson);
             testableBinder.Verify();
         }

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/DictionaryModelBinderTest.cs

@@ -40,19 +40,19 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var dictionary = Assert.IsAssignableFrom<IDictionary<int, string>>(result.Model);
+            var dictionary = Assert.IsAssignableFrom<IDictionary<int, string>>(bindingContext.Result.Model);
             Assert.NotNull(dictionary);
             Assert.Equal(2, dictionary.Count);
             Assert.Equal("forty-two", dictionary[42]);
             Assert.Equal("eighty-four", dictionary[84]);
 
             // This uses the default IValidationStrategy
-            Assert.DoesNotContain(result.Model, bindingContext.ValidationState.Keys);
+            Assert.DoesNotContain(bindingContext.Result.Model, bindingContext.ValidationState.Keys);
         }
 
         [Theory]
@@ -80,19 +80,19 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            Assert.Same(dictionary, result.Model);
+            Assert.Same(dictionary, bindingContext.Result.Model);
             Assert.NotNull(dictionary);
             Assert.Equal(2, dictionary.Count);
             Assert.Equal("forty-two", dictionary[42]);
             Assert.Equal("eighty-four", dictionary[84]);
 
             // This uses the default IValidationStrategy
-            Assert.DoesNotContain(result.Model, bindingContext.ValidationState.Keys);
+            Assert.DoesNotContain(bindingContext.Result.Model, bindingContext.ValidationState.Keys);
         }
 
         // modelName, keyFormat, dictionary
@@ -135,23 +135,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = modelName;
+            bindingContext.ModelName = modelName;
-            context.ValueProvider = CreateEnumerableValueProvider(keyFormat, dictionary);
+            bindingContext.ValueProvider = CreateEnumerableValueProvider(keyFormat, dictionary);
-            context.FieldName = modelName;
+            bindingContext.FieldName = modelName;
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.DictionaryProperty));
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var resultDictionary = Assert.IsAssignableFrom<IDictionary<string, string>>(result.Model);
+            var resultDictionary = Assert.IsAssignableFrom<IDictionary<string, string>>(bindingContext.Result.Model);
             Assert.Equal(dictionary, resultDictionary);
         }
 
@@ -171,23 +171,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = "prefix";
+            bindingContext.ModelName = "prefix";
-            context.ValueProvider = CreateTestValueProvider("prefix[{0}]", dictionary);
+            bindingContext.ValueProvider = CreateTestValueProvider("prefix[{0}]", dictionary);
-            context.FieldName = context.ModelName;
+            bindingContext.FieldName = bindingContext.ModelName;
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.DictionaryProperty));
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var resultDictionary = Assert.IsAssignableFrom<IDictionary<string, string>>(result.Model);
+            var resultDictionary = Assert.IsAssignableFrom<IDictionary<string, string>>(bindingContext.Result.Model);
             Assert.Empty(resultDictionary);
         }
 
@@ -221,23 +221,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(long)), 
                 new SimpleTypeModelBinder(typeof(int)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = "prefix";
+            bindingContext.ModelName = "prefix";
-            context.ValueProvider = CreateEnumerableValueProvider("prefix[{0}]", stringDictionary);
+            bindingContext.ValueProvider = CreateEnumerableValueProvider("prefix[{0}]", stringDictionary);
-            context.FieldName = context.ModelName;
+            bindingContext.FieldName = bindingContext.ModelName;
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.DictionaryWithValueTypesProperty));
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var resultDictionary = Assert.IsAssignableFrom<IDictionary<long, int>>(result.Model);
+            var resultDictionary = Assert.IsAssignableFrom<IDictionary<long, int>>(bindingContext.Result.Model);
             Assert.Equal(dictionary, resultDictionary);
         }
 
@@ -258,13 +258,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 { "prefix[27].Name", "Fred" },
             };
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = "prefix";
+            bindingContext.ModelName = "prefix";
-            context.ValueProvider = CreateEnumerableValueProvider("{0}", stringDictionary);
+            bindingContext.ValueProvider = CreateEnumerableValueProvider("{0}", stringDictionary);
-            context.FieldName = context.ModelName;
+            bindingContext.FieldName = bindingContext.ModelName;
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.DictionaryWithComplexValuesProperty));
 
@@ -279,17 +279,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 }));
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var resultDictionary = Assert.IsAssignableFrom<IDictionary<int, ModelWithProperties>>(result.Model);
+            var resultDictionary = Assert.IsAssignableFrom<IDictionary<int, ModelWithProperties>>(bindingContext.Result.Model);
             Assert.Equal(dictionary, resultDictionary);
 
             // This requires a non-default IValidationStrategy
-            Assert.Contains(result.Model, context.ValidationState.Keys);
+            Assert.Contains(bindingContext.Result.Model, bindingContext.ValidationState.Keys);
-            var entry = context.ValidationState[result.Model];
+            var entry = bindingContext.ValidationState[bindingContext.Result.Model];
             var strategy = Assert.IsType<ShortFormDictionaryValidationStrategy<int, ModelWithProperties>>(entry.Strategy);
             Assert.Equal(
                 new KeyValuePair<string, int>[]
@@ -313,24 +313,24 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = modelName;
+            bindingContext.ModelName = modelName;
 
-            context.ValueProvider = CreateEnumerableValueProvider(keyFormat, dictionary);
+            bindingContext.ValueProvider = CreateEnumerableValueProvider(keyFormat, dictionary);
-            context.FieldName = context.ModelName;
+            bindingContext.FieldName = bindingContext.ModelName;
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.CustomDictionaryProperty));
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var resultDictionary = Assert.IsAssignableFrom<SortedDictionary<string, string>>(result.Model);
+            var resultDictionary = Assert.IsAssignableFrom<SortedDictionary<string, string>>(bindingContext.Result.Model);
             Assert.Equal(expectedDictionary, resultDictionary);
         }
 
@@ -342,23 +342,23 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.IsTopLevelObject = true;
+            bindingContext.IsTopLevelObject = true;
 
             // Lack of prefix and non-empty model name both ignored.
-            context.ModelName = "modelName";
+            bindingContext.ModelName = "modelName";
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(Dictionary<string, string>));
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(Dictionary<string, string>));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Empty(Assert.IsType<Dictionary<string, string>>(result.Model));
+            Assert.Empty(Assert.IsType<Dictionary<string, string>>(bindingContext.Result.Model));
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
         }
 
         [Theory]
@@ -371,21 +371,21 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(int)), 
                 new SimpleTypeModelBinder(typeof(int)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = ModelNames.CreatePropertyModelName(prefix, "ListProperty");
+            bindingContext.ModelName = ModelNames.CreatePropertyModelName(prefix, "ListProperty");
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithDictionaryProperties),
                 nameof(ModelWithDictionaryProperties.DictionaryProperty));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(default(ModelBindingResult), result);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         // Model type -> can create instance.

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/FormCollectionModelBinderTest.cs

@@ -29,13 +29,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormCollectionModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
             Assert.Empty(bindingContext.ValidationState);
 
-            var form = Assert.IsAssignableFrom<IFormCollection>(result.Model);
+            var form = Assert.IsAssignableFrom<IFormCollection>(bindingContext.Result.Model);
             Assert.Equal(2, form.Count);
             Assert.Equal("value1", form["field1"]);
             Assert.Equal("value2", form["field2"]);
@@ -50,11 +50,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormCollectionModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var form = Assert.IsAssignableFrom<IFormCollection>(result.Model);
+            var form = Assert.IsAssignableFrom<IFormCollection>(bindingContext.Result.Model);
             Assert.Empty(form);
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/FormFileModelBinderTest.cs

@@ -26,12 +26,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var entry = bindingContext.ValidationState[result.Model];
+            var entry = bindingContext.ValidationState[bindingContext.Result.Model];
             Assert.False(entry.SuppressValidation);
             Assert.Equal("file", entry.Key);
             Assert.Null(entry.Metadata);
@@ -47,17 +47,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
 
-            var entry = bindingContext.ValidationState[result.Model];
+            var entry = bindingContext.ValidationState[bindingContext.Result.Model];
             Assert.False(entry.SuppressValidation);
             Assert.Equal("file", entry.Key);
             Assert.Null(entry.Metadata);
 
-            var files = Assert.IsAssignableFrom<IList<IFormFile>>(result.Model);
+            var files = Assert.IsAssignableFrom<IList<IFormFile>>(bindingContext.Result.Model);
             Assert.Equal(2, files.Count);
         }
 
@@ -79,12 +79,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var bindingContext = GetBindingContext(destinationType, httpContext);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.IsAssignableFrom(destinationType, result.Model);
+            Assert.IsAssignableFrom(destinationType, bindingContext.Result.Model);
-            Assert.Equal(formFiles, result.Model as IEnumerable<IFormFile>);
+            Assert.Equal(formFiles, bindingContext.Result.Model as IEnumerable<IFormFile>);
         }
 
         [Fact]
@@ -97,11 +97,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var file = Assert.IsAssignableFrom<IFormFile>(result.Model);
+            var file = Assert.IsAssignableFrom<IFormFile>(bindingContext.Result.Model);
             Assert.Equal("file1.txt", file.FileName);
         }
 
@@ -115,11 +115,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Fact]
@@ -133,11 +133,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Theory]
@@ -159,11 +159,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var file = Assert.IsAssignableFrom<IFormFile>(result.Model);
+            var file = Assert.IsAssignableFrom<IFormFile>(bindingContext.Result.Model);
 
             Assert.Equal(expected, file.Name);
         }
@@ -179,11 +179,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Fact]
@@ -197,11 +197,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new FormFileModelBinder();
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Fact]
@@ -214,11 +214,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var bindingContext = GetBindingContextForReadOnlyArray(httpContext);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Fact]
@@ -231,11 +231,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var bindingContext = GetBindingContext(typeof(ISet<IFormFile>), httpContext);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         private static DefaultModelBindingContext GetBindingContextForReadOnlyArray(HttpContext httpContext)

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/HeaderModelBinderTests.cs

@@ -22,13 +22,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
         {
             // Arrange
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContext(type);
+            var bindingContext = GetBindingContext(type);
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         [Fact]
@@ -39,17 +39,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var header = "Accept";
             var headerValue = "application/json,text/json";
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContext(type);
+            var bindingContext = GetBindingContext(type);
 
-            modelBindingContext.FieldName = header;
+            bindingContext.FieldName = header;
-            modelBindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
+            bindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(headerValue.Split(','), result.Model);
+            Assert.Equal(headerValue.Split(','), bindingContext.Result.Model);
         }
 
         [Fact]
@@ -60,17 +60,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var header = "User-Agent";
             var headerValue = "UnitTest";
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContext(type);
+            var bindingContext = GetBindingContext(type);
 
-            modelBindingContext.FieldName = header;
+            bindingContext.FieldName = header;
-            modelBindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
+            bindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(headerValue, result.Model);
+            Assert.Equal(headerValue, bindingContext.Result.Model);
         }
 
         [Theory]
@@ -86,18 +86,18 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var header = "Accept";
             var headerValue = "application/json,text/json";
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContext(destinationType);
+            var bindingContext = GetBindingContext(destinationType);
 
-            modelBindingContext.FieldName = header;
+            bindingContext.FieldName = header;
-            modelBindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
+            bindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.IsAssignableFrom(destinationType, result.Model);
+            Assert.IsAssignableFrom(destinationType, bindingContext.Result.Model);
-            Assert.Equal(headerValue.Split(','), result.Model as IEnumerable<string>);
+            Assert.Equal(headerValue.Split(','), bindingContext.Result.Model as IEnumerable<string>);
         }
 
         [Fact]
@@ -107,17 +107,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var header = "Accept";
             var headerValue = "application/json,text/json";
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContextForReadOnlyArray();
+            var bindingContext = GetBindingContextForReadOnlyArray();
 
-            modelBindingContext.FieldName = header;
+            bindingContext.FieldName = header;
-            modelBindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
+            bindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         [Fact]
@@ -127,17 +127,17 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var header = "Accept";
             var headerValue = "application/json,text/json";
             var binder = new HeaderModelBinder();
-            var modelBindingContext = GetBindingContext(typeof(ISet<string>));
+            var bindingContext = GetBindingContext(typeof(ISet<string>));
 
-            modelBindingContext.FieldName = header;
+            bindingContext.FieldName = header;
-            modelBindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
+            bindingContext.HttpContext.Request.Headers.Add(header, new[] { headerValue });
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
         }
 
         private static DefaultModelBindingContext GetBindingContext(Type modelType)

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/KeyValuePairModelBinderTest.cs

@@ -24,11 +24,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new KeyValuePairModelBinder<int, string>(CreateIntBinder(false), CreateStringBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
             Assert.Equal("someName", bindingContext.ModelName);
             var error = Assert.Single(bindingContext.ModelState["someName.Key"].Errors);
@@ -46,10 +46,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new KeyValuePairModelBinder<int, string>(CreateIntBinder(), CreateStringBinder(false));
             
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
             Assert.Equal("someName", bindingContext.ModelName);
             var state = bindingContext.ModelState["someName.Value"];
@@ -69,10 +69,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new KeyValuePairModelBinder<int, string>(CreateIntBinder(false), CreateStringBinder(false));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(default(ModelBindingResult), result);
+            Assert.False(bindingContext.Result.IsModelSet);
             Assert.True(bindingContext.ModelState.IsValid);
             Assert.Equal(0, bindingContext.ModelState.ErrorCount);
         }
@@ -87,11 +87,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new KeyValuePairModelBinder<int, string>(CreateIntBinder(), CreateStringBinder());
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(new KeyValuePair<int, string>(42, "some-value"), result.Model);
+            Assert.Equal(new KeyValuePair<int, string>(42, "some-value"), bindingContext.Result.Model);
         }
 
         [Theory]
@@ -103,7 +103,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             bool isSuccess)
         {
             // Arrange
-            ModelBindingResult? innerResult;
+            ModelBindingResult innerResult;
             if (isSuccess)
             {
                 innerResult = ModelBindingResult.Success(model);
@@ -128,7 +128,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var result = await binder.TryBindStrongModel<int>(bindingContext, innerBinder, "Key", "someName.Key");
 
             // Assert
-            Assert.Equal(innerResult.Value, result);
+            Assert.Equal(innerResult, result);
             Assert.Empty(bindingContext.ModelState);
         }
 
@@ -140,24 +140,24 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.IsTopLevelObject = true;
+            bindingContext.IsTopLevelObject = true;
 
             // Lack of prefix and non-empty model name both ignored.
-            context.ModelName = "modelName";
+            bindingContext.ModelName = "modelName";
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(KeyValuePair<string, string>));
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(KeyValuePair<string, string>));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            var model = Assert.IsType<KeyValuePair<string, string>>(result.Model);
+            var model = Assert.IsType<KeyValuePair<string, string>>(bindingContext.Result.Model);
             Assert.Equal(default(KeyValuePair<string, string>), model);
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
         }
 
         [Theory]
@@ -170,21 +170,21 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 new SimpleTypeModelBinder(typeof(string)), 
                 new SimpleTypeModelBinder(typeof(string)));
 
-            var context = CreateContext();
+            var bindingContext = CreateContext();
-            context.ModelName = ModelNames.CreatePropertyModelName(prefix, "KeyValuePairProperty");
+            bindingContext.ModelName = ModelNames.CreatePropertyModelName(prefix, "KeyValuePairProperty");
 
             var metadataProvider = new TestModelMetadataProvider();
-            context.ModelMetadata = metadataProvider.GetMetadataForProperty(
+            bindingContext.ModelMetadata = metadataProvider.GetMetadataForProperty(
                 typeof(ModelWithKeyValuePairProperty),
                 nameof(ModelWithKeyValuePairProperty.KeyValuePairProperty));
 
-            context.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
+            bindingContext.ValueProvider = new TestValueProvider(new Dictionary<string, object>());
 
             // Act
-            var result = await binder.BindModelResultAsync(context);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(default(ModelBindingResult), result);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         private static DefaultModelBindingContext CreateContext()
@@ -225,7 +225,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     var model = 42;
                     return ModelBindingResult.Success(model);
                 }
-                return null;
+                return ModelBindingResult.Failed();
             });
             return mockIntBinder;
         }
@@ -239,7 +239,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     var model = "some-value";
                     return ModelBindingResult.Success(model);
                 }
-                return null;
+                return ModelBindingResult.Failed();
             });
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/ServicesModelBinderTest.cs

@@ -19,16 +19,15 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var type = typeof(IService);
 
             var binder = new ServicesModelBinder();
-            var modelBindingContext = GetBindingContext(type);
+            var bindingContext = GetBindingContext(type);
 
             // Act
-            var result = await binder.BindModelResultAsync(modelBindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.NotNull(result.Model);
 
-            var entry = modelBindingContext.ValidationState[result.Model];
+            var entry = bindingContext.ValidationState[bindingContext.Result.Model];
             Assert.True(entry.SuppressValidation);
             Assert.Null(entry.Key);
             Assert.Null(entry.Metadata);

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/SimpleTypeModelBinderTest.cs

@@ -50,10 +50,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(destinationType);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
         }
 
         [Theory]
@@ -75,11 +75,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(destinationType);
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
 
             var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
             Assert.Equal("The value '' is invalid.", error.ErrorMessage, StringComparer.Ordinal);
@@ -100,11 +100,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(int));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
             var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
             Assert.Equal(message, error.ErrorMessage);
@@ -118,10 +118,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(int));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Equal(ModelBindingResult.Failed(), result);
+            Assert.Equal(ModelBindingResult.Failed(), bindingContext.Result);
             Assert.Empty(bindingContext.ModelState);
         }
 
@@ -138,10 +138,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(string));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -160,10 +160,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(string));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -180,11 +180,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(int?));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(12, result.Model);
+            Assert.Equal(12, bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -201,11 +201,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(double?));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(12.5, result.Model);
+            Assert.Equal(12.5, bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -222,11 +222,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(int));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(42, result.Model);
+            Assert.Equal(42, bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -243,11 +243,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(decimal));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            Assert.Equal(12.5M, result.Model);
+            Assert.Equal(12.5M, bindingContext.Result.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
         }
 
@@ -264,11 +264,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(decimal));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.False(result.IsModelSet);
+            Assert.False(bindingContext.Result.IsModelSet);
-            Assert.Null(result.Model);
+            Assert.Null(bindingContext.Result.Model);
 
             var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
             Assert.Equal("The value '12,5' is not valid for Decimal.", error.ErrorMessage, StringComparer.Ordinal);
@@ -288,11 +288,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(IntEnum));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var boundModel = Assert.IsType<IntEnum>(result.Model);
+            var boundModel = Assert.IsType<IntEnum>(bindingContext.Result.Model);
             Assert.Equal(IntEnum.Value1, boundModel);
         }
 
@@ -309,11 +309,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(IntEnum));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var boundModel = Assert.IsType<IntEnum>(result.Model);
+            var boundModel = Assert.IsType<IntEnum>(bindingContext.Result.Model);
             Assert.Equal(IntEnum.Value1, boundModel);
         }
 
@@ -335,11 +335,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var binder = new SimpleTypeModelBinder(typeof(FlagsEnum));
 
             // Act
-            var result = await binder.BindModelResultAsync(bindingContext);
+            await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(result.IsModelSet);
+            Assert.True(bindingContext.Result.IsModelSet);
-            var boundModel = Assert.IsType<FlagsEnum>(result.Model);
+            var boundModel = Assert.IsType<FlagsEnum>(bindingContext.Result.Model);
             Assert.Equal((FlagsEnum)expected, boundModel);
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/ModelBindingHelperTest.cs

@@ -22,25 +22,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
     public class ModelBindingHelperTest
     {
-        public static TheoryData<ModelBindingResult?> UnsuccessfulModelBindingData
+        [Fact]
-        {
+        public async Task TryUpdateModel_ReturnsFalse_IfBinderIsUnsuccessful()
-            get
-            {
-                return new TheoryData<ModelBindingResult?>
-                {
-                    null,
-                    ModelBindingResult.Failed(),
-                };
-            }
-        }
-
-        [Theory]
-        [MemberData(nameof(UnsuccessfulModelBindingData))]
-        public async Task TryUpdateModel_ReturnsFalse_IfBinderIsUnsuccessful(ModelBindingResult? binderResult)
         {
             // Arrange
             var metadataProvider = new EmptyModelMetadataProvider();
-            var binder = new StubModelBinder(binderResult);
+            var binder = new StubModelBinder(ModelBindingResult.Failed());
             var model = new MyModel();
 
             // Act
@@ -141,14 +128,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             Assert.Equal("MyPropertyValue", model.MyProperty);
         }
 
-        [Theory]
+        [Fact]
-        [MemberData(nameof(UnsuccessfulModelBindingData))]
+        public async Task TryUpdateModel_UsingPropertyFilterOverload_ReturnsFalse_IfBinderIsUnsuccessful()
-        public async Task TryUpdateModel_UsingPropertyFilterOverload_ReturnsFalse_IfBinderIsUnsuccessful(
-            ModelBindingResult? binderResult)
         {
             // Arrange
             var metadataProvider = new EmptyModelMetadataProvider();
-            var binder = new StubModelBinder(binderResult);
+            var binder = new StubModelBinder(ModelBindingResult.Failed());
             var model = new MyModel();
             Func<ModelMetadata, bool> propertyFilter = (m) => true;
 
@@ -224,14 +209,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             Assert.Equal("Old-ExcludedPropertyValue", model.ExcludedProperty);
         }
 
-        [Theory]
+        [Fact]
-        [MemberData(nameof(UnsuccessfulModelBindingData))]
+        public async Task TryUpdateModel_UsingIncludeExpressionOverload_ReturnsFalse_IfBinderIsUnsuccessful()
-        public async Task TryUpdateModel_UsingIncludeExpressionOverload_ReturnsFalse_IfBinderIsUnsuccessful(
-            ModelBindingResult? binderResult)
         {
             // Arrange
             var metadataProvider = new EmptyModelMetadataProvider();
-            var binder = new StubModelBinder(binderResult);
+            var binder = new StubModelBinder(ModelBindingResult.Failed());
             var model = new MyModel();
 
             // Act
@@ -472,14 +455,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 ex.Message);
         }
 
-        [Theory]
+        [Fact]
-        [MemberData(nameof(UnsuccessfulModelBindingData))]
+        public async Task TryUpdateModelNonGeneric_PropertyFilterOverload_ReturnsFalse_IfBinderIsUnsuccessful()
-        public async Task TryUpdateModelNonGeneric_PropertyFilterOverload_ReturnsFalse_IfBinderIsUnsuccessful(
-            ModelBindingResult? binderResult)
         {
             // Arrange
             var metadataProvider = new EmptyModelMetadataProvider();
-            var binder = new StubModelBinder(binderResult);
+            var binder = new StubModelBinder(ModelBindingResult.Failed());
             var model = new MyModel();
             Func<ModelMetadata, bool> propertyFilter = (m) => true;
 
@@ -557,14 +538,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             Assert.Equal("Old-ExcludedPropertyValue", model.ExcludedProperty);
         }
 
-        [Theory]
+        [Fact]
-        [MemberData(nameof(UnsuccessfulModelBindingData))]
+        public async Task TryUpdateModelNonGeneric_ModelTypeOverload_ReturnsFalse_IfBinderIsUnsuccessful()
-        public async Task TryUpdateModelNonGeneric_ModelTypeOverload_ReturnsFalse_IfBinderIsUnsuccessful(
-            ModelBindingResult? binderResult)
         {
             // Arrange
             var metadataProvider = new EmptyModelMetadataProvider();
-            var binder = new StubModelBinder(binderResult);
+            var binder = new StubModelBinder(ModelBindingResult.Failed());
 
             var model = new MyModel();
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/StubModelBinder.cs

@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             _callback = context => TaskCache.CompletedTask;
         }
 
-        public StubModelBinder(ModelBindingResult? result)
+        public StubModelBinder(ModelBindingResult result)
         {
             _callback = context =>
             {
@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             };
         }
 
-        public StubModelBinder(Func<ModelBindingContext, ModelBindingResult?> callback)
+        public StubModelBinder(Func<ModelBindingContext, ModelBindingResult> callback)
         {
             _callback = context =>
             {
@@ -45,7 +45,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             };
         }
 
-        public StubModelBinder(Func<ModelBindingContext, Task<ModelBindingResult?>> callback)
+        public StubModelBinder(Func<ModelBindingContext, Task<ModelBindingResult>> callback)
         {
             _callback = async context =>
             {
@@ -66,8 +66,8 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             {
                 throw new ArgumentNullException(nameof(bindingContext));
             }
-            Debug.Assert(bindingContext.Result == null);
 
+            Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
             await _callback.Invoke(bindingContext);
         }
     }

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ActionParametersIntegrationTest.cs

@@ -49,7 +49,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var model = new Person3();
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -94,7 +94,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -143,7 +143,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var model = new Person4();
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -189,7 +189,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
 
             var modelState = testContext.ModelState;
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -230,7 +230,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -274,7 +274,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -321,7 +321,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -366,7 +366,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ArrayModelBinderIntegrationTest.cs

@@ -31,7 +31,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -75,7 +75,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -115,7 +115,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -155,7 +155,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -190,7 +190,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -235,7 +235,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -276,7 +276,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -317,7 +317,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/BinderTypeBasedModelBinderIntegrationTest.cs

@@ -36,7 +36,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -73,7 +73,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
-            Assert.False(modelBindingResult.Value.IsModelSet);
+            Assert.False(modelBindingResult.IsModelSet);
 
             // ModelState (not set unless inner binder sets it)
             Assert.True(modelState.IsValid);
@@ -84,75 +84,6 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
         {
         }
 
-        [Fact]
-        public async Task BindParameter_WithModelBinderType_NonGreedy_NoData()
-        {
-            // Arrange
-            var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();
-            var parameter = new ParameterDescriptor()
-            {
-                Name = "Parameter1",
-                BindingInfo = new BindingInfo()
-                {
-                    BinderType = typeof(NullResultModelBinder)
-                },
-
-                ParameterType = typeof(Person2)
-            };
-
-            // No data is passed.
-            var testContext = ModelBindingTestHelper.GetTestContext();
-            var modelState = testContext.ModelState;
-
-            // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
-
-            // Assert
-
-            // ModelBindingResult
-            Assert.False(modelBindingResult.Value.IsModelSet);
-
-            // ModelState
-            Assert.True(modelState.IsValid);
-            Assert.Empty(modelState.Keys);
-        }
-
-        // ModelBinderAttribute can be used without specifying the binder type.
-        // In such cases BinderTypeBasedModelBinder acts like a non greedy binder where
-        // it returns an empty ModelBindingResult allowing other ModelBinders to run.
-        [Fact]
-        public async Task BindParameter_WithOutModelBinderType()
-        {
-            // Arrange
-            var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();
-            var parameter = new ParameterDescriptor()
-            {
-                Name = "Parameter1",
-                BindingInfo = new BindingInfo()
-                {
-                    BinderType = typeof(NullResultModelBinder)
-                },
-
-                ParameterType = typeof(Person2)
-            };
-
-            // No data is passed.
-            var testContext = ModelBindingTestHelper.GetTestContext();
-            var modelState = testContext.ModelState;
-
-            // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
-
-            // Assert
-
-            // ModelBindingResult
-            Assert.False(modelBindingResult.Value.IsModelSet);
-
-            // ModelState
-            Assert.True(modelState.IsValid);
-            Assert.Empty(modelState.Keys);
-        }
-
         // Ensures that prefix is part of the result returned back.
         [Fact]
         [ReplaceCulture]
@@ -176,7 +107,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -219,7 +150,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -258,7 +189,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -286,7 +217,8 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 {
                     throw new ArgumentNullException(nameof(bindingContext));
                 }
-                Debug.Assert(bindingContext.Result == null);
+
+                Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 if (bindingContext.ModelType != typeof(Address))
                 {
@@ -313,7 +245,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 {
                     throw new ArgumentNullException(nameof(bindingContext));
                 }
-                Debug.Assert(bindingContext.Result == null);
+                Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 var model = "Success";
                 bindingContext.ModelState.SetModelValue(
@@ -334,7 +266,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 {
                     throw new ArgumentNullException(nameof(bindingContext));
                 }
-                Debug.Assert(bindingContext.Result == null);
+                Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 bindingContext.Result =  ModelBindingResult.Success(model: null);
                 return TaskCache.CompletedTask;
@@ -349,25 +281,11 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 {
                     throw new ArgumentNullException(nameof(bindingContext));
                 }
-                Debug.Assert(bindingContext.Result == null);
+                Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 bindingContext.Result = ModelBindingResult.Failed();
                 return TaskCache.CompletedTask;
             }
         }
-
-        private class NullResultModelBinder : IModelBinder
-        {
-            public Task BindModelAsync(ModelBindingContext bindingContext)
-            {
-                if (bindingContext == null)
-                {
-                    throw new ArgumentNullException(nameof(bindingContext));
-                }
-                Debug.Assert(bindingContext.Result == null);
-
-                return TaskCache.CompletedTask;
-            }
-        }
     }
 }

test/Microsoft.AspNetCore.Mvc.IntegrationTests/BodyValidationIntegrationTests.cs

@@ -55,7 +55,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -95,7 +95,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinding.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var result = await argumentBinding.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelState.IsValid);
@@ -130,7 +130,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -182,7 +182,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -223,7 +223,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -263,7 +263,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -299,7 +299,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -342,7 +342,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -379,7 +379,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -420,7 +420,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -462,7 +462,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -521,7 +521,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -559,7 +559,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -623,7 +623,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -680,7 +680,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ByteArrayModelBinderIntegrationTest.cs

@@ -45,7 +45,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -90,7 +90,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -129,7 +129,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 

test/Microsoft.AspNetCore.Mvc.IntegrationTests/CancellationTokenModelBinderIntegrationTest.cs

@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -111,7 +111,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 

test/Microsoft.AspNetCore.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs

@@ -39,7 +39,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -85,7 +85,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -119,7 +119,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -151,7 +151,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -190,7 +190,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -229,7 +229,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -262,7 +262,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -300,7 +300,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -359,7 +359,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -410,7 +410,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -462,7 +462,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -505,7 +505,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -556,7 +556,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -606,7 +606,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -663,7 +663,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -702,7 +702,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -926,7 +926,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/DictionaryModelBinderIntegrationTest.cs

@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -75,7 +75,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -113,7 +113,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -164,7 +164,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -199,7 +199,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -231,7 +231,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -292,7 +292,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -332,7 +332,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -371,7 +371,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -411,7 +411,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -522,7 +522,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ExcludeBindingMetadataProviderIntegrationTest.cs

@@ -53,8 +53,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             // ModelBindingResult

test/Microsoft.AspNetCore.Mvc.IntegrationTests/FormCollectionModelBindingIntegrationTest.cs

@@ -51,7 +51,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -101,7 +101,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult
@@ -141,7 +141,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 

test/Microsoft.AspNetCore.Mvc.IntegrationTests/FormFileModelBindingIntegrationTest.cs

@@ -51,7 +51,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -100,8 +100,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var result = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -146,8 +145,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var result = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -191,8 +189,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var result = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -246,7 +243,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult
@@ -295,7 +292,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
-            Assert.False(modelBindingResult.Value.IsModelSet);
+            Assert.False(modelBindingResult.IsModelSet);
 
             // ModelState
             Assert.True(modelState.IsValid);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/GenericModelBinderIntegrationTest.cs

@@ -42,7 +42,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -80,7 +80,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -119,7 +119,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -175,7 +175,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                     throw new ArgumentNullException(nameof(bindingContext));
                 }
 
-                Debug.Assert(bindingContext.Result == null);
+                Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 var allowedBindingSource = bindingContext.BindingSource;
                 if (allowedBindingSource == null ||
@@ -211,7 +211,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -245,7 +245,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -280,7 +280,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -325,7 +325,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -370,7 +370,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -405,7 +405,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -449,7 +449,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -493,7 +493,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -529,7 +529,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -577,7 +577,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -625,7 +625,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/HeaderModelBinderIntegrationTest.cs

@@ -47,7 +47,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -87,7 +87,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -129,7 +129,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -175,8 +175,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var result = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -223,8 +222,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var result = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var result = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -287,7 +285,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 

test/Microsoft.AspNetCore.Mvc.IntegrationTests/KeyValuePairModelBinderIntegrationTest.cs

@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -71,7 +71,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.False(modelBindingResult.IsModelSet);
@@ -117,7 +117,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.False(modelBindingResult.IsModelSet);
@@ -154,7 +154,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.False(modelBindingResult.IsModelSet);
@@ -201,7 +201,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.False(modelBindingResult.IsModelSet);
@@ -244,7 +244,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -284,7 +284,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -324,7 +324,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -360,7 +360,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -405,7 +405,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -446,7 +446,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -487,7 +487,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ModelPrefixSelectionIntegrationTest.cs

@@ -47,7 +47,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -96,7 +96,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -135,7 +135,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -184,7 +184,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -230,7 +230,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/MutableObjectModelBinderIntegrationTest.cs

@@ -66,7 +66,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -107,7 +107,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -148,7 +148,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -190,7 +190,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -231,7 +231,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -279,7 +279,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -322,7 +322,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -365,7 +365,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -419,7 +419,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -463,7 +463,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -508,7 +508,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -551,7 +551,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -592,7 +592,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -633,7 +633,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -679,7 +679,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -725,7 +725,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -763,7 +763,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -805,7 +805,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -851,7 +851,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -897,7 +897,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -935,7 +935,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -977,7 +977,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1023,7 +1023,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1069,7 +1069,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1107,7 +1107,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1149,7 +1149,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1195,7 +1195,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1241,7 +1241,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1279,7 +1279,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1327,7 +1327,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1371,7 +1371,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1417,7 +1417,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1469,7 +1469,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1514,7 +1514,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1563,7 +1563,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1614,7 +1614,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1657,7 +1657,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1696,7 +1696,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1739,7 +1739,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1782,7 +1782,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1821,7 +1821,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1865,7 +1865,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1909,7 +1909,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ServicesModelBinderIntegrationTest.cs

@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -72,7 +72,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult
@@ -108,7 +108,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult
@@ -144,7 +144,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult

test/Microsoft.AspNetCore.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs

@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -84,7 +84,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -129,7 +129,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -173,7 +173,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -217,7 +217,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -275,7 +275,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -324,7 +324,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -376,7 +376,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             // ModelBindingResult
@@ -419,7 +419,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -457,7 +457,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
 
@@ -511,8 +511,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ??
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
-                default(ModelBindingResult);
 
             // Assert
             // ModelBindingResult

test/Microsoft.AspNetCore.Mvc.IntegrationTests/ValidationIntegrationTests.cs

@@ -183,7 +183,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -220,7 +220,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -271,7 +271,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -309,7 +309,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -362,7 +362,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -401,7 +401,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -454,7 +454,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -493,7 +493,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -541,7 +541,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -579,7 +579,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -627,7 +627,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -664,7 +664,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -715,7 +715,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -752,7 +752,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -792,7 +792,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -850,7 +850,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -887,7 +887,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -957,7 +957,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -994,7 +994,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1045,7 +1045,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1082,7 +1082,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1122,7 +1122,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1162,7 +1162,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1202,7 +1202,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             var modelState = testContext.ModelState;
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1333,7 +1333,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             modelState.SetModelValue("CustomParameter.message", "Hello", "Hello");
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1376,7 +1376,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             modelState.SetModelValue("message", "Hello", "Hello");
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1421,7 +1421,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             modelState.SetModelValue("other.key", "1", "1");
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);
@@ -1468,7 +1468,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             modelState.SetModelValue("other.key", "1", "1");
 
             // Act
-            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext) ?? default(ModelBindingResult);
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, testContext);
 
             // Assert
             Assert.True(modelBindingResult.IsModelSet);

test/Microsoft.AspNetCore.Mvc.WebApiCompatShimTest/HttpRequestMessage/HttpRequestMessageModelBinderTest.cs

@@ -25,9 +25,7 @@ namespace Microsoft.AspNetCore.Mvc.WebApiCompatShim
             await binder.BindModelAsync(bindingContext);
 
             // Assert
-            Assert.True(bindingContext.Result.HasValue);
+            var result = bindingContext.Result;
-
-            var result = bindingContext.Result.Value;
             Assert.True(result.IsModelSet);
             Assert.Same(expectedModel, result.Model);