Fail more gracefully when option collections cleared

- #4690
- move `ModelBindingMessageProvider` init from `DefaultBindingMetadataProvider` to `DefaultModelMetadata`
 - in addition to avoiding error cases, this removes some boilerplate
- add specific errors to `BodyModelBinderProvider`, `CompilerCache`, `CompositeViewEngine`, `ModelBinderFactory`,
  and `ObjectResultExecutor`
 - `DefaultRazorViewEngineFileProviderAccessor.FileProvider` now a `NullFileProvider` in empty case

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

@@ -15,19 +15,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
     /// </summary>
     public class DefaultBindingMetadataProvider : IBindingMetadataProvider
     {
-        private readonly ModelBindingMessageProvider _messageProvider;
-
-        public DefaultBindingMetadataProvider(ModelBindingMessageProvider messageProvider)
-        {
-            if (messageProvider == null)
-            {
-                throw new ArgumentNullException(nameof(messageProvider));
-            }
-
-            _messageProvider = messageProvider;
-        }
-
-        /// <inheritdoc />
         public void CreateBindingMetadata(BindingMetadataProviderContext context)
         {
             if (context == null)
@@ -65,10 +52,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 }
             }
 
-            // ModelBindingMessageProvider
-            // Provide a unique instance based on one passed to the constructor.
-            context.BindingMetadata.ModelBindingMessageProvider = new ModelBindingMessageProvider(_messageProvider);
-
             // PropertyFilterProvider
             var propertyFilterProviders = context.Attributes.OfType<IPropertyFilterProvider>().ToArray();
             if (propertyFilterProviders.Length == 0)

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

@@ -4,12 +4,10 @@
 using System;
 using System.Threading;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Binders;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
-using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
 using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Mvc.Internal
@@ -33,16 +31,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 
         public void Configure(MvcOptions options)
         {
-            // Set up default error messages
-            var messageProvider = options.ModelBindingMessageProvider;
-            messageProvider.MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember;
-            messageProvider.MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent;
-            messageProvider.ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid;
-            messageProvider.AttemptedValueIsInvalidAccessor = Resources.FormatModelState_AttemptedValueIsInvalid;
-            messageProvider.UnknownValueIsInvalidAccessor = Resources.FormatModelState_UnknownValueIsInvalid;
-            messageProvider.ValueIsInvalidAccessor = Resources.FormatHtmlGeneration_ValueIsInvalid;
-            messageProvider.ValueMustBeANumberAccessor = Resources.FormatHtmlGeneration_ValueMustBeNumber;
-
             // Set up ModelBinding
             options.ModelBinderProviders.Add(new BinderTypeModelBinderProvider());
             options.ModelBinderProviders.Add(new ServicesModelBinderProvider());
@@ -79,7 +67,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             // by altering the collection of providers.
             options.ModelMetadataDetailsProviders.Add(new ExcludeBindingMetadataProvider(typeof(Type)));
 
-            options.ModelMetadataDetailsProviders.Add(new DefaultBindingMetadataProvider(messageProvider));
+            options.ModelMetadataDetailsProviders.Add(new DefaultBindingMetadataProvider());
             options.ModelMetadataDetailsProviders.Add(new DefaultValidationMetadataProvider());
 
             // Set up validators

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

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Text;
 using System.Threading.Tasks;
@@ -117,6 +118,16 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             if (formatters == null || formatters.Count == 0)
             {
                 formatters = OptionsFormatters;
+
+                // Complain about MvcOptions.OutputFormatters only if the result has an empty Formatters.
+                Debug.Assert(formatters != null, "MvcOptions.OutputFormatters cannot be null.");
+                if (formatters.Count == 0)
+                {
+                    throw new InvalidOperationException(Resources.FormatOutputFormattersAreRequired(
+                        typeof(MvcOptions).FullName,
+                        nameof(MvcOptions.OutputFormatters),
+                        typeof(IOutputFormatter).FullName));
+                }
             }
 
             var objectType = result.DeclaredType;
@@ -136,7 +147,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             {
                 // No formatter supports this.
                 Logger.NoFormatter(formatterContext);
-                
+
                 context.HttpContext.Response.StatusCode = StatusCodes.Status406NotAcceptable;
                 return TaskCache.CompletedTask;
             }
@@ -189,7 +200,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             if (acceptableMediaTypes.Count == 0)
             {
                 // There is either no Accept header value, or it contained */* and we
-                // are not currently respecting the 'browser accept header'.            
+                // are not currently respecting the 'browser accept header'.
                 Logger.NoAcceptForNegotiation();
 
                 selectFormatterWithoutRegardingAcceptHeader = true;
@@ -399,7 +410,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 
             return null;
         }
-        
+
         /// <summary>
         /// Selects the <see cref="IOutputFormatter"/> to write the response based on the content type values
         /// present in <paramref name="sortedAcceptableContentTypes"/> and <paramref name="possibleOutputContentTypes"/>.
@@ -423,19 +434,19 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             IList<MediaTypeSegmentWithQuality> sortedAcceptableContentTypes,
             MediaTypeCollection possibleOutputContentTypes)
         {
-            for (var i = 0; i < sortedAcceptableContentTypes.Count; i++) 
+            for (var i = 0; i < sortedAcceptableContentTypes.Count; i++)
             {
                 var acceptableContentType = new MediaType(sortedAcceptableContentTypes[i].MediaType);
-                for (var j = 0; j < possibleOutputContentTypes.Count; j++) 
+                for (var j = 0; j < possibleOutputContentTypes.Count; j++)
                 {
                     var candidateContentType = new MediaType(possibleOutputContentTypes[j]);
-                    if (candidateContentType.IsSubsetOf(acceptableContentType)) 
+                    if (candidateContentType.IsSubsetOf(acceptableContentType))
                     {
-                        for (var k = 0; k < formatters.Count; k++) 
+                        for (var k = 0; k < formatters.Count; k++)
                         {
                             var formatter = formatters[k];
                             formatterContext.ContentType = new StringSegment(possibleOutputContentTypes[j]);
-                            if (formatter.CanWriteResult(formatterContext)) 
+                            if (formatter.CanWriteResult(formatterContext))
                             {
                                 return formatter;
                             }
@@ -443,7 +454,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                     }
                 }
             }
-            
+
             return null;
         }
 

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

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.AspNetCore.Mvc.Internal;
 
@@ -48,6 +49,14 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             if (context.BindingInfo.BindingSource != null &&
                 context.BindingInfo.BindingSource.CanAcceptDataFrom(BindingSource.Body))
             {
+                if (_formatters.Count == 0)
+                {
+                    throw new InvalidOperationException(Resources.FormatInputFormattersAreRequired(
+                        typeof(MvcOptions).FullName,
+                        nameof(MvcOptions.InputFormatters),
+                        typeof(IInputFormatter).FullName));
+                }
+
                 return new BodyModelBinder(_formatters, _readerFactory);
             }
 

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/EmptyModelMetadataProvider.cs

@@ -1,52 +1,25 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
+using System.Collections.Generic;
-using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
     public class EmptyModelMetadataProvider : DefaultModelMetadataProvider
     {
         public EmptyModelMetadataProvider()
-            : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
+            : base(
-            {
+                  new DefaultCompositeMetadataDetailsProvider(new List<IMetadataDetailsProvider>()),
-                new MessageOnlyBindingProvider()
+                  new OptionsAccessor())
-            }))
         {
         }
 
-        private class MessageOnlyBindingProvider : IBindingMetadataProvider
+        private class OptionsAccessor : IOptions<MvcOptions>
         {
-            private readonly ModelBindingMessageProvider _messageProvider = CreateMessageProvider();
+            public MvcOptions Value { get; } = new MvcOptions();
-
-            public void CreateBindingMetadata(BindingMetadataProviderContext context)
-            {
-                if (context == null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
-                // Don't bother with ModelBindingMessageProvider copy constructor. No other provider can change the
-                // delegates.
-                context.BindingMetadata.ModelBindingMessageProvider = _messageProvider;
-            }
-
-            private static ModelBindingMessageProvider CreateMessageProvider()
-            {
-                return new ModelBindingMessageProvider
-                {
-                    MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember,
-                    MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent,
-                    ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid,
-                    AttemptedValueIsInvalidAccessor = Resources.FormatModelState_AttemptedValueIsInvalid,
-                    UnknownValueIsInvalidAccessor = Resources.FormatModelState_UnknownValueIsInvalid,
-                    ValueIsInvalidAccessor = Resources.FormatHtmlGeneration_ValueIsInvalid,
-                    ValueMustBeANumberAccessor = Resources.FormatHtmlGeneration_ValueMustBeNumber,
-                };
-            }
         }
     }
 }

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

@@ -17,6 +17,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
         private readonly ICompositeMetadataDetailsProvider _detailsProvider;
         private readonly DefaultMetadataDetails _details;
 
+        // Default message provider for all DefaultModelMetadata instances; cloned before exposing to
+        // IBindingMetadataProvider instances to ensure customizations are not accidentally shared.
+        private readonly ModelBindingMessageProvider _modelBindingMessageProvider;
+
         private ReadOnlyDictionary<object, object> _additionalValues;
         private ModelMetadata _elementMetadata;
         private bool? _isBindingRequired;
@@ -36,6 +40,22 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
             IModelMetadataProvider provider,
             ICompositeMetadataDetailsProvider detailsProvider,
             DefaultMetadataDetails details)
+            : this(provider, detailsProvider, details, new ModelBindingMessageProvider())
+        {
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="DefaultModelMetadata"/>.
+        /// </summary>
+        /// <param name="provider">The <see cref="IModelMetadataProvider"/>.</param>
+        /// <param name="detailsProvider">The <see cref="ICompositeMetadataDetailsProvider"/>.</param>
+        /// <param name="details">The <see cref="DefaultMetadataDetails"/>.</param>
+        /// <param name="modelBindingMessageProvider">The <see cref="Metadata.ModelBindingMessageProvider"/>.</param>
+        public DefaultModelMetadata(
+            IModelMetadataProvider provider,
+            ICompositeMetadataDetailsProvider detailsProvider,
+            DefaultMetadataDetails details,
+            ModelBindingMessageProvider modelBindingMessageProvider)
             : base(details.Key)
         {
             if (provider == null)
@@ -53,9 +73,15 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
                 throw new ArgumentNullException(nameof(details));
             }
 
+            if (modelBindingMessageProvider == null)
+            {
+                throw new ArgumentNullException(nameof(modelBindingMessageProvider));
+            }
+
             _provider = provider;
             _detailsProvider = detailsProvider;
             _details = details;
+            _modelBindingMessageProvider = modelBindingMessageProvider;
         }
 
         /// <summary>
@@ -82,6 +108,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
                 if (_details.BindingMetadata == null)
                 {
                     var context = new BindingMetadataProviderContext(Identity, _details.ModelAttributes);
+
+                    // Provide a unique ModelBindingMessageProvider instance so providers' customizations are per-type.
+                    context.BindingMetadata.ModelBindingMessageProvider =
+                        new ModelBindingMessageProvider(_modelBindingMessageProvider);
+
                     _detailsProvider.CreateBindingMetadata(context);
                     _details.BindingMetadata = context.BindingMetadata;
                 }

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

@@ -6,6 +6,7 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Reflection;
 using Microsoft.Extensions.Internal;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
 {
@@ -23,11 +24,35 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
         /// </summary>
         /// <param name="detailsProvider">The <see cref="ICompositeMetadataDetailsProvider"/>.</param>
         public DefaultModelMetadataProvider(ICompositeMetadataDetailsProvider detailsProvider)
+            : this(detailsProvider, new ModelBindingMessageProvider())
         {
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="DefaultModelMetadataProvider"/>.
+        /// </summary>
+        /// <param name="detailsProvider">The <see cref="ICompositeMetadataDetailsProvider"/>.</param>
+        /// <param name="optionsAccessor">The accessor for <see cref="MvcOptions"/>.</param>
+        public DefaultModelMetadataProvider(
+            ICompositeMetadataDetailsProvider detailsProvider,
+            IOptions<MvcOptions> optionsAccessor)
+            : this(detailsProvider, GetMessageProvider(optionsAccessor))
+        {
+        }
+
+        private DefaultModelMetadataProvider(
+            ICompositeMetadataDetailsProvider detailsProvider,
+            ModelBindingMessageProvider modelBindingMessageProvider)
+        {
+            if (detailsProvider == null)
+            {
+                throw new ArgumentNullException(nameof(detailsProvider));
+            }
+
             DetailsProvider = detailsProvider;
+            ModelBindingMessageProvider = modelBindingMessageProvider;
 
             _cacheEntryFactory = CreateCacheEntry;
-
             _metadataCacheEntryForObjectType = GetMetadataCacheEntryForObjectType();
         }
 
@@ -36,6 +61,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
         /// </summary>
         protected ICompositeMetadataDetailsProvider DetailsProvider { get; }
 
+        /// <summary>
+        /// Gets the <see cref="Metadata.ModelBindingMessageProvider"/>.
+        /// </summary>
+        /// <value>Same as <see cref="MvcOptions.ModelBindingMessageProvider"/> in all production scenarios.</value>
+        protected ModelBindingMessageProvider ModelBindingMessageProvider { get; }
+
         /// <inheritdoc />
         public virtual IEnumerable<ModelMetadata> GetMetadataForProperties(Type modelType)
         {
@@ -78,6 +109,16 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
             return cacheEntry.Metadata;
         }
 
+        private static ModelBindingMessageProvider GetMessageProvider(IOptions<MvcOptions> optionsAccessor)
+        {
+            if (optionsAccessor == null)
+            {
+                throw new ArgumentNullException(nameof(optionsAccessor));
+            }
+
+            return optionsAccessor.Value.ModelBindingMessageProvider;
+        }
+
         private ModelMetadataCacheEntry GetCacheEntry(Type modelType)
         {
             ModelMetadataCacheEntry cacheEntry;
@@ -123,7 +164,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
         /// </remarks>
         protected virtual ModelMetadata CreateModelMetadata(DefaultMetadataDetails entry)
         {
-            return new DefaultModelMetadata(this, DetailsProvider, entry);
+            return new DefaultModelMetadata(this, DetailsProvider, entry, ModelBindingMessageProvider);
         }
 
         /// <summary>

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Metadata/ModelBindingMessageProvider.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using Microsoft.AspNetCore.Mvc.Core;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
 {
@@ -23,6 +24,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
         /// </summary>
         public ModelBindingMessageProvider()
         {
+            MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember;
+            MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent;
+            ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid;
+            AttemptedValueIsInvalidAccessor = Resources.FormatModelState_AttemptedValueIsInvalid;
+            UnknownValueIsInvalidAccessor = Resources.FormatModelState_UnknownValueIsInvalid;
+            ValueIsInvalidAccessor = Resources.FormatHtmlGeneration_ValueIsInvalid;
+            ValueMustBeANumberAccessor = Resources.FormatHtmlGeneration_ValueMustBeNumber;
         }
 
         /// <summary>

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/ModelBinderFactory.cs

@@ -46,12 +46,20 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 throw new ArgumentNullException(nameof(context));
             }
 
+            if (_providers.Length == 0)
+            {
+                throw new InvalidOperationException(Resources.FormatModelBinderProvidersAreRequired(
+                    typeof(MvcOptions).FullName,
+                    nameof(MvcOptions.ModelBinderProviders),
+                    typeof(IModelBinderProvider).FullName));
+            }
+
             IModelBinder binder;
             if (TryGetCachedBinder(context.Metadata, context.CacheToken, out binder))
             {
                 return binder;
             }
-            
+
             // Perf: We're calling the Uncached version of the API here so we can:
             // 1. avoid allocating a context when the value is already cached
             // 2. avoid checking the cache twice when the value is not cached

src/Microsoft.AspNetCore.Mvc.Core/Properties/Resources.Designer.cs

@@ -1162,6 +1162,54 @@ namespace Microsoft.AspNetCore.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("CouldNotCreateIModelBinder"), p0);
         }
 
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to bind from the body.
+        /// </summary>
+        internal static string InputFormattersAreRequired
+        {
+            get { return GetString("InputFormattersAreRequired"); }
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to bind from the body.
+        /// </summary>
+        internal static string FormatInputFormattersAreRequired(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("InputFormattersAreRequired"), p0, p1, p2);
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to model bind.
+        /// </summary>
+        internal static string ModelBinderProvidersAreRequired
+        {
+            get { return GetString("ModelBinderProvidersAreRequired"); }
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to model bind.
+        /// </summary>
+        internal static string FormatModelBinderProvidersAreRequired(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ModelBinderProvidersAreRequired"), p0, p1, p2);
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to format a response.
+        /// </summary>
+        internal static string OutputFormattersAreRequired
+        {
+            get { return GetString("OutputFormattersAreRequired"); }
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to format a response.
+        /// </summary>
+        internal static string FormatOutputFormattersAreRequired(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("OutputFormattersAreRequired"), p0, p1, p2);
+        }
+
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

src/Microsoft.AspNetCore.Mvc.Core/Resources.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
+  <!--
-    Microsoft ResX Schema 
+    Microsoft ResX Schema
-    
+
     Version 2.0
-    
+
-    The primary goals of this format is to allow a simple XML format 
+    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the 
+    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes 
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
+
-    There are any number of "resheader" rows that contain simple 
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
+
-    Each data row contains a name, and value. The row also contains a 
+    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support 
+    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture. 
+    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the 
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
+
-    The mimetype is used for serialized objects, and tells the 
+    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not 
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
+
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can 
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -343,4 +343,13 @@
   <data name="CouldNotCreateIModelBinder" xml:space="preserve">
     <value>Could not create a model binder for model object of type '{0}'.</value>
   </data>
+  <data name="InputFormattersAreRequired" xml:space="preserve">
+    <value>'{0}.{1}' must not be empty. At least one '{2}' is required to bind from the body.</value>
+  </data>
+  <data name="ModelBinderProvidersAreRequired" xml:space="preserve">
+    <value>'{0}.{1}' must not be empty. At least one '{2}' is required to model bind.</value>
+  </data>
+  <data name="OutputFormattersAreRequired" xml:space="preserve">
+    <value>'{0}.{1}' must not be empty. At least one '{2}' is required to format a response.</value>
+  </data>
 </root>

src/Microsoft.AspNetCore.Mvc.Razor/Internal/CompilerCache.cs

@@ -116,6 +116,15 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
                     return cacheEntry;
                 }
 
+                if (_fileProvider is NullFileProvider)
+                {
+                    var message = Resources.FormatFileProvidersAreRequired(
+                        typeof(RazorViewEngineOptions).FullName,
+                        nameof(RazorViewEngineOptions.FileProviders),
+                        typeof(IFileProvider).FullName);
+                    throw new InvalidOperationException(message);
+                }
+
                 fileInfo = _fileProvider.GetFileInfo(normalizedPath);
                 if (!fileInfo.Exists)
                 {

src/Microsoft.AspNetCore.Mvc.Razor/Internal/DefaultRazorViewEngineFileProviderAccessor.cs

@@ -18,7 +18,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
         public DefaultRazorViewEngineFileProviderAccessor(IOptions<RazorViewEngineOptions> optionsAccessor)
         {
             var fileProviders = optionsAccessor.Value.FileProviders;
-            if (fileProviders.Count == 1)
+            if (fileProviders.Count == 0)
+            {
+                FileProvider = new NullFileProvider();
+            }
+            else if (fileProviders.Count == 1)
             {
                 FileProvider = fileProviders[0];
             }

src/Microsoft.AspNetCore.Mvc.Razor/Properties/Resources.Designer.cs

@@ -494,6 +494,22 @@ namespace Microsoft.AspNetCore.Mvc.Razor
             return GetString("RazorPage_NestingAttributeWritingScopesNotSupported");
         }
 
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.
+        /// </summary>
+        internal static string FileProvidersAreRequired
+        {
+            get { return GetString("FileProvidersAreRequired"); }
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.
+        /// </summary>
+        internal static string FormatFileProvidersAreRequired(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("FileProvidersAreRequired"), p0, p1, p2);
+        }
+
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

src/Microsoft.AspNetCore.Mvc.Razor/Resources.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
+  <!--
-    Microsoft ResX Schema 
+    Microsoft ResX Schema
-    
+
     Version 2.0
-    
+
-    The primary goals of this format is to allow a simple XML format 
+    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the 
+    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes 
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
+
-    There are any number of "resheader" rows that contain simple 
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
+
-    Each data row contains a name, and value. The row also contains a 
+    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support 
+    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture. 
+    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the 
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
+
-    The mimetype is used for serialized objects, and tells the 
+    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not 
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
+
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can 
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -209,4 +209,7 @@
   <data name="RazorPage_NestingAttributeWritingScopesNotSupported" xml:space="preserve">
     <value>Nesting of TagHelper attribute writing scopes is not supported.</value>
   </data>
+  <data name="FileProvidersAreRequired" xml:space="preserve">
+    <value>'{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.</value>
+  </data>
 </root>

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Properties/Resources.Designer.cs

@@ -890,6 +890,22 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
             return string.Format(CultureInfo.CurrentCulture, GetString("CreateModelExpression_NullModelMetadata"), p0, p1);
         }
 
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.
+        /// </summary>
+        internal static string ViewEnginesAreRequired
+        {
+            get { return GetString("ViewEnginesAreRequired"); }
+        }
+
+        /// <summary>
+        /// '{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.
+        /// </summary>
+        internal static string FormatViewEnginesAreRequired(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("ViewEnginesAreRequired"), p0, p1, p2);
+        }
+
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Resources.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
+  <!--
-    Microsoft ResX Schema 
+    Microsoft ResX Schema
-    
+
     Version 2.0
-    
+
-    The primary goals of this format is to allow a simple XML format 
+    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the 
+    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes 
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
+
-    There are any number of "resheader" rows that contain simple 
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
+
-    Each data row contains a name, and value. The row also contains a 
+    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support 
+    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture. 
+    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the 
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
+
-    The mimetype is used for serialized objects, and tells the 
+    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not 
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
+
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can 
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -283,4 +283,7 @@
   <data name="CreateModelExpression_NullModelMetadata" xml:space="preserve">
     <value>The {0} was unable to provide metadata for expression '{1}'.</value>
   </data>
+  <data name="ViewEnginesAreRequired" xml:space="preserve">
+    <value>'{0}.{1}' must not be empty. At least one '{2}' is required to locate a view for rendering.</value>
+  </data>
 </root>

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewEngines/CompositeViewEngine.cs

@@ -37,6 +37,14 @@ namespace Microsoft.AspNetCore.Mvc.ViewEngines
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(viewName));
             }
 
+            if (ViewEngines.Count == 0)
+            {
+                throw new InvalidOperationException(Resources.FormatViewEnginesAreRequired(
+                    typeof(MvcViewOptions).FullName,
+                    nameof(MvcViewOptions.ViewEngines),
+                    typeof(IViewEngine).FullName));
+            }
+
             // Do not allocate in the common cases: ViewEngines contains one entry or initial attempt is successful.
             IEnumerable<string> searchedLocations = null;
             List<string> searchedList = null;
@@ -77,6 +85,14 @@ namespace Microsoft.AspNetCore.Mvc.ViewEngines
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(viewPath));
             }
 
+            if (ViewEngines.Count == 0)
+            {
+                throw new InvalidOperationException(Resources.FormatViewEnginesAreRequired(
+                    typeof(MvcViewOptions).FullName,
+                    nameof(MvcViewOptions.ViewEngines),
+                    typeof(IViewEngine).FullName));
+            }
+
             // Do not allocate in the common cases: ViewEngines contains one entry or initial attempt is successful.
             IEnumerable<string> searchedLocations = null;
             List<string> searchedList = null;

test/Microsoft.AspNetCore.Mvc.Abstractions.Test/ModelBinding/ModelStateDictionaryTest.cs

@@ -2,9 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
+using Microsoft.Extensions.Options;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
@@ -887,20 +887,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             var expected = "Hmm, the supplied value is not valid for Length.";
             var dictionary = new ModelStateDictionary();
 
-            var messageProvider = new ModelBindingMessageProvider
+            var bindingMetadataProvider = new DefaultBindingMetadataProvider();
-            {
-                MissingBindRequiredValueAccessor = name => "Unexpected MissingBindRequiredValueAccessor use",
-                MissingKeyOrValueAccessor = () => "Unexpected MissingKeyOrValueAccessor use",
-                ValueMustNotBeNullAccessor = value => "Unexpected ValueMustNotBeNullAccessor use",
-                AttemptedValueIsInvalidAccessor =
-                    (value, name) => "Unexpected InvalidValueWithKnownAttemptedValueAccessor use",
-                UnknownValueIsInvalidAccessor = name => $"Hmm, the supplied value is not valid for { name }.",
-                ValueIsInvalidAccessor = value => "Unexpected InvalidValueWithUnknownModelErrorAccessor use",
-                ValueMustBeANumberAccessor = name => "Unexpected ValueMustBeANumberAccessor use",
-            };
-            var bindingMetadataProvider = new DefaultBindingMetadataProvider(messageProvider);
             var compositeProvider = new DefaultCompositeMetadataDetailsProvider(new[] { bindingMetadataProvider });
-            var provider = new DefaultModelMetadataProvider(compositeProvider);
+            var optionsAccessor = new OptionsAccessor();
+            optionsAccessor.Value.ModelBindingMessageProvider.UnknownValueIsInvalidAccessor =
+                name => $"Hmm, the supplied value is not valid for { name }.";
+
+            var provider = new DefaultModelMetadataProvider(compositeProvider, optionsAccessor);
             var metadata = provider.GetMetadataForProperty(typeof(string), nameof(string.Length));
 
             // Act
@@ -939,20 +932,13 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             var dictionary = new ModelStateDictionary();
             dictionary.SetModelValue("key", new string[] { "some value" }, "some value");
 
-            var messageProvider = new ModelBindingMessageProvider
+            var bindingMetadataProvider = new DefaultBindingMetadataProvider();
-            {
-                MissingBindRequiredValueAccessor = name => "Unexpected MissingBindRequiredValueAccessor use",
-                MissingKeyOrValueAccessor = () => "Unexpected MissingKeyOrValueAccessor use",
-                ValueMustNotBeNullAccessor = value => "Unexpected ValueMustNotBeNullAccessor use",
-                AttemptedValueIsInvalidAccessor =
-                    (value, name) => $"Hmm, the value '{ value }' is not valid for { name }.",
-                UnknownValueIsInvalidAccessor = name => "Unexpected InvalidValueWithUnknownAttemptedValueAccessor use",
-                ValueIsInvalidAccessor = value => "Unexpected InvalidValueWithUnknownModelErrorAccessor use",
-                ValueMustBeANumberAccessor = name => "Unexpected ValueMustBeANumberAccessor use",
-            };
-            var bindingMetadataProvider = new DefaultBindingMetadataProvider(messageProvider);
             var compositeProvider = new DefaultCompositeMetadataDetailsProvider(new[] { bindingMetadataProvider });
-            var provider = new DefaultModelMetadataProvider(compositeProvider);
+            var optionsAccessor = new OptionsAccessor();
+            optionsAccessor.Value.ModelBindingMessageProvider.AttemptedValueIsInvalidAccessor =
+                (value, name) => $"Hmm, the value '{ value }' is not valid for { name }.";
+
+            var provider = new DefaultModelMetadataProvider(compositeProvider, optionsAccessor);
             var metadata = provider.GetMetadataForProperty(typeof(string), nameof(string.Length));
 
             // Act
@@ -1303,5 +1289,10 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             // Assert
             Assert.Equal("value1", property.RawValue);
         }
+
+        private class OptionsAccessor : IOptions<MvcOptions>
+        {
+            public MvcOptions Value { get; } = new MvcOptions();
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.Core.Test/Infrastructure/ObjectResultExecutorTest.cs

@@ -393,6 +393,25 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 actionContext.HttpContext.Response.Headers[HeaderNames.ContentType]);
         }
 
+        [Fact]
+        public async Task ExecuteAsync_ThrowsWithNoFormatters()
+        {
+            // Arrange
+            var expected = $"'{typeof(MvcOptions).FullName}.{nameof(MvcOptions.OutputFormatters)}' must not be " +
+                $"empty. At least one '{typeof(IOutputFormatter).FullName}' is required to format a response.";
+            var executor = CreateExecutor();
+            var actionContext = new ActionContext
+            {
+                HttpContext = GetHttpContext(),
+            };
+            var result = new ObjectResult("some value");
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => executor.ExecuteAsync(actionContext, result));
+            Assert.Equal(expected, exception.Message);
+        }
+
         [Theory]
         [InlineData(new[] { "application/*" }, "application/*")]
         [InlineData(new[] { "application/xml", "application/*", "application/json" }, "application/*")]

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

@@ -1,7 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Binders;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
@@ -25,7 +24,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -49,7 +48,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -72,7 +71,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -96,7 +95,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -119,7 +118,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -143,7 +142,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -165,7 +164,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -188,7 +187,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -211,7 +210,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -234,7 +233,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -257,7 +256,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -283,7 +282,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -301,7 +300,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -319,7 +318,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -337,7 +336,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -360,7 +359,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -383,7 +382,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -406,7 +405,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -429,7 +428,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -448,7 +447,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOverridesInheritedBindNever)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -477,7 +476,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             context.BindingMetadata.IsBindingAllowed = initialValue;
             context.BindingMetadata.IsBindingRequired = initialValue;
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -508,7 +507,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             context.BindingMetadata.IsBindingAllowed = initialValue;
             context.BindingMetadata.IsBindingRequired = initialValue;
 
-            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
+            var provider = new DefaultBindingMetadataProvider();
 
             // Act
             provider.CreateBindingMetadata(context);
@@ -518,20 +517,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             Assert.Equal(initialValue, context.BindingMetadata.IsBindingRequired);
         }
 
-        private static ModelBindingMessageProvider CreateMessageProvider()
-        {
-            return new ModelBindingMessageProvider
-            {
-                MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember,
-                MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent,
-                ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid,
-                AttemptedValueIsInvalidAccessor = Resources.FormatModelState_AttemptedValueIsInvalid,
-                UnknownValueIsInvalidAccessor = Resources.FormatModelState_UnknownValueIsInvalid,
-                ValueIsInvalidAccessor = Resources.FormatHtmlGeneration_ValueIsInvalid,
-                ValueMustBeANumberAccessor = Resources.FormatHtmlGeneration_ValueMustBeNumber,
-            };
-        }
-
         [BindNever]
         private class BindNeverOnClass
         {

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

@@ -1,7 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Xunit;
 
@@ -24,7 +26,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 
         [Theory]
         [MemberData(nameof(NonBodyBindingSources))]
-        public void Create_WhenBindingSourceIsNotFromBody_ReturnsNull(BindingSource source)
+        public void GetBinder_WhenBindingSourceIsNotFromBody_ReturnsNull(BindingSource source)
         {
             // Arrange
             var provider = CreateProvider();
@@ -39,12 +41,25 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             Assert.Null(result);
         }
 
-        [Fact]
+        public void GetBinder_WhenNoInputFormatters_Throws()
-        public void Create_WhenBindingSourceIsFromBody_ReturnsBinder()
         {
             // Arrange
+            var expected = $"'{typeof(MvcOptions).FullName}.{nameof(MvcOptions.InputFormatters)}' must not be empty. " +
+                $"At least one '{typeof(IInputFormatter).FullName}' is required to bind from the body.";
             var provider = CreateProvider();
+            var context = new TestModelBinderProviderContext(typeof(Person));
+            context.BindingInfo.BindingSource = BindingSource.Body;
 
+            // Act & Assert
+            var exception = Assert.Throws<InvalidOperationException>(() => provider.GetBinder(context));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public void GetBinder_WhenBindingSourceIsFromBody_ReturnsBinder()
+        {
+            // Arrange
+            var provider = CreateProvider(new TestInputFormatter());
             var context = new TestModelBinderProviderContext(typeof(Person));
             context.BindingInfo.BindingSource = BindingSource.Body;
 
@@ -55,9 +70,11 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             Assert.IsType<BodyModelBinder>(result);
         }
 
-        private static BodyModelBinderProvider CreateProvider()
+        private static BodyModelBinderProvider CreateProvider(params IInputFormatter[] formatters)
         {
-            return new BodyModelBinderProvider(new List<IInputFormatter>(), new TestHttpRequestStreamReaderFactory());
+            return new BodyModelBinderProvider(
+                new List<IInputFormatter>(formatters),
+                new TestHttpRequestStreamReaderFactory());
         }
 
         private class Person
@@ -66,5 +83,18 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 
             public int Age { get; set; }
         }
+
+        private class TestInputFormatter : IInputFormatter
+        {
+            public bool CanRead(InputFormatterContext context)
+            {
+                throw new NotImplementedException();
+            }
+
+            public Task<InputFormatterResult> ReadAsync(InputFormatterContext context)
+            {
+                throw new NotImplementedException();
+            }
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Metadata/DefaultModelMetadataProviderTest.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Linq;
-using System.Reflection;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
@@ -173,7 +172,9 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Metadata
 
         private static DefaultModelMetadataProvider CreateProvider()
         {
-            return new DefaultModelMetadataProvider(new EmptyCompositeMetadataDetailsProvider());
+            return new DefaultModelMetadataProvider(
+                new EmptyCompositeMetadataDetailsProvider(),
+                new TestOptionsManager<MvcOptions>());
         }
 
         [Model("OnType")]

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

@@ -2,10 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Collections.Generic;
 using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Binders;
-using Microsoft.AspNetCore.Mvc.ModelBinding.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
 using Moq;
 using Xunit;
@@ -14,24 +12,41 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
     public class ModelBinderFactoryTest
     {
-        // No providers => can't create a binder
+        [Fact]
+        public void CreateBinder_Throws_WhenNoProviders()
+        {
+            // Arrange
+            var expected = $"'{typeof(MvcOptions).FullName}.{nameof(MvcOptions.ModelBinderProviders)}' must not be " +
+                $"empty. At least one '{typeof(IModelBinderProvider).FullName}' is required to model bind.";
+            var metadataProvider = new TestModelMetadataProvider();
+            var options = new TestOptionsManager<MvcOptions>();
+            var factory = new ModelBinderFactory(metadataProvider, options);
+            var context = new ModelBinderFactoryContext()
+            {
+                Metadata = metadataProvider.GetMetadataForType(typeof(string)),
+            };
+
+            // Act & Assert
+            var exception = Assert.Throws<InvalidOperationException>(() => factory.CreateBinder(context));
+            Assert.Equal(expected, exception.Message);
+        }
+
         [Fact]
         public void CreateBinder_Throws_WhenBinderNotCreated()
         {
             // Arrange
             var metadataProvider = new TestModelMetadataProvider();
             var options = new TestOptionsManager<MvcOptions>();
-            var factory = new ModelBinderFactory(metadataProvider, options);
+            options.Value.ModelBinderProviders.Add(new TestModelBinderProvider(_ => null));
 
+            var factory = new ModelBinderFactory(metadataProvider, options);
             var context = new ModelBinderFactoryContext()
             {
                 Metadata = metadataProvider.GetMetadataForType(typeof(string)),
             };
 
-            // Act
+            // Act & Assert
             var exception = Assert.Throws<InvalidOperationException>(() => factory.CreateBinder(context));
-
-            // Assert
             Assert.Equal(
                 $"Could not create a model binder for model object of type '{typeof(string).FullName}'.",
                 exception.Message);

test/Microsoft.AspNetCore.Mvc.DataAnnotations.Test/Internal/ModelMetadataProviderTest.cs

@@ -1046,31 +1046,17 @@ namespace Microsoft.AspNetCore.Mvc.DataAnnotations.Internal
             private readonly object[] _attributes;
 
             public AttributeInjectModelMetadataProvider(object[] attributes)
-                : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
+                : base(
-                    {
+                      new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
-                        new DefaultBindingMetadataProvider(CreateMessageProvider()),
+                      {
-                        new DataAnnotationsMetadataProvider(),
+                          new DefaultBindingMetadataProvider(),
-                    }))
+                          new DataAnnotationsMetadataProvider(),
+                      }),
+                      new TestOptionsManager<MvcOptions>())
             {
                 _attributes = attributes;
             }
 
-            private static ModelBindingMessageProvider CreateMessageProvider()
-            {
-                return new ModelBindingMessageProvider
-                {
-                    MissingBindRequiredValueAccessor =
-                        name => $"A value for the '{ name }' property was not provided.",
-                    MissingKeyOrValueAccessor = () => $"A value is required.",
-                    ValueMustNotBeNullAccessor = value => $"The value '{ value }' is invalid.",
-                    AttemptedValueIsInvalidAccessor =
-                        (value, name) => $"The value '{ value }' is not valid for { name }.",
-                    UnknownValueIsInvalidAccessor = name => $"The supplied value is invalid for { name }.",
-                    ValueIsInvalidAccessor = value => $"The value '{ value }' is invalid.",
-                    ValueMustBeANumberAccessor = name => $"The field { name } must be a number.",
-                };
-            }
-
             protected override DefaultMetadataDetails CreateTypeDetails(ModelMetadataIdentity key)
             {
                 var entry = base.CreateTypeDetails(key);

test/Microsoft.AspNetCore.Mvc.Razor.Test/Internal/CompilerCacheTest.cs

@@ -7,6 +7,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.AspNetCore.Mvc.Razor.Compilation;
+using Microsoft.Extensions.FileProviders;
 using Moq;
 using Xunit;
 
@@ -445,6 +446,23 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
             Assert.Same(result1.PageFactory, result2.PageFactory);
         }
 
+        [Fact]
+        public void GetOrAdd_ThrowsIfNullFileProvider()
+        {
+            // Arrange
+            var expected =
+                $"'{typeof(RazorViewEngineOptions).FullName}.{nameof(RazorViewEngineOptions.FileProviders)}' must " +
+                $"not be empty. At least one '{typeof(IFileProvider).FullName}' is required to locate a view for " +
+                "rendering.";
+            var fileProvider = new NullFileProvider();
+            var cache = new CompilerCache(fileProvider);
+
+            // Act & Assert
+            var exception = Assert.Throws<InvalidOperationException>(
+                () => cache.GetOrAdd(ViewPath, _ => { throw new InvalidTimeZoneException(); }));
+            Assert.Equal(expected, exception.Message);
+        }
+
         [Fact]
         public void GetOrAdd_CachesCompilationExceptions()
         {

test/Microsoft.AspNetCore.Mvc.Razor.Test/Internal/DefaultRazorViewEngineFileProviderAccessorTest.cs

@@ -11,7 +11,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
     public class DefaultRazorViewEngineFileProviderAccessorTest
     {
         [Fact]
-        public void FileProvider_ReturnsInstanceIfExactlyOneFileProviderIsSpecified()
+        public void FileProvider_ReturnsInstance_IfExactlyOneFileProviderIsRegistered()
         {
             // Arrange
             var fileProvider = new TestFileProvider();
@@ -29,7 +29,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
         }
 
         [Fact]
-        public void FileProvider_ReturnsCompositeFileProviderIfNoInstancesAreRegistered()
+        public void FileProvider_ReturnsNullFileProvider_IfNoInstancesAreRegistered()
         {
             // Arrange
             var options = new RazorViewEngineOptions();
@@ -41,11 +41,11 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
             var actual = fileProviderAccessor.FileProvider;
 
             // Assert
-            Assert.IsType<CompositeFileProvider>(actual);
+            Assert.IsType<NullFileProvider>(actual);
         }
 
         [Fact]
-        public void FileProvider_ReturnsCompositeFileProviderIfMoreThanOneInstanceIsRegistered()
+        public void FileProvider_ReturnsCompositeFileProvider_IfMoreThanOneInstanceIsRegistered()
         {
             // Arrange
             var options = new RazorViewEngineOptions();

test/Microsoft.AspNetCore.Mvc.TestCommon/TestModelMetadataProvider.cs

@@ -18,21 +18,21 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
         {
             var detailsProviders = new IMetadataDetailsProvider[]
             {
-                new DefaultBindingMetadataProvider(CreateMessageProvider()),
+                new DefaultBindingMetadataProvider(),
                 new DefaultValidationMetadataProvider(),
                 new DataAnnotationsMetadataProvider(),
                 new DataMemberRequiredBindingMetadataProvider(),
             };
 
             var compositeDetailsProvider = new DefaultCompositeMetadataDetailsProvider(detailsProviders);
-            return new DefaultModelMetadataProvider(compositeDetailsProvider);
+            return new DefaultModelMetadataProvider(compositeDetailsProvider, new TestOptionsManager<MvcOptions>());
         }
 
         public static IModelMetadataProvider CreateDefaultProvider(IList<IMetadataDetailsProvider> providers)
         {
             var detailsProviders = new List<IMetadataDetailsProvider>()
             {
-                new DefaultBindingMetadataProvider(CreateMessageProvider()),
+                new DefaultBindingMetadataProvider(),
                 new DefaultValidationMetadataProvider(),
                 new DataAnnotationsMetadataProvider(),
                 new DataMemberRequiredBindingMetadataProvider(),
@@ -41,7 +41,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             detailsProviders.AddRange(providers);
 
             var compositeDetailsProvider = new DefaultCompositeMetadataDetailsProvider(detailsProviders);
-            return new DefaultModelMetadataProvider(compositeDetailsProvider);
+            return new DefaultModelMetadataProvider(compositeDetailsProvider, new TestOptionsManager<MvcOptions>());
         }
 
         public static IModelMetadataProvider CreateProvider(IList<IMetadataDetailsProvider> providers)
@@ -53,7 +53,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             }
 
             var compositeDetailsProvider = new DefaultCompositeMetadataDetailsProvider(detailsProviders);
-            return new DefaultModelMetadataProvider(compositeDetailsProvider);
+            return new DefaultModelMetadataProvider(compositeDetailsProvider, new TestOptionsManager<MvcOptions>());
         }
 
         private readonly TestModelMetadataDetailsProvider _detailsProvider;
@@ -64,13 +64,15 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
         }
 
         private TestModelMetadataProvider(TestModelMetadataDetailsProvider detailsProvider)
-            : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
+            : base(
-                {
+                  new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
-                    new DefaultBindingMetadataProvider(CreateMessageProvider()),
+                  {
-                    new DefaultValidationMetadataProvider(),
+                      new DefaultBindingMetadataProvider(),
-                    new DataAnnotationsMetadataProvider(),
+                      new DefaultValidationMetadataProvider(),
-                    detailsProvider
+                      new DataAnnotationsMetadataProvider(),
-                }))
+                      detailsProvider
+                  }),
+                  new TestOptionsManager<MvcOptions>())
         {
             _detailsProvider = detailsProvider;
         }
@@ -106,20 +108,6 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             return ForProperty(typeof(TContainer), propertyName);
         }
 
-        private static ModelBindingMessageProvider CreateMessageProvider()
-        {
-            return new ModelBindingMessageProvider
-            {
-                MissingBindRequiredValueAccessor = name => $"A value for the '{ name }' property was not provided.",
-                MissingKeyOrValueAccessor = () => $"A value is required.",
-                ValueMustNotBeNullAccessor = value => $"The value '{ value }' is invalid.",
-                AttemptedValueIsInvalidAccessor = (value, name) => $"The value '{ value }' is not valid for { name }.",
-                UnknownValueIsInvalidAccessor = name => $"The supplied value is invalid for { name }.",
-                ValueIsInvalidAccessor = value => $"The value '{ value }' is invalid.",
-                ValueMustBeANumberAccessor = name => $"The field { name } must be a number.",
-            };
-        }
-
         private class TestModelMetadataDetailsProvider :
             IBindingMetadataProvider,
             IDisplayMetadataProvider,

test/Microsoft.AspNetCore.Mvc.ViewFeatures.Test/ViewEngines/CompositeViewEngineTest.cs

@@ -32,20 +32,20 @@ namespace Microsoft.AspNetCore.Mvc.ViewEngines
         }
 
         [Fact]
-        public void FindView_IsMainPage_ReturnsNotFoundResult_WhenNoViewEnginesAreRegistered()
+        public void FindView_IsMainPage_Throws_WhenNoViewEnginesAreRegistered()
         {
             // Arrange
+            var expected = $"'{typeof(MvcViewOptions).FullName}.{nameof(MvcViewOptions.ViewEngines)}' must not be " +
+                $"empty. At least one '{typeof(IViewEngine).FullName}' is required to locate a view for rendering.";
             var viewName = "test-view";
             var actionContext = GetActionContext();
             var optionsAccessor = new TestOptionsManager<MvcViewOptions>();
             var compositeViewEngine = new CompositeViewEngine(optionsAccessor);
 
-            // Act
+            // Act & Assert
-            var result = compositeViewEngine.FindView(actionContext, viewName, isMainPage: true);
+            var exception = Assert.Throws<InvalidOperationException>(
-
+                () => compositeViewEngine.FindView(actionContext, viewName, isMainPage: true));
-            // Assert
+            Assert.Equal(expected, exception.Message);
-            Assert.False(result.Success);
-            Assert.Empty(result.SearchedLocations);
         }
 
 
@@ -165,16 +165,16 @@ namespace Microsoft.AspNetCore.Mvc.ViewEngines
         public void GetView_ReturnsNotFoundResult_WhenNoViewEnginesAreRegistered(bool isMainPage)
         {
             // Arrange
+            var expected = $"'{typeof(MvcViewOptions).FullName}.{nameof(MvcViewOptions.ViewEngines)}' must not be " +
+                $"empty. At least one '{typeof(IViewEngine).FullName}' is required to locate a view for rendering.";
             var viewName = "test-view.cshtml";
             var optionsAccessor = new TestOptionsManager<MvcViewOptions>();
             var compositeViewEngine = new CompositeViewEngine(optionsAccessor);
 
-            // Act
+            // Act & Assert
-            var result = compositeViewEngine.GetView("~/Index.html", viewName, isMainPage);
+            var exception = Assert.Throws<InvalidOperationException>(
-
+                () => compositeViewEngine.GetView("~/Index.html", viewName, isMainPage));
-            // Assert
+            Assert.Equal(expected, exception.Message);
-            Assert.False(result.Success);
-            Assert.Empty(result.SearchedLocations);
         }
 
 
@@ -305,16 +305,16 @@ namespace Microsoft.AspNetCore.Mvc.ViewEngines
         public void FindView_ReturnsNotFoundResult_WhenNoViewEnginesAreRegistered()
         {
             // Arrange
+            var expected = $"'{typeof(MvcViewOptions).FullName}.{nameof(MvcViewOptions.ViewEngines)}' must not be " +
+                $"empty. At least one '{typeof(IViewEngine).FullName}' is required to locate a view for rendering.";
             var viewName = "my-partial-view";
             var optionsAccessor = new TestOptionsManager<MvcViewOptions>();
             var compositeViewEngine = new CompositeViewEngine(optionsAccessor);
 
-            // Act
+            // Act & AssertS
-            var result = compositeViewEngine.FindView(GetActionContext(), viewName, isMainPage: false);
+            var exception = Assert.Throws<InvalidOperationException>(
-
+                () => compositeViewEngine.FindView(GetActionContext(), viewName, isMainPage: false));
-            // Assert
+            Assert.Equal(expected, exception.Message);
-            Assert.False(result.Success);
-            Assert.Empty(result.SearchedLocations);
         }
 
         [Fact]