Add a switch to allow turning on ValidationVisitor shortcircuiting (#8599)

src/Microsoft.AspNetCore.Mvc.Core/CompatibilityVersion.cs

@@ -73,6 +73,7 @@ namespace Microsoft.AspNetCore.Mvc
         ///     <item><description><c>ApiBehaviorOptions.SuppressUseValidationProblemDetailsForInvalidModelStateResponses</c></description></item>
         ///     <item><description><c>MvcDataAnnotationsLocalizationOptions.AllowDataAnnotationsLocalizationForEnumDisplayAttributes</c></description></item>
         ///     <item><description><see cref="MvcOptions.EnableEndpointRouting" /></description></item>
+        ///     <item><description><see cref="MvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent"/></description></item>
         ///     <item><description><see cref="MvcOptions.MaxValidationDepth" /></description></item>
         ///     <item><description><c>RazorPagesOptions.AllowDefaultHandlingForOptionsRequests</c></description></item>
         ///     <item><description><c>RazorViewEngineOptions.AllowRecompilingViewsOnFileChange</c></description></item>

src/Microsoft.AspNetCore.Mvc.Core/DefaultObjectValidator.cs

@@ -5,7 +5,6 @@ using System.Collections.Generic;
 using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
-using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Mvc
 {
@@ -46,6 +45,7 @@ namespace Microsoft.AspNetCore.Mvc
                 validationState);
 
             visitor.MaxValidationDepth = _mvcOptions.MaxValidationDepth;
+            visitor.AllowShortCircuitingValidationWhenNoValidatorsArePresent = _mvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent;
 
             return visitor;
         }

src/Microsoft.AspNetCore.Mvc.Core/Infrastructure/MvcOptionsConfigureCompatibilityOptions.cs

@@ -38,6 +38,9 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
 
                     // Matches JsonSerializerSettingsProvider.DefaultMaxDepth
                     values[nameof(MvcOptions.MaxValidationDepth)] = 32;
+
+                    values[nameof(MvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent)] = true;
+
                 }
 
                 return values;

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Validation/ValidationVisitor.cs

@@ -110,6 +110,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Validation
         /// </summary>
         public bool ValidateComplexTypesIfChildValidationFails { get; set; }
 
+        /// <summary>
+        ///  Gets or sets a value that determines if <see cref="ValidationVisitor"/> can short circuit validation when a model
+        ///  does not have any associated validators.
+        /// </summary>
+        public bool AllowShortCircuitingValidationWhenNoValidatorsArePresent { get; set; }
+
         /// <summary>
         /// Validates a object.
         /// </summary>
@@ -267,7 +273,9 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Validation
             }
             // If the metadata indicates that no validators exist AND the aggregate state for the key says that the model graph
             // is not invalid (i.e. is one of Unvalidated, Valid, or Skipped) we can safely mark the graph as valid.
-            else if (metadata.HasValidators == false &&
+            else if (
+                AllowShortCircuitingValidationWhenNoValidatorsArePresent &&
+                metadata.HasValidators == false &&
                 ModelState.GetFieldValidationState(key) != ModelValidationState.Invalid)
             {
                 // No validators will be created for this graph of objects. Mark it as valid if it wasn't previously validated.

src/Microsoft.AspNetCore.Mvc.Core/MvcOptions.cs

@@ -32,6 +32,7 @@ namespace Microsoft.AspNetCore.Mvc
         private readonly CompatibilitySwitch<bool> _suppressBindingUndefinedValueToEnumType;
         private readonly CompatibilitySwitch<bool> _enableEndpointRouting;
         private readonly NullableCompatibilitySwitch<int> _maxValidationDepth;
+        private readonly CompatibilitySwitch<bool> _allowShortCircuitingValidationWhenNoValidatorsArePresent;
         private readonly ICompatibilitySwitch[] _switches;
 
         /// <summary>
@@ -58,6 +59,7 @@ namespace Microsoft.AspNetCore.Mvc
             _suppressBindingUndefinedValueToEnumType = new CompatibilitySwitch<bool>(nameof(SuppressBindingUndefinedValueToEnumType));
             _enableEndpointRouting = new CompatibilitySwitch<bool>(nameof(EnableEndpointRouting));
             _maxValidationDepth = new NullableCompatibilitySwitch<int>(nameof(MaxValidationDepth));
+            _allowShortCircuitingValidationWhenNoValidatorsArePresent = new CompatibilitySwitch<bool>(nameof(AllowShortCircuitingValidationWhenNoValidatorsArePresent));
 
             _switches = new ICompatibilitySwitch[]
             {
@@ -68,6 +70,7 @@ namespace Microsoft.AspNetCore.Mvc
                 _suppressBindingUndefinedValueToEnumType,
                 _enableEndpointRouting,
                 _maxValidationDepth,
+                _allowShortCircuitingValidationWhenNoValidatorsArePresent,
             };
         }
 
@@ -442,6 +445,44 @@ namespace Microsoft.AspNetCore.Mvc
             }
         }
 
+        /// <summary>
+        /// Gets or sets a value that determines if <see cref="ValidationVisitor"/>
+        /// can short-circuit validation when a model does not have any associated validators.
+        /// </summary>
+        /// <value>
+        /// The default value is <see langword="true"/> if the version is
+        /// <see cref="CompatibilityVersion.Version_2_2"/> or later; <see langword="false"/> otherwise.
+        /// </value>
+        /// <remarks>
+        /// When <see cref="ModelMetadata.HasValidators"/> is <see langword="true"/>, that is, it is determined
+        /// that a model or any of it's properties or collection elements cannot have any validators,
+        /// <see cref="ValidationVisitor"/> can short-circuit validation for the model and mark the object
+        /// graph as valid. Setting this property to <see langword="true"/>, allows <see cref="ValidationVisitor"/> to
+        /// perform this optimization.
+        /// <para>
+        /// This property is associated with a compatibility switch and can provide a different behavior depending on
+        /// the configured compatibility version for the application. See <see cref="CompatibilityVersion"/> for
+        /// guidance and examples of setting the application's compatibility version.
+        /// </para>
+        /// <para>
+        /// Configuring the desired value of the compatibility switch by calling this property's setter will take precedence
+        /// over the value implied by the application's <see cref="CompatibilityVersion"/>.
+        /// </para>
+        /// <para>
+        /// If the application's compatibility version is set to <see cref="CompatibilityVersion.Version_2_2"/> then
+        /// this setting will have the value <see langword="true"/> unless explicitly configured.
+        /// </para>
+        /// <para>
+        /// If the application's compatibility version is set to <see cref="CompatibilityVersion.Version_2_1"/> or
+        /// earlier then this setting will have the value <see langword="false"/> unless explicitly configured.
+        /// </para>
+        /// </remarks>
+        public bool AllowShortCircuitingValidationWhenNoValidatorsArePresent
+        {
+            get => _allowShortCircuitingValidationWhenNoValidatorsArePresent.Value;
+            set => _allowShortCircuitingValidationWhenNoValidatorsArePresent.Value = value;
+        }
+
         IEnumerator<ICompatibilitySwitch> IEnumerable<ICompatibilitySwitch>.GetEnumerator()
         {
             return ((IEnumerable<ICompatibilitySwitch>)_switches).GetEnumerator();

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

@@ -23,7 +23,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 {
     public class DefaultObjectValidatorTests
     {
-        private readonly MvcOptions _options = new MvcOptions();
+        private readonly MvcOptions _options = new MvcOptions { AllowShortCircuitingValidationWhenNoValidatorsArePresent = true };
 
         private ModelMetadataProvider MetadataProvider { get; } = TestModelMetadataProvider.CreateDefaultProvider();
 

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

@@ -129,7 +129,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             return new DefaultObjectValidator(
                 metadataProvider,
                 GetModelValidatorProviders(options),
-                options?.Value ?? new MvcOptions());
+                options?.Value ?? new MvcOptions { AllowShortCircuitingValidationWhenNoValidatorsArePresent = true });
         }
 
         private static IList<IModelValidatorProvider> GetModelValidatorProviders(IOptions<MvcOptions> options)
@@ -197,7 +197,8 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
             serviceCollection
                 .AddSingleton<ObjectPoolProvider, DefaultObjectPoolProvider>()
                 .AddSingleton<ILoggerFactory>(NullLoggerFactory.Instance)
-                .AddTransient<ILogger<DefaultAuthorizationService>, Logger<DefaultAuthorizationService>>();
+                .AddTransient<ILogger<DefaultAuthorizationService>, Logger<DefaultAuthorizationService>>()
+                .Configure<MvcOptions>(options => options.AllowShortCircuitingValidationWhenNoValidatorsArePresent = true);
 
             if (updateOptions != null)
             {

test/Microsoft.AspNetCore.Mvc.Test/IntegrationTest/CompatibilitySwitchIntegrationTest.cs

@@ -56,6 +56,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTest
             Assert.True(razorViewEngineOptions.AllowRecompilingViewsOnFileChange);
             Assert.False(razorPagesOptions.AllowDefaultHandlingForOptionsRequests);
             Assert.False(xmlOptions.AllowRfc7807CompliantProblemDetailsFormat);
+            Assert.False(mvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent);
         }
 
         [Fact]
@@ -93,6 +94,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTest
             Assert.True(razorViewEngineOptions.AllowRecompilingViewsOnFileChange);
             Assert.False(razorPagesOptions.AllowDefaultHandlingForOptionsRequests);
             Assert.False(xmlOptions.AllowRfc7807CompliantProblemDetailsFormat);
+            Assert.False(mvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent);
         }
 
         [Fact]
@@ -130,6 +132,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTest
             Assert.False(razorViewEngineOptions.AllowRecompilingViewsOnFileChange);
             Assert.True(razorPagesOptions.AllowDefaultHandlingForOptionsRequests);
             Assert.True(xmlOptions.AllowRfc7807CompliantProblemDetailsFormat);
+            Assert.True(mvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent);
         }
 
         [Fact]
@@ -167,6 +170,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTest
             Assert.False(razorViewEngineOptions.AllowRecompilingViewsOnFileChange);
             Assert.True(razorPagesOptions.AllowDefaultHandlingForOptionsRequests);
             Assert.True(xmlOptions.AllowRfc7807CompliantProblemDetailsFormat);
+            Assert.True(mvcOptions.AllowShortCircuitingValidationWhenNoValidatorsArePresent);
         }
 
         // This just does the minimum needed to be able to resolve these options.