Add helper methods on ControllerBase to return ProblemDetails (#12298)

* Add helper methods on ControllerBase to return ProblemDetails

* Introduce ControllerBase.Problem and ValidationProblem overload
  that accepts optional parameters
* Consistently use ClientErrorData when generating ProblemDetails
* Clean-up InvalidModelStateResponseFactory initialization.

Fixes https://github.com/aspnet/AspNetCore/issues/8537

src/Mvc/Mvc.Core/ref/Microsoft.AspNetCore.Mvc.Core.netcoreapp3.0.cs

@@ -271,6 +271,7 @@ namespace Microsoft.AspNetCore.Mvc
         public Microsoft.AspNetCore.Mvc.ModelBinding.IModelBinderFactory ModelBinderFactory { get { throw null; } set { } }
         public Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary ModelState { get { throw null; } }
         public Microsoft.AspNetCore.Mvc.ModelBinding.Validation.IObjectModelValidator ObjectValidator { get { throw null; } set { } }
+        public Microsoft.AspNetCore.Mvc.Infrastructure.ProblemDetailsFactory ProblemDetailsFactory { get { throw null; } set { } }
         public Microsoft.AspNetCore.Http.HttpRequest Request { get { throw null; } }
         public Microsoft.AspNetCore.Http.HttpResponse Response { get { throw null; } }
         public Microsoft.AspNetCore.Routing.RouteData RouteData { get { throw null; } }
@@ -445,6 +446,8 @@ namespace Microsoft.AspNetCore.Mvc
         [Microsoft.AspNetCore.Mvc.NonActionAttribute]
         public virtual Microsoft.AspNetCore.Mvc.PhysicalFileResult PhysicalFile(string physicalPath, string contentType, string fileDownloadName, System.DateTimeOffset? lastModified, Microsoft.Net.Http.Headers.EntityTagHeaderValue entityTag, bool enableRangeProcessing) { throw null; }
         [Microsoft.AspNetCore.Mvc.NonActionAttribute]
+        public virtual Microsoft.AspNetCore.Mvc.ObjectResult Problem(string detail = null, string instance = null, int? statusCode = default(int?), string title = null, string type = null) { throw null; }
+        [Microsoft.AspNetCore.Mvc.NonActionAttribute]
         public virtual Microsoft.AspNetCore.Mvc.RedirectResult Redirect(string url) { throw null; }
         [Microsoft.AspNetCore.Mvc.NonActionAttribute]
         public virtual Microsoft.AspNetCore.Mvc.RedirectResult RedirectPermanent(string url) { throw null; }
@@ -586,6 +589,8 @@ namespace Microsoft.AspNetCore.Mvc
         public virtual Microsoft.AspNetCore.Mvc.ActionResult ValidationProblem([Microsoft.AspNetCore.Mvc.Infrastructure.ActionResultObjectValueAttribute]Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary modelStateDictionary) { throw null; }
         [Microsoft.AspNetCore.Mvc.NonActionAttribute]
         public virtual Microsoft.AspNetCore.Mvc.ActionResult ValidationProblem([Microsoft.AspNetCore.Mvc.Infrastructure.ActionResultObjectValueAttribute]Microsoft.AspNetCore.Mvc.ValidationProblemDetails descriptor) { throw null; }
+        [Microsoft.AspNetCore.Mvc.NonActionAttribute]
+        public virtual Microsoft.AspNetCore.Mvc.ActionResult ValidationProblem(string detail = null, string instance = null, int? statusCode = default(int?), string title = null, string type = null, [Microsoft.AspNetCore.Mvc.Infrastructure.ActionResultObjectValueAttribute]Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary modelStateDictionary = null) { throw null; }
     }
     public partial class ControllerContext : Microsoft.AspNetCore.Mvc.ActionContext
     {
@@ -2439,6 +2444,12 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
             public long Length { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         }
     }
+    public abstract partial class ProblemDetailsFactory
+    {
+        protected ProblemDetailsFactory() { }
+        public abstract Microsoft.AspNetCore.Mvc.ProblemDetails CreateProblemDetails(Microsoft.AspNetCore.Http.HttpContext httpContext, int? statusCode = default(int?), string title = null, string type = null, string detail = null, string instance = null);
+        public abstract Microsoft.AspNetCore.Mvc.ValidationProblemDetails CreateValidationProblemDetails(Microsoft.AspNetCore.Http.HttpContext httpContext, Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary modelStateDictionary, int? statusCode = default(int?), string title = null, string type = null, string detail = null, string instance = null);
+    }
     public partial class RedirectResultExecutor : Microsoft.AspNetCore.Mvc.Infrastructure.IActionResultExecutor<Microsoft.AspNetCore.Mvc.RedirectResult>
     {
         public RedirectResultExecutor(Microsoft.Extensions.Logging.ILoggerFactory loggerFactory, Microsoft.AspNetCore.Mvc.Routing.IUrlHelperFactory urlHelperFactory) { }

src/Mvc/Mvc.Core/src/ControllerBase.cs

@@ -16,6 +16,7 @@ using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
 using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Mvc
@@ -31,6 +32,7 @@ namespace Microsoft.AspNetCore.Mvc
         private IModelBinderFactory _modelBinderFactory;
         private IObjectModelValidator _objectValidator;
         private IUrlHelper _url;
+        private ProblemDetailsFactory _problemDetailsFactory;
 
         /// <summary>
         /// Gets the <see cref="Http.HttpContext"/> for the executing action.
@@ -189,6 +191,28 @@ namespace Microsoft.AspNetCore.Mvc
             }
         }
 
+        public ProblemDetailsFactory ProblemDetailsFactory
+        {
+            get
+            {
+                if (_problemDetailsFactory == null)
+                {
+                    _problemDetailsFactory = HttpContext?.RequestServices?.GetRequiredService<ProblemDetailsFactory>();
+                }
+
+                return _problemDetailsFactory;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+
+                _problemDetailsFactory = value;
+            }
+        }
+
         /// <summary>
         /// Gets the <see cref="ClaimsPrincipal"/> for user associated with the executing action.
         /// </summary>
@@ -1821,6 +1845,34 @@ namespace Microsoft.AspNetCore.Mvc
         public virtual ConflictObjectResult Conflict([ActionResultObjectValue] ModelStateDictionary modelState)
             => new ConflictObjectResult(modelState);
 
+        /// <summary>
+        /// Creates an <see cref="ObjectResult"/> that produces a <see cref="ProblemDetails"/> response.
+        /// </summary>
+        /// <param name="statusCode">The value for <see cref="ProblemDetails.Status" />..</param>
+        /// <param name="detail">The value for <see cref="ProblemDetails.Detail" />.</param>
+        /// <param name="instance">The value for <see cref="ProblemDetails.Instance" />.</param>
+        /// <param name="title">The value for <see cref="ProblemDetails.Title" />.</param>
+        /// <param name="type">The value for <see cref="ProblemDetails.Type" />.</param>
+        /// <returns>The created <see cref="ObjectResult"/> for the response.</returns>
+        [NonAction]
+        public virtual ObjectResult Problem(
+            string detail = null,
+            string instance = null,
+            int? statusCode = null,
+            string title = null,
+            string type = null)
+        {
+            var problemDetails = ProblemDetailsFactory.CreateProblemDetails(
+                HttpContext,
+                statusCode: statusCode ?? 500,
+                title: title,
+                type: type,
+                detail: detail,
+                instance: instance);
+
+            return new ObjectResult(problemDetails);
+        }
+
         /// <summary>
         /// Creates an <see cref="BadRequestObjectResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response.
         /// </summary>
@@ -1837,31 +1889,64 @@ namespace Microsoft.AspNetCore.Mvc
         }
 
         /// <summary>
-        /// Creates an <see cref="BadRequestObjectResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response.
+        /// Creates an <see cref="ActionResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response
+        /// with validation errors from <paramref name="modelStateDictionary"/>.
         /// </summary>
+        /// <param name="modelStateDictionary">The <see cref="ModelStateDictionary"/>.</param>
         /// <returns>The created <see cref="BadRequestObjectResult"/> for the response.</returns>
         [NonAction]
         public virtual ActionResult ValidationProblem([ActionResultObjectValue] ModelStateDictionary modelStateDictionary)
-        {
+             => ValidationProblem(detail: null, modelStateDictionary: modelStateDictionary);
-            if (modelStateDictionary == null)
-            {
-                throw new ArgumentNullException(nameof(modelStateDictionary));
-            }
 
-            var validationProblem = new ValidationProblemDetails(modelStateDictionary);
-            return new BadRequestObjectResult(validationProblem);
-        }
 
         /// <summary>
-        /// Creates an <see cref="BadRequestObjectResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response
+        /// Creates an <see cref="ActionResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response
         /// with validation errors from <see cref="ModelState"/>.
         /// </summary>
-        /// <returns>The created <see cref="BadRequestObjectResult"/> for the response.</returns>
+        /// <returns>The created <see cref="ActionResult"/> for the response.</returns>
         [NonAction]
         public virtual ActionResult ValidationProblem()
+            => ValidationProblem(ModelState);
+
+        /// <summary>
+        /// Creates an <see cref="ActionResult"/> that produces a <see cref="StatusCodes.Status400BadRequest"/> response
+        /// with a <see cref="ValidationProblemDetails"/> value.
+        /// </summary>
+        /// <param name="detail">The value for <see cref="ProblemDetails.Detail" />.</param>
+        /// <param name="instance">The value for <see cref="ProblemDetails.Instance" />.</param>
+        /// <param name="statusCode">The status code.</param>
+        /// <param name="title">The value for <see cref="ProblemDetails.Title" />.</param>
+        /// <param name="type">The value for <see cref="ProblemDetails.Type" />.</param>
+        /// <param name="modelStateDictionary">The <see cref="ModelStateDictionary"/>. 
+        /// When <see langword="null"/> uses <see cref="ModelState"/>.</param>
+        /// <returns>The created <see cref="ActionResult"/> for the response.</returns>
+        [NonAction]
+        public virtual ActionResult ValidationProblem(
+            string detail = null,
+            string instance = null,
+            int? statusCode = null,
+            string title = null,
+            string type = null,
+            [ActionResultObjectValue] ModelStateDictionary modelStateDictionary = null)
         {
-            var validationProblem = new ValidationProblemDetails(ModelState);
+            modelStateDictionary ??= ModelState;
-            return new BadRequestObjectResult(validationProblem);
+
+            var validationProblem = ProblemDetailsFactory.CreateValidationProblemDetails(
+                HttpContext,
+                modelStateDictionary,
+                statusCode: statusCode,
+                title: title,
+                type: type,
+                detail: detail,
+                instance: instance);
+
+            if (validationProblem.Status == 400)
+            {
+                // For compatibility with 2.x, continue producing BadRequestObjectResult instances if the status code is 400.
+                return new BadRequestObjectResult(validationProblem);
+            }
+
+            return new ObjectResult(validationProblem);
         }
 
         /// <summary>

src/Mvc/Mvc.Core/src/DependencyInjection/ApiBehaviorOptionsSetup.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.Infrastructure;
@@ -10,13 +9,9 @@ using Microsoft.Extensions.Options;
 
 namespace Microsoft.Extensions.DependencyInjection
 {
-    internal class ApiBehaviorOptionsSetup :
+    internal class ApiBehaviorOptionsSetup : IConfigureOptions<ApiBehaviorOptions>
-        IConfigureOptions<ApiBehaviorOptions>,
-        IPostConfigureOptions<ApiBehaviorOptions>
     {
-        internal static readonly Func<ActionContext, IActionResult> DefaultFactory = DefaultInvalidModelStateResponse;
+        private ProblemDetailsFactory _problemDetailsFactory;
-        internal static readonly Func<ActionContext, IActionResult> ProblemDetailsFactory =
-            ProblemDetailsInvalidModelStateResponse;
 
         public void Configure(ApiBehaviorOptions options)
         {
@@ -25,20 +20,34 @@ namespace Microsoft.Extensions.DependencyInjection
                 throw new ArgumentNullException(nameof(options));
             }
 
-            options.InvalidModelStateResponseFactory = DefaultFactory;
+            options.InvalidModelStateResponseFactory = context =>
+            {
+                // ProblemDetailsFactory depends on the ApiBehaviorOptions instance. We intentionally avoid constructor injecting
+                // it in this options setup to to avoid a DI cycle.
+                _problemDetailsFactory ??= context.HttpContext.RequestServices.GetRequiredService<ProblemDetailsFactory>();
+                return ProblemDetailsInvalidModelStateResponse(_problemDetailsFactory, context);
+            };
+
             ConfigureClientErrorMapping(options);
         }
 
-        public void PostConfigure(string name, ApiBehaviorOptions options)
+        internal static IActionResult ProblemDetailsInvalidModelStateResponse(ProblemDetailsFactory problemDetailsFactory, ActionContext context)
         {
-            // We want to use problem details factory only if
+            var problemDetails = problemDetailsFactory.CreateValidationProblemDetails(context.HttpContext, context.ModelState);
-            // (a) it has not been opted out of (SuppressMapClientErrors = true)
+            ObjectResult result;
-            // (b) a different factory was configured
+            if (problemDetails.Status == 400)
-            if (!options.SuppressMapClientErrors &&
-                object.ReferenceEquals(options.InvalidModelStateResponseFactory, DefaultFactory))
             {
-                options.InvalidModelStateResponseFactory = ProblemDetailsFactory;
+                // For compatibility with 2.x, continue producing BadRequestObjectResult instances if the status code is 400.
+                result = new BadRequestObjectResult(problemDetails);
             }
+            else
+            {
+                result = new ObjectResult(problemDetails);
+            }
+            result.ContentTypes.Add("application/problem+json");
+            result.ContentTypes.Add("application/problem+xml");
+
+            return result;
         }
 
         // Internal for unit testing
@@ -91,33 +100,12 @@ namespace Microsoft.Extensions.DependencyInjection
                 Link = "https://tools.ietf.org/html/rfc4918#section-11.2",
                 Title = Resources.ApiConventions_Title_422,
             };
-        }
 
-        private static IActionResult DefaultInvalidModelStateResponse(ActionContext context)
+            options.ClientErrorMapping[500] = new ClientErrorData
-        {
-            var result = new BadRequestObjectResult(context.ModelState);
-
-            result.ContentTypes.Add("application/json");
-            result.ContentTypes.Add("application/xml");
-
-            return result;
-        }
-
-        internal static IActionResult ProblemDetailsInvalidModelStateResponse(ActionContext context)
-        {
-            var problemDetails = new ValidationProblemDetails(context.ModelState)
             {
-                Status = StatusCodes.Status400BadRequest,
+                Link = "https://tools.ietf.org/html/rfc7231#section-6.6.1",
+                Title = Resources.ApiConventions_Title_500,
             };
-
-            ProblemDetailsClientErrorFactory.SetTraceId(context, problemDetails);
-
-            var result = new BadRequestObjectResult(problemDetails);
-
-            result.ContentTypes.Add("application/problem+json");
-            result.ContentTypes.Add("application/problem+xml");
-
-            return result;
         }
     }
 }

src/Mvc/Mvc.Core/src/DependencyInjection/MvcCoreServiceCollectionExtensions.cs

@@ -149,8 +149,6 @@ namespace Microsoft.Extensions.DependencyInjection
                 ServiceDescriptor.Transient<IPostConfigureOptions<MvcOptions>, MvcCoreMvcOptionsSetup>());
             services.TryAddEnumerable(
                 ServiceDescriptor.Transient<IConfigureOptions<ApiBehaviorOptions>, ApiBehaviorOptionsSetup>());
-            services.TryAddEnumerable(
-                ServiceDescriptor.Transient<IPostConfigureOptions<ApiBehaviorOptions>, ApiBehaviorOptionsSetup>());
             services.TryAddEnumerable(
                 ServiceDescriptor.Transient<IConfigureOptions<RouteOptions>, MvcCoreRouteOptionsSetup>());
 
@@ -260,6 +258,7 @@ namespace Microsoft.Extensions.DependencyInjection
             services.TryAddSingleton<IActionResultExecutor<ContentResult>, ContentResultExecutor>();
             services.TryAddSingleton<IActionResultExecutor<JsonResult>, SystemTextJsonResultExecutor>();
             services.TryAddSingleton<IClientErrorFactory, ProblemDetailsClientErrorFactory>();
+            services.TryAddSingleton<ProblemDetailsFactory, DefaultProblemDetailsFactory>();
 
             //
             // Route Handlers

src/Mvc/Mvc.Core/src/Infrastructure/DefaultProblemDetailsFactory.cs

@@ -0,0 +1,97 @@
+// 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.Diagnostics;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Microsoft.Extensions.Options;
+
+namespace Microsoft.AspNetCore.Mvc.Infrastructure
+{
+    internal sealed class DefaultProblemDetailsFactory : ProblemDetailsFactory
+    {
+        private readonly ApiBehaviorOptions _options;
+
+        public DefaultProblemDetailsFactory(IOptions<ApiBehaviorOptions> options)
+        {
+            _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        }
+
+        public override ProblemDetails CreateProblemDetails(
+            HttpContext httpContext,
+            int? statusCode = null,
+            string title = null,
+            string type = null,
+            string detail = null,
+            string instance = null)
+        {
+            statusCode ??= 500;
+
+            var problemDetails = new ProblemDetails
+            {
+                Status = statusCode,
+                Title = title,
+                Type = type,
+                Detail = detail,
+                Instance = instance,
+            };
+
+            ApplyProblemDetailsDefaults(httpContext, problemDetails, statusCode.Value);
+
+            return problemDetails;
+        }
+
+        public override ValidationProblemDetails CreateValidationProblemDetails(
+            HttpContext httpContext,
+            ModelStateDictionary modelStateDictionary,
+            int? statusCode = null,
+            string title = null,
+            string type = null,
+            string detail = null,
+            string instance = null)
+        {
+            if (modelStateDictionary == null)
+            {
+                throw new ArgumentNullException(nameof(modelStateDictionary));
+            }
+
+            statusCode ??= 400;
+
+            var problemDetails = new ValidationProblemDetails(modelStateDictionary)
+            {
+                Status = statusCode,
+                Type = type,
+                Detail = detail,
+                Instance = instance,
+            };
+
+            if (title != null)
+            {
+                // For validation problem details, don't overwrite the default title with null.
+                problemDetails.Title = title;
+            }
+
+            ApplyProblemDetailsDefaults(httpContext, problemDetails, statusCode.Value);
+
+            return problemDetails;
+        }
+
+        private void ApplyProblemDetailsDefaults(HttpContext httpContext, ProblemDetails problemDetails, int statusCode)
+        {
+            problemDetails.Status ??= statusCode;
+
+            if (_options.ClientErrorMapping.TryGetValue(statusCode, out var clientErrorData))
+            {
+                problemDetails.Title ??= clientErrorData.Title;
+                problemDetails.Type ??= clientErrorData.Link;
+            }
+
+            var traceId = Activity.Current?.Id ?? httpContext?.TraceIdentifier;
+            if (traceId != null)
+            {
+                problemDetails.Extensions["traceId"] = traceId;
+            }
+        }
+    }
+}

src/Mvc/Mvc.Core/src/Infrastructure/ProblemDetailsClientErrorFactory.cs

@@ -2,37 +2,21 @@
 // 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.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Mvc.Infrastructure
 {
     internal class ProblemDetailsClientErrorFactory : IClientErrorFactory
     {
-        private static readonly string TraceIdentifierKey = "traceId";
+        private readonly ProblemDetailsFactory _problemDetailsFactory;
-        private readonly ApiBehaviorOptions _options;
 
-        public ProblemDetailsClientErrorFactory(IOptions<ApiBehaviorOptions> options)
+        public ProblemDetailsClientErrorFactory(ProblemDetailsFactory problemDetailsFactory)
         {
-            _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+            _problemDetailsFactory = problemDetailsFactory ?? throw new ArgumentNullException(nameof(problemDetailsFactory));
         }
 
         public IActionResult GetClientError(ActionContext actionContext, IClientErrorActionResult clientError)
         {
-            var problemDetails = new ProblemDetails
+            var problemDetails = _problemDetailsFactory.CreateProblemDetails(actionContext.HttpContext, clientError.StatusCode);
-            {
-                Status = clientError.StatusCode,
-                Type = "about:blank",
-            };
-
-            if (clientError.StatusCode is int statusCode &&
-                _options.ClientErrorMapping.TryGetValue(statusCode, out var errorData))
-            {
-                problemDetails.Title = errorData.Title;
-                problemDetails.Type = errorData.Link;
-
-                SetTraceId(actionContext, problemDetails);
-            }
 
             return new ObjectResult(problemDetails)
             {
@@ -44,11 +28,5 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
                 },
             };
         }
-
-        internal static void SetTraceId(ActionContext actionContext, ProblemDetails problemDetails)
-        {
-            var traceId = Activity.Current?.Id ?? actionContext.HttpContext.TraceIdentifier;
-            problemDetails.Extensions[TraceIdentifierKey] = traceId;
-        }
     }
 }

src/Mvc/Mvc.Core/src/Infrastructure/ProblemDetailsFactory.cs

@@ -0,0 +1,52 @@
+// 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.Http;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+
+namespace Microsoft.AspNetCore.Mvc.Infrastructure
+{
+    /// <summary>
+    /// Factory to produce <see cref="ProblemDetails" /> and <see cref="ValidationProblemDetails" />.
+    /// </summary>
+    public abstract class ProblemDetailsFactory
+    {
+        /// <summary>
+        /// Creates a <see cref="ProblemDetails" /> instance that configures defaults based on values specified in <see cref="ApiBehaviorOptions" />.
+        /// </summary>
+        /// <param name="httpContext">The <see cref="HttpContext" />.</param>
+        /// <param name="statusCode">The value for <see cref="ProblemDetails.Status"/>.</param>
+        /// <param name="title">The value for <see cref="ProblemDetails.Title" />.</param>
+        /// <param name="type">The value for <see cref="ProblemDetails.Type" />.</param>
+        /// <param name="detail">The value for <see cref="ProblemDetails.Detail" />.</param>
+        /// <param name="instance">The value for <see cref="ProblemDetails.Instance" />.</param>
+        /// <returns>The <see cref="ProblemDetails"/> instance.</returns>
+        public abstract ProblemDetails CreateProblemDetails(
+            HttpContext httpContext,
+            int? statusCode = null,
+            string title = null,
+            string type = null,
+            string detail = null,
+            string instance = null);
+
+        /// <summary>
+        /// Creates a <see cref="ValidationProblemDetails" /> instance that configures defaults based on values specified in <see cref="ApiBehaviorOptions" />.
+        /// </summary>
+        /// <param name="httpContext">The <see cref="HttpContext" />.</param>
+        /// <param name="modelStateDictionary">The <see cref="ModelStateDictionary" />.</param>
+        /// <param name="statusCode">The value for <see cref="ProblemDetails.Status"/>.</param>
+        /// <param name="title">The value for <see cref="ProblemDetails.Title" />.</param>
+        /// <param name="type">The value for <see cref="ProblemDetails.Type" />.</param>
+        /// <param name="detail">The value for <see cref="ProblemDetails.Detail" />.</param>
+        /// <param name="instance">The value for <see cref="ProblemDetails.Instance" />.</param>
+        /// <returns>The <see cref="ValidationProblemDetails"/> instance.</returns>
+        public abstract ValidationProblemDetails CreateValidationProblemDetails(
+            HttpContext httpContext,
+            ModelStateDictionary modelStateDictionary,
+            int? statusCode = null,
+            string title = null,
+            string type = null,
+            string detail = null,
+            string instance = null);
+    }
+}

src/Mvc/Mvc.Core/src/Resources.resx

@@ -510,4 +510,7 @@
   <data name="UnexpectedJsonEnd" xml:space="preserve">
     <value>Unexcepted end when reading JSON.</value>
   </data>
+  <data name="ApiConventions_Title_500" xml:space="preserve">
+    <value>An error occured while processing your request.</value>
+  </data>
 </root>

src/Mvc/Mvc.Core/test/ControllerBaseTest.cs

@@ -9,8 +9,11 @@ using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Abstractions;
+using Microsoft.AspNetCore.Mvc.Controllers;
 using Microsoft.AspNetCore.Mvc.DataAnnotations;
 using Microsoft.AspNetCore.Mvc.Formatters;
+using Microsoft.AspNetCore.Mvc.Infrastructure;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
 using Microsoft.AspNetCore.Routing;
@@ -2187,7 +2190,6 @@ namespace Microsoft.AspNetCore.Mvc.Core.Test
         {
             // Arrange
             var contentController = new ContentController();
-            var expected = MediaTypeHeaderValue.Parse("text/plain; charset=utf-8");
 
             // Act
             var contentResult = (ContentResult)contentController.Content_WithNoEncoding();
@@ -2290,6 +2292,163 @@ namespace Microsoft.AspNetCore.Mvc.Core.Test
             Assert.Equal(statusCode, result.StatusCode);
         }
 
+        [Fact]
+        public void ValidationProblemDetails_Works()
+        {
+            // Arrange
+            var context = new ControllerContext(new ActionContext(
+                new DefaultHttpContext { TraceIdentifier = "some-trace" },
+                new RouteData(),
+                new ControllerActionDescriptor()));
+
+            context.ModelState.AddModelError("key1", "error1");
+
+            var options = GetApiBehaviorOptions();
+            var controller = new TestableController
+            {
+                ProblemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(options)),
+                ControllerContext = context,
+            };
+
+            // Act
+            var actionResult = controller.ValidationProblem();
+
+            // Assert
+            var badRequestResult = Assert.IsType<BadRequestObjectResult>(actionResult);
+            var problemDetails = Assert.IsType<ValidationProblemDetails>(badRequestResult.Value);
+            Assert.Equal(400, problemDetails.Status);
+            Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.1", problemDetails.Type);
+            Assert.Equal("some-trace", problemDetails.Extensions["traceId"]);
+            Assert.Equal(new[] { "error1" }, problemDetails.Errors["key1"]);
+        }
+
+        [Fact]
+        public void ValidationProblemDetails_UsesSpecifiedTitle()
+        {
+            // Arrange
+            var detail = "My detail";
+            var title = "Custom title";
+            var type = "http://custom-link";
+            var options = GetApiBehaviorOptions();
+
+            var controller = new TestableController
+            {
+                ProblemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(options)),
+            };
+
+            // Act
+            var actionResult = controller.ValidationProblem(detail: detail, title: title, type: type);
+
+            // Assert
+            var badRequestResult = Assert.IsType<BadRequestObjectResult>(actionResult);
+            var problemDetails = Assert.IsType<ValidationProblemDetails>(badRequestResult.Value);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal(type, problemDetails.Type);
+            Assert.Equal(detail, problemDetails.Detail);
+        }
+
+        [Fact]
+        public void ProblemDetails_Works()
+        {
+            // Arrange
+            var context = new ControllerContext(new ActionContext(
+                new DefaultHttpContext { TraceIdentifier = "some-trace" },
+                new RouteData(),
+                new ControllerActionDescriptor()));
+
+            var options = GetApiBehaviorOptions();
+
+            var controller = new TestableController
+            {
+                ProblemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(options)),
+                ControllerContext = context,
+            };
+
+            // Act
+            var actionResult = controller.Problem();
+
+            // Assert
+            var badRequestResult = Assert.IsType<ObjectResult>(actionResult);
+            var problemDetails = Assert.IsType<ProblemDetails>(badRequestResult.Value);
+            Assert.Equal(500, problemDetails.Status);
+            Assert.Equal("An error occured while processing your request.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.6.1", problemDetails.Type);
+            Assert.Equal("some-trace", problemDetails.Extensions["traceId"]);
+        }
+
+        [Fact]
+        public void ProblemDetails_UsesPassedInValues()
+        {
+            // Arrange
+            var title = "The website is down.";
+            var detail = "Try again in a few minutes.";
+            var options = GetApiBehaviorOptions();
+
+            var controller = new TestableController
+            {
+                ProblemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(options)),
+            };
+
+            // Act
+            var actionResult = controller.Problem(detail, title: title);
+
+            // Assert
+            var badRequestResult = Assert.IsType<ObjectResult>(actionResult);
+            var problemDetails = Assert.IsType<ProblemDetails>(badRequestResult.Value);
+            Assert.Equal(500, problemDetails.Status);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.6.1", problemDetails.Type);
+            Assert.Equal(detail, problemDetails.Detail);
+        }
+
+        [Fact]
+        public void ProblemDetails_UsesPassedInStatusCode()
+        {
+            // Arrange
+            var options = GetApiBehaviorOptions();
+
+            var controller = new TestableController
+            {
+                ProblemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(options)),
+            };
+
+            // Act
+            var actionResult = controller.Problem(statusCode: 422);
+
+            // Assert
+            var badRequestResult = Assert.IsType<ObjectResult>(actionResult);
+            var problemDetails = Assert.IsType<ProblemDetails>(badRequestResult.Value);
+            Assert.Equal(422, problemDetails.Status);
+            Assert.Equal("Unprocessable entity.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc4918#section-11.2", problemDetails.Type);
+        }
+
+        private static ApiBehaviorOptions GetApiBehaviorOptions()
+        {
+            return new ApiBehaviorOptions
+            {
+                ClientErrorMapping =
+                {
+                    [400] = new ClientErrorData
+                    {
+                        Title = "One or more validation errors occurred.",
+                        Link = "https://tools.ietf.org/html/rfc7231#section-6.5.1"
+                    },
+                    [422] = new ClientErrorData
+                    {
+                        Title = "Unprocessable entity.",
+                        Link = "https://tools.ietf.org/html/rfc4918#section-11.2"
+                    },
+                    [500] = new ClientErrorData
+                    {
+                        Title = "An error occured while processing your request.",
+                        Link = "https://tools.ietf.org/html/rfc7231#section-6.6.1"
+                    }
+                }
+            };
+        }
+
         public static IEnumerable<object[]> RedirectTestData
         {
             get

src/Mvc/Mvc.Core/test/DependencyInjection/ApiBehaviorOptionsSetupTest.cs

@@ -6,31 +6,18 @@ using System.Diagnostics;
 using System.Linq;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Infrastructure;
 using Xunit;
 
 namespace Microsoft.Extensions.DependencyInjection
 {
     public class ApiBehaviorOptionsSetupTest
     {
-        [Fact]
-        public void Configure_AssignsInvalidModelStateResponseFactory()
-        {
-            // Arrange
-            var optionsSetup = new ApiBehaviorOptionsSetup();
-            var options = new ApiBehaviorOptions();
-
-            // Act
-            optionsSetup.Configure(options);
-
-            // Assert
-            Assert.Same(ApiBehaviorOptionsSetup.DefaultFactory, options.InvalidModelStateResponseFactory);
-        }
-
         [Fact]
         public void Configure_AddsClientErrorMappings()
         {
             // Arrange
-            var expected = new[] { 400, 401, 403, 404, 406, 409, 415, 422, };
+            var expected = new[] { 400, 401, 403, 404, 406, 409, 415, 422, 500, };
             var optionsSetup = new ApiBehaviorOptionsSetup();
             var options = new ApiBehaviorOptions();
 
@@ -41,50 +28,15 @@ namespace Microsoft.Extensions.DependencyInjection
             Assert.Equal(expected, options.ClientErrorMapping.Keys);
         }
 
-        [Fact]
-        public void PostConfigure_SetProblemDetailsModelStateResponseFactory()
-        {
-            // Arrange
-            var optionsSetup = new ApiBehaviorOptionsSetup();
-            var options = new ApiBehaviorOptions();
-
-            // Act
-            optionsSetup.Configure(options);
-            optionsSetup.PostConfigure(string.Empty, options);
-
-            // Assert
-            Assert.Same(ApiBehaviorOptionsSetup.ProblemDetailsFactory, options.InvalidModelStateResponseFactory);
-        }
-
-        [Fact]
-        public void PostConfigure_DoesNotSetProblemDetailsFactory_IfValueWasModified()
-        {
-            // Arrange
-            var optionsSetup = new ApiBehaviorOptionsSetup();
-            var options = new ApiBehaviorOptions();
-            Func<ActionContext, IActionResult> expected = _ => null;
-
-            // Act
-            optionsSetup.Configure(options);
-            // This is equivalent to user code updating the value via ConfigureOptions
-            options.InvalidModelStateResponseFactory = expected;
-            optionsSetup.PostConfigure(string.Empty, options);
-
-            // Assert
-            Assert.Same(expected, options.InvalidModelStateResponseFactory);
-        }
-
         [Fact]
         public void ProblemDetailsInvalidModelStateResponse_ReturnsBadRequestWithProblemDetails()
         {
             // Arrange
-            var actionContext = new ActionContext
+            var actionContext = GetActionContext();
-            {
+            var factory = GetProblemDetailsFactory();
-                HttpContext = new DefaultHttpContext { TraceIdentifier = "42" },
-            };
 
             // Act
-            var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(actionContext);
+            var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(factory, actionContext);
 
             // Assert
             var badRequest = Assert.IsType<BadRequestObjectResult>(result);
@@ -92,6 +44,30 @@ namespace Microsoft.Extensions.DependencyInjection
 
             var problemDetails = Assert.IsType<ValidationProblemDetails>(badRequest.Value);
             Assert.Equal(400, problemDetails.Status);
+            Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.1", problemDetails.Type);
+        }
+
+        [Fact]
+        public void ProblemDetailsInvalidModelStateResponse_UsesUserConfiguredLink()
+        {
+            // Arrange
+            var link = "http://mylink";
+            var actionContext = GetActionContext();
+
+            var factory = GetProblemDetailsFactory(options => options.ClientErrorMapping[400].Link = link);
+
+            // Act
+            var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(factory, actionContext);
+
+            // Assert
+            var badRequest = Assert.IsType<BadRequestObjectResult>(result);
+            Assert.Equal(new[] { "application/problem+json", "application/problem+xml" }, badRequest.ContentTypes.OrderBy(c => c));
+
+            var problemDetails = Assert.IsType<ValidationProblemDetails>(badRequest.Value);
+            Assert.Equal(400, problemDetails.Status);
+            Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+            Assert.Equal(link, problemDetails.Type);
         }
 
         [Fact]
@@ -100,13 +76,11 @@ namespace Microsoft.Extensions.DependencyInjection
             // Arrange
             using (new ActivityReplacer())
             {
-                var actionContext = new ActionContext
+                var actionContext = GetActionContext();
-                {
+                var factory = GetProblemDetailsFactory();
-                    HttpContext = new DefaultHttpContext { TraceIdentifier = "42" },
-                };
 
                 // Act
-                var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(actionContext);
+                var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(factory, actionContext);
 
                 // Assert
                 var badRequest = Assert.IsType<BadRequestObjectResult>(result);
@@ -119,18 +93,38 @@ namespace Microsoft.Extensions.DependencyInjection
         public void ProblemDetailsInvalidModelStateResponse_SetsTraceIdFromRequest_IfActivityIsNull()
         {
             // Arrange
-            var actionContext = new ActionContext
+            var actionContext = GetActionContext();
-            {
+            var factory = GetProblemDetailsFactory();
-                HttpContext = new DefaultHttpContext { TraceIdentifier = "42" },
-            };
 
             // Act
-            var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(actionContext);
+            var result = ApiBehaviorOptionsSetup.ProblemDetailsInvalidModelStateResponse(factory, actionContext);
 
             // Assert
             var badRequest = Assert.IsType<BadRequestObjectResult>(result);
             var problemDetails = Assert.IsType<ValidationProblemDetails>(badRequest.Value);
             Assert.Equal("42", problemDetails.Extensions["traceId"]);
         }
+
+        private static ProblemDetailsFactory GetProblemDetailsFactory(Action<ApiBehaviorOptions> configure = null)
+        {
+            var options = new ApiBehaviorOptions();
+            var setup = new ApiBehaviorOptionsSetup();
+
+            setup.Configure(options);
+            if (configure != null)
+            {
+                configure(options);
+            }
+
+            return new DefaultProblemDetailsFactory(Options.Options.Create(options));
+        }
+
+        private static ActionContext GetActionContext()
+        {
+            return new ActionContext
+            {
+                HttpContext = new DefaultHttpContext { TraceIdentifier = "42" },
+            };
+        }
     }
 }

src/Mvc/Mvc.Core/test/DependencyInjection/MvcCoreServiceCollectionExtensionsTest.cs

@@ -264,13 +264,6 @@ namespace Microsoft.AspNetCore.Mvc
                             typeof(ApiBehaviorOptionsSetup),
                         }
                     },
-                    {
-                        typeof(IPostConfigureOptions<ApiBehaviorOptions>),
-                        new Type[]
-                        {
-                            typeof(ApiBehaviorOptionsSetup),
-                        }
-                    },
                     {
                         typeof(IActionConstraintProvider),
                         new Type[]

src/Mvc/Mvc.Core/test/Formatters/TranscodingReadStreamTest.cs

@@ -1,8 +1,8 @@
 // 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.Collections.Generic;
 using System.IO;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Text.Json;

src/Mvc/Mvc.Core/test/Infrastructure/ProblemDetailsFactoryTest.cs

@@ -0,0 +1,188 @@
+// 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.Http;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Mvc.Infrastructure
+{
+    public class ProblemDetailsFactoryTest
+    {
+        private readonly ProblemDetailsFactory Factory = GetProblemDetails();
+
+        [Fact]
+        public void CreateProblemDetails_DefaultValues()
+        {
+            // Act
+            var problemDetails = Factory.CreateProblemDetails(GetHttpContext());
+
+            // Assert
+            Assert.Equal(500, problemDetails.Status);
+            Assert.Equal("An error occured while processing your request.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.6.1", problemDetails.Type);
+            Assert.Null(problemDetails.Instance);
+            Assert.Null(problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+        }
+
+        [Fact]
+        public void CreateProblemDetails_WithStatusCode()
+        {
+            // Act
+            var problemDetails = Factory.CreateProblemDetails(GetHttpContext(), statusCode: 406);
+
+            // Assert
+            Assert.Equal(406, problemDetails.Status);
+            Assert.Equal("Not Acceptable", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.6", problemDetails.Type);
+            Assert.Null(problemDetails.Instance);
+            Assert.Null(problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+        }
+
+        [Fact]
+        public void CreateProblemDetails_WithDetailAndTitle()
+        {
+            // Act
+            var title = "Some title";
+            var detail = "some detail";
+            var problemDetails = Factory.CreateProblemDetails(GetHttpContext(), statusCode: 406, title: title, detail: detail);
+
+            // Assert
+            Assert.Equal(406, problemDetails.Status);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.6", problemDetails.Type);
+            Assert.Null(problemDetails.Instance);
+            Assert.Equal(detail, problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+        }
+
+        [Fact]
+        public void CreateValidationProblemDetails_DefaultValues()
+        {
+            // Act
+            var modelState = new ModelStateDictionary();
+            modelState.AddModelError("some-key", "some-value");
+            var problemDetails = Factory.CreateValidationProblemDetails(GetHttpContext(), modelState);
+
+            // Assert
+            Assert.Equal(400, problemDetails.Status);
+            Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.1", problemDetails.Type);
+            Assert.Null(problemDetails.Instance);
+            Assert.Null(problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+            Assert.Collection(
+               problemDetails.Errors,
+               kvp =>
+               {
+                   Assert.Equal("some-key", kvp.Key);
+                   Assert.Equal(new[] { "some-value" }, kvp.Value);
+               });
+        }
+
+        [Fact]
+        public void CreateValidationProblemDetails_WithStatusCode()
+        {
+            // Act
+            var modelState = new ModelStateDictionary();
+            modelState.AddModelError("some-key", "some-value");
+            var problemDetails = Factory.CreateValidationProblemDetails(GetHttpContext(), modelState, 422);
+
+            // Assert
+            Assert.Equal(422, problemDetails.Status);
+            Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc4918#section-11.2", problemDetails.Type);
+            Assert.Null(problemDetails.Instance);
+            Assert.Null(problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+            Assert.Collection(
+               problemDetails.Errors,
+               kvp =>
+               {
+                   Assert.Equal("some-key", kvp.Key);
+                   Assert.Equal(new[] { "some-value" }, kvp.Value);
+               });
+        }
+
+        [Fact]
+        public void CreateValidationProblemDetails_WithTitleAndInstance()
+        {
+            // Act
+            var title = "Some title";
+            var instance = "some instance";
+            var modelState = new ModelStateDictionary();
+            modelState.AddModelError("some-key", "some-value");
+            var problemDetails = Factory.CreateValidationProblemDetails(GetHttpContext(), modelState, title: title, instance: instance);
+
+            // Assert
+            Assert.Equal(400, problemDetails.Status);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.1", problemDetails.Type);
+            Assert.Equal(instance, problemDetails.Instance);
+            Assert.Null(problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal("some-trace", kvp.Value);
+                });
+            Assert.Collection(
+               problemDetails.Errors,
+               kvp =>
+               {
+                   Assert.Equal("some-key", kvp.Key);
+                   Assert.Equal(new[] { "some-value" }, kvp.Value);
+               });
+        }
+
+        private static DefaultHttpContext GetHttpContext()
+        {
+            return new DefaultHttpContext
+            {
+                TraceIdentifier = "some-trace",
+            };
+        }
+
+        private static ProblemDetailsFactory GetProblemDetails()
+        {
+            var options = new ApiBehaviorOptions();
+            new ApiBehaviorOptionsSetup().Configure(options);
+            return new DefaultProblemDetailsFactory(Options.Create(options));
+        }
+    }
+}

src/Mvc/Mvc.Core/test/Infrastructure/ProblemDetalsClientErrorFactoryTest.cs

@@ -15,13 +15,14 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
         {
             // Arrange
             var clientError = new UnsupportedMediaTypeResult();
-            var factory = new ProblemDetailsClientErrorFactory(Options.Create(new ApiBehaviorOptions
+            var problemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(new ApiBehaviorOptions
             {
                 ClientErrorMapping =
                 {
                     [405] = new ClientErrorData { Link = "Some link", Title = "Summary" },
                 },
             }));
+            var factory = new ProblemDetailsClientErrorFactory(problemDetailsFactory);
 
             // Act
             var result = factory.GetClientError(GetActionContext(), clientError);
@@ -31,7 +32,6 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
             Assert.Equal(new[] { "application/problem+json", "application/problem+xml" }, objectResult.ContentTypes);
             var problemDetails = Assert.IsType<ProblemDetails>(objectResult.Value);
             Assert.Equal(415, problemDetails.Status);
-            Assert.Equal("about:blank", problemDetails.Type);
             Assert.Null(problemDetails.Title);
             Assert.Null(problemDetails.Detail);
             Assert.Null(problemDetails.Instance);
@@ -42,13 +42,14 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
         {
             // Arrange
             var clientError = new UnsupportedMediaTypeResult();
-            var factory = new ProblemDetailsClientErrorFactory(Options.Create(new ApiBehaviorOptions
+            var problemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(new ApiBehaviorOptions
             {
                 ClientErrorMapping =
                 {
                     [415] = new ClientErrorData { Link = "Some link", Title = "Summary" },
                 },
             }));
+            var factory = new ProblemDetailsClientErrorFactory(problemDetailsFactory);
 
             // Act
             var result = factory.GetClientError(GetActionContext(), clientError);
@@ -71,13 +72,14 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
             using (new ActivityReplacer())
             {
                 var clientError = new UnsupportedMediaTypeResult();
-                var factory = new ProblemDetailsClientErrorFactory(Options.Create(new ApiBehaviorOptions
+                var problemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(new ApiBehaviorOptions
                 {
                     ClientErrorMapping =
                 {
-                    [415] = new ClientErrorData { Link = "Some link", Title = "Summary" },
+                    [405] = new ClientErrorData { Link = "Some link", Title = "Summary" },
                 },
                 }));
+                var factory = new ProblemDetailsClientErrorFactory(problemDetailsFactory);
 
                 // Act
                 var result = factory.GetClientError(GetActionContext(), clientError);
@@ -96,13 +98,14 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
         {
             // Arrange
             var clientError = new UnsupportedMediaTypeResult();
-            var factory = new ProblemDetailsClientErrorFactory(Options.Create(new ApiBehaviorOptions
+            var problemDetailsFactory = new DefaultProblemDetailsFactory(Options.Create(new ApiBehaviorOptions
             {
                 ClientErrorMapping =
                 {
-                    [415] = new ClientErrorData { Link = "Some link", Title = "Summary" },
+                    [405] = new ClientErrorData { Link = "Some link", Title = "Summary" },
                 },
             }));
+            var factory = new ProblemDetailsClientErrorFactory(problemDetailsFactory);
 
             // Act
             var result = factory.GetClientError(GetActionContext(), clientError);

src/Mvc/test/Mvc.FunctionalTests/ApiBehaviorTest.cs

@@ -56,6 +56,10 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
                     {
                         Converters = { new ValidationProblemDetailsConverter() }
                     });
+
+                Assert.Equal("One or more validation errors occurred.", problemDetails.Title);
+                Assert.Equal("https://tools.ietf.org/html/rfc7231#section-6.5.1", problemDetails.Type);
+
                 Assert.Collection(
                     problemDetails.Errors.OrderBy(kvp => kvp.Key),
                     kvp =>

src/Mvc/test/WebSites/BasicWebSite/StartupWithCustomInvalidModelStateFactory.cs

@@ -24,15 +24,11 @@ namespace BasicWebSite
 
             services.Configure<ApiBehaviorOptions>(options =>
             {
-                var previous = options.InvalidModelStateResponseFactory;
                 options.InvalidModelStateResponseFactory = context =>
                 {
-                    var result = (BadRequestObjectResult)previous(context);
+                    var result = new BadRequestObjectResult(context.ModelState);
-                    if (context.ActionDescriptor.FilterDescriptors.Any(f => f.Filter is VndErrorAttribute))
+                    result.ContentTypes.Clear();
-                    {
+                    result.ContentTypes.Add("application/vnd.error+json");
-                        result.ContentTypes.Clear();
-                        result.ContentTypes.Add("application/vnd.error+json");
-                    }
 
                     return result;
                 };