Add ProblemDetails helpers to Results

src/Http/Http.Extensions/src/HttpValidationProblemDetails.cs

@@ -0,0 +1,45 @@
+// 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.Text.Json.Serialization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Microsoft.AspNetCore.Http.Extensions
+{
+    /// <summary>
+    /// A <see cref="ProblemDetails"/> for validation errors.
+    /// </summary>
+    [JsonConverter(typeof(HttpValidationProblemDetailsJsonConverter))]
+    public class HttpValidationProblemDetails : ProblemDetails
+    {
+        /// <summary>
+        /// Initializes a new instance of <see cref="HttpValidationProblemDetails"/>.
+        /// </summary>
+        public HttpValidationProblemDetails()
+            : this(new Dictionary<string, string[]>(StringComparer.Ordinal))
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="HttpValidationProblemDetails"/> using the specified <paramref name="errors"/>.
+        /// </summary>
+        /// <param name="errors">The validation errors.</param>
+        public HttpValidationProblemDetails(IDictionary<string, string[]> errors)
+            : this(new Dictionary<string, string[]>(errors, StringComparer.Ordinal))
+        {
+        }
+
+        private HttpValidationProblemDetails(Dictionary<string, string[]> errors)
+        {
+            Title = "One or more validation errors occurred.";
+            Errors = errors;
+        }
+
+        /// <summary>
+        /// Gets the validation errors associated with this instance of <see cref="HttpValidationProblemDetails"/>.
+        /// </summary>
+        public IDictionary<string, string[]> Errors { get; } = new Dictionary<string, string[]>(StringComparer.Ordinal);
+    }
+}

src/Http/Http.Extensions/src/Microsoft.AspNetCore.Http.Extensions.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>ASP.NET Core common extension methods for HTTP abstractions, HTTP headers, HTTP request/response, and session state.</Description>
@@ -11,9 +11,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="$(SharedSourceRoot)ObjectMethodExecutor\**\*.cs" />
-    <Compile Include="$(SharedSourceRoot)TryParseMethodCache.cs" />
-    <Compile Include="..\..\Shared\StreamCopyOperationInternal.cs" />
+    <Compile Include="$(SharedSourceRoot)ObjectMethodExecutor\**\*.cs" LinkBase="Shared"/>
+    <Compile Include="$(SharedSourceRoot)TryParseMethodCache.cs" LinkBase="Shared"/>
+    <Compile Include="..\..\Shared\StreamCopyOperationInternal.cs" LinkBase="Shared" />
+    <Compile Include="$(SharedSourceRoot)ProblemDetailsJsonConverter.cs" LinkBase="Shared"/>
+    <Compile Include="$(SharedSourceRoot)HttpValidationProblemDetailsJsonConverter.cs" LinkBase="Shared" />
   </ItemGroup>
 
   <ItemGroup>

src/Mvc/Mvc.Core/src/ProblemDetails.cs → src/Http/Http.Extensions/src/ProblemDetails.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Text.Json.Serialization;
-using Microsoft.AspNetCore.Mvc.Infrastructure;
+using Microsoft.AspNetCore.Http.Extensions;
 
 namespace Microsoft.AspNetCore.Mvc
 {

src/Http/Http.Extensions/src/PublicAPI.Unshipped.txt

@@ -89,6 +89,10 @@
 *REMOVED*~static Microsoft.AspNetCore.Http.SessionExtensions.GetString(this Microsoft.AspNetCore.Http.ISession session, string key) -> string
 *REMOVED*~static Microsoft.AspNetCore.Http.SessionExtensions.SetInt32(this Microsoft.AspNetCore.Http.ISession session, string key, int value) -> void
 *REMOVED*~static Microsoft.AspNetCore.Http.SessionExtensions.SetString(this Microsoft.AspNetCore.Http.ISession session, string key, string value) -> void
+Microsoft.AspNetCore.Http.Extensions.HttpValidationProblemDetails
+Microsoft.AspNetCore.Http.Extensions.HttpValidationProblemDetails.Errors.get -> System.Collections.Generic.IDictionary<string!, string![]!>!
+Microsoft.AspNetCore.Http.Extensions.HttpValidationProblemDetails.HttpValidationProblemDetails() -> void
+Microsoft.AspNetCore.Http.Extensions.HttpValidationProblemDetails.HttpValidationProblemDetails(System.Collections.Generic.IDictionary<string!, string![]!>! errors) -> void
 Microsoft.AspNetCore.Http.Extensions.QueryBuilder.Add(string! key, System.Collections.Generic.IEnumerable<string!>! values) -> void
 Microsoft.AspNetCore.Http.Extensions.QueryBuilder.Add(string! key, string! value) -> void
 Microsoft.AspNetCore.Http.Extensions.QueryBuilder.GetEnumerator() -> System.Collections.Generic.IEnumerator<System.Collections.Generic.KeyValuePair<string!, string!>>!
@@ -153,6 +157,19 @@ Microsoft.AspNetCore.Http.Headers.ResponseHeaders.SetCookie.get -> System.Collec
 Microsoft.AspNetCore.Http.Headers.ResponseHeaders.SetCookie.set -> void
 Microsoft.AspNetCore.Http.Headers.ResponseHeaders.SetList<T>(string! name, System.Collections.Generic.IList<T>? values) -> void
 Microsoft.AspNetCore.Http.RequestDelegateFactory
+Microsoft.AspNetCore.Mvc.ProblemDetails
+Microsoft.AspNetCore.Mvc.ProblemDetails.Detail.get -> string?
+Microsoft.AspNetCore.Mvc.ProblemDetails.Detail.set -> void
+Microsoft.AspNetCore.Mvc.ProblemDetails.Extensions.get -> System.Collections.Generic.IDictionary<string!, object?>!
+Microsoft.AspNetCore.Mvc.ProblemDetails.Instance.get -> string?
+Microsoft.AspNetCore.Mvc.ProblemDetails.Instance.set -> void
+Microsoft.AspNetCore.Mvc.ProblemDetails.ProblemDetails() -> void
+Microsoft.AspNetCore.Mvc.ProblemDetails.Status.get -> int?
+Microsoft.AspNetCore.Mvc.ProblemDetails.Status.set -> void
+Microsoft.AspNetCore.Mvc.ProblemDetails.Title.get -> string?
+Microsoft.AspNetCore.Mvc.ProblemDetails.Title.set -> void
+Microsoft.AspNetCore.Mvc.ProblemDetails.Type.get -> string?
+Microsoft.AspNetCore.Mvc.ProblemDetails.Type.set -> void
 override Microsoft.AspNetCore.Http.Extensions.QueryBuilder.Equals(object? obj) -> bool
 override Microsoft.AspNetCore.Http.Extensions.QueryBuilder.ToString() -> string!
 static Microsoft.AspNetCore.Http.Extensions.HttpRequestMultipartExtensions.GetMultipartBoundary(this Microsoft.AspNetCore.Http.HttpRequest! request) -> string!

src/Http/Http.Extensions/test/HttpValidationProblemDetailsJsonConverterTest.cs

@@ -0,0 +1,140 @@
+// 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.Linq;
+using System.Text;
+using System.Text.Json;
+using Microsoft.AspNetCore.Http.Json;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Http.Extensions
+{
+    public class HttpValidationProblemDetailsJsonConverterTest
+    {
+        private static JsonSerializerOptions JsonSerializerOptions => new JsonOptions().SerializerOptions;
+
+        [Fact]
+        public void Read_Works()
+        {
+            // Arrange
+            var type = "https://tools.ietf.org/html/rfc7231#section-6.5.4";
+            var title = "Not found";
+            var status = 404;
+            var detail = "Product not found";
+            var instance = "http://example.com/products/14";
+            var traceId = "|37dd3dd5-4a9619f953c40a16.";
+            var json = $"{{\"type\":\"{type}\",\"title\":\"{title}\",\"status\":{status},\"detail\":\"{detail}\", \"instance\":\"{instance}\",\"traceId\":\"{traceId}\"," +
+                "\"errors\":{\"key0\":[\"error0\"],\"key1\":[\"error1\",\"error2\"]}}";
+            var converter = new HttpValidationProblemDetailsJsonConverter();
+            var reader = new Utf8JsonReader(Encoding.UTF8.GetBytes(json));
+            reader.Read();
+
+            // Act
+            var problemDetails = converter.Read(ref reader, typeof(HttpValidationProblemDetails), JsonSerializerOptions);
+
+            Assert.Equal(type, problemDetails.Type);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal(status, problemDetails.Status);
+            Assert.Equal(instance, problemDetails.Instance);
+            Assert.Equal(detail, problemDetails.Detail);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal(traceId, kvp.Value.ToString());
+                });
+            Assert.Collection(
+                problemDetails.Errors.OrderBy(kvp => kvp.Key),
+                kvp =>
+                {
+                    Assert.Equal("key0", kvp.Key);
+                    Assert.Equal(new[] { "error0" }, kvp.Value);
+                },
+                kvp =>
+                {
+                    Assert.Equal("key1", kvp.Key);
+                    Assert.Equal(new[] { "error1", "error2" }, kvp.Value);
+                });
+        }
+
+        [Fact]
+        public void Read_WithSomeMissingValues_Works()
+        {
+            // Arrange
+            var type = "https://tools.ietf.org/html/rfc7231#section-6.5.4";
+            var title = "Not found";
+            var status = 404;
+            var traceId = "|37dd3dd5-4a9619f953c40a16.";
+            var json = $"{{\"type\":\"{type}\",\"title\":\"{title}\",\"status\":{status},\"traceId\":\"{traceId}\"," +
+                "\"errors\":{\"key0\":[\"error0\"],\"key1\":[\"error1\",\"error2\"]}}";
+            var converter = new HttpValidationProblemDetailsJsonConverter();
+            var reader = new Utf8JsonReader(Encoding.UTF8.GetBytes(json));
+            reader.Read();
+
+            // Act
+            var problemDetails = converter.Read(ref reader, typeof(HttpValidationProblemDetails), JsonSerializerOptions);
+
+            Assert.Equal(type, problemDetails.Type);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal(status, problemDetails.Status);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal(traceId, kvp.Value.ToString());
+                });
+            Assert.Collection(
+                problemDetails.Errors.OrderBy(kvp => kvp.Key),
+                kvp =>
+                {
+                    Assert.Equal("key0", kvp.Key);
+                    Assert.Equal(new[] { "error0" }, kvp.Value);
+                },
+                kvp =>
+                {
+                    Assert.Equal("key1", kvp.Key);
+                    Assert.Equal(new[] { "error1", "error2" }, kvp.Value);
+                });
+        }
+
+        [Fact]
+        public void ReadUsingJsonSerializerWorks()
+        {
+            // Arrange
+            var type = "https://tools.ietf.org/html/rfc7231#section-6.5.4";
+            var title = "Not found";
+            var status = 404;
+            var traceId = "|37dd3dd5-4a9619f953c40a16.";
+            var json = $"{{\"type\":\"{type}\",\"title\":\"{title}\",\"status\":{status},\"traceId\":\"{traceId}\"," +
+                "\"errors\":{\"key0\":[\"error0\"],\"key1\":[\"error1\",\"error2\"]}}";
+
+            // Act
+            var problemDetails = JsonSerializer.Deserialize<HttpValidationProblemDetails>(json, JsonSerializerOptions);
+
+            Assert.Equal(type, problemDetails.Type);
+            Assert.Equal(title, problemDetails.Title);
+            Assert.Equal(status, problemDetails.Status);
+            Assert.Collection(
+                problemDetails.Extensions,
+                kvp =>
+                {
+                    Assert.Equal("traceId", kvp.Key);
+                    Assert.Equal(traceId, kvp.Value.ToString());
+                });
+            Assert.Collection(
+                problemDetails.Errors.OrderBy(kvp => kvp.Key),
+                kvp =>
+                {
+                    Assert.Equal("key0", kvp.Key);
+                    Assert.Equal(new[] { "error0" }, kvp.Value);
+                },
+                kvp =>
+                {
+                    Assert.Equal("key1", kvp.Key);
+                    Assert.Equal(new[] { "error1", "error2" }, kvp.Value);
+                });
+        }
+    }
+}

src/Mvc/Mvc.Core/test/Infrastructure/ProblemDetailsJsonConverterTest.cs → src/Http/Http.Extensions/test/ProblemDetailsJsonConverterTest.cs

@@ -1,16 +1,18 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// 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.IO;
 using System.Text;
 using System.Text.Json;
+using Microsoft.AspNetCore.Http.Json;
+using Microsoft.AspNetCore.Mvc;
 using Xunit;
 
-namespace Microsoft.AspNetCore.Mvc.Infrastructure
+namespace Microsoft.AspNetCore.Http.Extensions
 {
     public class ProblemDetailsJsonConverterTest
     {
-        private static JsonSerializerOptions JsonSerializerOptions => new JsonOptions().JsonSerializerOptions;
+        private static JsonSerializerOptions JsonSerializerOptions => new JsonOptions().SerializerOptions;
 
         [Fact]
         public void Read_ThrowsIfJsonIsIncomplete()

src/Http/Http.Results/src/Microsoft.AspNetCore.Http.Results.csproj

@@ -16,6 +16,7 @@
     <Compile Include="$(SharedSourceRoot)ResponseContentTypeHelper.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)ResultsHelpers\*.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)RangeHelper\RangeHelper.cs" LinkBase="Shared" />
+    <Compile Include="$(SharedSourceRoot)ProblemDetailsDefaults.cs" LinkBase="Shared" />
   </ItemGroup>
 
   <ItemGroup>

src/Http/Http.Results/src/ObjectResult.cs

@@ -2,6 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http.Extensions;
+using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
@@ -12,7 +14,15 @@ internal partial class ObjectResult : IResult
         /// <summary>
         /// Creates a new <see cref="ObjectResult"/> instance with the provided <paramref name="value"/>.
         /// </summary>
-        public ObjectResult(object? value, int statusCode)
+        public ObjectResult(object? value)
+        {
+            Value = value;
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="ObjectResult"/> instance with the provided <paramref name="value"/>.
+        /// </summary>
+        public ObjectResult(object? value, int? statusCode)
         {
             Value = value;
             StatusCode = statusCode;
@@ -24,22 +34,61 @@ public ObjectResult(object? value, int statusCode)
         public object? Value { get; }
 
         /// <summary>
-        /// Gets or sets the HTTP status code.
+        /// Gets the HTTP status code.
         /// </summary>
-        public int StatusCode { get; }
+        public int? StatusCode { get; set; }
 
         public Task ExecuteAsync(HttpContext httpContext)
         {
             var loggerFactory = httpContext.RequestServices.GetRequiredService<ILoggerFactory>();
             var logger = loggerFactory.CreateLogger(GetType());
             Log.ObjectResultExecuting(logger, Value);
 
-            httpContext.Response.StatusCode = StatusCode;
+            if (Value is ProblemDetails problemDetails)
+            {
+                ApplyProblemDetailsDefaults(problemDetails);
+            }
+
+            if (StatusCode is { } statusCode)
+            {
+                httpContext.Response.StatusCode = statusCode;
+            }
 
             OnFormatting(httpContext);
             return httpContext.Response.WriteAsJsonAsync(Value);
         }
 
+        private void ApplyProblemDetailsDefaults(ProblemDetails problemDetails)
+        {
+            // We allow StatusCode to be specified either on ProblemDetails or on the ObjectResult and use it to configure the other.
+            // This lets users write <c>return Conflict(new Problem("some description"))</c>
+            // or <c>return Problem("some-problem", 422)</c> and have the response have consistent fields.
+            if (problemDetails.Status is null)
+            {
+                if (StatusCode is not null)
+                {
+                    problemDetails.Status = StatusCode;
+                }
+                else
+                {
+                    problemDetails.Status = problemDetails is HttpValidationProblemDetails ?
+                        StatusCodes.Status400BadRequest :
+                        StatusCodes.Status500InternalServerError;
+                }
+            }
+
+            if (StatusCode is null)
+            {
+                StatusCode = problemDetails.Status;
+            }
+
+            if (ProblemDetailsDefaults.Defaults.TryGetValue(problemDetails.Status.Value, out var defaults))
+            {
+                problemDetails.Title ??= defaults.Title;
+                problemDetails.Type ??= defaults.Type;
+            }
+        }
+
         protected virtual void OnFormatting(HttpContext httpContext)
         {
         }

src/Http/Http.Results/src/PublicAPI.Unshipped.txt

@@ -74,6 +74,7 @@ static Microsoft.AspNetCore.Http.Results.PhysicalFile(string! physicalPath, stri
 static Microsoft.AspNetCore.Http.Results.PhysicalFile(string! physicalPath, string! contentType, string? fileDownloadName, System.DateTimeOffset? lastModified, Microsoft.Net.Http.Headers.EntityTagHeaderValue! entityTag) -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.PhysicalFile(string! physicalPath, string! contentType, string? fileDownloadName, System.DateTimeOffset? lastModified, Microsoft.Net.Http.Headers.EntityTagHeaderValue! entityTag, bool enableRangeProcessing) -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.PhysicalFile(string! physicalPath, string! contentType, string? fileDownloadName, bool enableRangeProcessing) -> Microsoft.AspNetCore.Http.IResult!
+static Microsoft.AspNetCore.Http.Results.Problem(string? detail = null, string? instance = null, int? statusCode = null, string? title = null, string? type = null) -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.Redirect(string! url) -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.RedirectPermanent(string! url) -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.RedirectPermanentPreserveMethod(string! url) -> Microsoft.AspNetCore.Http.IResult!
@@ -102,3 +103,4 @@ static Microsoft.AspNetCore.Http.Results.StatusCode(int statusCode) -> Microsoft
 static Microsoft.AspNetCore.Http.Results.Unauthorized() -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.UnprocessableEntity() -> Microsoft.AspNetCore.Http.IResult!
 static Microsoft.AspNetCore.Http.Results.UnprocessableEntity(object? error) -> Microsoft.AspNetCore.Http.IResult!
+static Microsoft.AspNetCore.Http.Results.ValidationProblem(System.Collections.Generic.IDictionary<string!, string![]!>! errors, string? detail = null, string? instance = null, int? statusCode = null, string? title = null, string? type = null) -> Microsoft.AspNetCore.Http.IResult!