Add a System.Text.Json based IJsonHelper

src/Mvc/Mvc.Core/src/Formatters/TranscodingReadStream.cs

@@ -24,6 +24,7 @@ internal sealed class TranscodingReadStream : Stream
         private ArraySegment<byte> _byteBuffer;
         private ArraySegment<char> _charBuffer;
         private ArraySegment<byte> _overflowBuffer;
+        private bool _disposed;
 
         public TranscodingReadStream(Stream input, Encoding sourceEncoding)
         {
@@ -150,9 +151,9 @@ public override async Task<int> ReadAsync(byte[] buffer, int offset, int count,
                     readBuffer = readBuffer.Slice(bytesEncoded);
                 }
 
-            // We need to exit in one of the 2 conditions:
-            // * encoderCompleted will return false if "buffer" was too small for all the chars to be encoded.
-            // * no bytes were converted in an iteration. This can occur if there wasn't any input.
+                // We need to exit in one of the 2 conditions:
+                // * encoderCompleted will return false if "buffer" was too small for all the chars to be encoded.
+                // * no bytes were converted in an iteration. This can occur if there wasn't any input.
             } while (encoderCompleted && bytesEncoded > 0);
 
             return totalBytes;
@@ -224,11 +225,13 @@ public override void Write(byte[] buffer, int offset, int count)
 
         protected override void Dispose(bool disposing)
         {
-            ArrayPool<char>.Shared.Return(_charBuffer.Array);
-            ArrayPool<byte>.Shared.Return(_byteBuffer.Array);
-            ArrayPool<byte>.Shared.Return(_overflowBuffer.Array);
-
-            base.Dispose(disposing);
+            if (!_disposed)
+            {
+                _disposed = true;
+                ArrayPool<char>.Shared.Return(_charBuffer.Array);
+                ArrayPool<byte>.Shared.Return(_byteBuffer.Array);
+                ArrayPool<byte>.Shared.Return(_overflowBuffer.Array);
+            }
         }
     }
 }

src/Mvc/Mvc.Core/src/Formatters/TranscodingWriteStream.cs

@@ -21,6 +21,7 @@ internal sealed class TranscodingWriteStream : Stream
         private readonly Encoder _encoder;
         private readonly char[] _charBuffer;
         private int _charsDecoded;
+        private bool _disposed;
 
         public TranscodingWriteStream(Stream stream, Encoding targetEncoding)
         {
@@ -154,13 +155,11 @@ private static void ThrowArgumentException(byte[] buffer, int offset, int count)
 
         protected override void Dispose(bool disposing)
         {
-            if (disposing)
+            if (!_disposed)
             {
+                _disposed = true;
                 ArrayPool<char>.Shared.Return(_charBuffer);
             }
-
-
-            base.Dispose(disposing);
         }
     }
 }

src/Mvc/Mvc.Core/src/Infrastructure/SystemTextJsonResultExecutor.cs

@@ -0,0 +1,133 @@
+// 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.IO;
+using System.Text;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Core;
+using Microsoft.AspNetCore.Mvc.Formatters;
+using Microsoft.AspNetCore.Mvc.Formatters.Json;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Microsoft.Net.Http.Headers;
+
+namespace Microsoft.AspNetCore.Mvc.Infrastructure
+{
+    internal sealed class SystemTextJsonResultExecutor : IActionResultExecutor<JsonResult>
+    {
+        private static readonly string DefaultContentType = new MediaTypeHeaderValue("application/json")
+        {
+            Encoding = Encoding.UTF8
+        }.ToString();
+
+        private readonly MvcOptions _mvcOptions;
+        private readonly ILogger<SystemTextJsonResultExecutor> _logger;
+
+        public SystemTextJsonResultExecutor(
+            IOptions<MvcOptions> mvcOptions,
+            ILogger<SystemTextJsonResultExecutor> logger)
+        {
+            _mvcOptions = mvcOptions.Value;
+            _logger = logger;
+        }
+
+        public async Task ExecuteAsync(ActionContext context, JsonResult result)
+        {
+            if (context == null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            if (result == null)
+            {
+                throw new ArgumentNullException(nameof(result));
+            }
+
+            var jsonSerializerOptions = GetSerializerOptions(result);
+
+            var response = context.HttpContext.Response;
+
+            ResponseContentTypeHelper.ResolveContentTypeAndEncoding(
+                result.ContentType,
+                response.ContentType,
+                DefaultContentType,
+                out var resolvedContentType,
+                out var resolvedContentTypeEncoding);
+
+            response.ContentType = resolvedContentType;
+
+            if (result.StatusCode != null)
+            {
+                response.StatusCode = result.StatusCode.Value;
+            }
+
+            Log.JsonResultExecuting(_logger, result.Value);
+
+            // Keep this code in sync with SystemTextJsonOutputFormatter
+            var writeStream = GetWriteStream(context.HttpContext, resolvedContentTypeEncoding);
+            try
+            {
+                var type = result.Value?.GetType() ?? typeof(object);
+                await JsonSerializer.WriteAsync(result.Value, type, writeStream, jsonSerializerOptions);
+                await writeStream.FlushAsync();
+            }
+            finally
+            {
+                if (writeStream is TranscodingWriteStream transcoding)
+                {
+                    await transcoding.DisposeAsync();
+                }
+            }
+        }
+
+        private Stream GetWriteStream(HttpContext httpContext, Encoding selectedEncoding)
+        {
+            if (selectedEncoding.CodePage == Encoding.UTF8.CodePage)
+            {
+                // JsonSerializer does not write a BOM. Therefore we do not have to handle it
+                // in any special way.
+                return httpContext.Response.Body;
+            }
+
+            return new TranscodingWriteStream(httpContext.Response.Body, selectedEncoding);
+        }
+
+        private JsonSerializerOptions GetSerializerOptions(JsonResult result)
+        {
+            var serializerSettings = result.SerializerSettings;
+            if (serializerSettings == null)
+            {
+                return _mvcOptions.SerializerOptions;
+            }
+            else
+            {
+                if (!(serializerSettings is JsonSerializerOptions settingsFromResult))
+                {
+                    throw new InvalidOperationException(Resources.FormatProperty_MustBeInstanceOfType(
+                        nameof(JsonResult),
+                        nameof(JsonResult.SerializerSettings),
+                        typeof(JsonSerializerOptions)));
+                }
+
+                return settingsFromResult;
+            }
+        }
+
+        private static class Log
+        {
+            private static readonly Action<ILogger, string, Exception> _jsonResultExecuting = LoggerMessage.Define<string>(
+                LogLevel.Information,
+                new EventId(1, "JsonResultExecuting"),
+                "Executing JsonResult, writing value of type '{Type}'.");
+
+            public static void JsonResultExecuting(ILogger logger, object value)
+            {
+                var type = value == null ? "null" : value.GetType().FullName;
+                _jsonResultExecuting(logger, type, null);
+            }
+        }
+    }
+}

src/Mvc/Mvc.Core/src/JsonResult.cs

@@ -68,17 +68,7 @@ public override Task ExecuteResultAsync(ActionContext context)
             }
 
             var services = context.HttpContext.RequestServices;
-            var executor = services.GetService<IActionResultExecutor<JsonResult>>();
-            if (executor == null)
-            {
-                throw new InvalidOperationException(Resources.FormatReferenceToNewtonsoftJsonRequired(
-                    $"{nameof(JsonResult)}.{nameof(ExecuteResultAsync)}",
-                    "Microsoft.AspNetCore.Mvc.NewtonsoftJson",
-                    nameof(IMvcBuilder),
-                    "AddNewtonsoftJson",
-                    "ConfigureServices(...)"));
-            }
-
+            var executor = services.GetRequiredService<IActionResultExecutor<JsonResult>>();
             return executor.ExecuteAsync(context, this);
         }
     }

src/Mvc/Mvc.Core/src/Properties/AssemblyInfo.cs

@@ -27,6 +27,7 @@
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.Formatters.Xml.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.IntegrationTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.Localization.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
+[assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.NewtonsoftJson.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.Razor.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.RazorPages.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Mvc.TagHelpers.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]

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

@@ -501,4 +501,7 @@
     <value>Model binding system exceeded {0}.{1} ({2}). Reduce the potential nesting of '{3}'. For example, this type may have a property with a model binder that always succeeds. See the {0}.{1} documentation for more information.</value>
     <comment>{0} is MvcOptions, {1} is MaxModelBindingRecursionDepth, {2} is option value, {3} is (loopy or deeply nested) top-level model type.</comment>
   </data>
-</root>
+  <data name="Property_MustBeInstanceOfType" xml:space="preserve">
+    <value>Property '{0}.{1}' must be an instance of type '{2}'.</value>
+  </data>  
+</root>