using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

using System.Threading.Tasks;

using System.Runtime.InteropServices;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/67486440/jtoken-writetoasync-dosent-write-to-stream-corrlectly

​

    class TestClass

    {

        public static void TestNonAsync()

        {

            JArray arr = new JArray();

​

            var stream = new MemoryStream();

​

            using (var requestWriter = new StreamWriter(stream, new UTF8Encoding(false), leaveOpen: true))

            using (var jsonWriter = new JsonTextWriter(requestWriter))

            {

                arr.WriteTo(jsonWriter);

            }

            var resultJson = Encoding.UTF8.GetString(stream.GetBuffer(), 0, checked((int)stream.Length));

            Console.WriteLine(BitConverter.ToString(stream.GetBuffer(), 0, checked((int)stream.Length)));

            Console.WriteLine(resultJson);

            Console.WriteLine(arr.ToString());

            Assert.AreEqual(arr.ToString(), resultJson);

        }

        public static async Task TestAsync()

        {

            JArray arr = new JArray();

​

            var stream = new MemoryStream();

​

            await using (var requestWriter = new StreamWriter(stream, new UTF8Encoding(false), leaveOpen: true))

            {

                var jsonWriter = new JsonTextWriter(requestWriter); 

                try

                {

                    await arr.WriteToAsync(jsonWriter);

                }

                finally

                {

                    await jsonWriter.CloseAsync();

                }

            }

            var resultJson = Encoding.UTF8.GetString(stream.GetBuffer(), 0, checked((int)stream.Length));

            Console.WriteLine(BitConverter.ToString(stream.GetBuffer(), 0, checked((int)stream.Length)));

            Console.WriteLine(resultJson);

            Console.WriteLine(arr.ToString());

            Assert.AreEqual(arr.ToString(), resultJson);

        }   

    }

​

    public class Program

    {

        public static async Task Main(string[] args)

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Assembly.GetName().Name,  typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.TestNonAsync();

                await TestClass.TestAsync();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.Location.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​