//https://stackoverflow.com/questions/65304693/jobject-tostring-formatting-issue-for-list

​

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 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/65304693/jobject-tostring-formatting-issue-for-list

​

    public static partial class JsonExtensions

    {

        public static string ToFormattedString(this JToken token, params JsonConverter[] converters)

        {

            if (token == null)

                throw new ArgumentNullException();

            using (var sw = new StringWriter(CultureInfo.InvariantCulture))

            {

                using (var jw = new JsonTextWriter(sw) { Formatting = Formatting.Indented })

                    FormattedWriteTo(token, jw, 0, converters);

                return sw.ToString();

            }

        }

​

        static void FormattedWriteTo(JToken token, JsonTextWriter writer, int depth, params JsonConverter[] converters)

        {

            if (token == null)

            {

                writer.WriteNull();

            }

            else if (token is JObject obj)

            {

                IList<JToken> asList = obj;

                writer.WriteStartObject();

                for (int i = 0, n = asList.Count; i < n; i++)

                    FormattedWriteTo(asList[i], writer, depth+1, converters);

                writer.WriteEndObject();                

            }

            else if (token is JArray array)

            {

                // Disable formatting for arrays.  

                // You could smarten this up further by e.g. checking to see whether the array contents are all primitive JValue tokens.

                var old = writer.Formatting;

                // The question requires an extra space between the property name and the array value.

                if (depth > 0 && old == Formatting.Indented)

                    writer.WriteWhitespace(" ");

                writer.Formatting = Formatting.None;

                writer.WriteStartArray();

                for (int i = 0, n = array.Count; i < n; i++)

                    FormattedWriteTo(array[i], writer, depth+1, converters);

                writer.WriteEndArray();

                writer.Formatting = old;

            }

            else if (token is JProperty property)

            {

                writer.WritePropertyName(property.Name);

                FormattedWriteTo(property.Value, writer, depth+1, converters);

            }

            else

            { 

                // JValue, JRaw, JConstructor

                token.WriteTo(writer);

            }

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var myObj = new 

            {

                Vector = new List<int>{

                    1,2,3,4,5

                }

            };

​

            Console.WriteLine(JToken.FromObject(myObj).ToFormattedString());

            Assert.IsTrue(JToken.FromObject(myObj).ToFormattedString() == GetRequiredJson());

            var myObj2 = new 

            {

​

                Dates = new [] { new [] { new DateTime(2020, 12, 16) }, new [] { new DateTime(2020, 12, 17) }},

                Data = new

                {

                    Vector = new List<int>{

                        1,2,3,4,5

                    },

                }

            };

            Console.WriteLine(JToken.FromObject(myObj2).ToFormattedString());

        }   

        static string GetRequiredJson() => @"{

  ""Vector"": [1,2,3,4,5]

}";

    }

​

    public class Program

    {

        public static void Main()

        {

            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.Test();

            }

            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;

        }

    }

​