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.Text.Json;

using System.Text.Json.Serialization;

​

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

​

//https://stackoverflow.com/questions/61598778/how-to-pretty-print-format-system-text-jsonelement-to-a-string

​

    public static partial class JsonExtensions

    {

        public static string ToString(this JsonElement element, bool indent)

            => element.ValueKind == JsonValueKind.Undefined ? "" : JsonSerializer.Serialize(element, new JsonSerializerOptions { WriteIndented = indent } );

    }

​

    class TestClass

    {

        public static void Test()

        {

            var defaultJson1 = default(JsonElement).ToString(true);

            var defaultJson2 = default(JsonElement).ToString();

            Assert.AreEqual(defaultJson2, defaultJson1);

​

            using var doc = JsonDocument.Parse(GetJson());

            var myJsonElement = doc.RootElement;

            Test(myJsonElement, false);

            Test(myJsonElement, true);

​

            var indentedJson = myJsonElement.ToString(true);            

        }   

        static void Test(JsonElement myJsonElement, bool indent)

        {

            Console.WriteLine(myJsonElement.ToString(indent));

        }

        static string GetJson() => @"{

    ""glossary"": {

        ""title"": ""example glossary"",

        ""GlossDiv"": {

            ""title"": ""S"",

            ""GlossList"": {

                ""GlossEntry"": {

""ID"": ""SGML"",""SortAs"": ""SGML"",""GlossTerm"": ""Standard Generalized Markup Language"",

                    ""Acronym"": ""SGML"",

                    ""Abbrev"": ""ISO 8879:1986"",

                    ""GlossDef"": {

                        ""para"": ""A meta-markup language, used to create markup languages such as DocBook."",

                        ""GlossSeeAlso"": [""GML"", ""XML""]

                    },

                    ""GlossSee"": ""markup""

                }

            }

        }

    }

}";

    }

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("System.Text.Json version: " + 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.CodeBase.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;

        }

    }

​