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 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/58239396/how-to-add-a-jobject-inside-an-existing-jarray#58239396

​

    class TestClass

    {

        public static void Test()

        {

            var sampleObj = JObject.Parse(@"{

      ""operator"": ""AND"",

      ""rules"": [

        {

          ""field"": ""Entity.Country"",

          ""condition"": ""="",

          ""value"": ""'USA'""

        },

        {

          ""field"": ""Entity.ShortName"",

          ""condition"": ""="",

          ""value"": ""'Adele'""

        }

      ]

    }");

            var Parent = JObject.Parse(@"{

    ""operator"": ""AND"",

    ""rules"": [{

            ""field"": ""Entity.Country"",

            ""condition"": ""="",

            ""value"": ""'USA'""

        },

        {

            ""field"": ""Entity.ShortName"",

            ""condition"": ""="",

            ""value"": ""'Adele'""

        },

        {

            ""operator"": ""AND"",

            ""rules"": [{

                    ""field"": ""Entity.Country"",

                    ""condition"": ""="",

                    ""value"": ""'USA'""

                },

                {

                    ""field"": ""Entity.ShortName"",

                    ""condition"": ""="",

                    ""value"": ""'Adele'""

                }

            ]

        }

    ]

}");

            //Parent.Value<JArray>("rules").Add(sampleObj);

            //Parent.Value<JArray>("rules").Add(sampleObj);

            //var array = Parent["rules"] as JArray ?? (JArray)(Parent["rules"] = new JArray());

            //Maybe this looks cleader (though it does the same thing?)

            var array = Parent.Value<JArray>("rules") ?? (JArray)(Parent["rules"] = new JArray());

            array.Add(sampleObj);

            Console.WriteLine(Parent);

            // Ensure that Parent.Value<JArray>("rules") works correctly when the value is null.

            Console.WriteLine("Testing Parent[\"rules\"] = null:");

            Parent["rules"] = null;

            array = Parent.Value<JArray>("rules") ?? (JArray)(Parent["rules"] = new JArray());

            array.Add(sampleObj);

            Console.WriteLine(Parent);

        }   

    }

​

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("Json.NET 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;

        }

    }

​