using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.IO;

using System.Data;

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/32571695/order-of-fields-when-serializing-the-derived-class-in-json-net

​

    public class BaseFirstContractResolver : DefaultContractResolver

    {

        protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization) =>

            base.CreateProperties(type, memberSerialization)

                ?.OrderBy(p => p.DeclaringType.BaseTypesAndSelf().Count()).ToList();

    }

​

    public static class TypeExtensions

    {

        public static IEnumerable<Type> BaseTypesAndSelf(this Type type)

        {

            while (type != null)

            {

                yield return type;

                type = type.BaseType;

            }

        }

    }

​

    public class Base

    {

        public string Id { get; set; }

        public string Name { get; set; }

        public string LastName { get; set; }

    }

​

    public class Middle : Base

    {

        public string MidProperty { get; set; }

    }

​

    public class Derived : Middle

    {

        public string Address { get; set; }

        public DateTime DateOfBirth { get; set; }

    }

​

    public class TestClass

    {

        static IContractResolver baseFirstResolver = new BaseFirstContractResolver { /* Set any required properties here e.g. */ NamingStrategy = new SnakeCaseNamingStrategy() };

​

        public static void Test()

        {

            var derived = new Derived { Address = "test", DateOfBirth = DateTime.Today, Id = "007", Name = "test name", LastName = "test last name", MidProperty = "MidProperty value" };

            var settings = new JsonSerializerSettings 

            { 

                ContractResolver = baseFirstResolver, 

                // Add your other settings here.

                TypeNameHandling = TypeNameHandling.Objects 

            };

            var json = JsonConvert.SerializeObject(derived, typeof(Base), Formatting.Indented, settings);

            Console.WriteLine(json);

​

            Assert.IsTrue(new[] { "id", "name", "last_name", "mid_property", "address", "date_of_birth" }.SequenceEqual(JObject.Parse(json).Properties().Select(p => p.Name).Where(n => n != "$type")));

        }

    }

​

    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;

        }

    }

​