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/63825826/how-to-override-the-required-always-in-newtonsoft-json

​

    public class OverrideToDefaultContractResolver : DefaultContractResolver

    {

        protected override JsonProperty CreateProperty(System.Reflection.MemberInfo member, MemberSerialization memberSerialization)

        {

            var property = base.CreateProperty(member, memberSerialization);

            property.Required = Required.Default;

            return property;

        }

        protected override JsonObjectContract CreateObjectContract(Type objectType)

        {

            var contract = base.CreateObjectContract(objectType);

            contract.ItemRequired = Required.Default;

            return contract;

        }

        protected override JsonProperty CreatePropertyFromConstructorParameter(JsonProperty matchingMemberProperty, ParameterInfo parameterInfo)

        {

            var property = base.CreatePropertyFromConstructorParameter(matchingMemberProperty, parameterInfo);

            property.Required = Required.Default;

            return property;

        }

    }

​

    [JsonObject(ItemRequired = Required.Always)]

    public class MyClass

    {

        public MyClass([JsonProperty("MyRequiredProperty4", Required = Required.Always)] string MyRequiredProperty4) => this.MyRequiredProperty4 = MyRequiredProperty4;

        [JsonProperty("MyRequiredProperty", Required = Required.Always, NullValueHandling = NullValueHandling.Ignore)]

        public string MyRequiredProperty { get; set; }

        [Required]

        public string MyRequiredProperty2 { get; set; }

        [JsonRequired]

        public string MyRequiredProperty3 { get; set; }

        public string MyRequiredProperty4 { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var resolver = new OverrideToDefaultContractResolver();

            var settings = new JsonSerializerSettings { ContractResolver = new OverrideToDefaultContractResolver() };

            MyClass obj = JsonConvert.DeserializeObject<MyClass>(@"{""Nope"": ""Hi there""}", settings);

            obj.Dump();

            //Console.WriteLine($"Json property: {obj.MyRequiredProperty}");

        }   

    }

​

    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.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;

        }

    }

​