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 Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

​

    // https://stackoverflow.com/questions/50702505/json-net-deserialization-child-properties-that-come-as-an-array-when-empty

​

    public static class JsonExtensions

    {

        public static TJToken RemoveEmptyArrayProperties<TJToken>(this TJToken root) where TJToken : JToken

        {

            var container = root as JContainer;

            if (container == null)

                return root;

            var query = container.DescendantsAndSelf()

                .OfType<JProperty>()

                .Where(p => p.Value is JArray && ((JArray)p.Value).Count == 0);

            foreach (var property in query.ToList())

            {

                property.Remove();

            }

​

            return root;

        }

    }

​

    public class Foo

    {

        public string bar { get; set; }

    }

​

    public class RootObject

    {

        public Foo foo { get; set; }

    }

    class TestClass

    {

        public static void Test()

        {

            foreach (var jsonString in GetJson())

            {

                var root = JObject.Parse(jsonString)

                    .RemoveEmptyArrayProperties()

                    .ToObject<RootObject>();

                var newJson = JsonConvert.SerializeObject(root);

                Console.WriteLine(newJson);

            }

        }

​

        static string[] GetJson()

        {

            var json = new[]

            {

                @"{

    ""foo"": {

        ""bar"": ""hello world""

    }

    }",

                @"{

        ""foo"": []

    }",

​

            };

            return json;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            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 class AssertionFailedException : System.Exception

    {

        public AssertionFailedException() : base() { }

​

        public AssertionFailedException(string s) : base(s) { }

    }

​

    public static class Assert

    {

        public static void IsTrue(bool value)

        {

            IsTrue(value, "failed");

        }

​

        public static void IsTrue(bool value, string message)

        {

            if (value == false)

                throw new AssertionFailedException(message ?? "failed");

        }

    }

​