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/53219668/cannot-deserialize-the-current-json-object-empty-array

​

    public class JsonSingleOrEmptyArrayConverter<T> : JsonConverter where T : class

    {

        //https://stackoverflow.com/questions/29449641/deserialize-json-when-type-can-be-different?rq=1

        public override bool CanConvert(Type objectType)

        {

            return typeof(T).IsAssignableFrom(objectType);

        }

​

        public override bool CanWrite { get { return false; } }

​

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

        {

            var contract = serializer.ContractResolver.ResolveContract(objectType);

            // Allow for dictionary contracts as well as objects contracts, since both are represented by 

            // an unordered set of name/value pairs that begins with { (left brace) and ends with } (right brace).

            if (!(contract is Newtonsoft.Json.Serialization.JsonObjectContract 

                  || contract is Newtonsoft.Json.Serialization.JsonDictionaryContract))

            {

                throw new JsonSerializationException(string.Format("Unsupported objectType {0} at {1}.", objectType, reader.Path));

            }

​

            switch (reader.SkipComments().TokenType)

            {

                case JsonToken.StartArray:

                    {

                        int count = 0;

                        while (reader.Read())

                        {

                            switch (reader.TokenType)

                            {

                                case JsonToken.Comment:

                                    break;

                                case JsonToken.EndArray:

                                    // You might want to allocate an empty object here if existingValue is null

                                    // If so, do

                                    // return existingValue ?? contract.DefaultCreator();

                                    return existingValue;

                                default:

                                    {

                                        count++;

                                        if (count > 1)

                                            throw new JsonSerializationException(string.Format("Too many objects at path {0}.", reader.Path));

                                        existingValue = existingValue ?? contract.DefaultCreator();

                                        serializer.Populate(reader, existingValue);

                                    }

                                    break;

                            }

                        }

                        // Should not come here.

                        throw new JsonSerializationException(string.Format("Unclosed array at path {0}.", reader.Path));

                    }

​

                case JsonToken.Null:

                    return null;

​

                case JsonToken.StartObject:

                    existingValue = existingValue ?? contract.DefaultCreator();

                    serializer.Populate(reader, existingValue);

                    return existingValue;

​

                default:

                    throw new InvalidOperationException("Unexpected token type " + reader.TokenType.ToString());

            }

        }

​

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

        {

            throw new NotImplementedException();

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader SkipComments(this JsonReader reader)

        {

            while (reader.TokenType == JsonToken.Comment && reader.Read())

                ;

            return reader;

        }

    }

​

    public class CObject 

    {

        [JsonProperty(PropertyName = "Name")]

        public string Name { get; set; }

​

        [JsonProperty(PropertyName = "ClassName")]

        public string ClassName { get; set; }

​

        [JsonProperty(PropertyName = "Children")]

        public IDictionary<string, CObject> Children { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            foreach (var json in GetJson())

                Test(json);

        }   

​

        static void Test(string Json)

        {

            var settings = new JsonSerializerSettings

            {

                MissingMemberHandling = MissingMemberHandling.Ignore,

                NullValueHandling = NullValueHandling.Ignore,               

                Converters = { new JsonSingleOrEmptyArrayConverter<IDictionary<string, CObject>>() },

            };

            var obj = JsonConvert.DeserializeObject<IDictionary<string, CObject>>(Json, settings);

            var json2 = JsonConvert.SerializeObject(obj, Formatting.Indented, settings);

            Console.WriteLine("\nRe-serialized JSON: ");

            Console.WriteLine(json2);           

        }

        static string [] GetJson()

        {

            var json = new [] { 

                @"{

    ""Space"": {

        ""ClassName"": ""SpaceObject"",

        ""Name"": ""Space"",

        ""Children"": {

            ""Object1"": {

                ""ClassName"": ""Object"",

                ""Name"": ""Object1"",

                ""Children"": []

            },

            ""Object2"": {

                ""ClassName"": ""Object"",

                ""Name"": ""Object2"",

                ""Children"": []

            }

        }

    }

}",

            @"[]"

                ,

            };

            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;

            }

        }

    }

​