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 Newtonsoft.Json.Bson;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/58635698/unity-json-net-bson-self-referencing-loop

​

    public static partial class BsonExtensions

    {

        // In Json.NET 10.0.1 and later use https://www.nuget.org/packages/Newtonsoft.Json.Bson

        public static void SerializeToFile<T>(T obj, string path, JsonSerializerSettings settings = null)

        {

            using (var stream = new FileStream(path, FileMode.Create))

            using (var writer = new BsonWriter(stream)) // BsonDataWriter in Json.NET 10.0.1 and later

            {

                JsonSerializer.CreateDefault(settings).Serialize(writer, obj);

            }

        }

        public static T DeserializeFromFile<T>(string path, JsonSerializerSettings settings = null)

        {

            using (var stream = new FileStream(path, FileMode.Open))

            using (var reader = new BsonReader(stream)) // BsonDataReader in Json.NET 10.0.1 and later

            {

                var serializer = JsonSerializer.CreateDefault(settings);

                //https://www.newtonsoft.com/json/help/html/DeserializeFromBsonCollection.htm

                if (serializer.ContractResolver.ResolveContract(typeof(T)) is JsonArrayContract)

                    reader.ReadRootValueAsArray = true;

                return serializer.Deserialize<T>(reader);

            }

        }

    }

​

    public class RootObject

    {

        public RootObject MySelf { get { return this; } }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var path = "Question58635698.bson";

            try

            {

                Test(path);

            }

            finally

            {

                File.Delete(path);

            }

        }

        public static void Test(string path)

        {

            var objectToSave = new [] { new RootObject() };

​

            BsonExtensions.SerializeToFile(objectToSave, path, 

                                           new JsonSerializerSettings 

                                           { 

                                               ReferenceLoopHandling = ReferenceLoopHandling.Ignore 

                                           });

            var objectToRetrieve = BsonExtensions.DeserializeFromFile<RootObject []>(path, 

                                                                                  new JsonSerializerSettings 

                                                                                  { 

                                                                                      ReferenceLoopHandling = ReferenceLoopHandling.Ignore 

                                                                                  });

            Console.WriteLine("{0} round-tripped successfully.", objectToRetrieve.GetType().FullName);

        }   

    }

​

    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;

        }

    }

​