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.Text.Json;

using System.Text.Json.Serialization;

​

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

​

//https://stackoverflow.com/questions/59028159/exception-when-testing-custom-jsoncovnerter

​

    public class DateTimeConverter : JsonConverter<DateTime>

    {

        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)

        {

            var dateTimeString = reader.GetString();

            dateTimeString = dateTimeString.Replace("/Date(", "");

            dateTimeString = dateTimeString.Replace(")/", "");

            var epoch = Convert.ToInt64(dateTimeString);

            var dateTimeOffset = DateTimeOffset.FromUnixTimeMilliseconds(epoch);

            return dateTimeOffset.UtcDateTime;

        }

​

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)

        {

            writer.WriteStringValue(value.ToUniversalTime().ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ssZ"));

        }

    }

​

    public class DateTimeConverterTest

    {

        private readonly DateTimeConverter testee;

​

        public DateTimeConverterTest()

        {

            this.testee = new DateTimeConverter();

        }

​

        //[Fact]

        public void Read_WhenCalledWithSerializedDateTime_ThenReturnDeserializedDateTime()

        {

            var a = "\"/Date(1573581177000)/\"";

            Console.WriteLine(a);

            var utf8JsonReader = new Utf8JsonReader(Encoding.UTF8.GetBytes(a), false, new JsonReaderState(new JsonReaderOptions()));

            // Reader always starts out without having read anything yet, so TokenType == JsonTokenType.None initially

            Assert.IsTrue(utf8JsonReader.TokenType == JsonTokenType.None);

            utf8JsonReader.Read();

            var deserializedDateTime = this.testee.Read(ref utf8JsonReader, typeof(DateTime), new JsonSerializerOptions {IgnoreNullValues = true});

            deserializedDateTime.Dump();

        }

​

        private class TestClass

        {

            public DateTime PublikationsDatum { get; set; }

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("System.Text.Json version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                new DateTimeConverterTest().Read_WhenCalledWithSerializedDateTime_ThenReturnDeserializedDateTime();

            }

            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;

        }

    }

​