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 System.Text.Json;

using System.Text.Json.Serialization;

​

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

​

//https://stackoverflow.com/questions/64033919/how-to-debug-system-text-json-deserializer

​

    public class Window    

    {

        public string title { get; set; } 

        public string name { get; set; } 

        public int width { get; set; } 

        public int height { get; set; } 

    }

​

    public class Image    

    {

        public string src { get; set; } 

        public string name { get; set; } 

        public int hOffset { get; set; } 

        public int vOffset { get; set; } 

        public string alignment { get; set; } 

    }

​

    public class Text    

    {

        public string data { get; set; } 

        public int size { get; set; } 

        public string style { get; set; } 

        public string name { get; set; } 

        public int hOffset { get; set; } 

        public int vOffset { get; set; } 

        public string alignment { get; set; } 

        public string onMouseUp { get; set; } 

    }

​

    public class Widget    

    {

        public string debug { get; set; } 

        public Window window { get; set; } 

        public Image image { get; set; } 

        public Text text { get; set; } 

    }

​

    public class Root    

    {

        public Widget widget { get; set; } 

    }

​

    class TestClass

    {

        public static void Test()

        {

            var json = GetJson();

            var root = JsonSerializer.Deserialize<Root>(json);

            root.Dump();

        }   

        static string GetJson()

            => @"{""widget"": {

    ""debug"": ""on"",

    ""window"": {

        ""title"": ""Sample Konfabulator Widget"",

        ""name"": ""main_window"",

        ""width"": ""500"", // ERROR ADDED HERE

        ""height"": 500

    },

    ""image"": { 

        ""src"": ""Images/Sun.png"",

        ""name"": ""sun1"",

        ""hOffset"": 250,

        ""vOffset"": 250,

        ""alignment"": ""center""

    },

    ""text"": {

        ""data"": ""Click Here"",

        ""size"": 36,

        ""style"": ""bold"",

        ""name"": ""text1"",

        ""hOffset"": 250,

        ""vOffset"": 100,

        ""alignment"": ""center"",

        ""onMouseUp"": ""sun1.opacity = (sun1.opacity / 100) * 90;""

    }

}}    ";

    }

​

    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

            {

                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;

        }

    }

​