using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

​

using System.Text.Json;

using System.Text.Json.Serialization;

​

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

​

//https://stackoverflow.com/questions/77303564/enum-string-serialization-not-working-as-expected-in-net-6-0

​

    public class OptOutJsonConverterFactory : JsonConverterFactoryDecorator

    {

        readonly HashSet<Type> optOutTypes;

        public OptOutJsonConverterFactory(JsonConverterFactory innerFactory, params Type [] optOutTypes) : base(innerFactory) => this.optOutTypes = optOutTypes.ToHashSet();

​

        public override bool CanConvert(Type typeToConvert) => base.CanConvert(typeToConvert) && !optOutTypes.Contains(typeToConvert);

    }

    public class JsonConverterFactoryDecorator : JsonConverterFactory

    {

        readonly JsonConverterFactory innerFactory;

        public JsonConverterFactoryDecorator(JsonConverterFactory innerFactory)

        {

            if (innerFactory == null)

                throw new ArgumentNullException(nameof(innerFactory));

            this.innerFactory = innerFactory;

        }

​

        public override bool CanConvert(Type typeToConvert) => innerFactory.CanConvert(typeToConvert);

        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options) => innerFactory.CreateConverter(typeToConvert, options);

    }

​

    public enum LeadType

    {

        PREVIOUS_CUSTOMER,

        CURRENT_CUSTOMER,

    }

​

    public class ProductLead

    {

        public LeadType LeadType { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var options = new

            {

                JsonSerializerOptions = new JsonSerializerOptions(),

            };

            options.JsonSerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;

            options.JsonSerializerOptions.Converters.Add(

                new OptOutJsonConverterFactory(new JsonStringEnumConverter(JsonNamingPolicy.CamelCase),

                                               typeof(LeadType)));

            // Add a non-camel-case fallback converter for the opted out enum types:

            options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());

            var model = new ProductLead

            {

                LeadType = LeadType.PREVIOUS_CUSTOMER

            };

            var json = JsonSerializer.Serialize(model, options.JsonSerializerOptions);

            Console.WriteLine(json);

            Assert.AreEqual("""{"leadType":"PREVIOUS_CUSTOMER"}""", json);

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            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;

            }

        }

    }

​