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 System.Text.Json.Serialization.Metadata;

using System.Text.Json.Nodes;

​

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

​

//https://stackoverflow.com/questions/77575596/use-a-blanket-policy-to-serialize-enums-as-strings-with-snake-case

​

#nullable enable

​

    public class MyModel { }

​

    public enum FirstEnum { }

    public enum SecondEnum { }

    public enum LastEnum { }

​

    public class SnakeCaseLowerStringEnumConverter<TEnum>() 

        : JsonStringEnumConverter<TEnum>(JsonNamingPolicy.SnakeCaseLower) 

        where TEnum : struct, Enum;

​

    [JsonSourceGenerationOptions(

        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,

        PropertyNamingPolicy = JsonKnownNamingPolicy.SnakeCaseLower,

        Converters = new[] { 

            // Add all known enums here

            typeof(SnakeCaseLowerStringEnumConverter<FirstEnum>), 

            typeof(SnakeCaseLowerStringEnumConverter<SecondEnum>),

            //...

            typeof(SnakeCaseLowerStringEnumConverter<LastEnum>)})]

    // Add all known enums here also

    [JsonSerializable(typeof(FirstEnum)), 

     JsonSerializable(typeof(SecondEnum)),

     //...

     JsonSerializable(typeof(LastEnum))]

    // And also add all other root types to be serialized in this context

    [JsonSerializable(typeof(MyModel)),] 

    public partial class SnakeCaseLowerContext : JsonSerializerContext { }

​

​

    class TestClass

    {

        public static void Test()

        {

        }   

    }

​

    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;

            }

        }

    }

​