Generic method patching unreliable

[grant77]

Hi Pardeike,

I cannot seem to get a method with 2 generic arguments to work. This is my very first day using this thing so maybe I am doing something wrong. In my demo below, I cannot get the "Test3" method to work. The output looks like this:

Prefix Called
Test1 Called
Prefix Called
Test2 Called
Test3 Called

    class Program
    {
        static void Main(string[] args)
        {
            var harmony = new Harmony("abc");
            harmony.PatchAll();

            var dummy = new Dummy();
            dummy.Test1();
            dummy.Test2<int>();
            dummy.Test3<int, string>(); // <== DOESN'T WORK!!!
            Console.ReadLine();
        }
    }

    class Dummy
    {
        public void Test1() => Console.WriteLine("Test1 Called");
        public void Test2<TItem>() => Console.WriteLine("Test2 Called");
        public void Test3<TItem1, TItem2>() => Console.WriteLine("Test3 Called");
    }

    [HarmonyPatch]
    class MyPatches
    {
        static IEnumerable<MethodBase> TargetMethods() => new[]
        {
            typeof(Dummy).GetMethod("Test1"),
            typeof(Dummy).GetMethod("Test2").MakeGenericMethod(typeof(int)),
            typeof(Dummy).GetMethod("Test3").MakeGenericMethod(typeof(int), typeof(string)),
        };
        static void Prefix() => Console.WriteLine("Prefix Called");
    }

[pardeike]

What environment is used for these tests? Processor, .NET version. What happens if you add more generics?

[grant77]

TargetFramework: netcoreapp3.1
RID: win10-x64
Processor: Intel64 Family 6 Model 63 Stepping 0

I modified the program to add more generics. In doing so, I discovered it works when i use "int" for all my generic type arguments. If I use "string", however, it does not work.

Here is my modified application:

    class Program
    {
        static void Main(string[] args)
        {
            var harmony = new Harmony("abc");
            harmony.PatchAll();

            var dummy = new Dummy();
            dummy.Test1();
            dummy.Test2<int>();
            dummy.Test3<int, int>();
            dummy.Test3<int, string>(); // <== BAD !!!!!!!!!!!!!!!!!!!
            dummy.Test4<int, int, int>();
            dummy.Test5<int, int, int, int>();
            dummy.Test6<int, int, int, int, int>();

            Console.ReadLine();
        }
    }

    class Dummy
    {
        public void Test1() => Console.WriteLine("Test1 Called");
        public void Test2<A>() => Console.WriteLine("Test2 Called");
        public void Test3<A, B>() => Console.WriteLine("Test3 Called");
        public void Test4<A, B, C>() => Console.WriteLine("Test4 Called");
        public void Test5<A, B, C, D>() => Console.WriteLine("Test5 Called");
        public void Test6<A, B, C, D, E>() => Console.WriteLine("Test6 Called");
    }

    [HarmonyPatch]
    class MyPatches
    {
        static IEnumerable<MethodBase> TargetMethods() => new[]
        {
            typeof(Dummy).GetMethod("Test1"),
            typeof(Dummy).GetMethod("Test2").MakeGenericMethod(typeof(int)),
            typeof(Dummy).GetMethod("Test3").MakeGenericMethod(typeof(int), typeof(int)),
            typeof(Dummy).GetMethod("Test3").MakeGenericMethod(typeof(int), typeof(string)), // <== BAD !!!!!!!!!!!!!!!!!!!
            typeof(Dummy).GetMethod("Test4").MakeGenericMethod(typeof(int), typeof(int), typeof(int)),
            typeof(Dummy).GetMethod("Test5").MakeGenericMethod(typeof(int), typeof(int), typeof(int), typeof(int)),
            typeof(Dummy).GetMethod("Test6").MakeGenericMethod(typeof(int), typeof(int), typeof(int), typeof(int), typeof(int)),
        };

        static void Prefix() => Console.WriteLine("Prefix Called");
    }

[pardeike]

Since this is a rather tricky issue, I welcome you to participate in the discussion at the official discord: https://discord.gg/y2thPry