ProxyGenerator/src/ProxyInterfaceSourceGenerator/Extensions/MethodSymbolExtensions.cs

using System.Linq;
using Microsoft.CodeAnalysis;

namespace ProxyInterfaceSourceGenerator.Extensions
{
    internal static class MethodSymbolExtensions
    {
        public static string GetMethodNameWithOptionalTypeParameters(this IMethodSymbol method) =>
            !method.IsGenericMethod ? method.Name : $"{method.Name}<{string.Join(", ", method.TypeParameters.Select(tp => tp.Name))}>";

        public static string GetWhereStatement(this IMethodSymbol method) =>
            !method.IsGenericMethod ? string.Empty : string.Join("", method.TypeParameters.Select(tp => tp.GetWhereStatement()));
    }
}