ArcToolkitCLI/ArcToolkitCLI/Program.cs

using System.Linq;
using ArcToolkitCLI.Commands;
using CommandLine;

namespace ArcToolkitCLI
{
    internal class Program
    {
        private static int Main(string[] args)
        {
            var commandTypes = typeof(Program).Assembly.GetTypes()
                .Where(t => !t.IsInterface && !t.IsAbstract && typeof(ICommand).IsAssignableFrom(t)).ToArray();
            return Parser.Default.ParseArguments(args, commandTypes)
                .MapResult((object t) => ((ICommand) t).Run(), errs => 1);
        }
    }
}