Declarative syntax for System.CommandLine via attributes (a new project)

[calacayir]

System.CommandLine is a very good parser but you need a lot of boilerplate code to get going and the API is hard to discover. This becomes complicated to newcomers and also you would have a lot of ugly code in your Program.cs to maintain. What if you had an easy class-based layer combined with a good parser?

DotMake Command-Line comes to the rescue!

DotMake.CommandLine is a library which provides declarative syntax for System.CommandLine via attributes for easy, fast, strongly-typed (no reflection) usage. The library includes a source generator which automagically converts your classes to CLI commands and properties to CLI options or CLI arguments.

Usage

Create a simple class like this:

using System;
using DotMake.CommandLine;

[CliCommand(Description = "A root cli command")]
public class RootCliCommand
{
    [CliOption(Description = "Description for Option1")]
    public string Option1 { get; set; } = "DefaultForOption1";
 
    [CliArgument(Description = "Description for Argument1")]
    public string Argument1 { get; set; }
 
    public void Run()
    {
        Console.WriteLine($@"Handler for '{GetType().FullName}' is run:");
        Console.WriteLine($@"Value for {nameof(Option1)} property is '{Option1}'");
        Console.WriteLine($@"Value for {nameof(Argument1)} property is '{Argument1}'");
        Console.WriteLine();
    }
}

In Program.cs, add this single line:

Cli.Run<RootCliCommand>(args);

And that's it! You now have a fully working command-line app. You just specify the name of your class which represents your root command to Cli.Run<> method and everything is wired.

If you want to go async, just use this:

await Cli.RunAsync<RootCliCommand>(args);

You get this result:

Easy!