Commands with subcommands and params

There is a way to register command with arguments, options and subcommands.

This helps to implement complex nested logic.

Arguments and options can be defined for parent both commands and child commands.

Note

If you call a command with an argument equal to the name of the subcommand, it will call the subcommand instead of the parent command.

#!/usr/bin/env ruby
require "bundler/setup"
require "dry/cli"

module Foo
  module CLI
    module Commands
      extend Dry::CLI::Registry

      class Account < Dry::CLI::Command
        desc 'Information about account'

        argument :format, default: "short", values: %w[long short], desc: "Output format"

        def call(**options)
          puts "Information about account in #{options.fetch(:format)} format."
        end

        class Users < Dry::CLI::Command
          desc 'Information about account users'

          def call(**_options)
            puts "Information about account users."
          end
        end
      end

      register "account", Account
      register "account users", Account::Users
    end
  end
end

Dry::CLI.new(Foo::CLI::Commands).call

$ foo account -h
Command:
  foo account

Usage:
  foo account [FORMAT] | foo account SUBCOMMAND

Description:
  Information about account

Subcommands:
  users                           # Information about account users

Arguments:
  FORMAT                # Output format: (long/short)

Options:
  --help, -h                        # Print this help

$ foo account
# Information about account in short format.

$ foo account long
# Information about account in long format.

$ foo account users
# Information about account users.