brew/Library/Homebrew/cask/cmd/--version.rb

module Hbc
  class Cmd
    class Version < AbstractCommand
      def self.command_name
        "--#{super}"
      end

      def initialize(*)
        super
        return if args.empty?
        raise ArgumentError, "#{self.class.command_name} does not take arguments."
      end

      def run
        puts Hbc.full_version
      end

      def self.help
        "displays the Homebrew Cask version"
      end
    end
  end
end