pry--pry/lib/pry/extended_commands/user_command_api.rb

class Pry
  module ExtendedCommands

    UserCommandAPI = Pry::CommandSet.new do

      command "define-command", "Define a command in the session, use same syntax as `command` method for command API" do |arg|
        next output.puts("Provide an arg!") if arg.nil?

        prime_string = "command #{arg_string}\n"
        command_string = Pry.active_instance.r(target, prime_string)

        eval_string.replace <<-HERE
          _pry_.commands.instance_eval do
            #{command_string}
          end
        HERE

      end

    end
  end
end