Parser.rb

class Parser
  def initialize(array=nil)
    @array = array
  end
  def hasMoreCommands
    !@array.nil? and @array.size > 0 
  end
end

raise "default parser should not have any commands" if Parser.new().hasMoreCommands == true
raise "parser with data should have commands" if Parser.new(['@7','D=M']).hasMoreCommands == false