Object.antialias_method

antialias_method.rb

class Object
  def self.antialias_method(new_name, old_name)
    define_method(new_name) { !send(old_name) }
  end
end

require 'test/unit'
class AntialiasTest < Test::Unit::TestCase
  class Person
    def registered?
      true
    end
    antialias_method(:unregistered?, :registered?)
  end

  def test_antialias_method_defines_inverse_method
    assert_respond_to(Person.new, :unregistered?)
    assert_equal(Person.new.unregistered?, false)
  end
end