compleat_rubyist_first_metaprogramming

require 'test/unit'

class Thingy
  def method_missing(method_name,*args)
    @attrs ||= {}

    case method_name.to_s
      when /^set_(.+)/ then
        @attrs[$1] = args.first
      when /^get_(.+)/ then
        @attrs[$1]
      else
        super
    end
  end
end

class ThingyTest < Test::Unit::TestCase

  def test_thingy_should_support_should_set_name
    a = Thingy.new

    a.set_name("Gavin")
  end

  def test_thingy_set_attr_should_only_take_first_arg
    a = Thingy.new

    a.set_name("Gavin", "is so cool")

    assert a.get_name == "Gavin"
  end

  def test_thingy_should_support_should_set_address
    a = Thingy.new

    a.set_address("Home")
  end

  def test_thingy_should_suppport_get_name
    a = Thingy.new

    a.set_name("Gavin")

    assert a.get_name == "Gavin"
  end

  def test_thingy_should_not_handle_set_without_an_attr
    a = Thingy.new
    assert_raise NoMethodError do
      a.set_
    end    
  end

  def test_thingy_should_not_handle_get_without_an_attr
    a = Thingy.new
    assert_raise NoMethodError do
      a.get_
    end    
  end

  def test_thingy_should_still_throw_method_missing_for_other_methods
    a = Thingy.new
    assert_raise NoMethodError do
      a.wtf
    end
  end
end