What is this?

Something you come up with when you know a little ruby and words public_exec stuck in your head for a couple days: instance_exec on wrapper around receiver to conceal private methods, with aliased setters

cat spec/show_off_spec.rb

describe RedBikini do

  before{RedBikini.add_to_wardrobe! Person}

  example 'punchline', contrived: true do
    time = '17:00'

    expect("Tom, Gia and 'Happy' Mike are heading to the cinema at 17:00").to eq(
      Person.such_that do
        name_is 'Mike'
        friends_are %w[Tom Gia]
        set_nickname 'Happy'
      end.confide('the cinema') do |where|
        "#{friends * ', '} and '#{nickname}' #{name} are heading to #{where} at #{time}"
      end
    )

  end

  describe 'access' do
    let(:josephine){ Person.new(1,'Josephine')}
    specify do
      expect{josephine.tell{credit_card_number}}
      .to raise_error NoMethodError # private
    end
    specify do
      expect{josephine.expose{girly_secrets}}
      .to raise_error NoMethodError # protected
    end
  end

  describe 'Kernel#which' do
    example :even_more_contrived do
      [Person.new(nil, 'George'),
       Person.new(nil, 'Kevin' ),
       Person.new(nil, 'Steven'),
       Person.new(22)].

      find_all(&which{name and name =~ /ev/}).

      map(&:name).
      should eq %w[Kevin Steven]
    end
  end

end

cat spec/person.rb

  Person = Struct.new(:id, :name, :friends, :nickname) do
    OWN_CONST = 'Person const'
    def === other
      other.respond_to? :id and id == other.id
    end
    private
    def credit_card_number
      'meh'
    end
    protected
    def girly_secrets
      'nah'
    end
  end

Red Bikini?

Red for ruby, bikini for informal communication Think of objects in bikini

Why?

It just would not let me go

So...

You probably shouldn't use this for serious things, but I wouldn't discourage you from it of course. Some kind of DSL sounds as a candidate topic.

I would note that inside it uses instance exec applied to a wrapper around reciever, so it wouldn`t bind calling context methods (which is good), but binds locals and constants.

• Also, or/equal (||=) won't work directly without specifiyng explicit receiver of course (self.attr ||= will work)
• Also, self wouldn't work with case operator - I don't want to hack reciever class .=== just for that. Although, you may use _self for this (original object).

rspec --tag gotcha --format documentation

Run options: include {:gotcha=>true}

RedBikini closure stuff
  Host const shadows own with same name

RedBikini operators
  {attr ||= val} will create block-local var shadowing attr

RedBikini hacked typing
  ClassInBikini === self # => false

Finished in 0.00404 seconds
3 examples, 0 failures

Detailed behavior