person_spec.rb

  # person.rb

    validates_presence_of :address

  # blueprints.rb

    Person.blueprint do
      name     { "John"       }
      surname  { "Doe"        }
      address  { Address.make }
    end

  # person_spec.rb

  it "builds a valid person with machinist" do
    Person.make.should be_valid
  end