module ThoughtBot::Shoulda::ActiveRecord::Macros

def should_have_readonly_attributes(*attributes)
  get_options!(attributes)
  klass = model_class
  attributes.each do |attribute|
    attribute = attribute.to_sym
    should "make #{attribute} read-only" do
      readonly = klass.readonly_attributes || []
      assert readonly.include?(attribute.to_s),
             (readonly.empty? ?
               "#{klass} attribute #{attribute} is not read-only" :
               "#{klass} is making #{readonly.to_a.to_sentence} read-only, but not #{attribute}.")
    end
  end
end