Development Blog: Viget Labs

class Test::Unit::TestCase
  def self.should_sum_total_ratings
    klass = model_class

    context "finding total ratings" do
      setup do
        @ratable = Factory(klass.to_s.downcase)
      end

      should "have zero total ratings if no rated talks" do
        assert_equal 0, @ratable.total_ratings
      end

      should "have one total rating if one delivery & content rating" do
        talk = block_given? ? yield(@ratable) : @ratable
        Factory(:content_rating,  :talk => talk)
        Factory(:delivery_rating, :talk => talk)

        assert_equal 1, @ratable.reload.total_ratings
      end
    end
  end
end

This way, if we’re testing a talk, we can just say:

class TalkTest < Test::Unit::TestCase
  context "A Talk" do
    should_sum_total_ratings
  end
end

But if we’re testing something that has a relationship with multiple talks, our macro accepts a block that serves as a factory to create a talk with the appropriate relationship. For events, we can do something like:

class EventTest < Test::Unit::TestCase
  context "An Event" do
    should_sum_total_ratings do |event|
      Factory(:talk, :event => event)
    end
  end
end

I'm pretty happy with this solution, but having to type “event” three times still seems a little verbose. If you've got any suggestions for refactoring, let us know in the comments.