This is done in various files (click_tag_test,favorite_tag_test,etc...) and could be more dry....

Drying up Tests

#Basically, across five different files, we have:
#Model here is one of these: [Click,Favorite,Friendship,Reply,Retweet]

test "create should record model tags" do
  ad, user = ads(:sample), users(:sample)
  assert_kind_of Fitness, ALGORITHM.calculate_fitness_for(ad, user)
  assert some_crap
  assert_difference('ModelTag.count'){ Model.create!(models(:sample).attributes) }
end

test "create should not record model tags if no common tags" do
  ad, user = ads(:sample), users(:sample)
  ad.tags = []
  ad.save(false)
  assert  some_crap
  assert_no_difference('ModelTag.count'){ Model.create!(models(:sample).attributes) }
end


#you could pass in the model like that, and call it by either model.to_s or model.classify.constantize (depending on how its set up)
#but the real issue is the models(:sample) bit, where i'm not sure how to call that "models" bit dynamically to make this work.
#a send seems incorrect, because it is a method of an object, whereas this is a global local variable?