I love some of shoulda’s macros, partially because it forces me to think about my tests and put them in setup blocks, which ends up making things cleaner.

So I ran into a case where I do an action and use should_change to make sure that a certain number of rows were added to a table, then I do it again and make sure they don’t change. So I used a nested set of contexts to handle this:

1
2
3
4
5
6
7
8
9
10
11
12
13

context "do it once" do
  setup do
    post :method, :foo => {...}
  end
  should_change("something", :by => 6) {Something.count}
  #... other tests ...
  context "do it a second time" do
     setup do
       post :method, :foo => {...}
     end
     # should it change by 6 or 0?
  end
end

I wasn’t sure if the should_change applied to both the setup blocks or only the second. Turns out it’s only the second, so it should not change in the second test. Here’s proof:

1
2
3
4
5
6
7
8
9
10
11
12
13
14

require 'test_helper'
class SomethingControllerTest
  context "outer" do
    setup do
      @user = Factory.create(:valid_user)
    end
    should_change("number of users", :by => 1) { User.count }
    context "inner" do
      setup do
      end
      should_change("number of users", :by => 0) { User.count }
    end
  end
end

Since I didn’t write my tests before I wrote the code I wasn’t sure if my code was bad or my test was. Now I know how the test could be structured and I could test properly.