session[] doesn't persist across cucumber steps

Question

Every time this step

Given /blah.../
    ...
    cart = session[:cart] ||= Cart.new
    ...
end

runs in a scenario, it creates a new cart as opposed to (starting from the second call) picking one up from the session. Anyone knows how to fix that?

I am on rails 2.2.2, cucumber 0.3.98, webrat 0.4.4

P.S. Possibly adding selenium into the circuit might help. But, since a preliminary attempt to get cucumber/selenuim working didn't succeed, I thought a little call for wisdom was in order before standing up against Dark Force of 'things that never just work'

Answer 1

In the way Webrat simulates a browser for testing your application you don't get any session support. This means that storing information in the session hash works for the current request, but the information doesn't get stored for subsequent requests.

Depending on a session which is created in previous scenario's isn't really a good way of testing. Each scenario you create should be self-containing. In the 'Given' steps you should make sure the prerequisites for the steps are met, if this includes setting up a shopping cart, you should do so.

Another tip: you can concatenate several Given/When/Then blocks in one scenario if you want to test further once you made some assertions:

Scenario: Foobar
Given the cart exists
When I click checkout
Then I should see '$100'
When I click 'Pay'
Then I should see 'Paid'

It seems tempting to concatenate all you scenario's in one, but this makes it harder to debug your application once the scenario fails. I prefer a lot of short scenarios!

Answer 2

There is not really a clean way to do this because cucumber is simulating your browser. All your browsers knows of sessions is an opaque cookie that rails politely turns into a hash for each request.

The best solution is to make your application create a cart in the usual fashion, that is logging in, selection a product and adding it to the cart. This can all be done in one step, but I would do it in separate steps because it is reusable and also because it follows more closely what your user is likely to have done.

Scenario: Foobar
  Given I am a logged in user
  And I add a "wizbang" to my cart
  When I click checkout
  Then I should see '$100'
  When I click 'Pay'
  Then I should see 'Paid'

If the problem is maintaining information between steps, you can use IVars that will persist through the whole senario. ie:

@cart ||= Cart.new