Writing acceptance tests is enough? Are controller/model/view tests necessary?

rubyonrails-talk
1

I'm new in BDD, i'm writing now my first app in BDD way. I'm using RSpec with Steak for acceptance tests ( https://github.com/cavalle/steak ).

I wrote first acceptance test for user signuping:

user clicks sign up link on homepage fills all fields in sign up form clicks submit button checks for activation email

Should I test views here? Homepage to contain Sign up link with good href and new user form for contain all fields and good action= and method="post"?

Is views testing practiced in BDD at all? Or, are in BDD accteptance tests enough and there is no need for model/controller/view tests? Becouse if we test all the features, all behaviour which we want from our app in acceptance tests, what for would be other tests? For example, if we have scenario when user goes to homepage, clicks sign up and signs up, there is no need to even write 'should be success' for home controller and users controller, becouse we already test it in that scenario. Similar with models - if signing up and validating works well, there is no need for model tests.

What are you think about it? What are real-life practices of BDD?

2

The general rule is: acceptance tests are for your customers, unit and functional tests are for you.

Well-written acceptance tests prove that users can complete entire, potentially-complicated interactions and see the right thing on the screen. If you are developing for a customer or with a project manager, acceptance tests should correspond to the requirements or user stories, and if they all pass that should prove that you have done your job.

Well-written unit tests prove that small pieces of your code are modular and behave correctly. A customer is not interested in them, as they likely specify behavior about which objects send which messages to each other.

Why have unit tests if acceptance tests prove your application works? Well, let's say something goes wrong in an acceptance test and the user account can't be created. You now have a fun list of things to check:

1. Maybe the test is just written wrong.

2. Maybe the html is just getting rendered wrong.

3. Maybe the controller just isn't sending the right redirect.

4. Maybe the model validations are failing?

5. Maybe the model internal logic isn't working?

6. Maybe the controller isn't getting the right params?

7. Maybe the form isn't displaying the fields correctly?

Unit tests should cover points 4&5, functional tests would cover 3&6. When something goes wrong in the acceptance tests, you look at the results from the unit and functional tests to tell you where it is going wrong.

You also use unit and functional tests to prove the behavior of your objects in order to change your code to be better but without breaking anything.