Exploration Through Example

Example-driven development, Agile testing, context-driven testing, Agile programming, Ruby, and other things of interest to Brian Marick

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Fri, 09 Jun 2006

Sentence style for tests

Steve Freeman and Nat Pryce will have a paper titled "Evolving an Embedded Domain-Specific Language in Java" at OOPSLA. It's about the evolution of jMock from the first version to the current one, which is something of a domain-specific language for testing. It's a good paper.

I've been doing some work recently on an old renderer-presenter project, and I was inspired by the paper to rip out my old tests of a rendered page and replace them with tests in their style. Here's the result. It first has flexmock sentence descriptions of how the renderer uses the presenter. Then come other sentence descriptions of the important parts of the page structure.

def test_patient_display_page_minimal_structure     # No audits, no visits, no "add audit" button     certain_calls_never_vary     # ... but these do:     @presenter.should_receive(:patient_visits).once.and_return([])     @presenter.should_receive(:patient_audits).once.and_return([])     @presenter.should_receive(:possible_audit_button).once.                and_return(:missing_audit_button.marker)       page.should_have_normal_structure       page.title.should_have_id(:patient_display_page).                and_should_include(:current_animal).                and_should_include(:current_client)       page.main_text.should_have_no_list_named(:visits).                    should_have_no_list_named(:audits).                    should_have_a_form_with_action(:want_add_visit_form).                    should_have_no_form_with_action(:want_add_audit_form).                    and_should_have_a_help_popup_named(:patient_display_page)   end

I rather like that, today at least. It's much more understandable than my previous tests. After only a few months, I had to go digging to figure them out, but I doubt I'll have to do that for these. Moreover, I think these tests would be more-or-less directly transcribable from a wireframe diagram or sketch of a page on a whiteboard. They're also, with a little practice, reviewable by the product director.

(I'm still very much up in the air about how much automated testing how close to the GUI we should do, but this has nudged my balance toward more automated tests.)

I also remain fond of workflow tests in this style:

def test_approvals_can_happen_without_logging_in     @sanjay_student.logs_in     @sanjay_student.adds_a_patient            (@dr_dawn.is_sent_an_approval_url)       # without logging in...     @dr_dawn.goes_to(her.approval_url)     @dr_dawn.approves_new_case            (@dr_dawn.should_be_on_beginning_page)            # no place else to go for now.            # can't show further approvals because not logged in.            # this will change in some later iteration.   end

These workflow tests can be derived from interaction design work as easily as Fit tests are. They're less readable than Fit tests, but not impossibly code-like. These workflow tests are end-to-end. They go through HTTP (using my own browser object, rather than Watir or Selenium), into the renderer/presenter layer, down into the business logic, and through Lafcadio into MySQL.

And, finally, I also am starting to write RubyFIT tests in the style that I've heard Jim Shore call "business-facing unit tests":

Adding a Case Students can add cases on their own, but they must be approved by the clinician. When students add a case, clinicians get sent email with a clickable link. When approved, they're taken to the approval page. Their sidebar also shows that same approval URL. AddCaseFixture user type allowed?() approval needed?() clinician yes no student yes yes admin no -

I feel reasonably comfortable with the way this project is test-driven from (what would be in reality) business-facing sketches on the whiteboard down to individual lines of code. Well, except for the Javascript. That wasn't test-driven.

## Posted at 13:18 in category /testing [permalink] [top]