Rescope a fixture

[timdiels]

I'd like to change the scope of a fixture within a class, e.g.

class TestIndexPage:

  @pytest.fixture
  def response(self, django_app):
    return django_app.get(...)

  def test_valid_html(self, response):
    assert_is_valid_html(response.text)

  @pytest.mark.parametrize('href', logo_hrefs)
  def test_logo_shown(self, response, href):
    assert response.html.body.find('a', href=href)
    ...

gets the response again for each test function, but this is more isolation than I need as my tests don't modify the response. I'd like response to be class scoped to improve performance, but django_app is function scoped. The only way of changing the scope that I can think of is copy pasting the response fixture, and recursively all of its dependencies to change the scope:

@fixture(scope='class')
def response_class(self, django_app_class):
  ...

@fixture(scope='class')
def django_app_class(self, db_class):
  ...

@fixture(scope='class')
def db_class(self, more_stuff_class):
  ...

...

This also assumes the function scoped django_app is not set up in case it would interfere; it's not needed by these tests, but it is used by other tests outside of this class. The alternative is to simply merge all tests into 1, but I'd rather avoid that.

Is there perhaps some juicy feature I'm overlooking?

[pytestbot]

GitMate.io thinks possibly related issues are #538 (Fixture scope documentation), #2246 (Question regarding fixture visibility), #1588 (Proposal to expand fixtures), #1461 (Suggestion: merge .fixture and .yield_fixture), and #1681 (invocation-scoped fixtures).

[nicoddemus]

Unfortunately I don't think there's any easy solution to this; if your django application does not hold state, perhaps you can change it into a session-scoped fixture instead? You probably only need to actually cleanup/rollback the database before each test, not the django_app object. @pytest-dev/pytest-django-developers might have other thoughts/suggestions.

[timdiels]

Thanks, that answers my question. For the record, I've mixed things up a bit when simplifying my example; django_app does not depend on db, but my response fixture depends on user which depends on db etc. I could try a session scoped django app since it has no dependencies.

[nicoddemus]

@timdiels thanks for the follow up. Can we close this?

[timdiels]

Yes