Make function run before all fixtures

[andyhasit]

I want to conditionally code for some tests before the test's other fixtures run. Its to execute SQL to toggle logging on or off, which needs to happen before the other fixtures create records in the DB.

I ideally want to inspect the test's name to determine whether to toggle logging, alternatively I'm happy to use a fixture.

• I can't seem to do this using a fixture because I have no way of guaranteeing it would run before the other fixtures, which vary in scope, and I'm not able to go and change those scopes. The only way I can see of creating a fixture that runs before all other is using (scope="session", autouse=True) but I need it to run right before each test, so function scoped.
• I can't seem to do this using any of the pytest_runtest_* hooks as the fixtures run before those.

Surely I'm just not finding a builtin hook that runs at the point I need it? I've spent hours poring over the docs and stackoverflow and still can't find it.

[andyhasit]

Sorry, I just realised what I'm asking for is not possible, as a test could require a fixture of higher scope than function.

I'll just need to create a function-scoped fixture which sends the statements and require that in other fixtures I use on those tests, which would force them to be function-scoped too.

I think it's either that or separating it into two runs with mutually exclusive ignore and exclude patterns which isn't terrible but is really not great either.

[RonnyPfannschmidt]

@andyhasit

pytest/src/_pytest/runner.py

Lines 153 to 155 in e54c6a1

	def pytest_runtest_setup(item: Item) -> None:
	_update_current_test_var(item, "setup")
	item.session._setupstate.setup(item)

impleemnts te setup

even high scope scopes - so having that hook is perfectly fine to implement it - however you need a @hookimpl(tryfirst=true)

[andyhasit]

@RonnyPfannschmidt I believe you meant something like this:

@pytest.hookimpl(tryfirst=True)
def pytest_runtest_setup(item):
    if "audit" in item.name:
        print("enable db logging")
    else:
        print("disable db logging")

However that does not work for my stated aim, which is:

to execute SQL to toggle logging on or off, which needs to happen before the other fixtures create records in the DB.

Consider the following:

@pytest.fixture(scope="session")
def fixt_a():
    print('create db object a')

@pytest.fixture
def fixt_b():
    print('create db object b')

def test_normal(fixt_a, fixt_b):
    print('test_normal')

def test_with_audit(fixt_a, fixt_b):
    print('test_with_audit')

Which produces the following output:

disable db logging
create db object a
create db object b
test_normal
enable db logging
create db object b
test_with_audit

Because fixture a is session scoped, it only runs once, meaning object a will only be created once, while logging is disabled, and test_with_audit will not find log record for object a.

The resolution to this problem is, as I stated in my answer, that what I'm asking for is not possible, and the only solution is to either have two completely separate runs, or to use a fixture and ensure it is always of a higher scope than any fixtures which create db records (although I may have missed some options).

Additionally, I need to disable logging after running those tests which need it enabled. I settled on module scope as it's easy to group tests which need this into modules.

@pytest.fixture(scope="module")
def enable_audit_trigger(test_db):
    test_db.enable_triggers()
    yield
    test_db.disable_triggers()

I think there is still a hole in my plan: I currently have no way of ensuring that tests which require this fixture don't also require fixtures which create database records at a higher scope, or at module scope but run first.