pytest-xdist: How to execute a method (where I initialize DB mocks for all the tests in that file) before the test methods are executed

Question

I have a test suite that used to be executed with pytest and I used the method before_all_tests(request) in each test file to initialize the db mockups for those tests.

I wanted to use pytest-xdist to run them parallelly, but before_all_tests(request) is not being executed if I run pytest -n X (parallelly).

Now I don't know how to re-write all my code so that I can only initialize the mocks of the tests being executed :(

I use markers to categorize tests, so sometimes I only run tests under a single category or just a bunch of them. I don't want to initialize the mocks of all the tests files because not all of them will be executed at that time.

Can anybody help me? I can post some code if necessary.

Thanks in advance!!