Parametrizing class with class scope fixtures

[TilmanK]

Hey,

I need help with a problem, that I'm unable to solve by myself. I've implemented a test broken down in several methods, like in this example: https://docs.pytest.org/en/6.2.x/fixture.html#running-multiple-assert-statements-safely

I'm currently trying to parametrize that test so that the class is "executed" twice with different parameters. Each run requires the class (and especially the fixture to prepare the test) to be run independently - meaning the fixture have to be torn down...

I was able to parametrize the test by using @pytest.mark.parametrize("par" ("foo", "bar"), indirect=True) and writing a fixture with the name par. But then the teardown of the fixtures does not happen in between.

Does somebody know how to do this?

Thanks!
Tilman

[RonnyPfannschmidt]

Without seeing more of the code we can only guess

[TilmanK]

Sorry for being imprecise. The question really is: How can I parametrize the example from the docs.

Here's a minimum example showing the problem:

import pytest


class FooBar:
    def __init__(self):
        self.foo = False
        self.bar = False


@pytest.fixture(scope="class")
def create_object():
    return FooBar()


@pytest.mark.parametrize("foo_bar", ("foo", "bar"), indirect=True)
class TestFooBar:
    @pytest.fixture(scope="class")
    def foo_bar(self, request):
        return request.param

    @pytest.fixture(scope="class", autouse=True)
    def prepare(self, create_object, foo_bar):
        if foo_bar == "foo":
            create_object.foo = True
        elif foo_bar == "bar":
            create_object.bar = True

    def test_exclusive(self, create_object):
        assert (create_object.foo and not create_object.bar) or (
            not create_object.foo and create_object.bar
        )

Output of pytest -vv

test_foobar.py::TestFooBar::test_exclusive[foo] PASSED                                                                                                                                                                                                                                                           [ 50%]
test_foobar.py::TestFooBar::test_exclusive[bar] FAILED                                                                                                                                                                                                                                                           [100%]

====================================================================================================================================================== FAILURES ======================================================================================================================================================= 
___________________________________________________________________________________________________________________________________________ TestFooBar.test_exclusive[bar] ____________________________________________________________________________________________________________________________________________ 

self = <test_foobar.TestFooBar object at 0x0000026E65C97760>, create_object = <test_foobar.FooBar object at 0x0000026E65C97250>

    def test_exclusive(self, create_object):
        """Check that the dialog isn't visible anymore after accepting it."""
>       assert (create_object.foo and not create_object.bar) or (
            not create_object.foo and create_object.bar
        )
E       assert ((True and not True) or (not True))
E        +  where True = <test_foobar.FooBar object at 0x0000026E65C97250>.foo
E        +  and   True = <test_foobar.FooBar object at 0x0000026E65C97250>.bar
E        +  and   True = <test_foobar.FooBar object at 0x0000026E65C97250>.foo

test_foobar.py:31: AssertionError
=============================================================================================================================================== short test summary info =============================================================================================================================================== 
FAILED test_foobar.py::TestFooBar::test_exclusive[bar] - assert ((True and not True) or (not True))
============================================================================================================================================= 1 failed, 1 passed in 0.12s ============================================================================================================================================= 

I'd expect pytest to create a new FooBar object for each run, but it doesn't...

[RonnyPfannschmidt]

Pytest creates new objects if the parameters /scope change

As you pretty much mutilate "unrelated" fixtures in other fixtures, everything breaking and the world being on fire is the expected outcome

If you want new fixtures per parameter, take the parameters as fixture input so pytest can actually know the relations

[TilmanK]

So, what you're saying is, that I need to pass the parameters on create_object, right? Only this forces a new FooBar object.

[RonnyPfannschmidt]

That's a rough approximation