Unexpected or undocumented behavior of pytest.mark.parametrize?

[Thomasillo]

Consider the following file test_stuff.py

import pytest

@pytest.fixture(scope="function")
def fixt_1():
    return 7

@pytest.fixture(scope="function")
def fixt_2(fixt_1):
    return fixt_1 * 2

@pytest.mark.parametrize("fixt_1", [4, 5])
def test_stuff(fixt_2):
    assert fixt_2 < 10

The second case fails, the first does not.
If this is intended behavior, I couldn't find documentation about this.

pytest version: 6.2.5

[asottile]

8 is less than 10 but 10 is not less than 10 -- seems expected?

[Thomasillo]

8 is less than 10 but 10 is not less than 10 -- seems expected?

Absolutely, no PhD in math necessary for that.

What is not expected resp. undocumented is the possibility to use pytest.mark.parametrize to parametrize the return value of a fixture that is only indirectly used by the parametrized test.

[asottile]

oh true, it is overwriting a fixture that does seem wrong

[nicoddemus]

Yes, this is an "undocumented" feature (I'm putting that in quotes because seems mostly like an accident in implementation IMO). I think we discussed this in the past, either to change the behavior, document it, or leave it undocumented, don't have the time to dig and find the issue right now unfortunately.

[asottile]

looks like this is a dupe of #5712

[nicoddemus]

Ahh right, thanks for digging it up @asottile!

[The-Compiler]

Should we close this then?

[nicoddemus]

Yes, thanks @The-Compiler!