3.6.0 breaks usefixtures when using unittest/unittest2

[owenleonard]

Thanks for submitting an issue!

Here's a quick checklist in what to include:

• Include a detailed description of the bug or suggestion
  @pytest.mark.usefixtures() on test cases in classes that inherit from unittest.TestCase and unittest2.TestCase no longer works. The fixtures are completely ignored.

Given your README.rst says Can run unittest (or trial), nose test suites out of the box;, I'm assuming this is an appropriate bug to file.

• pip list of the virtual environment you are using
  In both venvs, I installed pytest and unittest2. The remaining packages are just dependencies

python 3.6.3

Owens-MacBook-Pro:bug owen$ pip list
Package        Version
-------------- -------
atomicwrites   1.1.5
attrs          18.1.0
linecache2     1.0.0
more-itertools 4.1.0
pip            10.0.1
pluggy         0.6.0
py             1.5.3
pytest         3.6.0
setuptools     39.2.0
six            1.11.0
traceback2     1.4.0
unittest2      1.1.0
wheel          0.31.1

python 2.7.10

Owens-MacBook-Pro:bug owen$ pip list
Package        Version
-------------- -------
atomicwrites   1.1.5
attrs          18.1.0
funcsigs       1.0.2
linecache2     1.0.0
more-itertools 4.1.0
pip            10.0.1
pluggy         0.6.0
py             1.5.3
pytest         3.6.0
setuptools     39.2.0
six            1.11.0
traceback2     1.4.0
unittest2      1.1.0
wheel          0.31.1

• pytest and operating system versions
  pytest 3.6.0
  macOS High Sierra 10.13.4

• Minimal example if possible

conftest.py

import pytest


@pytest.fixture(scope='function')
def fixture1():
    print("in fixture1")
    yield


@pytest.fixture(scope='function')
def fixture2():
    print("in fixture2")
    yield

tests.py

import pytest
# import unittest
# import unittest2


# class Tests(unittest.TestCase):
# class Tests(unittest2.TestCase):
class Tests(object):

    @pytest.mark.usefixtures("fixture1")
    def test_one(self):
        print("inside test_one")

    @pytest.mark.usefixtures("fixture1", "fixture2")
    def test_two(self):
        print("inside test_two")

Results identical between python 2.7.10 and 3.6.3:

using class Tests(object)

Owens-MacBook-Pro:bug owen$ pytest -s tests.py
=============================== test session starts ===============================
platform darwin -- Python 2.7.10, pytest-3.6.0, py-1.5.3, pluggy-0.6.0
rootdir: /Users/owen/repos/sandbox/bug, inifile:
collected 2 items

tests.py in fixture1
inside test_one
.in fixture1
in fixture2
inside test_two
.

============================ 2 passed in 0.02 seconds =============================

using class Tests(unittest.TestCase)

Owens-MacBook-Pro:bug owen$ pytest -s tests.py
=============================== test session starts ===============================
platform darwin -- Python 2.7.10, pytest-3.6.0, py-1.5.3, pluggy-0.6.0
rootdir: /Users/owen/repos/sandbox/bug, inifile:
collected 2 items

tests.py inside test_one
.inside test_two
.

============================ 2 passed in 0.01 seconds =============================

Notice in fixture1 and in fixture2 is not printed

using class Tests(unittest2.TestCase)

Owens-MacBook-Pro:bug owen$ pytest -s tests.py
=============================== test session starts ===============================
platform darwin -- Python 2.7.10, pytest-3.6.0, py-1.5.3, pluggy-0.6.0
rootdir: /Users/owen/repos/sandbox/bug, inifile:
collected 2 items

tests.py inside test_one
.inside test_two
.

============================ 2 passed in 0.04 seconds =============================

Notice in fixture1 and in fixture2 is not printed

I also installed pytest 3.5.1 instead of 3.6.0 to show it was working before using unittest2:

Owens-MacBook-Pro:bug owen$ pytest -s tests.py
=============================== test session starts ===============================
platform darwin -- Python 2.7.10, pytest-3.5.1, py-1.5.3, pluggy-0.6.0
rootdir: /Users/owen/repos/sandbox/bug, inifile:
collected 2 items

tests.py running fixture1
inside test_one
.running fixture1
running fixture2
inside test_two
.

============================ 2 passed in 0.02 seconds =============================

[pytestbot]

GitMate.io thinks possibly related issues are #3181 (3.4.0 logging changes break devpi tests), #1862 (pytest 3.0 breaks Jenkins' "Publish JUnit test result report" for doctests), #2968 (Memory usage in 3.3.0), #386 (tests fail with pexpect-3.0), and #1367 (Support for Python 3.4 unittest subtests).

[RonnyPfannschmidt]

this issue has 2 strange parts

1. marks where not correctly added from unit-test tests - which is a oversight on my part (i have a fix for that by now)
2. the marks for filling fixtures are not considered correctly
   (i have no idea yet how to sort that part out

[RonnyPfannschmidt]

it seems that at getfixtureinfo time there are no markers on the objects

[RonnyPfannschmidt]

due to a simply rotten implicit dependency in various parts of the node structure, the marker bugs where simply hiding the unit-test fixture initialization bug

now that markers get loaded correctly, the bad way the unittest plugin handles the actual test objects hides the markers until its too late

a fix may take a bit

[RonnyPfannschmidt]

found a plausible place for a quick-fix - getfixtureinfo is broken for Function due to using parent instead of the actual function

in parametrized test support this however is replaced by a FunctionDefinition providing the correct details

[RonnyPfannschmidt]

@owenleonard #3500 should fix your issue, i hope you can verify soon

[owenleonard]

Commented on the PR, but I'll comment here, too. The changes work for my use cases. Thanks for the quick response and fix!