scope=session fixtures setup/teardown multiple times

[cielavenir]

__init__.py

import pytest
import inspect
@pytest.fixture(scope="session")
def F(request):
  print('setup')
  yield inspect.stack()[0]
  print('teardown')

test_1.py

from . import F
def test_1(F):
  print(F)

test_2.py

from . import F
def test_2(F):
  print(F)

this pytest tree shows:

test_1.py setup
(<frame object at 0x7ff2c97fa730>)
.                                                                                                                                                              
test_2.py setup
(<frame object at 0x7ff2c97faaa0>)
.teardown
teardown

I expect setup/teardown only once, since there are only one fixture definition.

If this is because global session fixtures are gathered multiple times, I think this can be fixed by checking module name in gathering.

[cielavenir]

full log (Py2/Py3) https://gist.github.com/cielavenir/5cefaefe2a9374a666c97c851aead289

[pytestbot]

GitMate.io thinks possibly related issues are #1878 (session scoped fixtures get executed multiple times. I suspect I am using pytest wrong), #1738 (Have a way to force session scope teardown ), #583 (Add a class example for Setup/TearDown with fixtures), #3094 (Use fixtures to implement xUnit setup/teardown ), and #503 (Session fixtures invoked multiple times with xdist).

[cielavenir]

I tried to patch FixtureManager like:

            faclist = self._arg2fixturedefs.setdefault(name, [])
            if fixture_def.has_location:
                if fixture_def.scope!='session' or all(fdef.func!=fixture_def.func for fdef in faclist):
                    faclist.append(fixture_def)

and now test_2.py cannot find fixture F. It looks like I really have to put fixtures in conftest.py. Sorry to have bothered you (you can close this)

[cielavenir]

looks like patching also baseid works...

            faclist = self._arg2fixturedefs.setdefault(name, [])
            if fixture_def.has_location:
                if fixture_def.scope=='session':
                    fixture_def.baseid=''
                if fixture_def.scope!='session' or all(fdef.func!=fixture_def.func for fdef in faclist):
                    faclist.append(fixture_def)

[RonnyPfannschmidt]

importation counts as extra definition - so this is a user error

there is a plan to warn on multiple imports of the same fixture (as one issupposed to use a plugin/conftest

[cielavenir]

fixed locally as https://github.com/cielavenir/pytest-session-fixture-globalize
this can be closed

[RonnyPfannschmidt]

@cielavenir please document that this plugin may break even for minor or patch pytest releases ^^ its dabbling with the internals