Passing (yield) fixtures as test parameters (with a temp directory)

Question

Question

Is it possible to pass yielding pytest fixtures (for setup and teardown) as parameters to test functions?

Context

I\'m testing an object th

Answer 1

Try making your data function / generator into a fixture. Then use request.getfixturevalue() to dynamically run the named fixture.

import pytest, tempfile, os, shutil
from contextlib import contextmanager

@pytest.fixture # This works with pytest>3.0, on pytest<3.0 use yield_fixture
def datadir():
    datadir = tempfile.mkdtemp()  # setup
    yield datadir
    shutil.rmtree(datadir)        # teardown

class Thing:
    def __init__(self, datadir, errorfile):
        self.datadir = datadir
        self.errorfile = errorfile


@pytest.fixture
def thing1(datadir):
    errorfile = os.path.join(datadir, 'testlog1.log')
    yield Thing(datadir=datadir, errorfile=errorfile)

@pytest.fixture
def thing2(datadir):
    errorfile = os.path.join(datadir, 'testlog2.log')
    yield Thing(datadir=datadir, errorfile=errorfile)

@pytest.mark.parametrize('thing_fixture_name', ['thing1', 'thing2'])
def test_attr(request, thing):
    thing = request.getfixturevalue(thing) # This works with pytest>3.0, on pytest<3.0 use getfuncargvalue
    print(thing.datadir)
    assert os.path.exists(thing.datadir)

Going one step futher, you can parametrize the thing fixtures like so:

class Thing:
    def __init__(self, datadir, errorfile):
        self.datadir = datadir
        self.errorfile = errorfile

@pytest.fixture(params=['test1.log', 'test2.log'])
def thing(request):
    with tempfile.TemporaryDirectory() as datadir:
        errorfile = os.path.join(datadir, request.param)
        yield Thing(datadir=datadir, errorfile=errorfile)

def test_thing_datadir(thing):
    assert os.path.exists(thing.datadir)