How to exchange objects with devices for all tests using pytest?

Question

What is the best way to identify an object in a device with a session scope and autouse = True, so it will be available for all tests?

@pytest.fixture(scope='session', autouse=True)
def setup_func(request):
    obj = SomeObj()

Next, I want some kind of magic that I previously created objto appear in every test context without the need for each test to determine the fixture setup_func.

def test_one():
   obj.do_something_fancy()

Answer 1

My recommendation will add the device to conftest.pyand will definitely return the object that you want to create from the lamp.

As already noted, this makes "autouse" seemingly worthless.

conftest.py:

@pytest.fixture(scope='session', autouse=True)
def someobj(request):
    return SomeObj()

(, test_foo.py):

def test_foo(someobj):
    assert isinstance(someobj, SomeObj)

---

, .

, conftest.py:

someobj = None
@pytest.fixture(scope='session', autouse=True)
def prep_someobj(request):
    someobj = SomeObj()

:

from . import conftest

def test_foo():
    assert isinstance(conftest.someobj, SomeObj)

-, , .

Answer 2

- . , , , . ,

class SomeObj():
    """This object definition may exist in another module and be imported."""
    def __init__(self):
        self.x = 5

    def do_something_fancy(self, y):
        return self.x * y


class TestX():
    # Object instance to share across tests
    someobj = SomeObj()

    def test_x(self):
        assert TestX.someobj.x == 5

    def test_fancy(self):
        fancy_factor = 10
        result = TestX.someobj.do_something_fancy(fancy_factor)
        assert result == 50