pytest fixture – get value and avoid error "Fixture 'X' called directly"

Question

I have updated pytest to 4.3.0 and now I need to rework test code since calling fixtures directly is deprecated.

I have an issue with fixtures used in an unittest.TestCase, how do I get the value returned from the fixture and not a reference to the function itself ?

Example :

@pytest.fixture
def test_value():
    return 1

@pytest.mark.usefixtures("test_value")
class test_class(unittest.TestCase):
    def test_simple_in_class(self):
        print(test_value)    # prints the function reference and not the value
        print(test_value())  # fails with Fixtures are not meant to be called directly

def test_simple(test_value):
    print(test_value)  # prints 1

How can I get test_value in the test_simple_in_class() method ?

Asked By: JohnLoopM

||

Source

Answer 1

There was a big discussion on this already. You can read through that or refer to the deprecation documentation.

In your contrived example it seems this is the answer:

@pytest.fixture(name="test_value")
def test_simple_in_class(self):
    print(test_value())

However, I suggest checking the docs. The other example might be what you want. You can read the discussion I linked to for some of the reasoning. The debate got a bit heated though.

Answered By: kabanus

Answer 2

The solution to my simple example if anyone is interested.

def my_original_fixture():
    return 1

@pytest.fixture(name="my_original_fixture")
def my_original_fixture_indirect():
    return my_original_fixture()

@pytest.mark.usefixtures("my_original_fixture")
class test_class(unittest.TestCase):
    def test_simple_in_class(self):
        print(my_original_fixture())

def test_simple(my_original_fixture):
    print(my_original_fixture)

Answered By: JohnLoopM

Answer 3

I came to the following solution, it’s possible to import runtime_test_params somewhere where this is needed and use "parameterless" access. This requires no changes to the parameterless_function function API.

import pytest

runtime_test_params = {
    "runtime_param": ""
}

@pytest.fixture(autouse=True ,params=["fixture param 1", "fixture param 2"], scope="session")
def sample_fixture(request):
    runtime_test_params["runtime_param"] = request.param
    yield request.param


def parameterless_function():
    print(f"parameterless_function {runtime_test_params}")


def test_parameterless_function():
    parameterless_function()

Answered By: Ihor

pytest fixture – get value and avoid error "Fixture 'X' called directly"

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