Docs: using pytest.mark.usefixtures in code snippets

[jamesbraza]

Is your feature request related to a problem? Please describe.

Many of the pytest-oriented examples in https://pytest-pyfakefs.readthedocs.io/en/stable/usage.html use a fake_fs fixture in the test signature, but don't actually use it in the test body.

Here's a more specific example: https://pytest-pyfakefs.readthedocs.io/en/stable/usage.html#access-to-files-in-the-real-file-system

def test_using_fixture1(my_fs):  # Linters don't like this line
    with open(os.path.join(fixture_path, "fixture1.txt")) as f:
        contents = f.read()

Multiple linters detect this line as unused code:

• pylint: invalid-name gets emitted on test functions or methods
• flake8-unused-arguments: ARG001 gets emitted if test function, or ARG002 gets emitted if test method

Describe the solution you'd like

This can be ameliorated with using pytest.mark.usefixtures decorator:

@pytest.mark.usefixtures("my_fs")
def test_using_fixture1():
    with open(os.path.join(fixture_path, "fixture1.txt")) as f:
        contents = f.read()

Can we move code snippets in the pyfakefs docs to use pytest.mark.usefixtures?

[mrbean-bremen]

Thanks, this would make sense, probably with a line explaining it.
If you want to make a PR, go ahead - otherwise this gets at the end of my personal backlog 😀