distributing fixtures

[cjw296]

What approaches have worked for people when in comes to distributing pytest fixtures in a Python distribution on pypi?

I have some fixtures that I'm sure I'll end up using across several projects, but while the following works, I can see linters being unhappy with it as an unused import:

from mypackage import myfixture

I can imagine a trivial function might make that happy, but the imports become uglier:

from mypackage import myfixture as myfixture_

def use(fixture: T) -> T:
    return fixture

myfixture = use(myfixture_)

...and even then, I can see type checkers getting confused or unhappy.

What's working for other folks?

[kwist-sgr]

from mypackage import myfixture  # noqa

?

[cjw296]

No, # noqa is exactly the thing I'm trying to avoid.

[The-Compiler]

You can turn your fixtures into a installable plugin via the pytest11 entry point, and the fixtures will be available as soon as the plugin is installed.

Alternatively, you can set pytest_plugins in a conftest.py to any installed module that contains fixtures you want pytest to pick up.

[cjw296]

This feels more like going down the patch of having fixtures ending up auto-used and controlled by command line options, which is definitely something I don't want.

Put differently: I don't want to develop plugins, I want to distribute fixtures and use them on several projects.

[The-Compiler]

I'm not sure how you get to that conclusion. A plugin is a collection of fixtures and plugin hooks, and a conftest.py is simply a project-specific plugin.

[cjw296]

Can you point me to a simple example of a distribution that provides a pytest fixture that is only used by way of "normal" pytest dependency usage?

A fixture such as this:

def myfixture() -> Iterable[Foo]:
    with make_foo() as foo:
        yield foo

Related question: what happens if two installed distributions both use the pytest11 entry point to provide a fixture with the same name?

[The-Compiler]

Can you point me to a simple example of a distribution that provides a pytest fixture that is only used by way of "normal" pytest dependency usage?

pytest-mock comes to mind which has the mocker fixture as its main entry point. Nowadays it does a bit more too (improving mock assertion output, adding some config options), but especially in older versions you can see the kind of thing I mean.

But there is really nothing special here. You put your fixture into a Python project and make sure it has the pytest11 entry point, and that's it.

Related question: what happens if two installed distributions both use the pytest11 entry point to provide a fixture with the same name?

Not sure off-hand, I believe one might shadow the other, or maybe pytest complains about it. The usual solution to that is to have some sort of naming convention that makes it clear that your fixtures belong to the given plugin (though that might be less important if you don't distribute it publicly).