Allow having multiple conftest.py on same level

[ikonst]

In our project, the conftest.py files have grown so large that we felt the need to refactor them into smaller modules. However, modules imported by conftest.py using import cannot contribute fixtures.

We've tried using pytest_plugins but unfortunately (as the documentation says and as my testing confirms), importing a plugin with fixtures in one conftest.py makes them available in tests in parent and sibling hierarchies.

I'd like to propose a simple solution, to have pytest look for conftest.py and then conftest_*.py (under the same directory). This way, unruly conftest.py files could be easily split up.

(Let me know if it's an acceptable solution, I can implement it.)

[pytestbot]

GitMate.io thinks possibly related issues are #3212 (Having all options from all conftest.py for all collected tests), #1931 (Nested conftest.py), #2532 (TypeError on conftest.py during collection), #11 (documentation typo "conftest.py"), and #1404 (conftest.py loaded in wrong order.).

[nicoddemus]

Hi @ikonst,

For your use case, where you want fixtures in separate files just as a means to keep things more manageable, you can import the fixtures normally into the conftest.py file:

# conftest.py
from ._app_fixture import app
from ._regression_fixture import regression

And so on. Importing fixtures into test files in general is not recommended as it might lead to subtle problems, but importing them into the conftest.py file (and nowhere else) looks like it will solve your problem.

[ikonst]

Would that force me to import fixtures one by one, though?

e.g. let's say I have 100 fixtures: 50 are data model fixtures (that I'd like to store in "conftest_data_models.py") and 50 are network call fixtures ("conftest_network_calls.py").

[nicoddemus]

No, you can import them using *; as long as they are in the module's namespace by the time pytest looks for fixtures, it will work.

[RonnyPfannschmidt]

@ikonst note that due to bugs pytest_plugins in conftests also breaks strangely

[blueyed]

I wonder if it would be feasible or possible already to have a module "conftest"?
I.e. conftest/__init__.py and several other files in conftest/, that get imported in __init__.py.

[nicoddemus]

Currently we look explicitly for conftest.py files:

pytest/src/_pytest/config.py

Lines 367 to 370 in 4d0297b

	conftestpath = parent.join("conftest.py")
	if conftestpath.isfile():
	mod = self._importconftest(conftestpath)
	clist.append(mod)

As to change this to support packages, it is possible I guess, but it would mean to change other places that also look for conftest.py files, for example:

pytest/src/_pytest/doctest.py

Lines 354 to 355 in 4d0297b

	if self.fspath.basename == "conftest.py":
	module = self.config.pluginmanager._importconftest(self.fspath)

pytest/src/_pytest/fixtures.py

Lines 1054 to 1057 in 4d0297b

	if p.basename.startswith("conftest.py"):
	nodeid = p.dirpath().relto(self.config.rootdir)
	if p.sep != nodes.SEP:
	nodeid = nodeid.replace(p.sep, nodes.SEP)

Because of the possibility of introducing more bugs, I'm not sure it is worth trying to add support for this given that the "workaround" is pretty simple: import your symbols into the conftest.py file, which you would need to do anyway with the conftest/__init__.py approach.

[RonnyPfannschmidt]

im -1 on this

[nicoddemus]

Yep, I agree with @RonnyPfannschmidt here.

@ikonst did importing the fixtures into the conftest.py fixed your original issue?

[ikonst]

Thanks for all your help. I'll test this on my codebase and report back.

[nicoddemus]

Thanks!

[ikonst]

from .fixtures.models import * worked out great

[blueyed]

Great.
Closing this issue then.

[ikonst]

To follow up, my approach to import all fixtures under fixtures/* is adding to conftest.py:

from pkgutil import walk_packages

from . import fixtures

for package in walk_packages(fixtures.__path__, prefix=fixtures.__name__ + '.'):
    module = package.module_finder.find_module(package.name).load_module()
    globals().update({k: v for k, v in vars(module).items() if not k.startswith('_')})

Having to copy-paste this code snippet across multiple conftest.py files seems suboptimal, but so does implicitly specifying all fixtures, e.g.

from .fixtures.foo import *  # noqa
from .fixtures.bar import *  # noqa

and the # noqas are somewhat noisy.

Furthermore, I didn't find a way to write a pytest plugin to hook into loading of conftest.py files, in order to inject this functionality.

[tpvasconcelos]

@nicoddemus any suggestions on how to achieve this when using the recommended importlib import mode? It seems to be impossible to perform any imports since tests/ is not recognised as a package and isn't inserted in the sys.path like in the default prepend import mode.

Any suggestions are welcome here! :)

[tpvasconcelos]

For reference, I opted for using the pythonpath option to point to a separate directory containing helpers/utilities for the test suite.

---

As an example,

1. Add an extras/ directory to sys.path using the pythonpath option in the pytest.ini config file

   pythonpath = extras

2. Add your helper modules/package here:

   .
   ├── pytest.ini
   ├── extras/
   │   └── test_helpers/
   │       ├── helper_module_foo.py
   │       └── helper_module_bar.py
   

3. Impor them from your test modules as:

   from test_helpers.helper_module_foo import foo
   from test_helpers.helper_module_bar import bar

4. Extra credit if you write tests for your test helpers.

The final project tree looks something like this for me:

.
├── pytest.ini
├── extras/
│   └── test_helpers/
│       ├── helper_module_foo.py
│       └── helper_module_bar.py
├── tests/
│   ├── conftest.py
│   ├── extras/
│   │   └── test_test_helpers/
│   │       ├── test_helper_module_foo.py
│   │       └── test_helper_module_foo.py
│   └── unit/
│       └── # my unit test suite goes here...

[danielschenk]

The from .foo import * workaround works fine for fixtures not starting with an underscore. However, in a project I'm working on we have some fixtures which we deem internal (eg. because they are intended to be purely autouse, or for use by another fixture in the same file only) which we start with an underscore to clarify this in a Pythonic way.

Since the star import only considers non-underscore items, this workaround does not feel great to me. I have to either do explicit imports or modify __all__ to get this working, or just don't use underscores anymore in my fixture names.

I think that automatic fixture imports only working from test files or conftest.py is one of the biggest hassles for medium to large size pytest projects. conftest.py tends to grow out of control and become hard to read/navigate pretty quickly, and having to create subfolders just to split across multiple conftest.py files also isn't really nice (imagine having 5 conftest.py tabs open in your IDE...).

[The-Compiler]

@danielschenk It sounds like you just want to use pytest_plugins instead, at least if this is in the root conftest.py file (which I assume it is).

[danielschenk]

@danielschenk It sounds like you just want to use pytest_plugins instead, at least if this is in the root conftest.py file (which I assume it is).

We will add sibling test folders in the near future which should be (largely) independent, so that is not going to work for me.