Warn when a test doesn't assert anything

[djmattyg007]

Is there a way to make pytest warn or even fail when a test doesn't assert anything? PHPUnit calls these "risky" or "useless" tests.

https://phpunit.readthedocs.io/en/9.5/risky-tests.html

[RonnyPfannschmidt]

AFAIK The recently added assertion Pass hook may help (im on mobile so I'll skip on adding the documentation link)

[djmattyg007]

Are you referring to this?

#8967

[RonnyPfannschmidt]

Yup

[djmattyg007]

Would you be able to elaborate on how I can use that to check for tests that don't assert anything?

[RonnyPfannschmidt]

any passed test which does not invoke the hook, didnt have a tracked assertion
a requirement however is working assertion rewrite

its not integrated with unittest assertions

[graingert]

I think it would be better as a feature request in https://pypi.org/project/flake8-pytest-style/

however there's a number of different ways to assert things about a system in a test that are not supported by the assertion pass hook eg some_mock_obj.assert_called_with fwiw I prefer assert some_mock_obj.mock_calls == [...] which is supported.

@djmattyg007 I've not been impacted by this specific misconfiguration. Only when tests are simply not executed at all (due to being async/deferred) and that I solve by enforcing 100% coverage on my test suite

[djmattyg007]

By the sounds of it, the answer to my question is "no, there isn't a way".

Which is perfectly fine, I don't know why people think half-explaining roundabout hacks is a good way of answering a question.

[graingert]

By the sounds of it, the answer to my question is "no, there isn't a way".

No that's not what I'm saying

Which is perfectly fine, I don't know why people think half-explaining roundabout hacks is a good way of answering a question.

I'm not sure what you mean.

[djmattyg007]

In my eyes, me having to write a whole bunch of bespoke code does not constitute the framework supporting a feature. It means the framework does not support the feature.

[nicoddemus]

@djmattyg007 the framework does not support the feature.

[nicoddemus]

Note that the way you phrased the question:

Is there a way to make pytest warn or even fail when a test doesn't assert anything?

Conveys that you were asking for advice, not a clear-cut "does pytest supports this out of the box?".