Add B015: pointless statement.

[kalekseev]

For me the main reason to have such check is pytest style asserts, they are quite easy to miss in the middle of the test function

def test_number of objects():
    ...setup code ...
    MyModel.objects.count() == 2   # should be `assert MyModel.objects.count() == 2`
    ...more asserts...

so tests are green and developer thinks he's asserted important results in the test.

Pylint has similar rule pointless-statement although it's more advanced but it's a pain to run pylint on tests and not all developers can tolerate false positives from it, so I think it would be a good addition to the flake8-bugbear.

Right now that rule checks only comparisons so maybe error should be: "pointless comparison" or we may try to make the rule more complete by including other cases, eg. uncalled functions:

service = Service()
service.run  # should be service.run()
...

[cooperlees]

Hi - Thanks! I like this check.

Can you add a description to the README like other checks please?

Other than that it looks good. This also reminds me I need to release a new version. So I'll do that once we merge this :)

[cooperlees]

Also, lets make the name specific (i.e. pointless comparisons) since all it does is comparisons ...

[kalekseev]

Done, though error looks a bit terse relative to others, not sure if we should add more details or is it too obvious to explain?

[cooperlees]

Just maybe be a little more verbose and I'll merge.

[cooperlees]

I was only considering my verbose message for the README. But can't hurt to be verbose there too.

Just need to make the linter happy on it's own code :P

[WhyNotHugo]

With the latest release, my CI system has picked up the latest version, and raised B015 for a few of tests.

Just wanna say thanks: this change helped me find 8 missing asserts in unit tests that could've let bugs go unnoticed!

[cooperlees]

Sir, Thankyou very much for sharing this. You often get complaints and not thanks. So it’s very nice to hear that everyone’s work here is helping people! Glad you have 8 more useful tests now!

[pquentin]

Yes, we fixed a number of tests thanks to this warning. Thanks a lot! 💯

[Zac-HD]

Just dropping by to say that this also caught a single missing assert in Hypothesis' tests! Thanks to @kalekseev for this new check and @cooperlees for what I know is usually a thankless task maintaining things 🥰

[kalekseev]

Thank you guys for such a great feedback, I appreciate that!