Forbid to have too many raise statements

[sobolevn]

Rule request

Thesis

Currently we check for a lot of function internals.
But, one can write any number of raise MyError statements. It is not checked at all.

We need to create new TooManyRaisesViolation with configuration to be able to find these problems. I can suggest to use 4 as maximum amount of raise uses. Or even 3.

This is a complexity violation.

[iZafiro]

Hi! Can I take this issue? Thanks!

[sobolevn]

Sure! Thank you! Make sure to read our contributing guides

I am here to help: ask anything you need.

[iZafiro]

@sobolevn Hi! I've written the code by improving upon the _ComplexityCounter class in visitors\ast\complexity\function.py by adding an extra public attribute that counts the number of raise statements within a function. However, I get a lint error because the linter finds too many public attributes. If I change the MAX_ATTRIBUTES default (by one), the tests for TooManyPublicAttributesViolation fail. I was thinking that the best solution may be to make the linter ignore the class, so how can I do that? Thanks so much!

[sobolevn]

@iZafiro no, complexity violations generally should not be ignored. Instead, we should refactor our class to be simplier. Here's our policy: https://sobolevn.me/2019/10/complexity-waterfall

I see several solutions:

1. We can split _ComplexityCounter into several classes and refactor how it is used
2. We can change how properties are defined. For example you can create @final @dataclass class _ComplexityMetrics(object) with fields that you need.

Does this sound fine to you? 🙂

[iZafiro]

@sobolevn Yeah, I'll refactor the class then. :)