Remove most typing.cast() calls

[DanielNoord]

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Type of Changes

	Type
✓	🔨 Refactoring

Description

After merge of pylint-dev/astroid#1168 I was asked to work on this.
I left in three two calls.

One and two (because mypy/IDE fails to see L120-122):
https://github.com/PyCQA/pylint/blob/ab327e6c9394dcdf9492996865a8b120da6bd4bc/pylint/extensions/code_style.py#L120-L147

Three (because NodeNG.scope() is not typed and we therefore lose typing on scope):
https://github.com/PyCQA/pylint/blob/ab327e6c9394dcdf9492996865a8b120da6bd4bc/pylint/checkers/refactoring/recommendation_checker.py#L122-L124

[coveralls]

Pull Request Test Coverage Report for Build 1237960833

• 3 of 3 (100.0%) changed or added relevant lines in 3 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.002%) to 93.077%

---

Files with Coverage Reduction	New Missed Lines	%
pylint/checkers/refactoring/refactoring_checker.py	1	97.93%
pylint/checkers/refactoring/recommendation_checker.py	2	96.09%

Totals
Change from base Build 1236811898:	0.002%
Covered Lines:	13243
Relevant Lines:	14228

---

💛 - Coveralls

[cdce8p]

The cast in code_checker.py are necessary and thus cannot be removed unfortunately.

--
Regarding the recommendation_checker.py and scope:
I would recommend to move the cast call in front of the for loop. After that, loop_node should be detected correctly. I.e.

scope = cast(nodes.NodeNG, node.scope())

[DanielNoord]

The cast in code_checker.py are necessary and thus cannot be removed unfortunately.

I think this is a typo. I didn't change code_checker.py, which file are you referring to?

Regarding the recommendation_checker.py and scope:

Can we use cast to type scope to Union[Module, FunctionDef, ClassDef, Lambda, GeneratorExpr]? If we are changing things we might as well be as specific as possible.
I took a quick look at typing NodeNG.scope() in astroid but this isn't a 2-minute fix because node.parent is Optional[NodeNG], thus causing mypy issue.

[cdce8p]

I think this is a typo. I didn't change code_checker.py, which file are you referring to?

You mentioned it in the PR description. Only wanted to comment on that.

Can we use cast to type scope to Union[Module, FunctionDef, ClassDef, Lambda, GeneratorExpr]? If we are changing things we might as well be as specific as possible.

I wouldn't recommend that. My rule for cast is usually to choose the most basic type that is still enough. If the implementation changes (it likely won't in this case), it's more likely that the cast will still be accurate.

I took a quick look at typing NodeNG.scope() in astroid but this isn't a 2-minute fix because node.parent is Optional[NodeNG], thus causing mypy issue.

Left some comments on pylint-dev/astroid#1170.

[DanielNoord]

You mentioned it in the PR description. Only wanted to comment on that.

Ah, that was code_style.py. But yeah, can't do anything about it.

I wouldn't recommend that. My rule for cast is usually to choose the most basic type that is still enough. If the implementation changes (it likely won't in this case), it's more likely that the cast will still be accurate.

👍🏻

[DanielNoord]

This is (potentially) blocked by pylint-dev/astroid#1170 as it would allow removing one additional cast() call.

[Pierre-Sassoulas]

This is (potentially) blocked by pylint-dev/astroid#1170 as it would allow removing one additional cast() call.

We can wait for astroid 2.8, then, there's only two merge request to handle now : https://github.com/PyCQA/astroid/milestone/16

[cdce8p]

Temporarily marked it as draft. Just until the PR is merged

[Pierre-Sassoulas]

LGTM !

[DanielNoord]

Still blocked by pylint-dev/astroid#1170

[DanielNoord]

This does need astroid 2.8.1, but that shouldn't be a problem for now :)