gh-104050: Argument clinic: enable mypy's --warn-return-any setting#107405
Merged
AlexWaygood merged 4 commits intopython:mainfrom Jul 29, 2023
Merged
gh-104050: Argument clinic: enable mypy's --warn-return-any setting#107405AlexWaygood merged 4 commits intopython:mainfrom
--warn-return-any setting#107405AlexWaygood merged 4 commits intopython:mainfrom
Conversation
Contributor
|
Good sleuthing! |
| *, | ||
| filename: str = '-' | ||
| ) -> FunctionType: | ||
| ) -> Any: |
Contributor
There was a problem hiding this comment.
Should we add a comment as to why Any is the correct annotation here?
Member
Author
There was a problem hiding this comment.
You weren't going to make finally closing that issue easy, were you? ;)
Let me know if a5103be is too verbose...!
Member
Author
There was a problem hiding this comment.
Hmm, actually, now that I look at it again, the comment feels like it duplicates the docstring a little bit... not sure if it's worth it? I'll defer to you on whether it's helpful or not!
Contributor
There was a problem hiding this comment.
Sorry, you're right. The docstring should be enough!
Member
Author
There was a problem hiding this comment.
Okay -- removed the comment again and tweaked the docstring slightly! How's it look now?
This comment was marked as off-topic.
This comment was marked as off-topic.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Mypy's
--warn-return-anycheck flags when a function is declared to return a specific type, but mypy can't verify whether it's actually returning that type or not -- it can only infer a vague, unsafeAnytype as the returned type. This can often lead to bugs slipping beneath the radar.In the case of argument clinic, the check only flags a single function. But, turns out that it's a true positive! The function is incorrectly annotated at the moment -- the annotation says that it returns a
FunctionType, but that's not true. The function creates aFunctionTypeinstancefn, and then returns whatever callingfnreturns returns. Therefore, the proper return annotation for this function is-> Any, not-> FunctionType.Closes #104050!