Getting 'Untyped decorator makes function "*" untyped' when using decorator inside a function
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Description
Sorry for the long title! I found a small issue when using disallow-untyped-decorators and while having a decorated function inside another function, here's the reproduction:
from typing import Callable
def mydeco(f: Callable) -> Callable:
return f
# Failing case
def something():
class Query:
@mydeco
def search(self, input: str) -> str:
return input
reveal_type(Query.search)
# Failing case
def something():
@mydeco
def example() -> str:
return "str"
reveal_type(example)
# Ok case
class Query:
@mydeco
def search(self, input: str) -> str:
return input
reveal_type(Query.search)
# Ok case
@mydeco
def example() -> str:
return "str"
reveal_type(example)
I guess this is not a big deal since we don't normall define functions inside functions, but I got this issue while writing some tests and it'd be nice to get it fixed 😊
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the linked mypy-play reproduction and compare decorator handling for functions defined at module scope versus inside another function or class. Trace the type-checking path for nested decorated definitions; done means the reproduction no longer reports an untyped decorator and the reveal_type results remain appropriately typed.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100