`no-untyped-call` false positive when calling lambda with no input parameters
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bug
- Dominant language
- Python
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Description
from typing import Callable
(lambda: 1)() # no error
a = lambda: 1
b: Callable[[], int] = lambda: 1
reveal_type(a) # Revealed type is "def () -> builtins.int"
reveal_type(b) # Revealed type is "def () -> builtins.int"
a() # error: Call to untyped function (unknown) in typed context [no-untyped-call]
b() # no error
kinda related: #5069
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Research direction
Run the linked mypy-play reproducer first and compare it with related issue #5069. Trace how unannotated zero-argument lambdas are handled under no-untyped-call; done when the lambda call is not falsely reported while the typed Callable case and reveal_type results remain correct.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100