Parameters for a call to a function wrapped in a lru_cache are not checked

[andrewjw]

Bug Report

The parameters used in a call to a function which is wrapped in a functools.lru_cache are not checked.

To Reproduce

from datetime import date
from functools import lru_cache

@lru_cache
def f(v: str, at: date) -> str:
    return v

f()
f("abc")
f("abc", date.today())
f("abc", now=date.today())
f("abc", at=date.today())
f("abc", at="wrong_type")

Expected Behavior

This should raise several errors about the arguments being wrong. Commenting out the line @lru_cache correctly generates the following errors.

lru_cache_type_test.py:8: error: Missing positional arguments "v", "at" in call to "f"  [call-arg]
lru_cache_type_test.py:9: error: Missing positional argument "at" in call to "f"  [call-arg]
lru_cache_type_test.py:11: error: Unexpected keyword argument "now" for "f"  [call-arg]
lru_cache_type_test.py:13: error: Argument "at" to "f" has incompatible type "str"; expected "date"  [arg-type]

Actual Behavior

Success: no issues found in 1 source file

Your Environment

mypy 1.6.0 running on Python 3.11.6

[Hnasar]

We encounter this fairly often too. Just linking to some past discussion: #5107 (comment)

[andrewjw]

Ah, thanks for that. I assumed I wouldn't be the first to see this, but couldn't find this specific problem. I guess I didn't read that thread closely enough. I guess this can be closed unless the situation has changed since then, and it is possible to fix.