Callable generic type alias without parameter

[decorator-factory]

Question

When a generic callable type alias, like MyFunction = Callable[[T], T], is used standalone, does it mean a generic function type of Callable[[Any], Any]?

It seems to me that the latter should be used (to be consistent with generic classes, e.g. list means list[Any]). But Pyright disagrees. Is it an issue with pyright, or are both correct?

Code

from collections.abc import Callable
from typing import TypeVar

T = TypeVar("T")

def f1() -> Callable[[T], T]:
    ...
g1 = f1()
reveal_type(g1)
reveal_type(g1(42))

Hmm = Callable[[T], T]
def f2() -> Hmm:
    ...
g2 = f2()
reveal_type(g2)
reveal_type(g2(42))

Pyright's (1.1.237) answer

information: Type of "g1" is "(T@f1) -> T@f1"
information: Type of "g1(42)" is "int"
information: Type of "g2" is "(T@Hmm) -> T@Hmm"
information: Type of "g2(42)" is "int"

Mypy's (0.942) answer

main.py:9: note: Revealed type is "def [T] (T`-1) -> T`-1"
main.py:10: note: Revealed type is "builtins.int*"
main.py:16: note: Revealed type is "def (Any) -> Any"
main.py:17: note: Revealed type is "Any"

[erictraut]

I think this is an inconsistency (i.e. a bug) in pyright. It should mirror the behavior of mypy in this case. I'll fix it.

[erictraut]

I filed this tracking issue: microsoft/pyright#3346