False-positive inconsistent overload with TypeVar and Union

[cdce8p]

Environment data

• Language Server version: 2021.9.1
• OS and version: darwin x64
• Python version: 3.10.0rc2
• python.analysis.indexing: true
• python.analysis.typeCheckingMode: basic

Expected behaviour

no error

Actual behaviour

Overloaded function implementation is not consistent with signature of overload 1
  Type "(var: T@func | int) -> (T@func | int)" cannot be assigned to type "(var: T@func) -> T@func"
    Parameter 1: type "T@func" cannot be assigned to type "T@func | int"

Logs

--

Code Snippet / Additional information

from typing import TypeVar, overload

class X: ...
class Y: ...

T = TypeVar("T", bound=type[X])

@overload
def func(var: T) -> T:
    ...

@overload
def func(var: int) -> int:
    ...

def func(var: T | int) -> T | int:  # error
    ...


# The type is inferred correctly
reveal_type(func(X))  # Type of "func(X)" is "Type[X]"

Mypy output

Revealed type is "def () -> test3.X"

An error also occurs when changing the TypeVar definition to

T = TypeVar("T", X, Y)

Interestingly though, this seems to be fine:

T = TypeVar("T", bound=X)

[judej]

Thanks for the report

[erictraut]

Thanks for the bug report. This will be fixed in the next release.

[jakebailey]

This issue has been fixed in version 2021.9.2, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md#202192-16-september-2021