Type unknown with TypeVar default and overload #7173
Description
Describe the bug
Found this while writing tests for mypy, even though the first overload is technically redundant.
Code or Screenshots
from typing import Any
from typing_extensions import TypeVar, overload, assert_type
T1 = TypeVar("T1", default=str)
class A: ...
class B: ...
@overload
def func_1(x: A) -> A: ...
@overload
def func_1(x: B | T1) -> T1: ...
def func_1(x: Any) -> Any: ...
assert_type(func_1(A()), A)
assert_type(func_1(B()), str) # errortest.py
test.py:15:13 - error: "assert_type" mismatch: expected "str" but received "Unknown" (reportAssertTypeFailure)
In comparison, this works just fine
def func_2(x: B | T1) -> T1: ...
assert_type(func_2(A()), A)
assert_type(func_2(B()), str)VS Code extension or command-line
pyright 1.1.349