Regression: Type Confusion from Inline Class Naming #10418
Description
The following code produces two errors with pyright 1.1.400
from typing import Any, Generic, Protocol, TypeVar
Row = TypeVar("Row", covariant=True)
class Cursor(Generic[Row]):
def fetchone(self) -> Row: ...
class RowMaker(Protocol[Row]): ...
class BaseRowFactory(Protocol[Row]):
def __call__(self, cursor: Cursor[Any]) -> RowMaker[Row]: ...
class RowFactory(Protocol[Row]):
def __call__(self, cursor: Cursor[Any]) -> RowMaker[Row]: ...
class Connection:
def cursor(self, row_factory: RowFactory[Row]) -> Cursor[Row]: ...
_T = TypeVar("_T")
def class_row(cls: type[_T]) -> BaseRowFactory[_T]: ...
def example_1(connection: Connection) -> None:
class Row:
foo: bool
cursor = connection.cursor(row_factory=class_row(Row))
res = cursor.fetchone()
assert isinstance(res.foo, bool)
def example_2(connection: Connection) -> None:
class Row:
bar: str
cursor = connection.cursor(row_factory=class_row(Row))
res = cursor.fetchone()
assert isinstance(res.bar, str)
assert isinstance(res.foo, bool)the errors are
example.py:46:23 - error: Type of "bar" is unknown (reportUnknownMemberType)
examplepy:46:27 - error: Cannot access attribute "bar" for class "Row"
Attribute "bar" is unknown (reportAttributeAccessIssue)
In fact, res.bar should be available, and res.foo unavailable. If the class Row defined inline in example_2 is renamed so its name doesn't conflict with the name defined inline in example_1, the error disappears.
This appears to be due to a regression that appears in pyright 1.1.386, as 1.1.385 is the most recent version that correctly identifies foo as the undefined attribute, not bar.