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Attrs plugin mishandles typing.Self in generated inits #14685
Description
Bug Report
MyPy mishandles type comparisons when an argument in an attrs generated init uses typing.Self.
To Reproduce
import attrs
import typing
from typing_extensions import Self
@attrs.define()
class Dataclass:
child: typing.Optional[Self] = None
Dataclass(child=Dataclass())Expected Behavior
The attrs version of this code should pass type checking like MyPy does with the following dataclasses and normal init examples
import typing
import dataclasses
from typing_extensions import Self
@dataclasses.dataclass
class Dataclass:
child: typing.Optional[Self] = None
Dataclass(child=Dataclass())import typing
from typing_extensions import Self
class Dataclass:
def __init__(self, child: typing.Optional[Self] = None) -> None:
self.child = child
Dataclass(child=Dataclass())Actual Behavior
MyPy false-positive reports an incompatible type for the argument only when using attrs
test.py:12: error: Argument "child" to "Dataclass" has incompatible type "Dataclass"; expected "Optional[Self]" [arg-type]
Found 1 error in 1 file (checked 1 source file)Your Environment
- Mypy version used: 1.0.0
- Mypy command-line flags: --strict
- Mypy configuration options from
mypy.ini(and other config files): - Python version used: 3.10.9
- Attrs version used: 22.2.0
Activity
[-]Attrs plugin mishandles typing.Self in generated inits.[/-][+]Attrs plugin mishandles typing.Self in generated inits[/+]PhilReinhold commentedon Feb 15, 2023
I think this is related to the similar problem I was experiencing:
which when ran through mypy 1.0.0 gives
davfsa commentedon Feb 16, 2023
@PhilReinhold nope, that seems to be similar to #14685, which I have opened a pr (#14712) to try and fix