False positive with RUF009 using NewType, Final and dataclass

[inkhey]

Hello 👋 , I think I found a false positive on RUF009 rule.

test_ruff.py:

from dataclasses import dataclass
from typing import Final, NewType

State = NewType("State", str)


@dataclass
class System:
    state: Final[State] = State("Enabled")


@dataclass
class System2:
    state: Final[str] = "Enabled"

version:

❯ ruff --version
ruff 0.0.283

bug.toml:

select = ["RUF"]

output:

❯ ruff check --config=bug.toml test_ruff.py 
test_ruff.py:9:27: RUF009 Do not perform function call `State` in dataclass defaults
Found 1 error.

[zanieb]

Thanks for the report! We could special case this by looking up the binding for State and checking it it's a NewType declaration. However, this will not work across files, with aliased assignments, etc. because we do not have type inference.