738692baff
## Summary Related: - https://github.com/astral-sh/ty/issues/111 - https://github.com/astral-sh/ruff/pull/17974#discussion_r2108527106 Previously, when validating an attribute assignment, a `__setattr__` call check was only done if the attribute wasn't found as either a class member or instance member This PR changes the `__setattr__` call check to be attempted first, prior to the "[normal mechanism](https://docs.python.org/3/reference/datamodel.html#object.__setattr__)", as a defined `__setattr__` should take precedence over setting an attribute on the instance dictionary directly. if the return type of `__setattr__` is `Never`, an `invalid-assignment` diagnostic is emitted Once this is merged, a subsequent PR will synthesize a `__setattr__` method with a `Never` return type for frozen dataclasses. ## Test Plan Existing tests + mypy_primer --------- Co-authored-by: David Peter <mail@david-peter.de>