ruff/crates/ty_python_semantic/resources
David Peter 5a55bab3f3
[ty] Infer single-valuedness for enums based on int/str (#19510)
## Summary

We previously didn't recognize `Literal[Color.RED]` as single-valued, if
the enum also derived from `str` or `int`:
```py
from enum import Enum

class Color(str, Enum):
    RED = "red"
    GREEN = "green"
    BLUE = "blue"

def _(color: Color):
    if color == Color.RED:
        reveal_type(color)  # previously: Color, now: Literal[Color.RED]
```

The reason for that was that `int` and `str` have "custom" `__eq__` and
`__ne__` implementations that return `bool`. We do not treat enum
literals from classes with custom `__eq__` and `__ne__` implementations
as single-valued, but of course we know that `int.__eq__` and
`str.__eq__` are well-behaved.

## Test Plan

New Markdown tests.
2025-07-23 15:55:42 +02:00
..
corpus [ty] Fix panic for attribute expressions with empty value (#19069) 2025-07-09 08:46:33 +02:00
mdtest [ty] Infer single-valuedness for enums based on int/str (#19510) 2025-07-23 15:55:42 +02:00
primer [ty] Upgrade mypy_primer (#19207) 2025-07-08 15:56:54 +01:00
README.md Rename Red Knot (#17820) 2025-05-03 19:49:15 +02:00

Markdown files within the mdtest/ subdirectory are tests of type inference and type checking; executed by the tests/mdtest.rs integration test.

See crates/ty_test/README.md for documentation of this test format.