Files
ruff/crates/red_knot_python_semantic
David Peter 48e6541893 [red-knot] Negation reverses subtyping order (#15503)
## Summary

If `S <: T`, then `~T <: ~S`. This test currently fails with example
like:

```
S = tuple[()]
T = ~Literal[True] & ~Literal[False]
```

`T` is equivalent to `~(Literal[True] | Literal[False])` and therefore
equivalent to `~bool`, but the minimal example for a failure is what is
stated above. We correctly recognize that `S <: T`, but fail to see that
`~T <: ~S`, i.e. `bool <: ~tuple[()]`.

This is why the tests goes into the "flaky" section as well.

## Test Plan

```
export QUICKCHECK_TESTS=100000
while cargo test --release -p red_knot_python_semantic -- --ignored types::property_tests::flaky::negation_reverses_subtype_order; do :; done
```
2025-01-15 16:32:21 +01:00
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2024-10-20 22:35:35 +01:00