ruff/crates/ty_python_semantic/resources
TomerBin 9910ec700c
[ty] Better control flow for boolean expressions that are inside if (#18010)
## Summary
With this PR we now detect that x is always defined in `use`:
```py
if flag and (x := number):
    use(x)
```

When outside if, it's still detected as possibly not defined
```py
flag and (x := number)
# error: [possibly-unresolved-reference]
use(x)
```
In order to achieve that, I had to find a way to get access to the
flow-snapshots of the boolean expression when analyzing the flow of the
if statement. I did it by special casing the visitor of boolean
expression to return flow control information, exporting two snapshots -
`maybe_short_circuit` and `no_short_circuit`. When indexing
boolean expression itself we must assume all possible flows, but when
it's inside if statement, we can be smarter than that.

## Test Plan
Fixed existing and added new mdtests.
I went through some of mypy primer results and they look fine

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-16 11:59:21 +00:00
..
mdtest [ty] Better control flow for boolean expressions that are inside if (#18010) 2025-05-16 11:59:21 +00:00
primer [ty] Understand classes that inherit from subscripted Protocol[] as generic (#17832) 2025-05-09 17:39:15 +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.