mirror of
https://github.com/astral-sh/ruff
synced 2026-01-10 08:04:26 -05:00
29462ea1d4
This PR adds the new **_constraint implication_** relationship between types, aka `is_subtype_of_given`, which tests whether one type is a subtype of another _assuming that the constraints in a particular constraint set hold_. For concrete types, constraint implication is exactly the same as subtyping. (A concrete type is any fully static type that is not a typevar. It can _contain_ a typevar, though — `list[T]` is considered concrete.) The interesting case is typevars. The other typing relationships (TODO: will) all "punt" on the question when considering a typevar, by translating the desired relationship into a constraint set. At some point, though, we need to resolve a constraint set; at that point, we can no longer punt on the question. Unlike with concrete types, the answer will depend on the constraint set that we are considering.
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.