Skip to content

[ty] Avoid definition lookups in recursive TypedDict comparisons #30444

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
charliermarsh wants to merge 2 commits into
base: main
Choose a base branch
from
+13 −1
Draft

[ty] Avoid definition lookups in recursive TypedDict comparisons #30444

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
5e990b5
[ty] Compare TypedDict body scopes in recursive identity checks
charliermarsh Nov 15, 2026
5d9752c
[ty] Clarify recursive TypedDict identity comment
charliermarsh Nov 15, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 13 additions & 1 deletion crates/ty_python_semantic/src/types/cyclic.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,19 @@ impl<'db> Type<'db> {
a.definition(db) == b.definition(db)
}
(Type::TypeAlias(a), Type::TypeAlias(b)) => a.definition(db) == b.definition(db),
(Type::TypedDict(a), Type::TypedDict(b)) => a.definition(db) == b.definition(db),
(
Type::TypedDict(TypedDictType::Class(a)),
Type::TypedDict(TypedDictType::Class(b)),
) => {
// Different specializations of the same recursive TypedDict can form a cycle.
// Each class statement has a unique body scope, so comparing scopes tells us
// whether the types came from the same class, even after decorators.
// Other TypedDicts can only match by exact equality, which we checked above.
matches!(
(a.class_literal(db).as_static(), b.class_literal(db).as_static()),
(Some(a), Some(b)) if a.body_scope(db) == b.body_scope(db)
)
}
(Type::Recursive(a), Type::Recursive(b)) => a.definition(db) == b.definition(db),
_ => false,
}
Expand Down
Loading