[ty] Fix PEP 695 type aliases not expanding in overload resolution#22589
Merged
[ty] Fix PEP 695 type aliases not expanding in overload resolution#22589
Conversation
Typing ConformanceSummary
The percentage of diagnostics emitted that were expected errors held steady at 0.00%, and the percentage of expected errors that received a diagnostic held steady at 0.00%. |
|
carljm
force-pushed
the
cjm/expand-type-alias
branch
from
89f43e2 to
378a9ae
Compare
carljm
requested review from
AlexWaygood,
dcreager and
sharkdp
as code owners
dhruvmanila
approved these changes
Jan 15, 2026
Member
dhruvmanila
left a comment
dhruvmanila
left a comment
There was a problem hiding this comment.
Looks good! I've a couple of minor suggestions but otherwise it's good to go
Fixes astral-sh/ty#2488 When a type alias is defined using PEP 695's `type` statement syntax (e.g., `type Array = Eager | Lazy`), overload resolution was failing because the type alias was not being expanded into its underlying union type. This fix updates both `expand_type` and `is_expandable_type` in `arguments.rs` to handle `Type::TypeAlias` by recursively checking and expanding the alias's value type.
carljm
force-pushed
the
cjm/expand-type-alias
branch
from
378a9ae to
c7f6e2e
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes astral-sh/ty#2488
When a type alias is defined using PEP 695's
typestatement syntax (e.g.,type Array = Eager | Lazy), overload resolution was failing because the type alias was not being expanded into its underlying union type.This fix updates both
expand_typeandis_expandable_typeinarguments.rsto handleType::TypeAliasby recursively checking and expanding the alias's value type.