fix(generate-types): preserve infer inside tuple types in extends clause#41
Merged
Merged
Conversation
Render tuple types in conditional `extends` position element-wise so `infer` in an element or rest slot survives instead of collapsing to a free type reference, which produced invalid types.d.ts (TS2304). Fixes webpack/webpack#21191
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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Summary
generate-typesdropped theinferkeyword when a conditional type'sextendsclause usedinferinside a tuple element/rest slot (e.g.T extends readonly [infer H, ...any[]]), collapsinginfer H/...infer Rto free referencesH/Rand emitting invalidtypes.d.ts(TS2304: Cannot find name 'H'/'R').getExtendsStringhandledinferin type-parameter and array positions but not tuples. This renders tuples inextendsposition element-wise soinfersurvives, honoring rest/variadic/optional element flags and thereadonlymodifier.Closes webpack/webpack#21191
What kind of change does this PR introduce?
fix
Did you add tests for your changes?
No —
toolinghas no test harness forgenerate-types; verified by runninggenerate-typesagainst a fixture with the issue'sHead/Tailtypedefs (output now emitsinfer H/...infer Rand passestsc --strict, whereas the old output failed with TS2304) and confirmed by regenerating webpack'stypes.d.tsin webpack/webpack#21201.Does this PR introduce a breaking change?
No.
If relevant, what needs to be documented once your changes are merged or what have you already documented?
n/a
Use of AI
AI (Claude) was used to apply and verify the fix (fixture-based round-trip plus
tsc); reviewed before committing.Generated by Claude Code