Repository navigation
Read declared members while instantiating base types - #65479
Merged
Jake Bailey (jakebailey) merged 2 commits intoNov 14, 2026
Merged
Jake Bailey (jakebailey) merged 2 commits into
Jake Bailey (jakebailey) merged 2 commits into
Conversation
A class or interface makes its declared members available while its
members are resolved, so that resolving them can read one without
resolving them again. They were only available once its base types were
instantiated, yet instantiating them can need a declared member, when a
type argument of a base type refers back to the type. Zod 4.5 through
4.6.5 declares
interface $ZodRecordInternals<Key, Value>
extends $ZodTypeInternals<..., $InferZodRecordInput<Key, Value>> {
optin?: "optional" | undefined;
}
where $InferZodRecordInput checks whether Value is optional by reading
optin, which for z.json() leads back to the optin that
$ZodRecordInternals<ZodString, ZodJSONSchema> declares. Resolving its
members again instantiated the same base types until the depth limit,
reporting TS5115 for every use of z.json() in an array or a record, and
for Zod's own declarations without skipLibCheck. The declared members
are now available as soon as the base types are known, before they are
instantiated.
Fixes 64605
Jake Bailey (jakebailey)
requested review from
Anders Hejlsberg (ahejlsberg)
and
a balanced review from Copilot
November 13, 2026 05:04
Contributor
There was a problem hiding this comment.
🟢 Approval recommended
No active review issues block the change enabling declared-member access during base-type instantiation.
No open issues 🎉
What changed in this PR
Completes the earlier declared-member resolution fix for #64605 by making declared members available while the native TypeScript checker instantiates base types. This addresses circular type resolution in Zod-style recursive types.
Changes:
- Pushes the object-type resolution stack entry before base-type instantiation, then fills in its base types afterward.
- Adds a regression case for recursive base-type arguments and updates its type and symbol baselines.
| File | Description |
|---|---|
tsc/testdata/tests/cases/compiler/circularDeclaredPropertyAccess.ts |
Adds a Zod-style recursive base-type regression case. |
tsc/testdata/baselines/reference/compiler/circularDeclaredPropertyAccess.types |
Records expected types for the new case. |
tsc/testdata/baselines/reference/compiler/circularDeclaredPropertyAccess.symbols |
Records expected symbols for the new case. |
tsc/internal/checker/checker.go |
Makes declared members accessible during base-type instantiation. |
Review effort: Balanced
Anders Hejlsberg (ahejlsberg)
approved these changes
Nov 13, 2026
Jake Bailey (jakebailey)
deleted the
zod-base-instantiation-declared-members
branch
November 14, 2026 00:02
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
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.
This was found while working on #65064 where a zod type was misbehaving in webpack, and it turned out to also happen on main.
#65059 wasn't complete because
resolvingObjectTypeStackwas pushed to too late with the base types. A fix (maybe too nasty) is to push earlier and then update baseTypes.Fixes #64605