Codestin Search App

colinhacks · 2025-12-30T09:15:05Z

pullfrog

Low urgency — The approach addresses a real pain point (metadata lost when .meta() precedes refinements like .min()). The implementation is sound, though I have some concerns about edge cases in the deduplication logic and whether the override behavior change is intentional.

The play.ts file changes appear to be debug scaffolding that should not be merged.

^{｜ Fix all ➔ ｜ Fix 👍s ➔ ｜ View workflow run ｜ pullfrog.com ｜ 𝕏}

pullfrog · 2025-12-30T09:16:31Z

play.ts

@@ -1,6 +1,19 @@
-import * as z from "zod/v4";
+import * as z from "./packages/zod/src/index.js";


This looks like debug/exploration code that shouldn't be committed. Consider reverting this file or adding it to .gitignore.

pullfrog · 2025-12-30T09:16:31Z

packages/zod/src/v4/core/to-json-schema.ts

+      if (refSchema.$ref) {
+        for (const key in schema) {
+          if (key === "$ref" || key === "allOf") continue;
+          if (key in refSeen.def! && JSON.stringify(schema[key]) === JSON.stringify(refSeen.def![key])) {


JSON.stringify comparison for equality is O(n) and can be slow for deeply nested schemas. It's also order-dependent for object properties. If this path is hot, consider a shallow key comparison or structural equality check. That said, this is finalization code that runs once per schema, so it may be acceptable.

pullfrog · 2025-12-30T09:16:31Z

packages/zod/src/v4/core/to-json-schema.ts

-        jsonSchema: schema,
-        path: seen.path ?? [],
-      });
+    ctx.override({


The !seen.isParent guard was removed, doubling the overrideCount in tests. Is this intentional? If users were relying on overrides not being called for parent schemas (e.g., to avoid double-processing), this is a breaking change.

pullfrog · 2025-12-30T09:16:31Z

packages/zod/src/v4/core/to-json-schema.ts

+      // restore child's own properties (child wins)
+      Object.assign(schema, _cached);
+
+      const isParentRef = (zodSchema as any)._zod.parent === ref;


Using (zodSchema as any)._zod.parent bypasses type safety. Since zodSchema is typed as schemas.$ZodType, consider adding parent to the $ZodType interface if it's a supported property, or use a type guard.

Copilot

Pull request overview

This PR improves metadata tracking across child-parent schema relationships in Zod's JSON Schema generation. The main issue addressed is that metadata (like id and custom properties) was being lost when schemas were chained together, particularly when .meta() was called before constraint methods like .min().

Key Changes:

Enabled parent tracking in schema cloning by passing { parent: true } when .check() is called
Separated parent tracking from ref tracking in the JSON Schema generation process to handle cases where processors set a different ref than the parent chain
Added logic to propagate $ref from extracted parent schemas to their children

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
play.ts	Test file demonstrating the metadata ordering issue being fixed
packages/zod/src/v4/mini/schemas.ts	Added `{ parent: true }` parameter to clone calls in `.check()` method
packages/zod/src/v4/classic/schemas.ts	Added `{ parent: true }` parameter to clone calls in `.check()` method
packages/zod/src/v4/core/to-json-schema.ts	Core changes: added `parent` field to `Seen` interface, moved parent processing after processor execution, enhanced flattening logic to handle parent-child ref propagation
packages/zod/src/v4/core/json-schema-processors.ts	Optimized file processor to avoid duplicating common properties in anyOf branches
packages/zod/src/v4/classic/tests/to-json-schema.test.ts	Updated test expectations for override count (now runs on all schemas), added test for wrapper with id, updated file processor test expectations

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-12-30T09:20:55Z

packages/zod/src/v4/core/to-json-schema.ts

+      if (refSchema.$ref) {
+        for (const key in schema) {
+          if (key === "$ref" || key === "allOf") continue;
+          if (key in refSeen.def! && JSON.stringify(schema[key]) === JSON.stringify(refSeen.def![key])) {


Potential runtime error: The non-null assertion on refSeen.def! is unsafe. This code path is reached when refSchema.$ref exists (line 413). However, $ref can be set on a schema in two ways: (1) during extractToDef which also sets def, or (2) at line 431 which propagates $ref from a parent without setting def.

If schema A's parent B was extracted (has $ref and def), and A itself was not extracted, then line 431 sets A.schema.$ref = B.schema.$ref but A.def remains undefined. If another schema C references A, when processing C's ref (A) at line 413-420, the condition refSchema.$ref will be true, but refSeen.def will be undefined, causing a runtime error.

Consider checking if refSeen.def exists before accessing it, or ensuring that when $ref is propagated at line 431, the def is also set appropriately.

Suggested change

if (refSchema.$ref) {

for (const key in schema) {

if (key === "$ref" || key === "allOf") continue;

if (key in refSeen.def! && JSON.stringify(schema[key]) === JSON.stringify(refSeen.def![key])) {

if (refSchema.$ref && refSeen.def) {

for (const key in schema) {

if (key === "$ref" || key === "allOf") continue;

if (key in refSeen.def && JSON.stringify(schema[key]) === JSON.stringify(refSeen.def[key])) {

@colinhacks I'm getting this exact error when trying to upgrade from 4.2.1 to 4.3.5:

node_modules/.pnpm/[email protected]/node_modules/zod/v4/core/to-json-schema.cjs:267 if (key in refSeen.def && JSON.stringify(schema[key]) === JSON.stringify(refSeen.def[key])) { ^ TypeError: Cannot use 'in' operator to search for 'id' in undefined at flattenRef (node_modules/.pnpm/[email protected]/node_modules/zod/v4/core/to-json-schema.cjs:267:29)

Maybe it should have the safety checks suggested by copilot?
I can confirm adding refSeen.def && in the beginning of line 416 fixed the issue for me.

PR: #5644

Copilot · 2025-12-30T09:20:56Z

packages/zod/src/v4/classic/tests/to-json-schema.test.ts

  });

-  expect(overrideCount).toBe(6);
+  expect(overrideCount).toBe(12);


The override count expectation changed from 6 to 12. This change reflects that the override function now runs on parent schemas as well, which were previously skipped (by checking !seen.isParent). This doubles the count because each schema in the chain is now visited. While this aligns with the code change in the finalize function (removing the isParent check), consider adding a comment explaining why this number doubled to make the test more maintainable and document the expected behavior.

Improve metadata tracking across child-parent relationships

bf88dbe

Copilot AI review requested due to automatic review settings December 30, 2025 09:15

Copilot started reviewing on behalf of colinhacks December 30, 2025 09:15 View session

vercel bot deployed to Preview – zod-v4 December 30, 2025 09:16 View deployment

pullfrog bot reviewed Dec 30, 2025

View reviewed changes

Copilot AI reviewed Dec 30, 2025

View reviewed changes

colinhacks merged commit 9a5d3c6 into main Dec 30, 2025
17 checks passed

colinhacks deleted the inherit-meta-across-refien branch December 30, 2025 17:13

This was referenced Dec 30, 2025

JSON schema override is not applied when schema is overridden #5499

Closed

fix: JSON schema override is not applied when schema is overridden #5558

Closed

This was referenced Jan 14, 2026

Unhandled undefined in to-json-schema's flattenRef method #5635

Closed

Support for Schema Instance Parameter in Zod Global customError and localeError? #5240

Open

brunolemos mentioned this pull request Jan 18, 2026

Add safety check to handle undefined refSeen.def #5644

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Improve metadata tracking across child-parent relationships#5578

Improve metadata tracking across child-parent relationships#5578
colinhacks merged 1 commit intomainfrom
inherit-meta-across-refien

colinhacks commented Dec 30, 2025 •

edited

Loading

Uh oh!

pullfrog bot left a comment •

edited

Loading

Uh oh!

pullfrog bot Dec 30, 2025

Uh oh!

pullfrog bot Dec 30, 2025

Uh oh!

pullfrog bot Dec 30, 2025

Uh oh!

pullfrog bot Dec 30, 2025

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Dec 30, 2025

Uh oh!

brunolemos Jan 18, 2026 •

edited

Loading

Uh oh!

Copilot AI Dec 30, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		@@ -1,6 +1,19 @@
		import * as z from "zod/v4";
		import * as z from "./packages/zod/src/index.js";

Uh oh!

Conversation

colinhacks commented Dec 30, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

pullfrog bot left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

pullfrog bot Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

pullfrog bot Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

pullfrog bot Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

pullfrog bot Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

brunolemos Jan 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 30, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

colinhacks commented Dec 30, 2025 •

edited

Loading

pullfrog bot left a comment •

edited

Loading

brunolemos Jan 18, 2026 •

edited

Loading