fix(runtime): per-evaluation inherited static wins over last-wins registry props (#6552)

[proggeramlug]

Fixes #6552.

Symptom

test_gap_renamed_class_export_namespace.ts (the #1758/#1812 regression guard) fails on current main: every renamed class export read via import * as M resolves to the same inherited static — the direct export's DirectKeyword — instead of each alias's own origin class.

expected (node):                          got (perry, before):
(1) M.Number.ast._tag: NumberKeyword     (1) M.Number.ast._tag: DirectKeyword
(2) M.Widget.ast._tag: WidgetKeyword     (2) M.Widget.ast._tag: DirectKeyword

This re-breaks effect Schema decode (the #1785 shape: S.Number = class Number$ extends make(numberKeyword) {} re-exported as Number, then decodeUnknownSync(S.Number) reads S.Number.ast).

Root cause

Not the namespace/alias resolution the test header points at — that still resolves M.Number to the correct Number$ class-ref. The collapse is in the inherited-static read.

The three subclasses (Number$, Widget$, DirectCls) all extend make(...), where make returns the same class-expression template SchemaClass — one shared compile-time class-id. Each make() call's static ast overwrites CLASS_DYNAMIC_PROPS[template_id]["ast"], so the registry entry is last-wins (DirectKeyword).

fb04be0f — "fix(runtime): inherit static data fields from a parent class (#6443)" — added a parent-class-id-chain walk over CLASS_DYNAMIC_PROPS in get_field_by_name.rs, and placed it before the older #1788 per-evaluation prototype-object walk (resolve_proto_chain_field). For a subclass of a multiply-evaluated class expression, that registry read fires first and returns the last-wins value, preempting each subclass's pinned per-evaluation parent object.

(The issue guessed the #6537/#6529 window; the actual regressor is #6443, which lands in the #6504-era the issue verified as already-broken.)

Fix

crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs: interleave the two walks. At each level of the class-object proto chain, consult the class's pinned per-evaluation parent object (class_prototype_object) before the parent's CLASS_DYNAMIC_PROPS. The pinned object carries this evaluation's own edge, so it is authoritative; the registry read stays the fallback for a plain declaration parent (#6443: Auth.js SignInError.kind), which has no pinned object. Depth order is preserved, so a closer registry static still shadows a deeper per-evaluation one.

The proto-object read is not new to this path — the #1788 arm right below already reads class_prototype_object(class_id) the same way; this only reorders it relative to the registry read, level by level.

Testing

Byte-compared against node --experimental-strip-types (Node 26.5):

• test_gap_renamed_class_export_namespace — now identical (renamed global-colliding + non-colliding + direct exports).
• Class-expr/static regression sweep — 18/18 identical, including test_gap_static_field_inheritance (fix(runtime): inherit static data fields from a parent class #6443's own test, incl. delete Mid.foo fallthrough), test_gap_class_expr_perf_eval_statics (effect: HttpApi server dies at startup with "TypeError: undefined is not iterable" (logger/fork already work) #6438), and test_issue_effect_factory_static_dispatch.
• Edge cases confirmed vs node: multi-level grandchild of a per-eval parent; a closer runtime/registry static correctly shadowing a deeper per-eval static (the case a naive reorder would miscompile); plain-declaration static inheritance.

Per contributor convention, no version bump / CHANGELOG entry — leaving the metadata for the maintainer to fold in at merge.

Out of scope: test_gap_zlib_3285_params, noted in the issue as a likely separate regression from the same window — not touched here.

Summary by CodeRabbit

• Bug Fixes
  • Fixed inherited static property resolution for dynamically evaluated classes to use the current per-evaluation prototype precedence before falling back to registered dynamic values.
  • Corrected repeated class-expression evaluation behavior, including handling of explicitly overridden or deleted static fields.
  • Ensured renamed class exports with ast = null return null reliably.
• Tests
  • Added regression coverage for renamed class exports where static ast is explicitly null.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 78b4a75b-ff49-4119-8908-494d43af581e

📥 Commits

Reviewing files that changed from the base of the PR and between e42a3b8 and bdd300a.

📒 Files selected for processing (3)

• crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs
• test-files/_helpers/renamed_class_export.ts
• test-files/test_gap_renamed_class_export_namespace.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs

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📝 Walkthrough

Walkthrough

Static inherited data-property resolution now checks each ancestor’s per-evaluation pinned prototype before falling back to CLASS_DYNAMIC_PROPS. A regression fixture and assertion verify that an explicit null static value is returned without falling through to another evaluation.

Changes

Static inheritance resolution

Layer / File(s)	Summary
Pinned parent lookup precedence crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs	Ancestor static data lookup recursively checks pinned prototype objects first, treats non-undefined values including null as authoritative, and consults CLASS_DYNAMIC_PROPS only for non-deleted keys when pinned lookup is absent.
Null static value regression coverage test-files/_helpers/renamed_class_export.ts, test-files/test_gap_renamed_class_export_namespace.ts	Adds a renamed class with ast initialized to null and asserts namespace access returns null rather than an inherited value from another evaluation.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• PerryTS/perry#6443: Adjusts inherited static-field traversal and deleted-key handling in the same runtime lookup path.
• PerryTS/perry#6449: Introduces related pinned-parent precedence behavior in get_field_by_name.
• PerryTS/perry#6536: Changes static and inherited property-resolution precedence for per-evaluation class objects.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main runtime fix and matches the regression addressed by the PR.
Description check	✅ Passed	The description covers the problem, root cause, fix, and testing, and includes the linked issue.
Linked Issues check	✅ Passed	The changes address #6552 by fixing namespace-renamed class export static resolution and preserve the intended behavior.
Out of Scope Changes check	✅ Passed	The added test and null-handling follow-up are consistent with the stated regression fix and not unrelated scope.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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[coderabbitai]

Actionable comments posted: 1

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Verify each finding against current code. Fix only still-valid issues, skip the
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Inline comments:
In `@crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs`:
- Around line 1061-1065: Update the inherited-field lookup in
js_object_get_field_by_name so a property found on proto is returned when its
value is null; only undefined should continue the fallback to shared registry
data or higher ancestors. Preserve the existing prototype traversal and return
behavior for defined values.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 7d95f10c-c785-4ec4-9fc7-12b4769dc969

📥 Commits

Reviewing files that changed from the base of the PR and between 241d867 and e42a3b8.

📒 Files selected for processing (1)

• crates/perry-runtime/src/object/field_get_set/get_field_by_name.rs