test(v8): expand granular Node parity coverage

[TheHypnoo]

Summary

• expand the granular node:v8 parity suite from 4 to 46 deterministic fixtures
• cover exports/classes, structured clone semantics, serializer lifecycle, heap diagnostics and snapshots, promise hooks, GC profiling, version flags, string representation, and startup snapshot boundaries
• pin Node 26.5.0, Deno, and Bun primary-source evidence and document meaningful engine divergences and exclusions
• move v8 into the sequential runner lane and ratchet the measured baseline from 4/4 to 14/46

Coverage

• exports and classes: 8
• structured clone helpers: 12
• Serializer/Deserializer lifecycle: 8
• heap diagnostics and snapshots: 7
• promise hooks: 5
• GCProfiler: 2
• version flags: 2
• string representation: 1
• startup snapshots: 1

Verification

• Node 26.5.0 syntax checks pass for all 46 fixtures
• repeated Node oracle runs are byte-identical (bfff20a44ab6c45f283841fbdc092aca7a096eb031c2fe31525129d046f95c76)
• repeated focused Perry runs are identical: 14/46, with 31 diffs and 1 runtime timeout bucket
• detailed classification: 14 passes, 30 output mismatches, one stable serialize/builtins SIGSEGV, one stable serialize/references-cycles timeout, zero compile failures
• deno fmt --check test-parity/node-suite/v8
• cargo fmt --all -- --check
• release compiler/runtime package build
• JSON and baseline/count invariants
• Rust file-size gate and git diff --check
• no generated heap snapshots or temporary artifacts

Intentional boundaries

Exact serialized bytes, volatile heap sizes, GC/finalization timing, retention counts, raw profiler/coverage payloads, near-OOM behavior, stress/concurrency, private host-object hooks, and startup snapshot building remain outside this deterministic lane. Heap snapshot resources and temporary files are cleaned up through failure-safe paths.

Summary by CodeRabbit

• Tests

  • Expanded Node.js V8 compatibility coverage across serialization, heap statistics, heap snapshots, promise hooks, startup snapshots, strings, version tags, and runtime classes.
  • Added validation for supported inputs, error handling, object identity, lifecycle behavior, and data-shape consistency.
  • Updated parity tracking to include 46 V8 fixtures with improved baseline results.

• Documentation

  • Added guidance on suite scope, supported compatibility targets, intentional differences, and validation practices.

• Refactor

  • V8 parity checks now run sequentially for more deterministic results and safer handling of process-wide runtime state.

[coderabbitai]

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Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 75249986-37f1-488c-9a49-0df7603894e7

📥 Commits

Reviewing files that changed from the base of the PR and between 1d506a3 and 9b8f5a7.

📒 Files selected for processing (3)

• test-parity/node-suite/v8/serializer/release-reuse.ts
• test-parity/node-suite/v8/serializer/validation.ts
• test-parity/node_suite_baseline.json

📝 Walkthrough

Walkthrough

The PR adds 46 node:v8 parity fixtures covering exports, classes, serialization, heap diagnostics, promise hooks, strings, version tags, and startup snapshots. It documents the suite, moves it to sequential execution, and updates the baseline from 4 to 46 fixtures.

Changes

node:v8 parity suite

Layer / File(s)	Summary
Suite contract and execution baseline test-parity/node-suite/v8/README.md, scripts/node_suite_run.py, test-parity/node_suite_baseline.json	Documents the oracle, coverage, exclusions, validation results, and cleanup rules; runs v8 sequentially and records 46 fixtures.
Module, class, and profiler surfaces test-parity/node-suite/v8/exports/*, test-parity/node-suite/v8/classes/*, test-parity/node-suite/v8/gc-profiler/*	Adds checks for exports, descriptors, import identity, constructors, prototypes, receiver validation, inheritance, and GCProfiler lifecycle behavior.
Value serialization and deserialization test-parity/node-suite/v8/serialize/*	Adds round-trip and error fixtures for primitives, built-ins, collections, buffers, typed arrays, errors, shared references, cycles, and invalid inputs.
Serializer stream APIs test-parity/node-suite/v8/serializer/*	Adds coverage for headers, wire versions, raw values and views, input views, buffer transfer, release reuse, and validation errors.
Heap snapshots and statistics test-parity/node-suite/v8/heap-snapshot/*, test-parity/node-suite/v8/heap-statistics/*	Adds heap snapshot schema, stream lifecycle, cleanup, statistics shape, numeric invariants, supported modes, and invalid-input checks.
Promise hooks and runtime utilities test-parity/node-suite/v8/promise-hooks/*, test-parity/node-suite/v8/strings/*, test-parity/node-suite/v8/version-tag/*, test-parity/node-suite/v8/startup-snapshot/*	Adds promise hook surface, validation, parent tracking, lifecycle ordering, string representation, version-tag, and startup-snapshot checks.

Estimated code review effort: 4 (Complex) | ~60 minutes

Possibly related PRs

• PerryTS/perry#5097: Updates the node-suite slow-lane module allowlist.
• PerryTS/perry#6448: Changes sequential execution selection for another node-suite module.
• PerryTS/perry#6484: Updates the same slow-lane allowlist for a different module.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: expanding granular Node v8 parity coverage.
Description check	✅ Passed	The description covers summary, coverage, verification, and boundaries, but it omits the template's Changes, Related issue, Test plan, and Checklist sections.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch test/expand-node-v8-parity

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[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

test-parity/node_suite_baseline.json (1)

7-11: 🗄️ Data Integrity & Integration | 🟡 Minor | ⚡ Quick win

Update the overall baseline totals to reflect the v8 module changes.

The v8 module's metrics were updated, adding 10 to pass and 42 to total, but the overall metrics were not updated to match. The overall metrics should be updated to maintain data consistency.

📝 Proposed fix to update overall metrics

   "overall": {
-    "pass": 2810,
-    "total": 2863,
-    "pct": 98.1
+    "pass": 2820,
+    "total": 2905,
+    "pct": 97.1
   },

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@test-parity/node_suite_baseline.json` around lines 7 - 11, Update the overall
metrics object in node_suite_baseline.json to incorporate the v8 module changes:
increase pass by 10 and total by 42, then recalculate pct from those updated
totals so the aggregate remains consistent.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test-parity/node-suite/v8/serializer/release-reuse.ts`:
- Line 1: Explicitly import Buffer from node:buffer in
test-parity/node-suite/v8/serializer/release-reuse.ts at lines 1-1 for the
Buffer.isBuffer call, and in test-parity/node-suite/v8/serializer/validation.ts
at lines 1-1 for the Buffer.alloc call; no other changes are needed.

---

Outside diff comments:
In `@test-parity/node_suite_baseline.json`:
- Around line 7-11: Update the overall metrics object in
node_suite_baseline.json to incorporate the v8 module changes: increase pass by
10 and total by 42, then recalculate pct from those updated totals so the
aggregate remains consistent.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

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

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: ed1c261d-0c87-495c-b5a9-ad44cf2476cf

📥 Commits

Reviewing files that changed from the base of the PR and between 77def53 and 1d506a3.

📒 Files selected for processing (48)

• scripts/node_suite_run.py
• test-parity/node-suite/v8/README.md
• test-parity/node-suite/v8/classes/constructor-validation.ts
• test-parity/node-suite/v8/classes/instances-inheritance.ts
• test-parity/node-suite/v8/classes/prototypes.ts
• test-parity/node-suite/v8/classes/receiver-validation.ts
• test-parity/node-suite/v8/exports/descriptors.ts
• test-parity/node-suite/v8/exports/diagnostics-surface.ts
• test-parity/node-suite/v8/exports/import-identity.ts
• test-parity/node-suite/v8/exports/public-surface.ts
• test-parity/node-suite/v8/gc-profiler/dispose.ts
• test-parity/node-suite/v8/heap-snapshot/output.ts
• test-parity/node-suite/v8/heap-snapshot/semantic-schema.ts
• test-parity/node-suite/v8/heap-snapshot/twice.ts
• test-parity/node-suite/v8/heap-statistics/code-shape.ts
• test-parity/node-suite/v8/heap-statistics/cpp-shape.ts
• test-parity/node-suite/v8/heap-statistics/general-shape.ts
• test-parity/node-suite/v8/heap-statistics/spaces-shape.ts
• test-parity/node-suite/v8/promise-hooks/completion-order.ts
• test-parity/node-suite/v8/promise-hooks/init-parent.ts
• test-parity/node-suite/v8/promise-hooks/lifecycle-order.ts
• test-parity/node-suite/v8/promise-hooks/surface.ts
• test-parity/node-suite/v8/promise-hooks/validation.ts
• test-parity/node-suite/v8/serialize/buffers-views.ts
• test-parity/node-suite/v8/serialize/builtins.ts
• test-parity/node-suite/v8/serialize/corrupt-input.ts
• test-parity/node-suite/v8/serialize/error-like.ts
• test-parity/node-suite/v8/serialize/float16-array.ts
• test-parity/node-suite/v8/serialize/invalid-input.ts
• test-parity/node-suite/v8/serialize/invalid-values.ts
• test-parity/node-suite/v8/serialize/map-set.ts
• test-parity/node-suite/v8/serialize/objects-collections.ts
• test-parity/node-suite/v8/serialize/primitives.ts
• test-parity/node-suite/v8/serialize/references-cycles.ts
• test-parity/node-suite/v8/serialize/typed-arrays.ts
• test-parity/node-suite/v8/serializer/header-values.ts
• test-parity/node-suite/v8/serializer/input-view-family.ts
• test-parity/node-suite/v8/serializer/raw-primitives.ts
• test-parity/node-suite/v8/serializer/raw-views.ts
• test-parity/node-suite/v8/serializer/release-reuse.ts
• test-parity/node-suite/v8/serializer/transfer-array-buffer.ts
• test-parity/node-suite/v8/serializer/validation.ts
• test-parity/node-suite/v8/serializer/wire-version.ts
• test-parity/node-suite/v8/startup-snapshot/shape.ts
• test-parity/node-suite/v8/strings/one-byte.ts
• test-parity/node-suite/v8/version-tag/flags-isolated.ts
• test-parity/node-suite/v8/version-tag/stability.ts
• test-parity/node_suite_baseline.json