test_runner: avoid hanging on incomplete v8 frames by thisalihassan · Pull Request #62704 · nodejs/node

thisalihassan · 2026-04-12T10:23:12Z

The test runner could hang while draining child stdout when the buffered data started with bytes that matched the V8 serializer header (0xff 0x0f) but did not contain a complete serialized frame.

In that case #processRawBuffer() made no progress, and #drainRawBuffer() kept calling it in a loop forever.

This change makes the deserializer recover from that end-of-stream case by flushing the buffered bytes as stdout and continuing to resync. It also preserves the ordering of a trailing partial V8 header split across chunks.

Closes #62693

Assisted-by: Claude Opus

nodejs-github-bot · 2026-04-12T10:23:19Z

Review requested:

@nodejs/test_runner

aduh95 · 2026-04-12T10:41:24Z

+    // size, causing #processRawBuffer to make no progress and
+    // #drainRawBuffer to loop forever without the no-progress guard.
+    const reported = await collectReported([oversizedLengthHeader]);
+    assert(reported.every((event) => event.type === 'test:stdout'));


We can get a much more useful error output by using partialDeepStrictEqual here

Suggested change

assert(reported.every((event) => event.type === 'test:stdout'));

assert.partialDeepStrictEqual(reported, Array.from({ length: reported.length }, () => ({ type: 'test:stdout' }));

aduh95 · 2026-04-12T10:45:44Z

+          data: {
+            __proto__: null,
+            file: this.name,
+            message: TypedArrayPrototypeSubarray(bufferHead, 0, 1).toString('utf-8'),


If we're dealing with a single-byte UTF-8 char, we don't need the intermediate view I think

Suggested change

message: TypedArrayPrototypeSubarray(bufferHead, 0, 1).toString('utf-8'),

message: StringFromCharCode(bufferHead[0]),

it changes the output semantics here StringFromCharCode(0xff) gives "ÿ" but Buffer.from([0xff]).toString('utf8') gives "�" which matches the current stdout path so I’m keeping the UTF-8 decode

String.fromCodePoint then – but I'm surprised we would get non-ASCII chars here

Right, switched to StringFromCharCode the byte here is always the V8 version tag (0xFF)

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com>

avivkeller · 2026-04-12T12:14:19Z

Can you add a proper PR description?

codecov · 2026-04-12T12:39:32Z

Codecov Report

❌ Patch coverage is 95.65217% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.80%. Comparing base (0fea430) to head (e07cdd4).
⚠️ Report is 355 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/runner.js	95.65%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62704      +/-   ##
==========================================
- Coverage   89.80%   89.80%   -0.01%     
==========================================
  Files         699      699              
  Lines      216363   216417      +54     
  Branches    41370    41377       +7     
==========================================
+ Hits       194309   194356      +47     
- Misses      14140    14141       +1     
- Partials     7914     7920       +6

Files with missing lines	Coverage Δ
lib/internal/test_runner/runner.js	`93.68% <95.65%> (+0.03%)`	⬆️

... and 34 files with indirect coverage changes

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…-byte fallback path Signed-off-by: Ali Hassan <ali-hassan27@outlook.com>

thisalihassan · 2026-04-30T13:55:48Z

@aduh95 can you please take a relook at this again?

nodejs-github-bot · 2026-05-17T21:10:13Z

CI: https://ci.nodejs.org/job/node-test-pull-request/73512/

nodejs-github-bot · 2026-05-18T07:54:37Z

Landed in debe2ed

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: nodejs#62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: nodejs#62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

This test synthesizes fake V8-serialized messages with the serialization format version hardcoded to 15 (0x0f). Electron bundles Chromium's V8, whose value-serializer format version is 16 (0x10), so the hardcoded headers are not recognized by the test runner's deserializer and the bytes fall through the UTF-8 stdout path (0xff -> U+FFFD), failing the assertions. The version difference is environmental and cannot be reconciled without re-patching the test on every V8 bump. The failing subtests were introduced upstream in nodejs/node#62704 (test_runner: avoid hanging on incomplete v8 frames).

* chore: bump node in DEPS to v24.17.0 * chore: update patches (trivial only) Co-Authored-By: GPT-5.3-Codex <copilot@github.com> * chore: bump node in DEPS to v24.18.0 * fix(patch): BoringSSL and OpenSSL incompatibilities Ref: nodejs/node@677ca7e76c9 Co-Authored-By: GPT-5.3-Codex <copilot@github.com> * fix(patch): crypto tests to run with BoringSSL Ref: nodejs/node@61b20f60a39 Co-Authored-By: GPT-5.3-Codex <copilot@github.com> * fix(patch): expose built-in electron module in ESM loader Ref: nodejs/node@69df688fff4 Co-Authored-By: GPT-5.3-Codex <copilot@github.com> * chore: update patches (trivial only) * fix(patch): adapt ESM tests for Electron Ref: nodejs/node@69df688fff4 Co-Authored-By: GPT-5.3-Codex <copilot@github.com> * chore: update filenames.auto.gni * test: update JWK error message assertion for unsupported algorithm The error thrown for an unsupported OKP (Ed448) JWK changed from 'Invalid JWK data' to the more specific 'Invalid JWK OKP key'. Ref: nodejs/node#62499 * test: disable parallel/test-runner-v8-deserializer This test synthesizes fake V8-serialized messages with the serialization format version hardcoded to 15 (0x0f). Electron bundles Chromium's V8, whose value-serializer format version is 16 (0x10), so the hardcoded headers are not recognized by the test runner's deserializer and the bytes fall through the UTF-8 stdout path (0xff -> U+FFFD), failing the assertions. The version difference is environmental and cannot be reconciled without re-patching the test on every V8 bump. The failing subtests were introduced upstream in nodejs/node#62704 (test_runner: avoid hanging on incomplete v8 frames). * docs: update node upgrade skill to reflect boringSSL updates * chore: update patch after rebase --------- Co-authored-by: electron-roller[bot] <84116207+electron-roller[bot]@users.noreply.github.com> Co-authored-by: John Kleinschmidt <jkleinsc@electronjs.org> Co-authored-by: GPT-5.3-Codex <copilot@github.com>

nodejs-github-bot added needs-ci PRs that need a full CI run. test_runner Issues and PRs related to the test runner subsystem. labels Apr 12, 2026

aduh95 reviewed Apr 12, 2026

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test_runner: avoid hanging on incomplete v8 frames

825b3e3

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com>

thisalihassan force-pushed the fix/test-runner-hangs branch from 631f70a to 825b3e3 Compare April 12, 2026 11:20

thisalihassan requested a review from aduh95 April 12, 2026 11:21

Replace TypedArrayPrototypeSubarray StringFromCharCode in the byte-by…

e07cdd4

…-byte fallback path Signed-off-by: Ali Hassan <ali-hassan27@outlook.com>

MoLow approved these changes Apr 13, 2026

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atlowChemi approved these changes Apr 30, 2026

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atlowChemi mentioned this pull request May 5, 2026

test_runner: prevent infinite loop on malformed v8 header #63124

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nodejs-github-bot merged commit debe2ed into nodejs:main May 18, 2026
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aduh95 pushed a commit that referenced this pull request May 19, 2026

test_runner: avoid hanging on incomplete v8 frames

1dfa82a

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

aduh95 pushed a commit that referenced this pull request May 19, 2026

test_runner: avoid hanging on incomplete v8 frames

83054e8

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

github-actions Bot mentioned this pull request May 19, 2026

2026-05-20, Version 26.2.0 (Current) #63440

Merged

joyeecheung mentioned this pull request May 21, 2026

V8 serdes header changed nodejs/node-v8#311

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aduh95 pushed a commit that referenced this pull request May 23, 2026

test_runner: avoid hanging on incomplete v8 frames

6b339c1

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

aduh95 pushed a commit that referenced this pull request Jun 18, 2026

test_runner: avoid hanging on incomplete v8 frames

df183d7

Signed-off-by: Ali Hassan <ali-hassan27@outlook.com> PR-URL: #62704 Reviewed-By: Moshe Atlow <moshe@atlow.co.il> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

github-actions Bot mentioned this pull request Jun 19, 2026

2026-06-19, Version 24.18.0 'Krypton' (LTS) #64001

Closed

sxa mentioned this pull request Jun 22, 2026

2026-06-23, Version 24.18.0 'Krypton' (LTS) #64062

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test_runner: avoid hanging on incomplete v8 frames#62704

test_runner: avoid hanging on incomplete v8 frames#62704
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	assert(reported.every((event) => event.type === 'test:stdout'));
	assert.partialDeepStrictEqual(reported, Array.from({ length: reported.length }, () => ({ type: 'test:stdout' }));

	message: TypedArrayPrototypeSubarray(bufferHead, 0, 1).toString('utf-8'),
	message: StringFromCharCode(bufferHead[0]),

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