stream: refine stream/iter backpressure and error handling by jasnell · Pull Request #63697 · nodejs/node

jasnell · 2026-06-01T16:22:55Z

Improve the backpressure implementation alignment with the spec.
Improve error handling in a couple cases.

nodejs-github-bot · 2026-06-01T16:23:01Z

Review requested:

@nodejs/streams

codecov · 2026-06-01T18:09:33Z

Codecov Report

❌ Patch coverage is 83.01887% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.35%. Comparing base (faa413e) to head (28142cd).
⚠️ Report is 39 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/streams/iter/classic.js	62.50%	6 Missing ⚠️
lib/internal/streams/iter/consumers.js	91.42%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #63697      +/-   ##
==========================================
- Coverage   91.96%   90.35%   -1.62%     
==========================================
  Files         379      732     +353     
  Lines      166659   236588   +69929     
  Branches    25502    44567   +19065     
==========================================
+ Hits       153270   213763   +60493     
- Misses      13100    14544    +1444     
- Partials      289     8281    +7992

Files with missing lines	Coverage Δ
lib/internal/streams/iter/pull.js	`88.23% <ø> (+0.02%)`	⬆️
lib/internal/streams/iter/push.js	`90.84% <100.00%> (-0.79%)`	⬇️
lib/internal/streams/iter/types.js	`100.00% <ø> (ø)`
lib/internal/streams/iter/consumers.js	`96.76% <91.42%> (+0.15%)`	⬆️
lib/internal/streams/iter/classic.js	`89.26% <62.50%> (+0.35%)`	⬆️

... and 478 files with indirect coverage changes

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

nodejs-github-bot · 2026-06-02T23:52:15Z

CI: https://ci.nodejs.org/job/node-test-pull-request/73899/

In `Writer`, there are two queues that matter: the slot queue and the pending queue. The sync `writeSync`/`writevSync` only use the slot queue. If writes cannot be accepted directly into slots, they return `false`. The sync methods *never* enqueue into the pending queue. The async `write`/`writev` will first attempt to add to the slot queue; if it is full, then it will attempt to add to the pending queue; if that is also full, the backpressure policy kicks in. Signed-off-by: James M Snell <jasnell@gmail.com>

Signed-off-by: James M Snell <jasnell@gmail.com>

trivikr

Rebased after resolving conflicts with #63564

trivikr · 2026-06-09T01:31:12Z

Since I rebased the changes to resolve conflict, this needs approval from another reviewer for CI to start.

mcollina

lgtm

nodejs-github-bot · 2026-06-17T09:25:42Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74204/

gurgunday

lgtm

nodejs-github-bot · 2026-06-17T16:08:48Z

Landed in b03e6e0

In `Writer`, there are two queues that matter: the slot queue and the pending queue. The sync `writeSync`/`writevSync` only use the slot queue. If writes cannot be accepted directly into slots, they return `false`. The sync methods *never* enqueue into the pending queue. The async `write`/`writev` will first attempt to add to the slot queue; if it is full, then it will attempt to add to the pending queue; if that is also full, the backpressure policy kicks in. Signed-off-by: James M Snell <jasnell@gmail.com> PR-URL: #63697 Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

In `Writer`, there are two queues that matter: the slot queue and the pending queue. The sync `writeSync`/`writevSync` only use the slot queue. If writes cannot be accepted directly into slots, they return `false`. The sync methods *never* enqueue into the pending queue. The async `write`/`writev` will first attempt to add to the slot queue; if it is full, then it will attempt to add to the pending queue; if that is also full, the backpressure policy kicks in. Signed-off-by: James M Snell <jasnell@gmail.com> PR-URL: nodejs#63697 Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

In `Writer`, there are two queues that matter: the slot queue and the pending queue. The sync `writeSync`/`writevSync` only use the slot queue. If writes cannot be accepted directly into slots, they return `false`. The sync methods *never* enqueue into the pending queue. The async `write`/`writev` will first attempt to add to the slot queue; if it is full, then it will attempt to add to the pending queue; if that is also full, the backpressure policy kicks in. Signed-off-by: James M Snell <jasnell@gmail.com> PR-URL: #63697 Backport-PR-URL: #64675 Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

jasnell requested review from mcollina and trivikr June 1, 2026 16:22

nodejs-github-bot added lib / src Issues and PRs involving general changes in the lib/ or src/ directories. needs-ci PRs that need a full CI run. labels Jun 1, 2026

trivikr requested changes Jun 2, 2026

View reviewed changes

Comment thread lib/internal/streams/iter/classic.js

Comment thread lib/internal/streams/iter/consumers.js Outdated

trivikr reviewed Jun 2, 2026

View reviewed changes

Comment thread lib/internal/streams/iter/consumers.js Outdated

Comment thread lib/internal/streams/iter/push.js

jasnell force-pushed the jasnell/refine-stream-iter-backpressure branch from bea41b1 to 28142cd Compare June 2, 2026 11:45

jasnell requested a review from trivikr June 2, 2026 11:45

jasnell changed the title ~~Jasnell/refine stream iter backpressure~~ stream: refine stream/iter backpressure and error handling Jun 2, 2026

trivikr approved these changes Jun 2, 2026

View reviewed changes

trivikr added the request-ci Add this label to start a Jenkins CI on a PR. label Jun 2, 2026

github-actions Bot removed the request-ci Add this label to start a Jenkins CI on a PR. label Jun 2, 2026

trivikr added the author ready PRs with CI started, the required approvals, and no outstanding review comments. label Jun 6, 2026

jasnell added 2 commits June 8, 2026 18:25

stream: fixup error handling in stream/iter adapters

c29567e

Signed-off-by: James M Snell <jasnell@gmail.com>

trivikr force-pushed the jasnell/refine-stream-iter-backpressure branch from 28142cd to c29567e Compare June 9, 2026 01:28

trivikr approved these changes Jun 9, 2026

View reviewed changes

trivikr added the request-ci Add this label to start a Jenkins CI on a PR. label Jun 9, 2026

trivikr added review wanted PRs that need review. and removed author ready PRs with CI started, the required approvals, and no outstanding review comments. review wanted PRs that need review. labels Jun 9, 2026

trivikr added the review wanted PRs that need review. label Jun 16, 2026

mcollina approved these changes Jun 17, 2026

View reviewed changes

mcollina added request-ci Add this label to start a Jenkins CI on a PR. and removed request-ci Add this label to start a Jenkins CI on a PR. labels Jun 17, 2026

github-actions Bot removed the request-ci Add this label to start a Jenkins CI on a PR. label Jun 17, 2026

gurgunday approved these changes Jun 17, 2026

View reviewed changes

trivikr added commit-queue-squash PRs the Commit Queue should land as one squashed commit. commit-queue PRs queued for automated landing through the Commit Queue. labels Jun 17, 2026

nodejs-github-bot removed the commit-queue PRs queued for automated landing through the Commit Queue. label Jun 17, 2026

nodejs-github-bot merged commit b03e6e0 into nodejs:main Jun 17, 2026
95 of 96 checks passed

github-actions Bot mentioned this pull request Jun 22, 2026

2026-06-23, Version 26.4.0 (Current) #64058

Merged

aduh95 mentioned this pull request Jul 22, 2026

[v24.x backport] node:stream/iter and QUIC backports #64675

Closed

github-actions Bot mentioned this pull request Aug 21, 2026

2026-08-26, Version 24.20.0 'Krypton' (LTS) #65461

Merged

Navigation Menu

Uh oh!

Uh oh!

stream: refine stream/iter backpressure and error handling - #63697

stream: refine stream/iter backpressure and error handling#63697
nodejs-github-bot merged 2 commits into
nodejs:mainfrom
jasnell:jasnell/refine-stream-iter-backpressure

jasnell commented Jun 1, 2026

Uh oh!

nodejs-github-bot commented Jun 1, 2026

Uh oh!

codecov Bot commented Jun 1, 2026 •

edited

Loading

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

nodejs-github-bot commented Jun 2, 2026

Uh oh!

trivikr left a comment •

edited

Loading

Uh oh!

trivikr commented Jun 9, 2026 •

edited

Loading

Uh oh!

mcollina left a comment

Uh oh!

nodejs-github-bot commented Jun 17, 2026

Uh oh!

gurgunday left a comment

Uh oh!

Uh oh!

nodejs-github-bot commented Jun 17, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

Uh oh!

Uh oh!

Conversation

jasnell commented Jun 1, 2026

Uh oh!

nodejs-github-bot commented Jun 1, 2026

Uh oh!

codecov Bot commented Jun 1, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

nodejs-github-bot commented Jun 2, 2026

Uh oh!

trivikr 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!

trivikr commented Jun 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

mcollina left a comment

Choose a reason for hiding this comment

Uh oh!

nodejs-github-bot commented Jun 17, 2026

Uh oh!

gurgunday left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

nodejs-github-bot commented Jun 17, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

codecov Bot commented Jun 1, 2026 •

edited

Loading

trivikr left a comment •

edited

Loading

trivikr commented Jun 9, 2026 •

edited

Loading