stream: avoid draining merged iter sources by trivikr · Pull Request #64293 · nodejs/node

trivikr · 2026-07-04T22:43:25Z

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

trivikr · 2026-07-04T22:43:25Z

Fixes: #63566

stream/itermerge() was scheduling the next read from a source as soon as
that source produced a value. For fast sources, this could drain all inputs even
while the merged consumer was idle after a single next().

This defers each source's next read until the merged iterator resumes after
yielding the previous value.

Assisted-by: openai:gpt-5.5

nodejs-github-bot · 2026-07-04T22:43:30Z

Review requested:

@nodejs/streams

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

codecov · 2026-07-08T18:02:00Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.25%. Comparing base (799e910) to head (0b25aaa).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64293 +/- ##
=======================================
Coverage 90.25% 90.25% =======================================
Files 741 741 Lines 241165 241167 +2 Branches 45428 45419 -9 =======================================
+ Hits 217667 217669 +2 
Misses 15069 15069 Partials 8429 8429

Files with missing lines	Coverage Δ
lib/internal/streams/iter/consumers.js	`97.15% <100.00%> (+0.68%)`	⬆️

... and 26 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 · 2026-07-08T19:10:11Z

CI: https://ci.nodejs.org/job/node-test-pull-request/74677/

nodejs-github-bot · 2026-07-08T23:01:55Z

Landed in 0032189

Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5 PR-URL: #64293Fixes: #63566 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

nodejs-github-bot added needs-ci PRs that need a full CI run. stream Issues and PRs related to Node.js streams. labels Jul 4, 2026

trivikr added the request-ci Add this label to start a Jenkins CI on a PR. label Jul 4, 2026

stream: avoid draining merged iter sources
0b25aaa
Defer reading the next value from each source in merge() until the merged consumer resumes after receiving the previous value. Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com> Assisted-by: openai:gpt-5.5

trivikr force-pushed the stream-iter-merge-drain-consumer-idle branch from 61b6bd2 to 0b25aaaCompare July 8, 2026 16:05

jasnell approved these changes Jul 8, 2026
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github-actionsBot removed the request-ci Add this label to start a Jenkins CI on a PR. label Jul 8, 2026

trivikr added the author ready PRs with CI started, the required approvals, and no outstanding review comments. label Jul 8, 2026

gurgunday approved these changes Jul 8, 2026
View reviewed changes

efekrskl approved these changes Jul 8, 2026
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trivikr added the commit-queue PRs queued for automated landing through the Commit Queue. label Jul 8, 2026

nodejs-github-bot removed the commit-queue PRs queued for automated landing through the Commit Queue. label Jul 8, 2026

nodejs-github-bot merged commit 0032189 into nodejs:mainJul 8, 2026
72 checks passed

trivikr deleted the stream-iter-merge-drain-consumer-idle branch July 13, 2026 05:14

github-actionsBot mentioned this pull request Jul 21, 2026
2026-07-22, Version 26.6.0 (Current) #64655
Merged

github-actionsBot mentioned this pull request Aug 21, 2026
2026-08-26, Version 24.20.0 'Krypton' (LTS) #65461
Merged