benchmark: add test-only and mock timers cases

[luanmuniz]

Adds another small set of node:test benchmarks for areas listed in #55723.
A continuation of the work I started in #63754
This is a different PR because it brings a different set of attention points, and to keep both PR easy to review.

This PR covers:

• only mode with --test-only
• mock.timers.enable()
• mocked setTimeout
• mocked setInterval
• mocked setImmediate
• mocked scheduler.wait
• mocked AbortSignal.timeout
• mocked Date.now()
• mock.timers.setTime()
• mock.timers.runAll()

Notes

1. enable-* test the enable() + reset() instead of just enable. This happens because an error is thrown if enable is called multiple times without reset.
2. The scheduler.wait mode includes the final Promise.all() inside the measured section. My evaluation was that it was more appropriate to do so than not, since the scheduled waits are promise-based, but I am happy to adjust the structure if reviewers prefer a narrower measure.

Issue found while writing this

TLDR: I found an issue (that doesn't affect this PR) with using setImmediate and runAll together while writing the benchmark; guidance welcome;

While writing the benchmark, I found that setImmediate doesn't work with runAll(). The mocked setImmediate is scheduled with a special -1 time so it runs before zero-delay timers. runAll() computes longestTimer.runAt - this.#now in mock_timers.js:816, which becomes -1, and tick() rejects negative time in mock_timers.js:556.

I would love to open a new PR to fix this issue, but this is beyond my context of how the team working on this operates and what they think would be an appropriate fix. If the person reviewing the PR could provide some guidance on the best way to handle this issue, it would be much appreciated.

This issue doesn't impact this PR, all benchmarks still work with the current code (With tick(0) instead of runAll() for setImmediate).

[nodejs-github-bot]

Review requested:

• @nodejs/performance

[RafaelGSS]

This is unnecessary; it's a clojure. Adding an assert.ok is probably more useful.

[luanmuniz]

Hi @RafaelGSS, thanks for taking a look.

Just to make sure I understand the suggestion: are you suggesting replacing the avoidV8Optimization assignment with an assertion inside the benchmarked section?

I added the avoidV8Optimization bit to avoid making the benchmarked callback completely empty, as detailed in the previous PR: #63754 (comment)

My concern with adding assert.ok() inside the callback is that the assertion itself would become part of what is being measured. Adding extra work inside the benchmark was also something @avivkeller raised in the previous PR: #63754 (comment)

I’m happy to adjust it either way. Please let me know how to proceed.

Thank you for the guidance.

Obs: I see the comments about calbrate-n on the first PR and i will push that change very soon here too

[luanmuniz]

@RafaelGSS For consistency with the other PR, i've removed the avoidV8Optimization here too. If the current implementation is acceptable, could the thread be resolved and CI started?

[luanmuniz]

Hi there, sorry for the force-push. Like the other branch, I had a local git history issue while cleaning up the branch, and I force-pushed to get the PR back into the intended state. Apologies for the noise. I’ll be more careful with the branch history going forward.

I've used calibrate-n, and there are the results in case you want to take a look:
calibrate-mock-timers.txt
calibrate-test-only.txt

The numbers are already adjusted.

cc @RafaelGSS

[luanmuniz]

Ping @RafaelGSS
Friendly ping on this one.

I believe the review feedback has been addressed, but please let me know if there is anything else you’d like me to change before this can move forward.

Happy to adjust further if needed.

[luanmuniz]

@RafaelGSS Sorry to keep pinging, im waiting the existing PR's to be closed to continue working on the other benchmarks, i don't want to have more PR's open at the same time. Let me know if there is anything i can do to help you move this and the other tickets i have open. Thank you!

[luanmuniz]

@RafaelGSS @avivkeller @nodejs/benchmarking could someone help resolve the remaining avoidV8Optimization thread?

This now has an approval from @avivkeller after the latest commit. My remaining uncertainty is whether replacing the assignment with assert.ok() is considered required, since that would add assertion work to the measured callback.

If the current implementation is acceptable, could the thread be resolved and CI started? Otherwise, please let me know the specific implementation you would prefer.

[luanmuniz]

Fixed the commit-message lint failure by adding the benchmark subsystem and removing the trailing punctuation. The updated commit now passes core-validate-commit locally.

Could someone please reapprove the updated commit and trigger CI again?
Thank you!

[nodejs-github-bot]

Commit Queue failed

- Loading data for nodejs/node/pull/64097
✔  Done loading data for nodejs/node/pull/64097
----------------------------------- PR info ------------------------------------
Title      benchmark: add test-only and mock timers cases (#64097)
   ⚠  Could not retrieve the email or name of the PR author's from user's GitHub profile!
Branch     luanmuniz:benchmark-test-runner-only-mock-timers -> nodejs:main
Labels     benchmark, author ready, commit-queue, commit-queue-squash, test_runner
Commits    3
 - benchmark: add test-only and mock timers cases
 - benchmark: calibrate test runner benchmarks
 - benchmark: remove optimization guard
Committers 1
 - Luan Muniz <luan@luanmuniz.com.br>
PR-URL: https://github.com/nodejs/node/pull/64097
Reviewed-By: Aviv Keller <me@aviv.sh>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/64097
Reviewed-By: Aviv Keller <me@aviv.sh>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
--------------------------------------------------------------------------------
   ℹ  This PR was created on Tue, 23 Jun 2026 17:50:53 GMT
   ✔  Approvals: 2
   ✔  - Aviv Keller (@avivkeller): https://github.com/nodejs/node/pull/64097#pullrequestreview-4673879801
   ✔  - Rafael Gonzaga (@RafaelGSS) (TSC): https://github.com/nodejs/node/pull/64097#pullrequestreview-4954346663
   ✘  GitHub CI is still running
   ℹ  Green GitHub CI is sufficient
--------------------------------------------------------------------------------
   ✔  Aborted `git node land` session in /home/runner/work/node/node/.ncu

https://github.com/nodejs/node/actions/runs/32067715646

[RafaelGSS]

can you rebase so github ci is triggered again?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.94%. Comparing base (cf30b2e) to head (9dfd597).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #64097      +/-   ##
==========================================
+ Coverage   90.11%   91.94%   +1.82%     
==========================================
  Files         752      400     -352     
  Lines      251861   178855   -73006     
  Branches    47365    27313   -20052     
==========================================
- Hits       226955   164440   -62515     
+ Misses      16238    14087    -2151     
+ Partials     8668      328    -8340     

see 485 files with indirect coverage changes

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