feat(utils): add NodeJS profiler #1219

BioPhoton · 2026-01-16T18:37:36Z

Related: #1197

This PR includes:

adding NodeJSProfiler class
implemented performanceObserver for NodeJSProfiler
revamp PerformanceObserverSink - add getStatus for better testing, more robust and memory friendly buffer logic

Note

Introduces a Node.js profiling runtime with buffered performance entry handling and richer diagnostics.

Adds NodejsProfiler that wraps Profiler with a PerformanceObserverSink, manages WAL/sink lifecycle, runtime enable/disable, state transitions, flush(), and stats exposure (with optional debug transition markers via CP_PROFILER_DEBUG)
Rewrites PerformanceObserverSink with safe bounded queue (maxQueueSize), proactive flushing (flushThreshold), buffered capture, encode error handling (optional debug marks), getStats(), and validateFlushThreshold
Updates test/mocks: MockSink/MockTraceEventFileSink (Recoverable), new PerformanceObserver test utils, comprehensive unit/integration tests for sink and profilers
Adds profiler documentation covering setup, API, environment flags, and Node.js integration

^{Written by Cursor Bugbot for commit ac4a1fc. This will update automatically on new commits. Configure here.}

- Add explanation that sink determines output format (DevTools TraceEvent, OpenTelemetry, etc.) - Improve documentation clarity for flexible serialization capabilities - Fix duplicate imports in profiler unit test

- Replace method implementations with vi.fn() spy functions - Add vi import from vitest - Enables better testing with call tracking and assertions

nx-cloud · 2026-01-16T18:38:57Z

View your CI Pipeline Execution ↗ for commit ac4a1fc

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`nx run ci:code-pushup -- merge-diffs --files=/h...`	✅ Succeeded	5s	View ↗
`nx run-many --targets=code-pushup --parallel=fa...`	✅ Succeeded	1m 32s	View ↗
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`nx run-many -t unit-test,int-test`	✅ Succeeded	8s	View ↗

☁️ Nx Cloud last updated this comment at 2026-01-26 22:11:18 UTC

pkg-pr-new · 2026-01-16T18:39:14Z

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@code-pushup/cli

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@code-pushup/core

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@code-pushup/nx-plugin

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@code-pushup/coverage-plugin

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@code-pushup/js-packages-plugin

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@code-pushup/eslint-plugin

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@code-pushup/utils

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commit: ac4a1fc

github-actions · 2026-01-16T18:45:52Z

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared current commit 25388bf with previous commit ea27cdc.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Documentation	🔴 42	🟡 51
Performance	🔴 29	🔴 35
Code coverage	🟢 92	🟢 92
Bug prevention	🟡 75	🟡 75
Axe Accessibility	🟡 88	🟡 88
Code style	🟢 100	🟢 100	–
Security	🔴 47	🔴 47	–
Updates	🟡 78	🟡 78	–
Type Safety	🟡 67	🟡 67	–
Miscellaneous	🟡 67	🟡 67	–
Accessibility	🟢 92	🟢 92	–
Best Practices	🟢 100	🟢 100	–
SEO	🟢 92	🟢 92	–

👍 2 groups improved, 👎 1 group regressed, 👍 11 audits improved, 👎 2 audits regressed, 13 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score
JSDocs coverage	Documentation coverage	🔴 42	🟡 51
Lighthouse	Performance	🔴 29	🔴 35
Code coverage	Code coverage metrics	🟢 92	🟢 92

31 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value
JSDocs coverage	Properties coverage	🟥 30 undocumented properties	🟥 27 undocumented properties
Lighthouse	First Contentful Paint	🟥 3.9 s	🟥 3.1 s
Lighthouse	Speed Index	🟥 9.3 s	🟥 7.0 s
JSDocs coverage	Methods coverage	🟨 13 undocumented methods	🟨 9 undocumented methods
JSDocs coverage	Classes coverage	🟥 6 undocumented classes	🟨 5 undocumented classes
Lighthouse	Total Blocking Time	🟥 7,300 ms	🟥 1,940 ms
Lighthouse	Time to Interactive	🟥 17.7 s	🟥 13.7 s
JSDocs coverage	Variables coverage	🟥 272 undocumented variables	🟥 272 undocumented variables
JSDocs coverage	Types coverage	🟥 272 undocumented types	🟥 271 undocumented types
JSDocs coverage	Functions coverage	🟥 579 undocumented functions	🟥 579 undocumented functions
Code coverage	Line coverage	🟩 92.3 %	🟩 92.5 %
Code coverage	Branch coverage	🟨 89 %	🟨 88.9 %
Code coverage	Function coverage	🟩 94.1 %	🟩 94.1 %
Lighthouse	Minimizes main-thread work	🟥 24.2 s	🟥 10.9 s
Lighthouse	JavaScript execution time	🟥 9.6 s	🟥 4.3 s
Lighthouse	Avoids enormous network payloads	🟩 Total size was 2,098 KiB	🟩 Total size was 2,093 KiB
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Largest Contentful Paint	🟥 14.5 s	🟥 11.7 s
Lighthouse	Max Potential First Input Delay	🟥 3,650 ms	🟥 1,150 ms
Lighthouse	Server Backend Latencies	🟩 1,040 ms	🟩 600 ms
Lighthouse	Uses efficient cache policy on static assets	🟨 31 resources found	🟨 31 resources found
Lighthouse	Reduce unused CSS	🟥 Potential savings of 125 KiB	🟥 Potential savings of 125 KiB
Lighthouse	Reduce unused JavaScript	🟥 Potential savings of 226 KiB	🟥 Potential savings of 226 KiB
Lighthouse	Initial server response time was short	🟩 Root document took 560 ms	🟩 Root document took 500 ms
Lighthouse	Remove duplicate modules in JavaScript bundles	🟥 Potential savings of 88 KiB	🟥 Potential savings of 88 KiB
Lighthouse	Network Round Trip Times	🟩 20 ms	🟩 10 ms

653 other audits are unchanged.

github-actions · 2026-01-16T22:38:36Z

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared current commit 25388bf with previous commit ea27cdc.

💼 Project `utils`

🤨 Code PushUp report has both improvements and regressions.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Documentation	🔴 46	🟡 57
Code coverage	🟢 95	🟢 95

4 other categories are unchanged.

👍 1 group improved, 👎 1 group regressed, 👍 7 audits improved, 👎 2 audits regressed

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
JSDocs coverage	Documentation coverage	🔴 46	🟡 57
Code coverage	Code coverage metrics	🟢 95	🟢 95

13 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value
JSDocs coverage	Properties coverage	🟥 27 undocumented properties	🟥 24 undocumented properties
JSDocs coverage	Classes coverage	🟨 3 undocumented classes	🟨 2 undocumented classes
JSDocs coverage	Methods coverage	🟨 13 undocumented methods	🟨 9 undocumented methods
JSDocs coverage	Variables coverage	🟥 49 undocumented variables	🟥 49 undocumented variables
JSDocs coverage	Types coverage	🟥 66 undocumented types	🟥 65 undocumented types
JSDocs coverage	Functions coverage	🟥 241 undocumented functions	🟥 241 undocumented functions
Code coverage	Branch coverage	🟩 91.7 %	🟩 91.6 %
Code coverage	Function coverage	🟩 95.7 %	🟩 95.6 %
Code coverage	Line coverage	🟩 97.7 %	🟩 97.8 %

435 other audits are unchanged.

13 other projects are unchanged.

packages/utils/docs/profiler.md

packages/utils/src/lib/profiler/profiler.int.test.ts

packages/utils/docs/profiler.md

Co-authored-by: Hanna Skryl <80118140+hanna-skryl@users.noreply.github.com>

packages/utils/docs/profiler.md

packages/utils/src/lib/performance-observer.ts

packages/utils/src/lib/profiler/profiler.ts

packages/utils/src/lib/profiler/profiler.int.test.ts

packages/utils/src/lib/profiler/profiler.unit.test.ts

packages/utils/src/lib/performance-observer.ts

packages/utils/src/lib/profiler/profiler.ts

packages/utils/src/lib/profiler/profiler.unit.test.ts

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packages/utils/src/lib/performance-observer.ts

packages/utils/src/lib/profiler/profiler.ts

# Conflicts: # packages/utils/src/lib/profiler/profiler.int.test.ts # packages/utils/src/lib/profiler/profiler.unit.test.ts

BioPhoton added 4 commits January 16, 2026 17:52

feat: add NodeJSProfiler

b71f3c7

docs: clarify that sink defines output format in NodejsProfiler JSDoc

d8d5a93

- Add explanation that sink determines output format (DevTools TraceEvent, OpenTelemetry, etc.) - Improve documentation clarity for flexible serialization capabilities - Fix duplicate imports in profiler unit test

test: convert all MockSink and MockTraceEventFileSink methods to spies

673b5c4

- Replace method implementations with vi.fn() spy functions - Add vi import from vitest - Enables better testing with call tracking and assertions

refactor: add tests

7c14a0b

github-actions bot assigned BioPhoton Jan 16, 2026

github-actions bot added 📖 Project documentation improvements or additions to the project documentation 🔬 testing writing tests 🧩 utils labels Jan 16, 2026

BioPhoton mentioned this pull request Jan 16, 2026

Implement performance profiling and trace file generation #1197

Open

Merge branch 'main' into feat/utils/profiler-perf-buffer

b6babbe

refactor: fix lint

d328c9f

BioPhoton marked this pull request as ready for review January 16, 2026 22:22

BioPhoton requested review from hanna-skryl and matejchalk January 16, 2026 22:22

hanna-skryl reviewed Jan 16, 2026

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BioPhoton commented Jan 17, 2026

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Apply suggestions from code review

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Co-authored-by: Hanna Skryl <80118140+hanna-skryl@users.noreply.github.com>

BioPhoton commented Jan 18, 2026

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BioPhoton and others added 7 commits January 18, 2026 05:07

Update packages/utils/docs/profiler.md

f2b374e

Update packages/utils/docs/profiler.md

cb61834

fix: adjust observer logic

27e76f2

docs: update docs

e227c8f

refactor: wip

b347c9d

refactor: fix int tests

0125f7a

refactor: fix lint

8334310

BioPhoton requested a review from hanna-skryl January 18, 2026 17:41

BioPhoton added 4 commits January 19, 2026 03:18

refactor: wip

7e41c05

refactor: wip

d11088e

refactor: wip

9c03f7f

refactor: fix int test

9b75840

hanna-skryl reviewed Jan 20, 2026

View reviewed changes

hanna-skryl mentioned this pull request Jan 20, 2026

test: remove redundant vitest imports #1225

Merged

BioPhoton added 3 commits January 26, 2026 17:56

refactor: wip

6157b18

refactor: wip comments

7ed02d5

refactor: wip tests

a8ba2a6

cursor bot reviewed Jan 26, 2026

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BioPhoton added 4 commits January 26, 2026 21:51

refactor: wip tests

96079fa

Merge branch 'main' into feat/utils/profiler-perf-buffer

9b6719c

# Conflicts: # packages/utils/src/lib/profiler/profiler.int.test.ts # packages/utils/src/lib/profiler/profiler.unit.test.ts

refactor: wip tests

00bef3e

refactor: wip tests

13019da

BioPhoton requested a review from hanna-skryl January 26, 2026 20:59

refactor: wip

ac4a1fc

feat(utils): add NodeJS profiler #1219

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feat(utils): add NodeJS profiler #1219

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💼 Project `utils`