feat(utils): add WriteAheadLog classes

[BioPhoton]

Related: #1197

This PR includes:

• types for source sink flows
• wal.ts - general WriteAheadLog and sharded WAL inc format and filenames
• wal-trace-json.ts traceEvent specific login for a WAL
• profiler constants to control WAL leader
• moved trace utils into profiler

Note

This PR addresses a comment related to logging.
It could also be used as file output for the logger

Warning

All filesystem operations in WAL—and indirectly in the profiler—are synchronous by design.
The eslint rules are disables over file name pattern

Why synchronous fs is used for WAL code?

• Profilers are side-channels, not business logic
• Data must never be lost, reordered, or partially written
• process.on('exit')cannot safely run async I/O
• Sync writes guarantee ordering + durability
• Profiler I/O volume is small → overhead is negligible
• Crash-safety > throughput

---

Note

Introduces a synchronous Write-Ahead Log system and integrates it with profiler trace generation.

• New wal.ts: WriteAheadLogFile, ShardedWal, codecs (stringCodec, createTolerantCodec), sharding IDs/paths, finalize/cleanup helpers, and AppendableSink interface
• Profiler: add getProfilerId, new constants, and move/expand trace utils (trace-file-utils.ts) with encode/decode helpers, metadata, and entryToTraceEvents
• New wal-json-trace.ts: generate complete Chrome trace content and expose traceEventWalFormat
• Refactor PerformanceObserverSink to use AppendableSink.append and update mocks/tests; remove legacy sink-source.type.ts
• Set realistic time origin in tests; add many unit/integration tests
• ESLint: disable n/no-sync for wal*.ts files

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---

☁️ Nx Cloud last updated this comment at 2026-01-26 22:21:37 UTC

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commit: 953a3e7

[github-actions]

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared current commit 276ae6b with previous commit ea27cdc.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🔴 29	🔴 33
Documentation	🔴 42	🔴 46
Code coverage	🟢 92	🟢 93
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	–

👍 3 groups improved, 👍 13 audits improved, 12 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🔴 29	🔴 33
JSDocs coverage	Documentation coverage	🔴 42	🔴 46
Code coverage	Code coverage metrics	🟢 92	🟢 93

31 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	First Contentful Paint	🟥 3.9 s	🟥 3.2 s
Lighthouse	Speed Index	🟥 9.3 s	🟥 7.6 s
JSDocs coverage	Classes coverage	🟥 6 undocumented classes	🟨 6 undocumented classes
JSDocs coverage	Properties coverage	🟥 30 undocumented properties	🟥 41 undocumented properties
Lighthouse	Time to Interactive	🟥 17.7 s	🟥 13.7 s
Lighthouse	Total Blocking Time	🟥 7,300 ms	🟥 2,310 ms
JSDocs coverage	Functions coverage	🟥 579 undocumented functions	🟥 582 undocumented functions
JSDocs coverage	Types coverage	🟥 272 undocumented types	🟥 262 undocumented types
JSDocs coverage	Methods coverage	🟨 13 undocumented methods	🟨 15 undocumented methods
JSDocs coverage	Variables coverage	🟥 272 undocumented variables	🟥 280 undocumented variables
Code coverage	Branch coverage	🟨 89 %	🟨 89.2 %
Code coverage	Line coverage	🟩 92.3 %	🟩 92.6 %
Code coverage	Function coverage	🟩 94.1 %	🟩 94.3 %
Lighthouse	Minimizes main-thread work	🟥 24.2 s	🟥 11.9 s
Lighthouse	Avoids enormous network payloads	🟩 Total size was 2,098 KiB	🟩 Total size was 2,087 KiB
Lighthouse	JavaScript execution time	🟥 9.6 s	🟥 4.9 s
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Largest Contentful Paint	🟥 14.5 s	🟥 11.5 s
Lighthouse	Max Potential First Input Delay	🟥 3,650 ms	🟥 1,250 ms
Lighthouse	Server Backend Latencies	🟩 1,040 ms	🟩 300 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	Initial server response time was short	🟩 Root document took 560 ms	🟩 Root document took 580 ms
Lighthouse	Reduce unused JavaScript	🟥 Potential savings of 226 KiB	🟥 Potential savings of 226 KiB
Lighthouse	Network Round Trip Times	🟩 20 ms	🟩 20 ms

654 other audits are unchanged.

[github-actions]

Code PushUp

🥳 Code PushUp report has improved – compared current commit 276ae6b with previous commit ea27cdc.

💼 Project utils

🥳 Code PushUp report has improved.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Documentation	🔴 46	🟡 51
Code coverage	🟢 95	🟢 95

4 other categories are unchanged.

👍 2 groups improved, 👍 9 audits improved

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
JSDocs coverage	Documentation coverage	🔴 46	🟡 51
Code coverage	Code coverage metrics	🟢 95	🟢 95

13 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
JSDocs coverage	Classes coverage	🟨 3 undocumented classes	🟨 3 undocumented classes
JSDocs coverage	Properties coverage	🟥 27 undocumented properties	🟥 38 undocumented properties
JSDocs coverage	Types coverage	🟥 66 undocumented types	🟨 56 undocumented types
JSDocs coverage	Functions coverage	🟥 241 undocumented functions	🟥 244 undocumented functions
JSDocs coverage	Methods coverage	🟨 13 undocumented methods	🟨 15 undocumented methods
JSDocs coverage	Variables coverage	🟥 49 undocumented variables	🟥 57 undocumented variables
Code coverage	Branch coverage	🟩 91.7 %	🟩 92.2 %
Code coverage	Function coverage	🟩 95.7 %	🟩 96 %
Code coverage	Line coverage	🟩 97.7 %	🟩 97.9 %

435 other audits are unchanged.

---

13 other projects are unchanged.

[hanna-skryl]

The justification for sync file operations is well-reasoned 👍 I've added a few minor suggestions and comments.

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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