util: remove style caches from styleText slow path

[araujogui]

Remove the caches from the slow path since they don't improve performance there. validation dominates the cost, making the lookup savings negligible

util/style-text.js n=1000 validateStream=0 format='#ff0000' messageType='boolean' -0.36 % ±2.99% ±4.02% ±5.32%
util/style-text.js n=1000 validateStream=0 format='#ff0000' messageType='invalid' 0.40 % ±2.49% ±3.34% ±4.39%
util/style-text.js n=1000 validateStream=0 format='#ff0000' messageType='number' ** 2.27 % ±1.68% ±2.24% ±2.91%
util/style-text.js n=1000 validateStream=0 format='#ff0000' messageType='string' 0.82 % ±2.93% ±3.90% ±5.07%
util/style-text.js n=1000 validateStream=0 format='#rotating' messageType='boolean' * 1.25 % ±1.23% ±1.64% ±2.14%
util/style-text.js n=1000 validateStream=0 format='#rotating' messageType='invalid' -0.71 % ±5.57% ±7.50% ±9.94%
util/style-text.js n=1000 validateStream=0 format='#rotating' messageType='number' * 2.59 % ±2.08% ±2.77% ±3.61%
util/style-text.js n=1000 validateStream=0 format='#rotating' messageType='string' -2.07 % ±3.62% ±4.83% ±6.33%
util/style-text.js n=1000 validateStream=0 format='invalid' messageType='boolean' *** 2.36 % ±1.28% ±1.71% ±2.24%
util/style-text.js n=1000 validateStream=0 format='invalid' messageType='invalid' ** 1.57 % ±0.99% ±1.31% ±1.71%
util/style-text.js n=1000 validateStream=0 format='invalid' messageType='number' ** 3.25 % ±2.35% ±3.13% ±4.08%
util/style-text.js n=1000 validateStream=0 format='invalid' messageType='string' 2.07 % ±2.89% ±3.89% ±5.15%
util/style-text.js n=1000 validateStream=0 format='italic' messageType='boolean' * 1.62 % ±1.41% ±1.87% ±2.43%
util/style-text.js n=1000 validateStream=0 format='italic' messageType='invalid' *** 2.00 % ±0.79% ±1.05% ±1.36%
util/style-text.js n=1000 validateStream=0 format='italic' messageType='number' * 3.90 % ±3.08% ±4.15% ±5.50%
util/style-text.js n=1000 validateStream=0 format='italic' messageType='string' -1.52 % ±4.73% ±6.31% ±8.24%
util/style-text.js n=1000 validateStream=0 format='red' messageType='boolean' 1.68 % ±1.93% ±2.56% ±3.33%
util/style-text.js n=1000 validateStream=0 format='red' messageType='invalid' ** 2.29 % ±1.42% ±1.90% ±2.47%
util/style-text.js n=1000 validateStream=0 format='red' messageType='number' ** 2.72 % ±1.93% ±2.57% ±3.34%
util/style-text.js n=1000 validateStream=0 format='red' messageType='string' -0.34 % ±3.61% ±4.82% ±6.30%
util/style-text.js n=1000 validateStream=1 format='#ff0000' messageType='boolean' 0.14 % ±3.35% ±4.51% ±5.96%
util/style-text.js n=1000 validateStream=1 format='#ff0000' messageType='invalid' *** 1.91 % ±0.62% ±0.83% ±1.08%
util/style-text.js n=1000 validateStream=1 format='#ff0000' messageType='number' * 2.08 % ±1.72% ±2.29% ±2.98%
util/style-text.js n=1000 validateStream=1 format='#ff0000' messageType='string' *** 2.24 % ±0.82% ±1.09% ±1.42%
util/style-text.js n=1000 validateStream=1 format='#rotating' messageType='boolean' * 1.73 % ±1.31% ±1.75% ±2.28%
util/style-text.js n=1000 validateStream=1 format='#rotating' messageType='invalid' 0.64 % ±2.20% ±2.95% ±3.88%
util/style-text.js n=1000 validateStream=1 format='#rotating' messageType='number' *** 2.98 % ±1.39% ±1.86% ±2.43%
util/style-text.js n=1000 validateStream=1 format='#rotating' messageType='string' 0.30 % ±2.50% ±3.36% ±4.45%
util/style-text.js n=1000 validateStream=1 format='invalid' messageType='boolean' ** 2.27 % ±1.40% ±1.87% ±2.44%
util/style-text.js n=1000 validateStream=1 format='invalid' messageType='invalid' *** 1.86 % ±0.94% ±1.25% ±1.62%
util/style-text.js n=1000 validateStream=1 format='invalid' messageType='number' ** 3.84 % ±2.81% ±3.75% ±4.91%
util/style-text.js n=1000 validateStream=1 format='invalid' messageType='string' *** 2.26 % ±1.28% ±1.71% ±2.24%
util/style-text.js n=1000 validateStream=1 format='italic' messageType='boolean' *** 2.72 % ±1.51% ±2.02% ±2.64%
util/style-text.js n=1000 validateStream=1 format='italic' messageType='invalid' *** 2.01 % ±0.97% ±1.29% ±1.68%
util/style-text.js n=1000 validateStream=1 format='italic' messageType='number' * 2.19 % ±1.76% ±2.34% ±3.06%
util/style-text.js n=1000 validateStream=1 format='italic' messageType='string' 3.53 % ±3.78% ±5.10% ±6.75%
util/style-text.js n=1000 validateStream=1 format='red' messageType='boolean' 1.32 % ±1.68% ±2.25% ±2.95%
util/style-text.js n=1000 validateStream=1 format='red' messageType='invalid' *** 1.97 % ±1.08% ±1.44% ±1.88%
util/style-text.js n=1000 validateStream=1 format='red' messageType='number' * 2.37 % ±1.80% ±2.40% ±3.13%
util/style-text.js n=1000 validateStream=1 format='red' messageType='string' 2.26 % ±2.31% ±3.09% ±4.07%
Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 40 comparisons, you can thus
expect the following amount of false-positive results:
2.00 false positives, when considering a 5% risk acceptance (*, **, ***),
0.40 false positives, when considering a 1% risk acceptance (**, ***),
0.04 false positives, when considering a 0.1% risk acceptance (***)

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR refactors styleText to reduce reliance on the prebuilt style cache and to build ANSI sequences directly from inspect.colors, while also simplifying the hex-color styling path.

Changes:

• Lazily initializes the style cache only in the validateStream=false fast path.
• Replaces cached style lookups with direct reads from inspect.colors and inline ANSI open/close sequence construction.
• Reworks hex color handling to compute 24-bit ANSI sequences directly instead of using the hex style cache.

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.34%. Comparing base (f30139e) to head (6f4298d).
⚠️ Report is 68 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #63706 +/- ##
==========================================
- Coverage 90.35% 90.34% -0.01% 
==========================================
Files 732 732 Lines 236684 236690 +6 Branches 44579 44582 +3 ==========================================
- Hits 213855 213845 -10 - Misses 14544 14557 +13 - Partials 8285 8288 +3 

Files with missing lines	Coverage Δ
lib/util.js	94.60% <100.00%> (+<0.01%)	⬆️

... and 27 files with indirect coverage changes

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[araujogui]

CC @nodejs/performance

[mcollina]

lgtm

[gurgunday]

lgtm

[nodejs-github-bot]

Commit Queue failed

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----------------------------------- PR info ------------------------------------
Title util: remove style caches from styleText slow path (#63706)
Author Guilherme Araújo <arauujogui@gmail.com> (@araujogui)
Branch araujogui:util-styletext-no-cache -> nodejs:main
Labels util, needs-ci
Commits 1
- util: remove style caches from styleText slow path
Committers 1
- Guilherme Araújo <arauujogui@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/63706
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/63706
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
--------------------------------------------------------------------------------
ℹ This PR was created on Mon, 01 Jun 2026 22:01:24 GMT
✔ Approvals: 2
✔ - Matteo Collina (@mcollina) (TSC): https://github.com/nodejs/node/pull/63706#pullrequestreview-4435453199
✔ - Gürgün Dayıoğlu (@gurgunday): https://github.com/nodejs/node/pull/63706#pullrequestreview-4436132152
✔ Last GitHub CI successful
✘ No Jenkins CI runs detected
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https://github.com/nodejs/node/actions/runs/27086912762

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73986/

[nodejs-github-bot]

Landed in 4899634