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.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[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 3 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

🚀 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.

[araujogui]

CC @nodejs/performance