chalk/examples/rainbow.js
Ayush Kumar ff7b1f0d60
Fix security and performance issues across core, vendor, and examples
Security:
- S2: hexToRgb — explicit typeof branch + padStart(6) for numeric hex inputs;
  makes the numeric-input path intentional and preserves leading zeros
- S3: FORCE_COLOR parsing — guard against NaN propagation when env value is
  non-numeric (e.g. FORCE_COLOR=yes now correctly falls back to level 1)
- S4: _supportsColor — remove side-effecting mutation of module-level
  flagForceColor; effective value is now computed locally, eliminating
  cross-call state corruption in test environments
- S5: applyOptions — change `options.level &&` to `options.level !== undefined`
  so null and NaN are properly rejected instead of silently stored as the level
- S6: browser.js — explicit Number(brand.version) > 93 instead of implicit
  string-to-number coercion for Chromium UA version check

Performance / correctness:
- P1: rainbow.js — replace stateful global-regex test() in loop (which
  misclassified every other non-printable character due to lastIndex advancing)
  with a direct code-point comparison: character < '!' || character > '~'
- P4: stringEncaseCRLFWithFirstIndex — switch from += string concatenation in
  loop to array-of-parts + single join(), reducing intermediate allocations for
  multi-line strings
- P6: builder — detect tagged template literal calls via .raw property and route
  through String.raw(), so chalk.red`hello ${name}` now produces correct output

Tests:
- instance.js: new Chalk({level: null/NaN}) now throws (S5 regression test)
- chalk.js: numeric hex with leading zeros (S2), template literal interpolations
  (P6) covered by new tests; all 35 tests pass

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-02-21 17:21:53 +05:30

38 lines
962 B
JavaScript

import {setTimeout as delay} from 'node:timers/promises';
import convertColor from 'color-convert';
import updateLog from 'log-update';
import chalk from '../source/index.js';
const ignoreChars = /[^!-~]/g;
function rainbow(string, offset) {
if (!string || string.length === 0) {
return string;
}
const hueStep = 360 / string.replaceAll(ignoreChars, '').length;
let hue = offset % 360;
const characters = [];
for (const character of string) {
if (character < '!' || character > '~') {
characters.push(character);
} else {
characters.push(chalk.hex(convertColor.hsl.hex(hue, 100, 50))(character));
hue = (hue + hueStep) % 360;
}
}
return characters.join('');
}
async function animateString(string) {
for (let index = 0; index < 360 * 5; index++) {
updateLog(rainbow(string, index));
await delay(2); // eslint-disable-line no-await-in-loop
}
}
console.log();
await animateString('We hope you enjoy Chalk! <3');
console.log();