GitHub - lukeed/kleur: The fastest Node.js library for formatting terminal text...

readme.md

Features

• No dependencies
• Super lightweight & performant
• Supports nested & chained colors
• No String.prototype modifications
• Supports printf formatting
• Conditional color support
• Familiar API

Heavily inspired by ansi-colors. See Credits for more info!

Install

$ npm install --save kleur

Usage

const kleur = require('kleur');

// basic usage
kleur.red('red text');

// or variadic arguments
kleur.red('this', 'is', 'also', 'red');

// or printf formatting
kleur.red('%s, %s!', 'hello', 'world');

// chained methods
kleur.blue.bold.underline('howdy partner');

// nested methods
kleur.bold(`${ kleur.bgRed.white('[ERROR]') } ${ kleur.red.italic('Something happened')}`);

Chained Methods

console.log(kleur.bold.red('this is a bold red message'));
console.log(kleur.bold.italic('this is a bold italicized message'));
console.log(kleur.bold.yellow.bgRed.italic('this is a bold yellow italicized message'));
console.log(kleur.green.bold.underline('this is a bold green underlined message'));

Nested Methods

const { yellow, red, cyan } = require('kleur');

// with template literals
console.log(yellow(`foo ${red.bold('red')} bar ${cyan('cyan')} baz`));

// or variadic arguments
console.log(yellow('foo', red.bold('red'), 'bar', cyan('cyan'), 'baz'));

printf Formatting

See util.format for documentation

const { yellow, bgGreen, bold } = require('kleur');

// basic usage
console.log(bold.cyan('%s, %s!', 'Hello', 'World', '-Anonymous'));

// or with nested colors
console.log( bold('%s-like %s... %s!', 'printf', bgGreen.black('formatting'), yellow('YAY')) );

Clear Formatting

Manually strip all ANSI codes from a given string.

let str = kleur.blue('Howdy partner');
//=> styled

kleur.clear(str);
//=> 'Howdy partner'

Conditional Support

Toggle color support as needed; kleur assumes it's always enabled.

const kleur = require('kleur');

// manually disable
kleur.enabled = false;

// or use a library to detect support
kleur.enabled = require('color-support').stdout;

console.log(kleur.red('I will only be colored red if the terminal supports colors'));

API

Any kleur method returns a String (when invoked, not chained). It's up to the developer to pass the output to destinations like console.log, process.stdout.write, etc.

The methods below are grouped by type for legbility purposes only. They each can be chained or nested with one another.

Colors:

black — red — green — yellow — blue — magenta — cyan — white — gray

Backgrounds:

bgBlack — bgRed — bgGreen — bgYellow — bgBlue — bgMagenta — bgCyan — bgWhite

Modifiers:

reset — bold — dim — italic* — underline — inverse — hidden — strikethrough*

* Not widely supported

Benchmarks

Using Node v8.9.0

Load time

ansi-colors: 1.172ms
chalk: 11.799ms
clorox: 0.922ms
kleur: 0.694ms

Performance

# All Colors
  ansi-colors x 60,235 ops/sec ±0.57% (93 runs sampled)
  chalk x 7,125 ops/sec ±4.23% (69 runs sampled)
  clorox x 1,175 ops/sec ±3.95% (71 runs sampled)
  kleur x 74,307 ops/sec ±0.40% (96 runs sampled)

# Stacked colors
  ansi-colors x 13,547 ops/sec ±0.15% (97 runs sampled)
  chalk x 1,631 ops/sec ±4.83% (72 runs sampled)
  clorox x 454 ops/sec ±2.43% (40 runs sampled)
  kleur x 21,825 ops/sec ±0.31% (94 runs sampled)

# Nested colors
  ansi-colors x 27,553 ops/sec ±0.45% (93 runs sampled)
  chalk x 3,445 ops/sec ±4.31% (69 runs sampled)
  clorox x 552 ops/sec ±2.79% (45 runs sampled)
  kleur x 32,405 ops/sec ±0.36% (92 runs sampled)

Credits

This project (inadvertently) is very similar to Brian Woodward's awesome ansi-colors project. My original implementation involved writing into a global state — first by writing into an output string, and then by saving the keys array into the $ directly. Both approaches were leaky & allowed for accidental chains/overwrites. In turn, I borrowed ansi-colors's approach in writing keys state into each chain directly.

Aside from the performance boost, kleur exists as a separate module because I've no need for bright color variants nor the symbols. And since those are defining features of ansi-colors, they're not something that can be removed.

The benchmark suite is also imported directly from ansi-colors ?

License

MIT © Luke Edwards