kristoferbaxter / kleur

The fastest Node.js library for formatting terminal text with ANSI colors~!

The fastest Node.js library for formatting terminal text with ANSI colors~!

Features

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

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As of v3.0 the Chalk-style syntax (magical getter) is no longer used.
If you need or require that syntax, consider using ansi-colors, which maintains chalk parity.

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Install

$ npm install --save kleur

Usage

import { red, white, blue, bold } from 'kleur';

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

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

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

Chained Methods

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

Nested Methods

import { yellow, red, cyan } from 'kleur';

console.log(yellow(`foo ${red().bold('red')} bar ${cyan('cyan')} baz`));
console.log(yellow('foo ' + red().bold('red') + ' bar ' + cyan('cyan') + ' baz'));

Conditional Support

Toggle color support as needed; kleur includes simple auto-detection which may not cover all cases.

import kleur from 'kleur';

// disable with boolean result of right side assignment.
kleur.enabled = false;

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

API

Any kleur method returns a String when invoked with input; otherwise chaining is expected.

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 legibility purposes only. They each can be chained or nested with one another.

Colors:

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

Backgrounds:

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

Modifiers:

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

^{* Not widely supported}

Benchmarks

Using Node v10.13.0

Load time

chalk       ::  4.858ms
kleur       ::  0.482ms
ansi-colors ::  1.738ms

Performance

# All Colors
  ansi-colors  x 182,395 ops/sec ±0.51% (96 runs sampled)
  chalk        x 656,387 ops/sec ±0.80% (93 runs sampled)
  kleur        x 711,729 ops/sec ±0.33% (94 runs sampled)

# Stacked colors
  ansi-colors  x  23,900 ops/sec ±0.34% (92 runs sampled)
  chalk        x 306,865 ops/sec ±0.32% (97 runs sampled)
  kleur        x  76,154 ops/sec ±0.29% (95 runs sampled)

# Nested colors
  ansi-colors  x  69,508 ops/sec ±0.29% (95 runs sampled)
  chalk        x 124,142 ops/sec ±0.43% (91 runs sampled)
  kleur        x 138,659 ops/sec ±0.32% (98 runs sampled)

Credits

This project originally forked Brian Woodward's awesome ansi-colors library.

Beginning with [email protected], the Chalk-style syntax (magical getter) has been replaced with function calls per key:

// Old:
c.red.bold.underline('old');

// New:
c.red().bold().underline('new');

^{As I work more with Rust, the newer syntax feels so much better & more natural!}

If you prefer the old syntax, you may migrate to ansi-colors. Versions below [email protected] have been deprecated.

License

MIT © Luke Edwards