unicorn/lib/unicorn.js

Add some color to your command line.

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// Add some color to your command line.

// @author Rafael Rinaldi (rafaelrinaldi.com)
// @since May 31, 2013

var util = require('util'),
keys = require('mout/object/keys'),
choice = require('mout/random/choice'),

// Available styles.
styles = {

	// Colors. Left is the foreground value, right is the background value.
	black: [30, 40],
	red: [31, 41],
	green: [32, 42],
	yellow: [33, 43],
	blue: [34, 44],
	magenta: [35, 45],
	cyan: [36, 46],
	white: [37, 47],

	// Styles.
	normal: 0,
	bold: 1,
	underline: 4,
	blinking: 5,
	reverse: 7
},

styleNames = keys(styles),

STYLE_ENTRY = '\033[%sm',
RESET_ANSI = 0,

// Is Unicorn installed?
isInstalled = false;

// Installs unicorn's features.
exports.install = function() {
	if(isInstalled) return;

	isInstalled = true;

	// Extending `String` class and adding the style names as methods.
	styleNames.forEach(function(style) {
		String.prototype[style] = function(bg) {
			return format.call(this, style, bg);
		}
	});
}

/**
 * Add selected style to the string, already taking care of reseting it at the end.
 * @param  {String} style Style name.
 * @param  {Boolean} bg Is this a background value?
 * @return {String} Formatted string.
 */
function format(style, bg) {
	// Add style.
	return util.format(STYLE_ENTRY, getANSICode(style, bg))
	// Appends the original string.
	.concat(this.toString())
	// Reset style value.
	.concat(util.format(STYLE_ENTRY, RESET_ANSI));
}

/**
 * Returns the ANSI code from the given style name.
 * @param  {String} style Style name.
 * @param  {Boolean} bg Is this a background value?
 * @return {Number} The ANSI code.
 */
function getANSICode(style, bg) {
	var ansi = styles[style];

	if(Object.prototype.toString.call(ansi) === '[object Array]') {
		ansi = ansi[bg ? 1 : 0];
	}

	return ansi;
}

/**
 * Just for the LOL.
 * @return {String} Unicornfied string.
 */
String.prototype.unicorn = function() {
	var log = '',
		style;

	// Looping through all characters.
	this.split('').forEach(function(char) {
		// Random style.
		style = choice(styleNames);
		// Appending log message.
		log += format.call(char, style, Math.round(Math.random() * 1));
	});

	return log;
}