chalk/index.js

'use strict';
var escapeStringRegexp = require('escape-string-regexp');
var ansiStyles = require('ansi-styles');
var supportsColor = require('supports-color');
var defineProps = Object.defineProperties;
var isSimpleWindowsTerm = process.platform === 'win32' && !/^xterm/i.test(process.env.TERM);

function Chalk(options) {
	// detect mode if not set manually
	this.enabled = !options || options.enabled === undefined ? supportsColor : options.enabled;
}

// use bright blue on Windows as the normal blue color is illegible
if (isSimpleWindowsTerm) {
	ansiStyles.blue.open = '\u001b[94m';
}

var styles = {};

Object.keys(ansiStyles).forEach(function (key) {
	ansiStyles[key].closeRe = new RegExp(escapeStringRegexp(ansiStyles[key].close), 'g');

	styles[key] = {
		get: function () {
			return build.call(this, this._styles ? this._styles.concat(key) : [key]);
		}
	};
});

var proto = defineProps(function chalk() {}, styles);

function build(_styles) {
	var builder = function () {
		return applyStyle.apply(builder, arguments);
	};

	builder._styles = _styles;
	builder.enabled = this.enabled;
	// __proto__ is used because we must return a function, but there is
	// no way to create a function with a different prototype.
	/* eslint-disable no-proto */
	builder.__proto__ = proto;

	return builder;
}

function applyStyle() {
	// support varags, but simply cast to string in case there's only one arg
	var args = arguments;
	var argsLen = args.length;
	var str = argsLen !== 0 && String(arguments[0]);

	if (argsLen > 1) {
		// don't slice `arguments`, it prevents v8 optimizations
		for (var a = 1; a < argsLen; a++) {
			str += ' ' + args[a];
		}
	}

	if (!this.enabled || !str) {
		return str;
	}

	var nestedStyles = this._styles;
	var i = nestedStyles.length;

	// Turns out that on Windows dimmed gray text becomes invisible in cmd.exe,
	// see https://github.com/chalk/chalk/issues/58
	// If we're on Windows and we're dealing with a gray color, temporarily make 'dim' a noop.
	var originalDim = ansiStyles.dim.open;
	if (isSimpleWindowsTerm && (nestedStyles.indexOf('gray') !== -1 || nestedStyles.indexOf('grey') !== -1)) {
		ansiStyles.dim.open = '';
	}

	while (i--) {
		var code = ansiStyles[nestedStyles[i]];

		// Replace any instances already present with a re-opening code
		// otherwise only the part of the string until said closing code
		// will be colored, and the rest will simply be 'plain'.
		str = code.open + str.replace(code.closeRe, code.open) + code.close;

		// Close the coloring before a line break and reopening after next line
		// To fix a bleed issue on macs
		// see https://github.com/chalk/chalk/pull/92
		str = str.replace(/\n/gm, code.close + '\n' + code.open);
	}

	// Reset the original 'dim' if we changed it to work around the Windows dimmed gray issue.
	ansiStyles.dim.open = originalDim;

	return str;
}

defineProps(Chalk.prototype, styles);

module.exports = new Chalk();
module.exports.styles = ansiStyles;
module.exports.supportsColor = supportsColor;