Merge pull request #33 from seanmonstar/_styles

fix caching of styles, fixes #32

.jshintrc

@@ -9,6 +9,7 @@
 	"indent": 4,
 	"newcap": true,
 	"noarg": true,
+	"proto": true,
 	"quotmark": "single",
 	"undef": true,
 	"unused": "vars",

benchmark.js

@@ -11,6 +11,11 @@ suite('chalk', function () {
 		chalk.blue.bgRed.bold('the fox jumps over the lazy dog');
 	});
 
+	var cached = chalk.blue.bgRed.bold;
+	bench('cached styles', function () {
+		cached('the fox jumps over the lazy dog');
+	});
+
 	bench('nested styles', function () {
 		chalk.red('the fox jumps', chalk.underline.bgBlue('over the lazy dog') + '!');
 	});

index.js

@@ -7,6 +7,17 @@ var supportsColor = require('supports-color');
 var defineProps = Object.defineProperties;
 var chalk = module.exports;
 
+function build(_styles) {
+	var builder = function builder() {
+		return applyStyle.apply(builder, arguments);
+	};
+	builder._styles = _styles;
+	// __proto__ is used because we must return a function, but there is
+	// no way to create a function with a different prototype.
+	builder.__proto__ = proto;
+	return builder;
+}
+
 var styles = (function () {
 	var ret = {};
 
@@ -17,8 +28,7 @@ var styles = (function () {
 
 		ret[key] = {
 			get: function () {
-				this._styles.push(key);
-				return this;
+				return build(this._styles.concat(key));
 			}
 		};
 	});
@@ -26,15 +36,26 @@ var styles = (function () {
 	return ret;
 })();
 
+var proto = defineProps(function chalk() {}, styles);
+
 function applyStyle() {
 	// support varags, but simply cast to string in case there's only one arg
-	var str = arguments.length === 1 ? String(arguments[0]) : [].slice.call(arguments).join(' ');
+	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 (!chalk.enabled || !str) {
 		return str;
 	}
 
-	var nestedStyles = applyStyle._styles;
+	/*jshint validthis: true*/
+	var nestedStyles = this._styles;
 
 	for (var i = 0; i < nestedStyles.length; i++) {
 		var code = ansiStyles[nestedStyles[i]];
@@ -51,11 +72,9 @@ function init() {
 	var ret = {};
 
 	Object.keys(styles).forEach(function (name) {
-		var style = defineProps(applyStyle, styles);
 		ret[name] = {
 			get: function () {
-				style._styles = [];
-				return style[name];
+				return build([name]);
 			}
 		};
 	});

test.js

@@ -32,6 +32,17 @@ describe('chalk', function () {
 		assert.equal(chalk.reset(chalk.red.bgGreen.underline('foo') + 'foo'), '\u001b[0m\u001b[4m\u001b[42m\u001b[31mfoo\u001b[39m\u001b[49m\u001b[24mfoo\u001b[0m');
 	});
 
+	it('should be able to cache multiple styles', function() {
+		var red = chalk.red;
+		var blue = chalk.blue;
+		var redBold = red.bold;
+		var blueBold = blue.bold;
+
+		assert.notEqual(red('foo'), blue('foo'));
+		assert.notEqual(redBold('bar'), blueBold('bar'));
+		assert.notEqual(blue('baz'), blueBold('baz'));
+	});
+
 	it('should alias gray to grey', function () {
 		assert.equal(chalk.grey('foo'), '\u001b[90mfoo\u001b[39m');
 	});