Watches all .less files and renders css with every change

watch-less.js

#!/usr/bin/env node


/**
 * Watches all project .less files,
 * automatically renders css with every change
 * usage: $watch-less ~/Sites/myProject1 ~/Sites/myProject2
 */

var less = require('less'),
	fs = require('fs');

var VERBOSE = (process.argv.indexOf('-v') > -1);
if ( VERBOSE ){
	process.argv.splice( process.argv.indexOf('-v'), 1 );
}
var directories = ['/../app/stylesheets'];
var argvDirectories = [].slice.call(process.argv, 2, process.argv.length);
directories = directories.concat( argvDirectories );


directories.forEach(watchDirectoryForLess);

function watchDirectoryForLess( dir ){
	var absolutePath = __dirname + dir;
	fs.readdir(absolutePath, function (err, files){
		if(err) {
			console.log('There was an error reading your directory');
			if(VERBOSE)console.log( err );
		} else {

			forEachLessFileIn( files, function(path){
				var absoluteFilepath = absolutePath + '/' + path;
				console.log('Watching', absoluteFilepath);

				fs.watch(absoluteFilepath, function(event, filename){
						renderFile(absoluteFilepath);
				});
			});
		}

	});
}

function forEachLessFileIn (files, fn){
	files
	.filter(function(path){
		return path.match(/\.less$/); // Filter not .less files
	})
	.forEach(fn);
}


function renderFile(filename){
	fs.readFile(filename, function(err, lessCss){
		if(err) {
			console.log('There was an error reading your less file');
			if(VERBOSE)console.log( err );
		} else {
			lessCss = lessCss.toString();
			less.render(lessCss, function(err, css) {
				if( err ){
					console.log('There was an error rendering your CSS file');
					if(VERBOSE)console.log( err );
				} else {
					var newFilename = filename.replace(/\.less$/, '.css');
					fs.writeFile(newFilename, css);
					console.log( new Date().toString() + ' saved '+newFilename );
				}
			});
		}
	});
}