gulp-yuicompressor/yuicompressor.js

Minify files with yuicompressor

var spawn = require('child_process').spawn,
	fs = require('fs'),
	path = require('path'),
	jar,
	exists = fs.exists || path.exists,
	lists = fs.readdirSync(path.join(__dirname, './lib'));

lists.some(function(item) {
	if (path.extname(item) === '.jar') {
		jar = path.join(__dirname, './lib/', item);
		return true;
	}
});

exports.jar = jar;

var defaultOptions = {
	charset: 'utf8',
	type: 'js'
};

var validOptions = {
	charset: 1,
	type: 1,
	'line-break': 1,
	nomunge: 1,
	'preserve-semi': 1,
	'disable-optimizations': 1
};

var getString = function(str, callback, options) {
	exists(str, function(y) {
		if (y) {
			var ext = (path.extname(str)).replace('.', '');
			fs.readFile(str, 'utf8', function(err, data) {
				//Set the type from the file name
				options.type = ext;
				callback(err, data, options);
			});
		} else {
			callback(null, str, options);
		}
	});
};


var filterOptions = function(options) {
	Object.keys(options).forEach(function(key) {
		if (!validOptions[key]) {
			delete options[key];
		}
	});

	options.type = options.type || 'js';
	options.charset = options.charset || 'utf8';
	return options;
};

var compressString = function(str, options, callback) {
	//Now we have a string, spawn and pipe it in.

	options = filterOptions(options);

	var args = [
		'-jar',
		exports.jar
	], buffer = '', errBuffer = '', child;

	Object.keys(options).forEach(function(key) {
		args.push('--' + key);
		if (options[key] && options[key] !== true) {
			args.push(options[key]);
		}
	});

	child = spawn('java', args, {
		stdio: ['pipe', 'pipe', 'pipe']
	});

	child.stdin.write(str);
	child.stdin.end();

	child.stdout.on('data', function(chunk) {
		buffer += chunk;
	});
	child.stderr.on('data', function(chunk) {
		errBuffer += chunk;
	});

	child.on('exit', function() {
		var err = null;
		if (errBuffer.indexOf('[ERROR]') > -1) {
			err = errBuffer;
		}
		callback(err, buffer, errBuffer);
	});
};

var compress = function(str, options, callback) {
	if (typeof options === 'function') {
		callback = options;
		options = defaultOptions;
	}

	getString(str, function(err, str, options) {

		compressString(str, options, callback);

	}, options);
};

exports.compress = compress;
exports.compressString = compressString;