combine.js

#!/usr/bin/env node

var fs = require("fs"), path = require("path");

var run = function(root,start){
	var fs = require("fs"), path = require("path"); // intentionally redefined
	var ext = ".js", index = "index"+ext, pkg = "package.json";
	var locate = function(root,name){
		var p = name.split(path.sep);
		// all relative module references must be inside the specified directory
		if(p[0]==="..") throw new Error("Out of Scope");
		// navigate to the appropriate location
		for(var current = root; p.length>1; p.splice(0,1)) current = current[p[0]];
		// select module, appending the extension if required
		return current[p[0]+(p[0]+ext in current ? ext : "")];
	};
	return (function(name,relative){
		if(typeof(name)!="string" || name==="" || name.split(path.sep).length<2 ){
			// in case of invalid input or external modules
			return require(name);
		} else {
			var relname = path.normalize(path.join(relative,name)),
				current = locate(root,relname);
			// if this is a directory and a package.json exists, use the main value
			check: try {
				if(typeof(current)!=="object") break check;
				var data = JSON.parse(current[pkg]);
				if(typeof(data.main)!=="string") break check;
				current = locate(current,path.normalize(data.main));
				relname = path.join(relname,data.main);
			} catch(e){ }
			// if this is a directory, load the index file by default
			if(typeof(current)==="object"){
				current = current[index];
				relname = path.join(relname,index);
			}
			// load the module appropriately
			if(typeof(current)==="function"){
				var module = { exports:{}, filename: relname },
					f1 = arguments.callee,
					f2 = function(x){ return f1(x,path.dirname(relname)) };
				return current.cache || (current.cache = current(module, f2));
			} else if(typeof(current)==="string"){
				return current;
			} else throw new Error("Invalid Path");
		}
	})("."+path.sep+start,"."); // start execution
};

var compress = (function(){
	try {
		var uglify = require("uglify-js"),
			options = {
				fromString: true,
				reserved: ["module","require"]
			};
	} catch(e) {
		var uglify = null;
	}
	return function(str){
		if(!uglify) return str;
		return "(" + uglify.minify("_="+str,options).code.slice(2,-1) + ")";
	};
})();

var load = (function(){
	var ext = ".js",
		prefix = "(function(module,require){\ndelete arguments;",
		suffix = "\nreturn module.exports; })";
	// scan the directory recursively and read data into a JSON object
	return function(current,options){
		var name, result = {}, list = fs.readdirSync(current);
		// for each item in directory
		for(var i=0; i<list.length; ++i){
			var fullpath = path.join(current,name=list[i]),
				stats = fs.statSync(fullpath),
				relpath = path.relative(options.basedir,fullpath);
			// skip if found in exclusion list
			if(options.exclude.filter(function(x){ return relpath.match(x); }).length) continue;
			// if(options.exclude.indexOf( relpath )!=-1) continue;
			if(stats.isDirectory()){
				// recursively load if this is a directory
				result[name] = arguments.callee( fullpath, options );
			} else if(stats.isFile()){
				// read file and if executable, evaluate the wrapper function
				result[name] = fs.readFileSync(fullpath).toString();
				if(name.slice(-ext.length)===ext)
					try { result[name] = eval(compress(prefix+result[name]+suffix)); }
					catch(e){ }
			}
		}
		return result;
	};
})();

var combine = (function(){
	var stringify = function(x){
		// to prevent JSON.stringify from quoting <function>.toString()
		if(typeof(x)==="function") return x.toString();
		if(typeof(x)!="object") return JSON.stringify(x);
		return "{"+Object.keys(x).map(function(key){
			return JSON.stringify(key)+":"+stringify(x[key]);
		}).join(",")+"}";
	};
	return function(directory,options,start){
		// ensure that directory and start-file exist
		if( !fs.statSync(directory).isDirectory() ||
			!fs.statSync(path.join(directory,start)).isFile() )
			throw new Error("Invalid Options");
		// options sanitization
		if(typeof(options)!="object" || Array.isArray(options)) options = {};
		options.basedir = directory;
		options.exclude = !Array.isArray(options.exclude) ? [] :
			options.exclude.filter(function(x){
				return typeof(x)==="string" || x instanceof RegExp; });
		// generate output
		var x = compress("("+run.toString()+")"),
			y = stringify(load(directory,options));
		return x+"("+y+","+stringify(start)+")";
	};
})();

if(!module.parent){ // main
	var argv = require("optimist").default("e",[".git","node_modules"]).argv;
	if(argv._.length<3){
		console.log("\nIntent : Combine and compress multiple JavaScript files into a single equivalent file.");
		console.log("Usage : "+argv.$0+" <directory> <main-script> <output-file> (-e <exclude-path>)* [-r]\n");
	} else {
		argv.e = Array.isArray(argv.e) ? argv.e : [argv.e];
		var dir = argv._[0], start = argv._[1], target = argv._[2];
		var output = combine(dir,{exclude:argv.e},start);
		if(target==="-") process.stdout.write(output+"\n");
		else fs.writeFile(target,output);
		if(argv.r) eval(output);
	}
} else { // api
	module.exports = combine;
}