A simple node.js script that monitors changes to javascript files in my development directory tree. Once a change occurs, the script creates a minified version using the Closure compiler.

CompressJS.js

var watch = require("watch");
var cc = require("closurecompiler");
var fs = require("fs");

watch.watchTree("/Users/chris/Dropbox/Development",{"ignoreDotFiles":true},function(f,cstat,pstat){
	if(typeof(f)=="string" && f.toLowerCase().indexOf(".js")>1 && f.toLowerCase().indexOf(".min.")==-1){

		if(cstat.nlink===1){
			var fname = f.substring(f.lastIndexOf("/")+1);
			var fpath = f.substr(0,f.lastIndexOf("/"));
			
			fname = [fname.slice(0,fname.lastIndexOf(".")),fname.slice(fname.lastIndexOf(".")+1)];
			var nf = fpath+"/"+fname[0]+".min."+fname[1];
			
			
			console.log("Compiling File: "+fname.join(".")+" ...")
			
			var minfile = cc.compile([f],
				{ compilation_level : "SIMPLE_OPTIMIZATIONS" },
				function(error,result){
					if(result){
						fs.writeFile(nf,result,function(err){
							if(err){
								console.log("Error: Could not output to: "+nf);
								throw err;
							}
							else { console.log("Completed: "+fname.join(".")); }
						})
					
					}
					else { console.log("Error: "+error)}
				}
			
			);
		}
	}
});