a simple httpproxy that can beautify JavaScript

config.js

//a simple httpproxy that can beautify JavaScript

//fangyong 2012-11-29 [email protected]
//add javascript file names to the config array that you want to beautify
//change to your favorite port number

var config = [
		'ver.js',
		'mi.Login_new',
		'login_div.js',
		'ping.js',
		'crystal-min.js'
	];
config.port = 8084;

if(typeof exports !== 'undefined'){
	exports.config = config;
}

jsproxy.js

//$node jsproxy

//fangyong 2012-11-29 [email protected]

//when debugging a web page written by someone else, these compressed javascript files are impossible to debug.. they are single-lined, and they are often sized more than 6.5k ...

//now jsproxy comes to the rescue. configure which javascript files you want to beautify, set your browsers's proxy to jsproxy and you are all set.

//reqiures js_beautify in './'

//if it does not work for your other http connections(of course it does not, it's just a simple http proxy with 20+ lines of its core...), check out jsproxy.pac

//usually, it's safe to disable jsproxy when you have loaded these better javascript files, since they are often cached for a long time by the browser.

var config = require('./config').config;
var jsbeauty = require('./beautify').js_beautify;
var http = require('http');
var url = require("url");
var net = require("net");
var zlib = require('zlib');

var node_proxy = http.createServer(function (req, res) {
	console.log(req.url);
	var lo = false;
	for (var i = 0; i < config.length; i++) {
		if (req.url.indexOf(config[i]) != -1) {
			//contains url
			console.log('read from local');
			lo = true;
			break;
		};
	};

	var srvUrl = url.parse(req.url);	
	var proxy = http.createClient(srvUrl.port || 80, req.headers['host']);
	var proxy_request = proxy.request(req.method,req.url,req.headers);
	
	proxy.addListener('error',function(e){
		console.log("Got error: " + e.message);
	});

	proxy_request.addListener('response',function(proxy_response){

		var data = [];
		var readlen = 0;

		if(!lo){
			res.writeHead(proxy_response.statusCode, proxy_response.headers);
		}

		proxy_response.addListener('data',function(chunk){
			if(lo){
				//buffer to data
				data.push(chunk);
				readlen += chunk.length;
			}else{
				//directly send to client
				res.write(chunk,'binary');
			}
			
		});
		proxy_response.addListener('end',function(){
			if(lo){
				var buffer = null;
    			switch(data.length) {
        			case 0: buffer = new Buffer(0);
            			break;
        			case 1: buffer = data[0];
            			break;
        			default:
            			buffer = new Buffer(readlen);
            			for (var i = 0, pos = 0, l = data.length; i < l; i++) {
                			var chunk = data[i];
                			chunk.copy(buffer, pos);
                			pos += chunk.length;
            			}
        				break;
    			}
    			//buffer may be compressed by gzip
    			var encoding = proxy_response.headers['content-encoding'] || proxy_response.headers['Content-Encoding'];
    			console.log(encoding);
    			switch(encoding){
    				case 'gzip':    					
    				case 'deflate':
    					zlib.unzip(buffer,function(err, resultBuf){
    						if (!err) {    							
    							data = jsbeauty(resultBuf.toString());
    							console.log("result:"+data);
    							zlib.gzip(data,function(err,resToClient){    								
    								proxy_response.headers['content-length'] = resToClient.toString('binary').length;
    								res.writeHead(proxy_response.statusCode, proxy_response.headers);
    								res.write(resToClient.toString('binary'),'binary');
									res.end();
    							});
    						};
    					});
    					break;
    				default:    					
						data = jsbeauty(buffer.toString());
						//console.log(data);
						proxy_response.headers['content-length'] = data.length;
						res.writeHead(proxy_response.statusCode, proxy_response.headers);

						res.write(data);
						res.end();
    					break;
    			}    			
			}else
				res.end();
			
		});		
	});

	req.addListener('data',function(chunk){
		proxy_request.write(chunk,'binary');
	});
	req.addListener('end',function(){
		console.log('end');
		proxy_request.end();
	});

});

node_proxy.on('connect', function(req, cltSocket, head) {
  // connect to an origin server
  var srvUrl = url.parse('http://' + req.url);
  var srvSocket = net.connect(srvUrl.port, srvUrl.hostname, function() {
    cltSocket.write('HTTP/1.1 200 Connection Established\r\n' +
                    'Proxy-agent: Node-Proxy\r\n' +
                    '\r\n');
    srvSocket.write(head);
    srvSocket.pipe(cltSocket);
    cltSocket.pipe(srvSocket);
  });
});

node_proxy.listen(config.port, "127.0.0.1");

console.log('proxy server running at http://127.0.0.1:'+config.port+'/');

jsproxy.pac

//fangyong 2012-11-29 [email protected]

//when it comes to HTTP 1.1's 'Connection:Keep-Alive', there are some bugs...
//it can be fixed by changing all the 'Connection' to 'close'...but it's a dirty hack.
//any help will be welcomed with these bugs.

//if it really bothers your browser, set browser's proxy to this pac file.
//IE: Internet Options -> Connections -> Lan Settings -> Use automatic configuration script -> Address : file://c:/path/to/pac
//chrome/firefox are also tested with this pac file.

//you may need to change the port and config array as you could have done in config.js
function regExpMatch(url, pattern) {
	try { return new RegExp(pattern).test(url); } catch(ex) { return false; }
}

function FindProxyForURL(url, host) {
	var config = [
		'ver.js',
		'mi.Login_new',
		'login_div.js',
		'ping.js',
		'crystal-min.js'
	];
	for (var i = config.length - 1; i >= 0; i--) {
	 	if(shExpMatch(url,'*'+config[i]+'*'))
	 		return 'PROXY 127.0.0.1:8084';
	 };		
	return 'DIRECT';
}