HttpCheck in node.js

One of the most useful tools when you develop mobile portals is a simple web page to check the headers your browser is sending to the server. Which User-Agent? Accept-Language? Accept-Encoding? Accept-Charset?

A good opportunity to write a tiny node.js application (with just a bit of Underscore magic).

  var http = require('http'), 
      _ = require('./underscore'),
      port = process.env.PORT || 3000;

  var FullResponse = function(req) {

    var blanks = "                                   ";
    var fields = {"url": req.url, "method": req.method, "httpVersion": req.httpVersion, 
                "headers": req.headers, "data": ""};  
      
    var format = function(key, value, indent) {    
      if (_.isString(value))
        var valuePart = value+"\n";
      else
        var valuePart = "\n" + _.reduce(_.keys(value), function(sum, it) {  
          return sum + format(it, value[it], indent+1);  }, 
          "");
            
      return blanks.substring(0, indent * 2) + key+": " + valuePart;
    }        
    
    this.addData = function(data) {
      fields["data"] += data.toString("utf8");
    }
    
    this.printOut = function() {        
      return format("response", fields, 0);
    }
    
  }

  http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    var response = new FullResponse(req);  
    req.on("data", function(it) {
      response.addData(it);
    });  
    req.on("end", function() {
      res.end(response.printOut());  
    });  
  }).listen(port);
  console.log('Server running at port '+port);

  

Full source code on Github, the application is running at http://httpcheck.herokuapp.com.