Web API testing with Node

As I’m building an application that requires a backend web-service, I am building that service using Node. I intend that service to be RESTful. I need a tool to test this service, and have created a tool that runs under Node.  I use the assert library for verification.

var endpoint = 'localhost';
var http = require('http');
var assert = require('assert');
var opts = {
   host: endpoint,
   port: 8000,
   path: '/submit',
   method: 'POST',
   headers: { "Accept": "application/json", "Content-Type": "application/x-www-form-urlencoded" }
}
var req = http.request(opts, function(res) {
   res.setEncoding('utf8');
   var data = "";
   res.on('data', function(d) {
      data += d;
	});
	res.on('end', function() {
	   console.log(data);
	   //var result = eval(''+data);
	   //assert.strictEqual(data,'{"status":"ok","message":"this is fun"}');
	});
});
req.write('unit');
req.end();