Error when asserting url

[visal...@honestbee.com]

Hi I am totally a newbie to zombie and I was trying my hands at a basic code:

var assert = require("chai").assert;

var Browser = require('zombie');

 

Browser.localhost('xxx.com', 3030);

 

describe('User visits signup page', function() {

 var browser = new Browser();

  before(function() {

    browser.visit('/shop-now');

  });

  describe('submits postal codes', function(done) {

      console.log ("test");

 

     browser.assert.url('http://xxx.com/shop-now');

     done ();

  });

});

However, i am always getting the following error and I am really not sure where I am going wrong. I am actually not able to assert anything.

/Users/visalakshi/Documents/HB-Frontend/node_modules/zombie/lib/assert.js:75

      var absolute = URL.resolve(this.browser.location.href, expected);

                                                      ^

TypeError: Cannot read property 'href' of null

    at Assert.url (/Users/visalakshi/Documents/HB-Frontend/node_modules/zombie/lib/assert.js:75:55)

    at Suite.<anonymous> (/Users/visalakshi/Documents/HB-Frontend/test/zombieTest.js:31:21)

    at context.describe.context.context (/usr/local/lib/node_modules/mocha/lib/interfaces/bdd.js:74:10)

    at Suite.<anonymous> (/Users/visalakshi/Documents/HB-Frontend/test/zombieTest.js:21:3)

    at context.describe.context.context (/usr/local/lib/node_modules/mocha/lib/interfaces/bdd.js:74:10)

    at Object.<anonymous> (/Users/visalakshi/Documents/HB-Frontend/test/zombieTest.js:15:1)

    at Module._compile (module.js:460:26)

    at Object.Module._extensions..js (module.js:478:10)

    at Module.load (module.js:355:32)

    at Function.Module._load (module.js:310:12)

    at Module.require (module.js:365:17)

    at require (module.js:384:17)

    at /usr/local/lib/node_modules/mocha/lib/mocha.js:184:27

    at Array.forEach (native)

    at Mocha.loadFiles (/usr/local/lib/node_modules/mocha/lib/mocha.js:181:14)

    at Mocha.run (/usr/local/lib/node_modules/mocha/lib/mocha.js:393:31)

    at Object.<anonymous> (/usr/local/lib/node_modules/mocha/bin/_mocha:380:16)

    at Module._compile (module.js:460:26)

    at Object.Module._extensions..js (module.js:478:10)

    at Module.load (module.js:355:32)

    at Function.Module._load (module.js:310:12)

    at Function.Module.runMain (module.js:501:10)

    at startup (node.js:129:16)

    at node.js:814:3