steps.js

given(/^I am on the Cucumber.js GitHub repository$/, function(done) {
  this.visit('http://github.com/cucumber/cucumber-js', done);
});

when(/^I go to the README file$/, function(done) {
  done.pending();
});

then(/^I should see "(.*)" as the page title$/, function(title, done) {
  if (title === this.browser.text('title')) done();
  else done.fail(new Error("Expected to be on page with title " + title));
});

world.js

/**
 * Module dependencies.
 */

var zombie = require('zombie');

/**
 * Setup world env.
 */

module.exports = function (done) {
  this.browser = new zombie();

  this.visit = function(url, done) {
    this.browser.visit(url, done);
  };

  done();
};