When the Browser.visit() callback is fired, we check for errors. We also check whether the page was successfully loaded if the HTTP response status code was between 200 and 299. These 2XX response codes correspond to the ok request state and are part of the server's way of telling the user-agent that everything went well.
Despite receiving an ok response, we shouldn't take the server's word for granted. We may have received the response status code and an HTML document, but can't be sure that we got the intended document containing the markup for the user signup form.
In our case, we may wish to verify that the document has a heading element containing the New User string and that the new user form elements are present. Here is the code for the complete test:
it('should load the signup form', function(done) {
Browser.visit("http://localhost:3000/users/new", function(err, browser) {
if (err) throw err;
assert.ok(browser.success, 'page loaded');
...