AngularJS - scenario.js code - angularjs

Question

In the application building tutorial on angularjs.org, step-8, testing part, what does the following lines of code mean-
element.all(by.css('.phones li a')).first().click();
expect(browser.getLocationAbsUrl()).toBe('/phones/nexus-s');
Thanks in advance!
PS:
The exact URL is- https://docs.angularjs.org/tutorial/step_08 and the code file (scenarios.js) is-
'use strict';
// Angular E2E Testing Guide:
// https://docs.angularjs.org/guide/e2e-testing
describe('PhoneCat Application', function() {
describe('phoneList', function() {
beforeEach(function() {
browser.get('index.html');
});
it('should filter the phone list as a user types into the search box', function() {
var phoneList = element.all(by.repeater('phone in $ctrl.phones'));
var query = element(by.model('$ctrl.query'));
expect(phoneList.count()).toBe(20);
query.sendKeys('nexus');
expect(phoneList.count()).toBe(1);
query.clear();
query.sendKeys('motorola');
expect(phoneList.count()).toBe(8);
});
it('should be possible to control phone order via the drop-down menu', function() {
var queryField = element(by.model('$ctrl.query'));
var orderSelect = element(by.model('$ctrl.orderProp'));
var nameOption = orderSelect.element(by.css('option[value="name"]'));
var phoneNameColumn = element.all(by.repeater('phone in $ctrl.phones').column('phone.name'));
function getNames() {
return phoneNameColumn.map(function(elem) {
return elem.getText();
});
}
queryField.sendKeys('tablet'); // Let's narrow the dataset to make the assertions shorter
expect(getNames()).toEqual([
'Motorola XOOM\u2122 with Wi-Fi',
'MOTOROLA XOOM\u2122'
]);
nameOption.click();
expect(getNames()).toEqual([
'MOTOROLA XOOM\u2122',
'Motorola XOOM\u2122 with Wi-Fi'
]);
});
it('should render phone specific links', function() {
var query = element(by.model('$ctrl.query'));
query.sendKeys('nexus');
element.all(by.css('.phones li a')).first().click();
expect(browser.getLocationAbsUrl()).toBe('/phones/nexus-s');
});
});
});

Answer 1

It is testing of the routing to /phones/nexus-s.
It is written in Protractor.
The first line reads the DOM and finds all the .phones li a css rules. It then takes only the first one and calls click() on it.
element.all(by.css('.phones li a')).first().click();
The second line expects the output of the function browser.getLocationAbsUrl() to be the string /phone/nexus-s
expect(browser.getLocationAbsUrl()).toBe('/phones/nexus-s');
So all in all the test framework clicks a button and expects it to be routed to a new page.