Understanding Protractor and WebDriverJS control flow

Question

Can someone help me understand how WebDriverJS/Protractor works in this case?

function MyPageObject(buttonElementFinder) {
  this.getButtonByIndex = function(index) {
    return {
      myButton: buttonElementFinder.get(index)
    }
  }
}

1. describe('My button', function() {
2. 
3.   it('should contain the text foo', function() {
4.     var myElementFinder = element.all(by.css('.foo'));
5.     var pageObject = new MyPageObject(myElementFinder);
6.     var button = pageObject.getButtonByIndex(0);
7.     expect(button.text()).toBe('foo');
8.  });
9. 
10. });

Does the WebDriverJS control flow have an action added to it on line 6 because of the .get method of ElementFinders?

I presume the expect also adds another item to the control flow too on line 7?

Edit: I have update the code to use element.all.

Answer 1

var myElementFinder = element.all(by.css('.foo'));

myElementFinder is a ElementArrayFinder and is simply an object. Nothing async is happening here.

var pageObject = new MyPageObject(myElementFinder);

Obvious.

var button = pageObject.getButtonByIndex(0);

This will return an ElementFinder from buttonElementFinder.get. Nothing async is happening here.

expect(button.text()).toBe('foo');

button.text() returns a promise from Webdriver.schedule, which in turn is using the control flow which is retrieved using webdriver.promise.controlFlow(), which exposes an execute function.