How JavaScript closures can help in Protractor test automation?

Question

As I am working in protractor test automation and slowly diving into more & more advanced JavaScript features, I am wondering how can I take advantage of closure feature in Protractor test automation.

What are those typical test automation situations where closures might prove a useful feature to use?

I am asking this question purely from UI test automation perspective, not in general JavaScript programming. I would love to hear from senior folks who are using a protractor on an advanced level in large scale projects and share their experiences.

score 3 · Accepted Answer · edited May 23 '17 at 12:07

Here are some closure use cases that we've been using in our test automation project:

when a Page Object method has a promise resolution function in which you need to access the other Page Object fields or methods, you need to create a closure:

var SelectEnvironmentPage = function () {    
    this.title = this.container.element(by.css("b.modal-title"));
    this.goButton = element(by.id("selEnvBtnGo"));

    this.passIfPresent = function () {
        var self = this;
        this.title.isPresent().then(function (isTitlePresent) {
            if (isTitlePresent) {
                self.goButton.click().then(function () {
                    helpers.passMaxSessionPopup();
                });
            }
        });
    };
};

when extending ElementArrayFinder methods and defining the getWebElements() method

How JavaScript closures can help in Protractor test automation?

1 Answers1