Asserting an element is focused

Question

According to the How do I assert an element is focused? thread, you can check if an element is focused by switching to an activeElement() and assert this is the same element you've expected to have the focus:

expect(page.element.getAttribute('id')).toEqual(browser.driver.switchTo().activeElement().getAttribute('id'));

In my case, the currently focused element does not have an id attribute.

What should I do instead of checking an id?

Bonus question: Also, as you can see from my tries to solve it, it looks like I cannot expect/assert an element (or web element) as a complete object. Why?

---

I've tried:

expect(page.element).toEqual(browser.driver.switchTo().activeElement());

But is is failing with an error I cannot even understand - there is a huge traceback (it is about 10 minutes to scroll in the console), but no user-friendly error inside.

I've also tried to use getWebElement():

expect(page.element.getWebElement()).toEqual(browser.driver.switchTo().activeElement());

But this resulted into the following error:

Error: expect called with WebElement argument, expected a Promise. Did you mean to use .getText()?

Using the latest protractor development version.

Answer 1

In my answer I'm going to assume activeElem and pageElem are both protractor element finders, and are pointing to the same web element.

First to answer your question about why

expect(activeElem).toEqual(pageElem);

Gets into an infinite loop, it's because protractor patched jasmine's expect to resolve the promise before asserting, so that things like expect(activeElem.getText()).toEqual('text'); works without having to do

activeElem.getText().then(function(text) {
  expect(text).toEqual('text');
})

You could say, why not just resolve the promise once? But then there are nested promises.

So now you might be thinking this is an issue, but it really isn't because you would never compare two elementFinders in a real use case. Jasmine's toEqual does a reference check, and not a deep compare, so expect(activeElem).toEqual(pageElem), is just the same as a simple reference comparison: (activeElem === pageElem).toToTruthy(), and there's really no point doing that. (Note element(by.css('html')) === element(by.css('html')) is false because it's not the same reference.)

So, to answer the real question for this thread: how to see if two elementFinders have the same underlying webelements:

expect(activeElem.getId()).toEqual(pageElem.getId());

Answer 2

For the future readers, I've created a custom matcher to assert if an element is active/focused:

beforeEach(function() {
    jasmine.addMatchers({
        toBeActive: function() {
            return {
                compare: function(elm) {
                    return {
                        pass: elm.getId().then(function (activeElementID) {
                            return browser.driver.switchTo().activeElement().getId().then(function (currentElementID) {
                                return jasmine.matchersUtil.equals(currentElementID, activeElementID);
                            });
                        })
                    };
                }
            };
        }
    });
});

Usage:

expect(element(by.css("#myid")).toBeActive();