How do I check if my element has been focussed in a unit test

Question

I have the following directive to autofocus a field:

.directive('ngAutofocus', function ($timeout) {
    return {
        restrict: 'A',
        link: function (scope, elm) {
                $timeout(function () {
                elm[0].focus();
            });
        }
    };
}

How would I unit test this? I tried several things like the following selector but they all return errors or false:

console.log($(elm[0]).is(':focus'));

My unit test is set up like this:

elm = angular.element('<input type="text"  name="textfield1" ng-autofocus>');
$scope.$digest();
$compile(elm)($scope);

Solution 1

I figured it out, and it was pretty obvious actually;

it('should set the focus on timeout', function () {
    spyOn(elm[0],'focus');
    $timeout.flush();
    expect(elm[0].focus).toHaveBeenCalled();
})

My problem was two-fold:

1. I wasn't calling the timeout flush function so timeout wasn't occuring, and
2. I was trying to look at the focus attribute of the element whereas just looking at the call of the focus() function is much more like unit-testing. The focus attribute is something that really belongs to the e2e testing territory.

Solution 2

You can use document.activeElement to check focus. The only downside being that the HTML needs to be added to the document body for this to work.

https://developer.mozilla.org/en-US/docs/Web/API/Document/activeElement

Comments

[Lee Goddard]

Besides the remarks you make in your answer, readers should note your directive definition should read: .directive('ngAutofocus', '$timeout', function ($timeout) { -- otherwise $timeout is not transcluded by Angular.

[Maarten]

Are you sure? You probably mean with a [ added too, and not because transclusion but because of minification causing injection to break without it with certain minimizers. See github.com/johnpapa/…

[Lee Goddard]

yes to the [ - I should edit outside the comment box.

[Maarten]

then still, the injection helping is only needed in certain cases, and not required for the question

[Mobigital]

great option, should expand your post on the specifics!