Interruptible fade-out DOM animation

interruptibleFadeOut.js

function interruptibleFadeOut(element, options) {
    if (typeof options === 'number') {
        options = {fadeOut: options};
    }

    element = $(element);
    return new Promise(function(resolve) {
        // Event handlers used by the effect.
        var events = {
            mouseenter: function() { interruptAnimation(); },
            mouseleave: function() { delayedFadeOut(); },
            click: function() {
                interruptAnimation();
                delayedFadeOut();
            },
        };
        Object.keys(events).forEach(function(name) {
            element.on(name, events[name]);
        });

        // Helper functions.
        var interruptAnimation = function() {
            element.stop(true);
            element.css('opacity', 1.0);
        };
        var delayedFadeOut = function() {
            if (options.delay) {
                element.delay(options.delay);
            }
            element.fadeOut(options.fadeOut, function() {
                Object.keys(events).forEach(function(name) {
                    element.off(name, events[name]);
                });
                resolve();
            });
        };

        // Start the animation.
        if (options.fadeIn) {
            element.fadeIn(options.fadeIn);
        }
        delayedFadeOut();
    });
}