Progress Knight JS (observe current progress bars)

/* add current progress bar selector to target with CSS */
$(".progress-bar").has("div.current").addClass("current-pb");

// mutation observer instance
var target = $("div.progress-fill");
var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
        if (mutation.attributeName === "class") {
            var attributeValue = $(mutation.target).prop(mutation.attributeName);
            if ($(mutation.target).hasClass("current")) {
                $(mutation.target).parent().addClass("current-pb");
            } else {
                $(mutation.target).parent().removeClass("current-pb");
            }
        }
    });
});
// observe all progress bars
var i;
for (i = 0; i < target.length; i++) {
    observer.observe(target[i], { attributes: true });
}