MouseEvent.path property polyfill

mouseevent.path.polyfill.js

/**
 * MouseEvent path property polyfill
 */
export function MouseEventPathPolyfill() {
    if (!('path' in Event.prototype)) {
        Object.defineProperty(Event.prototype, 'path', {
            get: function () {
                const path = [];
                let currentElem = this.target;
                while (currentElem) {
                    path.push(currentElem);
                    currentElem = currentElem.parentElement;
                }
                if (path.indexOf(window) === -1 && path.indexOf(document) === -1)
                    path.push(document);
                if (path.indexOf(window) === -1)
                    path.push(window);
                return path;
            }
        });
    }
}


/**
 * returns the event’s path which is an array of the objects on which listeners will be invoked
 * @param e - MouseEvent
 * @returns {Array|EventTarget[]|*}
 */
export function eventPath(e) {
    if ('composedPath' in e) return e.composedPath();
    if ('path' in e) return e.path;
    //polyfill
    const path = [];
    let currentElem = e.target;
    while (currentElem) {
        path.push(currentElem);
        currentElem = currentElem.parentElement;
    }
    if (path.indexOf(window) === -1 && path.indexOf(document) === -1) path.push(document);
    if (path.indexOf(window) === -1) path.push(window);
    return path;
}