HTMLElement offsetParent is undefined

I have some code depending upon an HTMLElement’s offsetParent, specifically within an event listener. Code I have here:

window.addEventListener('mousemove', function(e) {
  const control = e.target.offsetParent;
  if (!control) {
    return;
  }

  const factor = this.state.duration / control.offsetWidth;
  const time = e.pageX * factor;
  actions.setCurrentTime(time);
});

However, when I test this with jest (and therefore JSDOM), I can’t seem to get offsetParent to be defined in any way.

Is this an unsupported attribute of an HTMLElement?

[panganibanpj]

I know this is old but if someone ever find this and has trouble, I got around it doing something similar to above:

Object.defineProperty(HTMLElement.prototype, 'offsetParent', {
    get() { return this.parentNode; },
});

[NtFreX]

@panganibanpj Thanks for the code snipped. I enhanced it with some of the mozilla specs.

Object.defineProperty(HTMLElement.prototype, 'offsetParent', {
    get() {
        let element = this;
        while (!isNullOrUndefined(element) &&
                    (isNullOrUndefined(element.style) ||
                    isNullOrUndefined(element.style.display) ||
                    element.style.display.toLowerCase() !== 'none')) {
            element = element.parentNode;
        }

        if (!isNullOrUndefined(element)) {
            return null;
        }

        if (!isNullOrUndefined(this.style) && !isNullOrUndefined(this.style.position) && this.style.position.toLowerCase() === 'fixed') {
            return null;
        }

        if (this.tagName.toLowerCase() === 'html' || this.tagName.toLowerCase() === 'body') {
            return null;
        }

        return this.parentNode;
    },
});