@material-ui/popper.js/src/utils/getParentNode.js

A fork of popper.js to avoid the deprecation warnings: https://github.com/mui-org/material-ui/issues/19358.

/**
 * Returns the parentNode or the host of the element
 * @method
 * @memberof Popper.Utils
 * @argument {Element} element
 * @returns {Element} parent
 */
export default function getParentNode(element) {
  if (element.nodeName === 'HTML') {
    return element;
  }
  return element.parentNode || element.host;
}