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

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

/**
 * Finds the root node (document, shadowDOM root) of the given element
 * @method
 * @memberof Popper.Utils
 * @argument {Element} node
 * @returns {Element} root node
 */
export default function getRoot(node) {
  if (node.parentNode !== null) {
    return getRoot(node.parentNode);
  }

  return node;
}