text: var getScrollingRoot = function getScrollingRoot() {
    return document.scrollingElement || document.documentElement;
  };
  
  /**
   * Recursively finds the scroll parent of a node. The scroll parrent of a node
   * is the closest node that is scrollable. A node is scrollable if:
   *  - it is allowed to scroll via CSS ('overflow-y' not visible or hidden);
   *  - and its children/content are "bigger" than the node's box height.
   *
   * The root of the document always scrolls by default.
   *
   * @param {HTMLElement} node Any DOM element.
   * @return {HTMLElement} The scroll parent element.
   */
  export function getScrollParent(node) {
    var parent = node.parentElement;
  
    if (parent == null) return getScrollingRoot();
  
    var _window$getComputedSt = window.getComputedStyle(parent),
        overflowY = _window$getComputedSt.overflowY;
  
    var canScroll = overflowY !== 'visible' && overflowY !== 'hidden';
  
    if (canScroll && parent.scrollHeight > parent.clientHeight) {
      return parent;
    }
  
    return getScrollParent(parent);
  }
  
  /**
   * Recursively traverses the tree upwards from the given node, capturing all
   * ancestor nodes that scroll along with their current 'overflow-y' CSS
   * property.
   *
   * @param {HTMLElement} node Any DOM element.
   * @param {Map<HTMLElement,string>} [acc] Accumulator map.
   * @return {Map<HTMLElement,string>} Map of ancestors with their 'overflow-y' value.
   */
  export function getScrollAncestorsOverflowY(node) {
    var acc = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : new Map();
  
    var scrollingRoot = getScrollingRoot();
    var scrollParent = getScrollParent(node);
    acc.set(scrollParent, scrollParent.style.overflowY);
  
    if (scrollParent === scrollingRoot) return acc;
    return getScrollAncestorsOverflowY(scrollParent, acc);
  }
  
  /**
   * Disabling the scroll on a node involves finding all the scrollable ancestors
   * and set their 'overflow-y' CSS property to 'hidden'. When all ancestors have
   * 'overflow-y: hidden' (up to the document element) there is no scroll
   * container, thus all the scroll outside of the node is disabled. In order to
   * enable scroll again, we store the previous value of the 'overflow-y' for
   * every ancestor in a closure and reset it back.
   *
   * @param {HTMLElement} node Any DOM element.
   */
  export default function disableScroll(node) {
    var scrollAncestorsOverflowY = getScrollAncestorsOverflowY(node);
    var toggle = function toggle(on) {
      return scrollAncestorsOverflowY.forEach(function (overflowY, ancestor) {
        ancestor.style.setProperty('overflow-y', on ? 'hidden' : overflowY);
      });
    };
  
    toggle(true);
    return function () {
      return toggle(false);
    };
  }