/**
 * Calculate scrollbars thickness
 * @returns {Object} result - result
 * @returns {number} result.vertical - vertical scrollbar width
 * @returns {number} result.horizontal - horizontal scrollbar height
 */
export function getScrollbarsThickness() {
  // Creating invisible container
  const outer = document.createElement('div');
  outer.style.visibility = 'hidden';
  outer.style.overflow = 'scroll'; // forcing scrollbar to appear
  outer.style.msOverflowStyle = 'scrollbar'; // needed for WinJS apps
  document.body.appendChild(outer);

  // Creating inner element and placing it in the container
  const inner = document.createElement('div');
  inner.style.height = '100%';
  outer.appendChild(inner);

  // Calculating difference between container's full size and the child size
  const scrollbarWidth = outer.offsetWidth - inner.offsetWidth;
  const scrollbarHeight = outer.offsetHeight - inner.offsetHeight;

  // Removing temporary elements from the DOM
  outer.parentNode.removeChild(outer);

  return { vertical: scrollbarWidth, horizontal: scrollbarHeight };
}