ant-design-vue/components/_util/getScroll.ts

export function isWindow(obj: any) {
  return obj !== null && obj !== undefined && obj === obj.window;
}

export default function getScroll(target: HTMLElement | Window | Document | null, top: Boolean) {
  if (typeof window === 'undefined') {
    return 0;
  }

  const method = top ? 'scrollTop' : 'scrollLeft';
  let result = 0;
  if (isWindow(target)) {
    result = (target as Window)[top ? 'pageYOffset' : 'pageXOffset'];
  } else if (target instanceof Document) {
    result = target.documentElement[method];
  } else if (target) {
    result = (target as HTMLElement)[method];
  }
  if (target && !isWindow(target) && typeof result !== 'number') {
    result = ((target as HTMLElement).ownerDocument || (target as Document)).documentElement[
      method
    ];
  }
  return result;
}