export function isWindow(obj: any) { return obj !== null && obj !== undefined && obj === obj.window; } export default function getScroll( target: HTMLElement | Window | Document | null, top: boolean, ): number { 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; }