getClosestOverflowElement.ts

/** Get the closest element that scrolls */
function getClosestOverflowElement(node: HTMLElement, includeHidden?: boolean) {
  if (node) {
    const { overflow, overflowX, overflowY } = getComputedStyle(node)
    const canScroll = (
      includeHidden ? /(auto|scroll|hidden)/ : /(auto|scroll)/
    ).test(overflow + overflowX + overflowY)
    if (node === document.body || canScroll) {
      return node
    } else {
      return getClosestOverflowElement(
        node.parentNode as HTMLElement,
        includeHidden
      )
    }
  } else {
    return document.body
  }
}