判断浏览器窗口滚动到最底部

<div @scroll="onScroll" class="allow-scroll">
    我是很高很长很长（超过外部div高度）的内容...
</div>

onScroll(e) {
  // Y轴滚动距离 偏移高度 总高度
  let { scrollTop, clientHeight, scrollHeight } = e.target
  console.log(`scrollTop + clientHeight ${scrollTop + clientHeight} >= scrollHeight-1 ${scrollHeight - 1}`)
  if (scrollTop + clientHeight >= scrollHeight - 1) {
    console.log('滚到底部啦！！！')
  }
}

let allowScroll = document.querySelector('.allow-scroll')
console.log({ allowScroll })
if (!allowScroll) {
  return
}
console.log(
  `allowScroll.scrollHeight ${allowScroll.scrollHeight} <= allowScroll.clientHeight ${allowScroll.clientHeight}`
)
if (allowScroll.scrollHeight <= allowScroll.clientHeight) {
  console.log('高度低于窗口可视区域高度')
}