为啥这段代码会造成内存泄露啊?

function handleData() {
  list = data.value;
  const now = new Date().getTime()
  list.forEach(item => {
    const isTop = item.remindEndTime > now
    item.shine = isTop;
    item.sort = isTop ? 0 : 1;
  })
  // 闪烁的放最前 再以更新时间排序
  list = orderBy(list, ['sort', 'updateTime'], ['asc', 'desc'])
  visibleData.value = list
  list = null
}

onMounted(() => {
  flightClient.subscribe(WS_PREFIX + '/xxx/xxx', res => {
    data.value = res
    handleData()
  })

  timer = setInterval(() => {
    handleData()
  }, 300)
})

onBeforeUnmount(() => {
  clearInterval(timer)
})

每次调用我都把 list 置为空了 为什么还是会导致内存蹭蹭涨?

如果把 list = orderBy(list, ['sort', 'updateTime'], ['asc', 'desc']) 这段代码去掉 就没问题了