use-mount

1import { useEffect } from 'react'
2import type { EffectCallback } from 'react'
3 
4type MountCallback = EffectCallback | (() => Promise<void | (() => void)>)
5 
6export function useMount(fn: MountCallback) {
7  useEffect(() => {
8    const result = fn?.()
9    // If fn returns a Promise, don't return it as cleanup function
10    if (
11      result &&
12      typeof result === 'object' &&
13      typeof (result as any).then === 'function'
14    ) {
15      return
16    }
17 
18    return result as ReturnType<EffectCallback>
19  }, [])
20}