react-spring/docs/app/hooks/useIsomorphicEffect.ts

import { useEffect, useLayoutEffect } from 'react'

// For server-side rendering: https://github.com/react-spring/zustand/pull/34
// Deno support: https://github.com/pmndrs/zustand/issues/347

const isSSR =
  typeof window === 'undefined' ||
  !window.navigator ||
  /ServerSideRendering|^Deno\//.test(window.navigator.userAgent)

export const useIsomorphicLayoutEffect = isSSR ? useEffect : useLayoutEffect