rerender memo

Extract to Memoized Components

Extract expensive work into memoized components to enable early returns before computation.

Incorrect (computes avatar even when loading):

function Profile({ user, loading }: Props) {
  const avatar = useMemo(() => {
    const id = computeAvatarId(user)
    return 
  }, [user])

  if (loading) return 
  return <div>{avatar}</div>
}

Correct (skips computation when loading):

const UserAvatar = memo(function UserAvatar({ user }: { user: User }) {
  const id = useMemo(() => computeAvatarId(user), [user])
  return 
})

function Profile({ user, loading }: Props) {
  if (loading) return 
  return (
    <div>
      
    </div>
  )
}

Note: If your project has React Compiler enabled, manual memoization with memo() and useMemo() is not necessary. The compiler automatically optimizes re-renders.