useConstant.ts19 lines · main

1	'use client'
2
3	// based on https://github.com/Andarist/use-constant
4	import { useRef } from 'react'
5
6	type ResultBox<T> = { v: T }
7
8	/**
9	* React hook for creating a value exactly once
10	*/
11	export function useConstant<T>(fn: () => T): T {
12	const ref = useRef<ResultBox<T> | null>(null)
13
14	if (!ref.current) {
15	ref.current = { v: fn() }
16	}
17
18	return ref.current.v
19	}