useCreation ​

import type { DependencyList } from 'react';
import { useRef } from 'react';
import depsAreSame from '../utils/depsAreSame';

export default function useCreation<T>(
	factory: () => T, // 函数，返回要持久化缓存的结果
	deps: DependencyList // 依赖项
) {
	const { current } = useRef({
		deps, // 依赖项
		obj: undefined as undefined | T, // 需要持久化缓存的值
		initialized: false, // 是否是第一次加载
	});

	// 第一次加载或者是依赖项发生变化才执行里面的代码
	if (current.initialized === false || !depsAreSame(current.deps, deps)) {
		current.deps = deps; // 跟新依赖项
		current.obj = factory(); // 更新缓存的值
		current.initialized = true; // 修改状态为非第一次加载
	}
	return current.obj as T;
}