FinalizationRegistry + WeakRef 实现对象回收回调

const fr = new FinalizationRegistry((...args) => console.log(args)); // 会在obj被回收以后输出 ['11111']
let obj ={a:123,b:3333};
fr.register(new WeakRef(obj), "11111");
obj = null;

参考

• WeakRef
• FinalizationRegistry