Object.defineProperty的错误

Question

const obj = {
  name: "allen",
  address: {
    country: "china",
    city: "beijing",
  },
  habits: ["读书", "写字"],
};

for (let key in obj) {
  Object.defineProperty(obj, key, {
    value: obj[key],
    set: (newValue) => {
      console.log(`${key}改变了:${obj[key]}=>${newValue}`);
    },
    get: () => obj[key],
  });
}

报错1：

TypeError: Invalid property descriptor. Cannot both specify accessors and a value or writable attribute

报错2：

RangeError: Maximum call stack size exceeded

Answer 1

TypeError: Invalid property descriptor. Cannot both specify accessors and a value or writable attribute

意思是get/set和value不能同时设置，从逻辑的角度看他们也是互斥的

RangeError: Maximum call stack size exceeded

get方法不断访问object[key]，也就是get方法本身，所以会无限嵌套导致栈溢出

Answer 2

value和get/set只能取其一

不熟悉的API请看官方文档