尝试删除不允许的属性时引发错误

Question

因此，我知道您可以通过将configurable对象的属性设置为来防止属性被删除false。但是，您从此delete操作中获得的唯一反馈是显示为true或false的布尔值。当删除不允许的属性时，有什么方法可以立即引发错误？const obj = {  deleteMe: "Some text",  dontDeleteMe: "Some other text"};Object.defineProperty(obj, 'dontDeleteMe', {    value: "Some text",    writable : true,    enumerable : true,    configurable : false});console.log(Object.keys(obj));delete obj.deleteMe;console.log(Object.keys(obj));delete obj.dontDeleteMe;console.log(Object.keys(obj));

Answer 1

如果添加，将引发错误use strict：

'use strict';

const obj = {

  deleteMe: "Some text",

  dontDeleteMe: "Some other text"

};

Object.defineProperty(obj, 'dontDeleteMe', {

    value: "Some text",

    writable : true,

    enumerable : true,

    configurable : false

});

console.log(Object.keys(obj));

delete obj.deleteMe;

console.log(Object.keys(obj));

delete obj.dontDeleteMe;

console.log(Object.keys(obj));

带代理：

const obj = {

  deleteMe: "Some text",

  dontDeleteMe: "Some other text"

};

Object.defineProperty(obj, 'dontDeleteMe', {

    value: "Some text",

    writable : true,

    enumerable : true,

    configurable : false

});

const handler1 = {

  deleteProperty(target, prop) {

    delete target[prop];

    if (target[prop]) {

      throw new Error(`Invalid attempt to delete '${prop}' property`);

    }

    return true;

  }

};

const proxyObj = new Proxy(obj, handler1);

console.log(Object.keys(proxyObj));

delete proxyObj.deleteMe;

console.log(Object.keys(proxyObj));

delete proxyObj.dontDeleteMe;

console.log(Object.keys(proxyObj));

Answer 2

如果您不想使用“使用严格”（无论出于何种原因），这将是代理解决方案：

const obj = {

  deleteMe: "Some text",

  dontDeleteMe: "Some other text"

};

const deleteHandler = {

  deleteProperty(target, prop) {

    if (prop in target) {

      const deleted = delete target[prop];

      if (!deleted) {

        console.error(`deletion not allowed: ${prop}`);

      }

    }

  }

};

Object.defineProperty(obj, 'dontDeleteMe', {

  value: "Some text",

  writable: true,

  enumerable: true,

  configurable: false

});

const proxyObj = new Proxy(obj, deleteHandler);

console.log(Object.keys(proxyObj));

delete proxyObj.deleteMe;

console.log(Object.keys(proxyObj));

delete proxyObj.dontDeleteMe;

console.log(Object.keys(proxyObj));