extends

// class Drinks {
//     constructor(capacity) {
//         this.capacity = capacity;
//     }
// }
// class Coke extends Drinks {
//     constructor(capacity) {
//         super(capacity);
//     }
// }


// #region ES5

function Drinks(capacity) {
    this.capacity = capacity;
}

function Coke() {
    Drinks.call(this, ...arguments);
}

Coke.prototype = Object.create(Drinks.prototype, {
    constructor: { value: Coke }
}); // Coke.prototype.__proto__ === Drinks.prototype

Object.setPrototypeOf(Coke, Drinks); // Coke.__proto__ === Function.prototype -> Coke.__proto__ === Drinks


// Object.create
// |__创建一个空对象，这个对象的原型对象指向Drinks.prototype  
// |__第二个参数是生成的这个对象的属性描述，对应Object.defineProperties() 的第二个参数


// #endregion


function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }



function _inherits(subClass, superClass) {
    if (typeof superClass !== "function" && superClass !== null) {
        throw new TypeError("Super expression must either be null or a function");
    }
    subClass.prototype = Object.create(superClass && superClass.prototype, {
        constructor: { value: subClass, writable: true, configurable: true }
    });
    Object.defineProperty(subClass, "prototype", { writable: false });

    if (superClass) _setPrototypeOf(subClass, superClass);
    // Coke.__proto__ === Function.prototype  ---→   Coke.__proto__ === Drinks
}
function _setPrototypeOf(o, p) {
    _setPrototypeOf = Object.setPrototypeOf
        ? Object.setPrototypeOf.bind()
        : function _setPrototypeOf(o, p) {
            o.__proto__ = p; return o;
        };
    return _setPrototypeOf(o, p);
}
function _createSuper(Derived) {
    var hasNativeReflectConstruct = _isNativeReflectConstruct();
    return function _createSuperInternal() {
        var Super = _getPrototypeOf(Derived), // 获取Coke的原型对象——Drinks构造函数
            result;
        if (hasNativeReflectConstruct) {
            var NewTarget = _getPrototypeOf(this).constructor; // 当前实例的构造函数——Coke
            result = Reflect.construct(Super, arguments, NewTarget);

            /**
             * https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect/construct
             *
             * [参数1]被运行的构造函数
             * [参数3]作为新创建对象的原型对象的 constructor 属性
             * 
             * result = new Super(...arguments);
             * result.__proto__.constructor = NewTarget;
             * 表示result是从NewTarget创建的，而不是Super创建的
             * 优先通过Reflect.construct去调用构造函数，保证new.target不丢失
             * 通过apply调用构造函数的时候，new.target是undefined
             */
        } else {
            result = Super.apply(this, arguments); // 执行完Super返回undefined
        }

        /**
         * 第1种：调用构造函数创建的对象result，没有修改this这个实例，result一定有值
         * 第2种：修改了this，result是构造函数的显式返回值，值可能有或没有
         */

        // 父类构造函数执行完如果有显式的返回值   
        return _possibleConstructorReturn(this, result);
    };
}
function _possibleConstructorReturn(self, call) {
    if (call && (_typeof(call) === "object" || typeof call === "function")) {
        return call;
    } else if (call !== void 0) {
        throw new TypeError("Derived constructors may only return object or undefined");
    }
    return _assertThisInitialized(self);
}
function _assertThisInitialized(self) {
    if (self === void 0) {
        throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
    }
    return self;
}
function _isNativeReflectConstruct() {
    if (typeof Reflect === "undefined" || !Reflect.construct)
        return false;
    if (Reflect.construct.sham)
        return false;
    if (typeof Proxy === "function")
        return true;
    try {
        Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () { }));
        return true;
    } catch (e) {
        return false;
    }
}
function _getPrototypeOf(o) {
    _getPrototypeOf = Object.setPrototypeOf
        ?
        Object.getPrototypeOf.bind()
        :
        function _getPrototypeOf(o) {
            return o.__proto__ || Object.getPrototypeOf(o);
        };
    return _getPrototypeOf(o);
}

var Coke = /*#__PURE__*/function (_Drinks) {
    _inherits(Coke, _Drinks); // 实现对父类原型链属性的继承
    var _super = _createSuper(Coke); // 返回值可以先理解为父类的构造函数  _createSuper返回1个函数，执行后返回1个对象
    function Coke(capacity) {
        _classCallCheck(this, Coke);
        return _super.call(this, capacity); // 注意这个构造函数的显式return
    }
    return _createClass(Coke);
}(Drinks);