问为什么我的处理数组的方法在ECMA6的类中不起作用

EN

class Product {
    constructor(name, count, price) {
        this.name = name;
        this.count = count;
        this.price = price;
    }
}
class Shop extends Product {
    constructor(products) {
        super();
        this.products = [];
    }

    addProduct(newProduct) {
        this.products.push(newProduct);
    }

    deleteProductByName(productName) {
        let i = this.products.length;
        while (i--) {
            if (productName in this.products[i]) {
                this.products.splice(i, 1);
            }
        }
    }

    getAllProductNames() {
        return this.products.map(object => Object.values(object)[0].name);
    }

    get totalProductsPrice() {
        return this.products.map(object => Object.values(object)[0].price).
        reduce((p, c) => p + c);
    }
}
const shop = new Shop();
shop.addProduct(new Product("product 1", 1, 200));
shop.addProduct(new Product("product 1", 1, 500));
shop.addProduct(new Product("product 2", 2, 1000));

console.log(shop.totalProductsPrice);
console.log(shop.getAllProductNames());
shop.deleteProductByName("product 2");
console.log(shop.products);