有没有办法使用 TypeScript 装饰器更改返回值？

问：

我正在尝试改变各种方法的行为。该行为包括检查发送的参数中是否存在值，并在该方法返回的值上设置属性。

例：

function ParseDiscounts {
    return function (
        target: any,
        propertyKey: string,
        descriptor: PropertyDescriptor,
    ) {
        const originalMethod = descriptor.value;
        descriptor.value = async function (...args: any[]) {
            if(args[0].discounts !== undefined) {
                /**
                 *
                 * here is where supposed to add a property on the return
                 * something like resultToBeParsed.isDiscountApplied = true
                 *
                 * */
            }
            const result = await originalMethod.apply(this, args);
            return result;
        };
        return descriptor;
    };
}

class Order {
    @ParseDiscounts()
    createOrder(discountPayload) {
        /**
         * Do everything that it is supposed to do while only at the return of the function
         * the `isDiscountApplied = true` is added to the result through the decorator
         * */
        return resultToBeParsed
    }
}

const firstOrder = new Order()
const firstResult = firstOrder.createOrder({ otherProperties: 'blah, blah, blah', discounts: [1,2,3]})
// firstResult.isDiscountApplied = true

const secondOrder = new Order()
const secondResult = secondOrder.createOrder({ otherProperties: 'blah, blah, blah'})
// secondResult.isDiscountApplied = false

当有任何折扣 whithin discountPayload 时，我希望添加一个属性resultToBeParsedisDiscountApplied = false (e.g.)

我知道我可以做一些事情，比如创建一个 whithin 装饰器并分配结果 whithin，但我也想操纵方法返回周期（我什至不知道这是否可能）。parsedResponse

我不知道这是否是最好的方法，真的，如果你们知道更好的东西，我会很高兴听到......我这样做是因为有很多地方我会使用它。