NodeJS中最好的DDD建模方法是什么？

Question

我已经对Java有一定的经验，并且习惯于使用DDD方法进行建模。因此，现在我从JS和NodeJS开始，我想知道哪种是在Javascript中使用类似方法（没有ES6）进行设计的最佳实践。

这里有一个我要尝试做的事的示例，但我不知道这些是否是更好的方法。我感谢一些意见。

function Purchase(pCustomer, pOrders, pPayment, pTotal) {
    let idPurchase = PurchaseId.purchaseId();
    let customer = pCustomer;
    let payment = pPayment;
    let orders = pOrders;
    let deliveryAddress;
    let billingAddress;
    let total = pTotal;

    // Return an object exposed to the public
    return {
        setOrders: function (o) {
            orders = o
        },
        setDeliveryAddress: function (address1, address2, zipCode, city) {
            deliveryAddress = new Address(address1, address2, zipCode, city);
        },
        setBillingAddress: function (address1, address2, zipCode, city) {
            billingAddress = new Address(address1, address2, zipCode, city);
        },
        getId: function () {
            return idPurchase;
        },
        getOrders: function () {
            return orders;
        },
        getCustomer: function () {
            return customer;
        },
        toJSON: function () {
            return {
                idPurchase: idPurchase,
                customerOnPurchase: customer.toJSON(),
                deliveryAddress: deliveryAddress.toJSON(),
                billingAddress: billingAddress.toJSON(),
                total: total,
            }
        }
    }
}

module.exports = Purchase;