Javascript 模块化 Promise 链乱序

Question

我试图找出为什么我的 Promise 链执行无序，尽管编写了一个非嵌套的 then 链。我的函数已经模块化，以减少链中发生的代码膨胀(我期望有五个 then 方法)，并且我不确定这些模块中的某些内容是否导致顺序跳转，或者是否是由于我的原因总体 promise 结构。

这是终端输出:

Executing (a6bf615e-5497-47b2-8aea-3f7d70927cba): START TRANSACTION;
Executing (a6bf615e-5497-47b2-8aea-3f7d70927cba): SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
Step 1: Document Find
Step 3: Cancel Stripe Subscription
string //console.log(typeof subscriptionId);
sub_jsdfjsdfjdsfjsdfj //console.log(subscriptionId)
Executing (a6bf615e-5497-47b2-8aea-3f7d70927cba): SELECT ....
Step 2: Set Array
[ 13, 14 ] //console.log(documentArr);
undefined //console.log(canceledStripeAccount);
undefined //console.log(canceledAt)

这是我的 promise 结构:

var sequelize = require('sequelize');
var models = require('../../../models/db-index');
var deleteAccount = require('./delete-account');


//DELETE /settings/account
exports.delete = function(req, res){
    var documents;
    var documentArr;
    var canceledStripeAccount;
    var canceledAt;

    return models.sequelize.transaction().then(function(t){

        return deleteAccount.queryAllDocuments(req.session.organizationId, t)
        .then(function(_document){
                console.log("Step 2: Set Array");
                documentArr = _document;
                console.log(documentArr);
        })
        .then(deleteAccount.cancelStripeAccount(req.session.subscriptionId, canceledStripeAccount, canceledAt))
        .then(function(canceledStripeAccount){
            console.log(canceledStripeAccount);
            console.log(canceledAt)
        });
    });
};

模块文件:

var models = require('../../../models/db-index');
var components = require('./components');
var stripe = require('stripe')(process.env.STRIPE_API_KEY);

module.exports = {

    queryAllDocuments: function(organization, t){
        console.log("Step 1: Document Find");
        return models.Document.findAll({
            include: [{
                model: models.User,
                include: [{
                    model: models.Organization,
                    where: {
                        organizationId: organization
                    }
                }]
            }],
            transaction: t
        })
    },

    cancelStripeAccount: function(subscriptionId, canceledStripeAccount, canceledAt){
        console.log("Step 3: Cancel Stripe Subscription");
        console.log(typeof subscriptionId);
        console.log(subscriptionId)
        return stripe.subscriptions.del(subscriptionId).then(function(_canceledStripeAccount){
            return canceledStripeAccount = _canceledStripeAccount;
            //canceledAt = canceledStripeAccount.canceled_at;
        })
    }

}

Answer 1

您在 .then() 甚至调用其回调之前直接调用该函数(并将返回值从该函数传递给 .then()):

.then(deleteAccount.cancelStripeAccount(req.session.subscriptionId, 
        canceledStripeAccount, canceledAt))

相反，.then() 应该传递一个函数引用，以便它可以稍后调用该函数:

.then(() => deleteAccount.cancelStripeAccount(req.session.subscriptionId,
              canceledStripeAccount, canceledAt))