捕获自定义错误在Bluebird中不起作用

本文介绍了捕获自定义错误在Bluebird中不起作用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我试图抛出然后在Bluebird Promise链中捕获自定义错误，但是我无法捕获到自定义错误.例如:

I am trying to throw and then catch a custom error in a Bluebird promise chain, but I can't get it to catch the custom error. For example:

function login(req, res, next) { function LoginError() {} return User.where('id', req.body.userId).fetch() .then(function (location) { if (req.body.password !== location.get('password')) { throw new LoginError(); } // returns a promise return Subscription.where('userId', location.get('userId')).fetch(); }) .then(function (subscription) { return res.send(JSON.stringify(subscription)); }) .catch(LoginError, function (err) { return res.send('Login error'); }) .catch(function (err) { res.send('Other error: ' + JSON.stringify(err)); }); }

当密码不匹配且抛出LoginError时，错误将捕获在第二个catch块中，而不是LoginError的catch块中.我在做什么错了?

When the password doesn't match and it throws LoginError, the error is caught in the second catch block, not the catch block for LoginError. What am I doing wrong?

我正在使用Express.js，Bluebird和Bookshelf/Knex，其中User是Bookshelf模型.

I'm using Express.js, Bluebird, and Bookshelf/Knex where User is a Bookshelf model.

推荐答案

Bluebird在 catch 通过继承:

Bluebird distinguishes error constructors from predicate functions in a catch by their inheritance:

将参数视为您想要的错误类型 过滤器，您需要构造函数使其.prototype属性为 instanceof Error.

For a parameter to be considered a type of error that you want to filter, you need the constructor to have its .prototype property be instanceof Error.

这样的构造函数可以像这样最少创建:

Such a constructor can be minimally created like so:

function MyCustomError() {} MyCustomError.prototype = Object.create(Error.prototype);

您需要对LoginError做同样的事情.

You will need to do the same for your LoginError.

或者，如果您使用的是ES6，则class LoginError extends Error {}.

Or if you're using ES6, then class LoginError extends Error {}.