对象#<承诺>没有方法“捕获" [英] Object #&lt;Promise&gt; has no method &#39;catch&#39;

问题描述

我的用户库有以下注册代码

My user lib have following code for register

function register {
// do some validation on lib level

//user is instance of user collection
user.save()
    .then(function(error,records, numberOfRecords) {
        // got any kind of error
        if (error) {
            next('fail',msg,{error_code : 510, exception : ex} )
            return ;        
       }
        next('success','good', records );
    })
    .catch(function(ex) {
        var msg =  ex.message;
        error = ex
        system.log.error(msg);
        next('fail',msg,{error_code : 510, exception : ex} );
    }).done();
}

在我的 mongoes modal 中，我已经实现了中间件

In my mongooes modal, I have implemented middle-ware

    User.pre('save', function (next) {

          // just checking error is available in catch schope or not
          var err = new Error('I am doing some experiment on it');
          next(err);
    });

var Promise = require('bluebird');

var User = mongoose.model('User');
Promise.promisifyAll(User);
Promise.promisifyAll(User.prototype);

遇到以下问题

TypeError: Object #<Promise> has no method 'catch'
    at User.register (/server/core/modules/user.js:69:10)
    at router.post.http.request (/server/routes/user.js:55:8)
    at Layer.handle [as handle_request] (/node_modules/express/lib/router/layer.js:82:5)
    at next (/node_modules/express/lib/router/route.js:110:13)
    at Route.dispatch (/node_modules/express/lib/router/route.js:91:3)
    at Layer.handle [as handle_request] (/node_modules/express/lib/router/layer.js:82:5)
    at /node_modules/express/lib/router/index.js:267:22
    at Function.proto.process_params (/node_modules/express/lib/router/index.js:321:12)
    at next (/node_modules/express/lib/router/index.js:261:10)
    at Function.proto.handle (/node_modules/express/lib/router/index.js:166:3)
    at router (/node_modules/express/lib/router/index.js:35:12)
    at Layer.handle [as handle_request] (/node_modules/express/lib/router/layer.js:82:5)
    at trim_prefix (/node_modules/express/lib/router/index.js:302:13)
    at /node_modules/express/lib/router/index.js:270:7
    at Function.proto.process_params (/node_modules/express/lib/router/index.js:321:12)
    at next (/node_modules/express/lib/router/index.js:261:10)
    at /server/router.js:45:3

我的问题是 ::
如何解决这个问题??
如何将错误从 mongooes 中间件捕获到我的 lib 函数(catch)??

My Question is ::
How to resolve this issue ??
How can I catch error from mongooes middleware to my lib function (catch)??

推荐答案

看来你用的不是 Bluebird，而是 mongoose promises (mpromise)，其中 没有 .catch 方法.

It seems you're not using Bluebird, but mongoose promises (mpromise), which don't have a .catch method.

你可以通过

• 使用 user.saveAsync().then(…)，因为您已经承诺了 User 模型
• 使用 Promise.resolve(user.save()).then(...) 将猫鼬承诺转换为蓝鸟承诺

• using user.saveAsync().then(…), as you've promisified the User model
• using Promise.resolve(user.save()).then(…) to cast the mongoose promise into a Bluebird one

这篇关于对象#<承诺>没有方法“捕获"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！