如何从 Mongoose Schema 中获取特定的错误消息？

Question

我正在尝试在 Mongoose 中设置用户验证，并努力让特定消息出现。这是我的模型

const userSchema = new Schema({
    name: { 
        type: String, 
        required: [true, "Name required"]
    },
    email: { 
        type: String, 
        required: [true, "Email required"] 
    },
    password: { 
        type: String, 
        required: [true, "Password required"],
        minlength: [6, "Password must be at least six characters"]
     },
    date: { type: Date, default: Date.now },
    albums: [{ type: Schema.Types.ObjectId, ref: "Album"}]
})

我目前有这个方法来创建一个新用户。我相信我需要找到一种更好的方法来查看电子邮件是否存在，可能在模型中，但现在这就是我所拥有的。

registerUser(req, res) {
    const { name, email, password } = req.body
    db.User.findOne({ email: email })
        .then(exists => {
            if (exists) res.redirect("/register")
            else {
                db.User.create({ name, email, password })
                    .then((err, res) => {
                        if (err) console.log(err.errors.password.message)
                    })
            }
        })
},

我输入了无效的密码长度以尝试获取消息，但我收到一个大错误：

(node:49238) UnhandledPromiseRejectionWarning: ValidationError: User validation failed: password: Password must be at least six characters
[0]     at model.Document.invalidate (/Users/user/Desktop/untitled folder/portfolio-projects/project/node_modules/mongoose/lib/document.js:2579:32)
[0]     at /Users/user/Desktop/untitled folder/portfolio-projects/project/node_modules/mongoose/lib/document.js:2399:17
[0]     at /Users/user/Desktop/untitled folder/portfolio-projects/project/node_modules/mongoose/lib/schematype.js:1220:9
[0]     at processTicksAndRejections (internal/process/task_queues.js:79:11)
[0] (node:49238) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
[0] (node:49238) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. 

为了只收到错误消息，我需要进行哪些更改？

Answer 1

我过去在这方面遇到过问题，这帮助我解决了问题

 if(err) {
    if (err.name === 'ValidationError') {
      console.error(Object.values(err.errors).map(val => val.message))
    }
  }

这将返回Password must be at least six characters

更新-

首先，您需要修复您的代码，因为您将 promises 与 callbacks 混合在一起，就好像您使用的是 .then 语法，但此处没有 (err,res) 对象

更简洁的方法是

 registerUser(req, res) {
    const { name, email, password } = req.body
    db.User.findOne(email)
      .then(exists => {
        if (exists) res.redirect("/register")
        else {
          db.User.create({ name, email, password })
            .then(res => {
              console.log(res);
            }).catch(err => {
                if (err.name === 'ValidationError') {
                  console.error(Object.values(err.errors).map(val => val.message))
                }
            })
        }
      }).catch(err => console.error(err))
  };

您可以像这样使用Async/Await 进一步清理它

async registerUser(req, res) {
    const { name, email, password } = req.body
    try{
      const userExist = await db.User.findOne(email);
      if(userExist){
        res.redirect("/register")
      }
      else{
        const createdUser= await db.User.create({ name, email, password })
        res.redirect('')
      }
    }
    catch(err){
      if (err.name === 'ValidationError') {
        console.error(Object.values(err.errors).map(val => val.message))
      }
      else{
        console.error(err);
      }
    }