Mongoose validation error on POST request

Question

I'm trying to do a POST request using express on node.js and mongoose for mongoDB but using Postman to get data gives me this error:

Error
at MongooseError.ValidationError (C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\error\\validation.js:22:16)
at model.Document.invalidate (C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\document.js:1162:32)
at C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\document.js:1037:16
at validate (C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\schematype.js:651:7)
at C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\schematype.js:679:9
at Array.forEach (native)
at SchemaString.SchemaType.doValidate (C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\schematype.js:656:19)
at C:\\Users\\Matteo\\Desktop\\app1\\node_modules\\mongoose\\lib\\document.js:1035:9
at process._tickCallback (node.js:355:11)

I paste here my server.js file

var express = require('express')
var bodyParser = require('body-parser')
var mongoose = require('mongoose');
var app = express()
app.use(bodyParser.json())

mongoose.connect('mongodb://localhost/social', function(){
    console.log('mongodb connected')
})

var postSchema = new mongoose.Schema ({
    username : { type: String, required: true },
    body : { type: String, required: true },
    date : { type: Date, required: true, default: Date.now}
})
var Post = mongoose.model('Post', postSchema)

app.get('/api/posts', function(req, res, next){
    Post.find(function(err, posts){
        if(err) { return next(err) }
        res.json(posts)
    })
})

app.post('/api/posts', function(req, res, next){
    var post = new Post({
        username : req.body.username,
        body : req.body.body
    })
    post.save(function(err, post){
        if(err){ return next(err) }
        res.json(201, post)
    })
})

app.listen(3000, function(){
    console.log('Server listening on', 3000)
})

Can anyone help me or it is a problem of mongoose?

Answer 1

I think it's Mongoose Validation issue, req.body is actually a JSON formatted-data, console.log(req.body.username) returns the username value. To be general, try to use req.body, please make use to fill-out the required fields upon submission.

app.post('/api/posts', function(req, res, next){
var post = new Post(req.body);
post.save(function(err, post){
    if(err){ return next(err) }
    res.json(post)
})
})

Better to handle MongooseError.ValidationError when a user fails to fill-in required fields. Try to review your Mongoose Model.

Answer 2

I got a similar error today, and reading the docs helped me through.

The doc says:

Defining validators on nested objects in mongoose is tricky, because nested objects are not fully fledged paths.

var personSchema = new Schema({
  name: {
    first: String,
    last: String
  }
});

A schema like the above will throw similar error like in your question.

The docs points out the workaround:

var nameSchema = new Schema({
  first: String,
  last: String
});

personSchema = new Schema({
  name: {
    type: nameSchema,
    required: true
  }
});

Source: http://mongoosejs.com/docs/validation.html

Answer 3

in Postman, to test HTTP post actions with raw JSON data, need to select the raw option and also set the header parameters( select header parameter in postman and add in key:value feild which is given below ).

Content-Type: application/json

by default, it comes with Content-Type: text/plain which need to replace with Content-Type: application/json