handle mutiple duplicate error mongoose nodejs - node.js

Question

I have User Schema like this
const UserSchema = new Schema({
username: {
type: String,
unique: true,
required: true,
lowercase: true,
trim: true
},
email: {
type: String,
unique: true,
required: true
},
phoneNumber: {
type: Number,
unique: true,
required: true
},
});
When I post a user with duplicate name, phonenumber or email. I receive the error like this:
This is error message E11000 duplicate key error collection: project.users index: username_1 dup key: { : "john" }
So my question is that how I can know it is a duplicate name or duplicate phonenumber. I want to receive the error like this.
This phone number has been already used
This name has been already used

Answer 1

You can catch the error in your error handler. You can get the path name and value using regex. Simple example:
app.use((err, req, res, next) => {
if (err.code === 11000 || err.code === 11001) {
const pathRegex = err.message.match(/\.\$([a-z]+)/)
const path = pathRegex ? pathRegex[1] : '';
const keyRegex = err.message.match(/key:\s+{\s+:\s\"(.*)(?=\")/)
const key = keyRegex ? keyRegex[1] : '';
return res.status(409)
.json({ status: false, message: `${path} '${key}' already exists`})
}
}
You can also check mongoose-unique-validator that produces a mongoose 'ValidationError' that you can parse more easily.

Answer 2

Alternately you can use a path validation mechanism.
UserSchema.path('username').validate(function(value, done) {
this.model('User').count({ username: value }, function(err, count) {
if (err) {
return done(err);
}
done(!count);
});
}, 'User Name already exists');
UserSchema.path('email').validate(function(value, done) {
this.model('User').count({ email: value }, function(err, count) {
if (err) {
return done(err);
}
done(!count);
});
}, 'Email already exists');
UserSchema.path('phoneNumber').validate(function(value, done) {
this.model('User').count({ phoneNumber: value }, function(err, count) {
if (err) {
return done(err);
}
done(!count);
});
}, 'Phone already exists');