I have some backend code written in Nodejs that identifies the user and sends an OTP to their email.

Before I send the OTP via mail, I want to store it in my MongoDB database, so that I can later validate the user using the OTP.

Here's the NodeJS code:

//generates a cryptographically secure 6 digit long code:
const otp = otpgen_function()

//Store the OTP in DB:
const newToken = await new Token({user_id: user_record._id,token: otp})
const saveToken = await newToken.save()

Here's the schema of Token:

const mongoose = require('mongoose')
const ObjectId = mongoose.Schema.ObjectId
const TokenSchema = mongoose.Schema({
    user_id:{
        type: ObjectId,
        required: true,
        ref: 'mis'
    },
    token:{
        type: String,
        required: true,
    },
    createdAt:{
        type: Date,
        default: Date.now(),
        index: {expires:'15m'}
    }
}) 
module.exports = mongoose.model('Token',TokenSchema)

The createdAt field ensures that the OTP is deleted from the DB after 15 mins.

However, for some reason Mongoose doesn't save the OTP record when I call save()

In fact the behavior of save is very... erratic:

• Sometimes it saves the OTP record and it stays there,

• other times it is saved and can be seen in the collection, but disappears after a few seconds.

• However most of the time, it just doesn't save the record...

Any ideas as to what may be going wrong?

CodePudding user response：

Sometimes it may be complicated when trying to create a model with its constructor and save it. Have you tried Token.create() method ?

CodePudding user response：

So it turns out that the index I specified in the schema:

index: {expires:'15m'}

Was the source of the problem. Earlier for testing I had kept the expiry to a few seconds. Later, I changed the value to 15 minutes. However, mongoose didn't update the index in MongoDB, so I had to manually do it by executing the following in my MongoShell:

db.tokens.dropIndex('createdAt_1')

And then restarted my NodeJS server. Doing these things solved the issue