Default generated values (Short Url) changes after refreshing mongoose - node.js

Question

I'm using shortid package to shorten my URLs.
Currently, user have this kind of url: https://bucard.co.il/digitalCard/5edd4112eb6ba017d8a4595c (the long string is the _id),
and I want to make it like this: https://bucard.co.il/digitalCard/Y2i1_53Vc
So, I added ShortID field, and as in the documantion, I did this in models/VisitCard.js:
const mongoose = require('mongoose');
const shortid = require('shortid');
const VisitCardsSchema = mongoose.Schema({
ShortID: {
type: String,
default: shortid.generate
},
....
});
module.exports = mongoose.model('VisitCards', VisitCardsSchema);
And my get request in routes/VisitCard.js:
// Get a specific visit card
router.get('/:visitCardId', async (req, res) => {
try {
let cardShortId = req.params.visitCardId;
let allVisitCards = await VisitCard.find({}); // That's how I saw that all the values changed after every get request.
let visitCard = await VisitCard.findOne({ ShortID: cardShortId }); // Never found the card by the short id - even after coping the short id from above, after the next try it changes.
if (!visitCard) {
return res.status(404).json({
message: 'Not existing card.'
});
} else {
return res.status(200).json(visitCard);
}
} catch (error) {
console.log(error);
return res.status(404).json({
message: 'Some server issue accured...'
});
}
});
Now, the proplem is where after every refresh of the browser or another get request, all the ShortID's of all cards are changing (generated again). I want instead that the short url will not be refreshes after every restart of the server, and it will be stored in the Database.
How can I do that after each card gets it's shortID (by default) it will directlly be stored in the DB ?
By the way, I could just have that after every submits of visit card to put some random string to be stored with the other paramters, but I already have visit cards of users in my service.
THANK YOU !!!

Answer 1

Tried reproducing your issue:
const mongoose = require("mongoose");
const shortid = require("shortid");
mongoose.connect("mongodb://localhost/test9999", {
useNewUrlParser: true
});
const db = mongoose.connection;
db.on("error", console.error.bind(console, "connection error:"));
db.once("open", async function() {
await mongoose.connection.db.dropDatabase();
// we're connected!
console.log("Connected");
const VisitCardsSchema = mongoose.Schema({
name: String,
ShortID: {
type: String,
default: shortid.generate
}
});
const VisitCard = mongoose.model("VisitCard", VisitCardsSchema);
const v1 = new VisitCard({name: "abc"});
const v2 = new VisitCard({name: "cde"});
await v1.save();
await v2.save();
await VisitCard.find(function(err, vcs) {
if (err) return console.error(err);
console.log(vcs);
});
console.log("VCS second call:");
await VisitCard.find(function(err, vcs) {
if (err) return console.error(err);
console.log(vcs);
});
});
Apparently, it works perfectly fine. I even commented part with dropping db for a moment and values are persisted correctly.
The problem must be somewhere else - you sure you do not drop the db or the collection with each GET request somewhere else in the code?
This one: await mongoose.connection.db.dropDatabase(); drops entire db, mongooseconnection.connection.db.dropCollection drops a collection. Check if you can find such lines somewhere in your code.