Versioning models

[helloscoopa]

This might be a noob question, but I couldn't find a proper solution to overcome this at least for the architecture that I was about to build. So my question is, in my NodeJS backend I need to run multiple versions in the same repo. so what I did is started creating new folders for the versions.

models/
v1/user.js
v2/user.js

something like this. and I'm importing both of these modules in my startup scripts so that they can be used interchangeably.

v1/user.js

const mongoose = require("mongoose")

const userSchema = new mongoose.Schema({
    name: { type: String, required: true }
})

const User = mongoose.model("User", userSchema)

exports.User = User

v2/user.js

const mongoose = require("mongoose")

const userSchema = new mongoose.Schema({
    name: { type: String, required: true },
    new_field: { type: String, required: true }
})

const User = mongoose.model("User", userSchema)

exports.User = User

So in this context, I'm getting the error 'Cannot overwrite User model once compiled.' which makes perfect sense as I use the same name in both occurrences. I just need to know if there is a way to eliminate it. because at the end of the day we refer to what model we need to use in each transaction right so I feel just eliminating the error with some trick is theoretically doable.

or else please point me out a way to do this in another way, I need to keep the initial version of the model anyways because the v1 routes use that schema already where I can't randomly add more required fields into it.

Any help regarding this is highly appreciated.

[1finedev]

Mind if i ask, are you using the same database for both models?

[helloscoopa]

Yes, I am. I'm trying to do a model upgrade to the existing API without breaking the existing endpoints. As newly added props are required, I can't just add them into the old one. Also, the related endpoints will be depreciated once I write the new v2 endpoints. but between the switch (until the client apps get updated) I need both v1 and v2 endpoints to work which means I need to have both v1 and v2 models.

[1finedev]

but if it helps you can try either of this approach

//add this line before exporting your model to empty the models each time 
mongoose.models = {}; 
const User = mongoose.model("User", userSchema)

or try this

export const User = mongoose.models.User || mongoose.model('User', userSchema);

[helloscoopa]

Thanks, however doing mongoose.models = {} is not possible and models is not an assignable at least in the mongoose v5.13.5. but as it looks promising, I was looking for a way to properly remove a model which is already registered and found this.

So using delete mongoose.connection.models['User'], I can remove existing model compilations. So what I'm doing now is, before initializing each model, I clear the User model so that I clear if another version ever complied before. This worked out pretty fine for my requirement.

Thanks for your contribution, Cheers!

[1finedev]

Cheers