I want to create a function that creates the "user" document on mongoose. But in future updates of my app, I will need to append more indexes inside the document. So, I'm making a function to create the user if it not exists, and add index by index if it not exists.

In fact, I don't know what's the correct function to put right here (-> "add"). Can you, dear reader, show me the light?

let player = await User.findOne({ _id: id })
    if (!player) {

        User.create({ _id: id })
        
        player = await User.findOne({ _id: id })
    }

    if (!player.name) player."add"({ name: username })