Mongoose - Create document if not exists, otherwise, update- return document in either case

You are looking for the new option parameter. The new option returns the newly created document(if a new document is created). Use it like this:

var query = {},
    update = { expire: new Date() },
    options = { upsert: true, new: true, setDefaultsOnInsert: true };

// Find the document
Model.findOneAndUpdate(query, update, options, function(error, result) {
    if (error) return;

    // do something with the document
});

Since upsert creates a document if not finds a document, you don't need to create another one manually.

Since you wish to refactor parts of your code to be shorter and simpler,

1. Use async / await
2. Use .findOneAndUpdate() as suggested in this answer

---

let query = { /* query */ };
let update = {expire: new Date()};
let options = {upsert: true, new: true, setDefaultsOnInsert: true};
let model = await Model.findOneAndUpdate(query, update, options);