JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://raw.githubusercontent.com/alexanderbeletsky/backbone-computedfields/master/src/backbone.computedfields.js"></script>

JavaScript

var MyModel = Backbone.Model.extend({
    
    initialize: function () {
        this.computedFields = new Backbone.ComputedFields(this);
    },
    computed: {
        test: {
            get: function () {
                console.log('get');
                return 5;                
            }            
        }        
    }    
});

var m = new MyModel({});
console.log(m.get('test'));