cooperative-market/beesdoo_product/static/src/js/models.js

odoo.define('beesdoo_product.models', function (require) {
    "use strict";

    var models = require('point_of_sale.models');

    var _super_PosModel = models.PosModel.prototype;

    models.PosModel = models.PosModel.extend({

        initialize: function (session, attributes) {

            var product_model = _.find(this.models, function(model){
                return model.model === 'product.product';
            });
            product_model.fields.push('total_with_vat');

            // Inheritance
            return _super_PosModel.initialize.call(this, session, attributes);
        },

    });
});