var loopback = require('../../'); var server = module.exports = loopback(); var CartItem = require('./models').CartItem; var memory = loopback.createDataSource({ connector: loopback.Memory }); server.use(loopback.rest()); server.model(CartItem); CartItem.attachTo(memory); // test data CartItem.create([ {item: 'red hat', qty: 6, price: 19.99, cartId: 1}, {item: 'green shirt', qty: 1, price: 14.99, cartId: 1}, {item: 'orange pants', qty: 58, price: 9.99, cartId: 1} ]); CartItem.sum(1, function(err, total) { console.log(total); }); server.listen(3000);