pager_hapijs_routes.js

const routes = [
    {
        method: 'GET',
        path: '/locations',
        handler: async (request, h) => {

            const db = server.app.db;
            const locationCollection = db.collection('locations');

            // query all locations
            const documents = await locationCollection.find({}).toArray();
            return documents;
        }
    },
    {
        method: 'GET',
        path: '/locations/{locationId}/items',
        handler: async (request, h) => {
            const locationId = parseInt(request.params.locationId, 10);

            const db = server.app.db;
            const itemCollection = db.collection('items');

            const items = await itemCollection
                .find({ locationId })
                .toArray();

            if (!items.lenth) {
                const locationCollection = await db.collection('locations');
                const location = await locationCollection.findOne({locationId});

                if (!location) {
                    return h.response('Not Found').code(404);
                }
            }

            return items;
        },
    },
    {
        method: 'POST',
        path: '/locations/{locationId}/order',
        handler: async (request, h) => {
            const order = request.payload;

            const db = server.app.db;
            const itemCollection = db.collection('items');

            const itemIds = order.items.map(item => item.itemId);

            const prices = await itemCollection
                .find({ itemId: { $in: itemIds } })
                .project({itemId: 1, price: 1})
                .toArray();

            // Transform [{ itemId, price }, ...] into { itemId: price, ...}
            const priceLookup = prices.reduce((result, { itemId, price }) => {
                result[itemId] = price;
                return result;
            }, {});

            order.total = order.items.reduce((result, orderItem) => {
                // result += qty * price
                result += orderItem.quantity * priceLookup[orderItem.itemId];
                return result;
            }, 0);

            const orderCollection = db.collection('orders');

            const result = await orderCollection.insertOne(order);

            if (result.insertedCount) {
                order._id = result.insertedId;
                return h.response(order).code(201);
            }
            return h.response('Error').code(400);
        },
    }
];