How to resolve asynchronous function it's not returning data in time when fastify sends the request

Question

Items in the first log does work while in the second log gives just empty array I guess it's because it's not loaded yet, how to fix

I was trying async and await but nothing works

const db = require("playerio-node");

const index = async(fastify, options, done) => {

    fastify.get("/pricing", async(req, res) => {
        let items = [];
        db.PlayerIO.authenticate(
            "HIDDEN",
            "HIDDEN",
            {
                userId: "Stock",
                auth: require("../../../../../index").hashGenerator("Stock")
            },
            {},
             (client) => {
                client.bigDB.loadOrCreate("StockItems", "Stock", function (obj) {
                    req.config.stockItems.map(item => {
                        items.push({
                            name: item.name,
                            img: item.img,
                            price: item.price,
                            stock: obj[item.img] ?? 5
                        })
                    })
                    req.render("/dynamic/pricing/index.liquid", { stockItems: items, Chests: req.config.chests});
                });
            },
            (error) => {
                console.log(error)
            }
        );

        return req
    });

    done()
};

module.exports = index;

Answer 1

There are multiple improvements to do in your handler

• the plugin function is an async function and it has the done argument

It is important to not mix callbacks and async/Promise, otherwise the hook chain will be executed twice.

https://fastify.dev/docs/latest/Reference/Hooks/#respond-to-a-request-from-a-hook It is true for hooks but for plugins as well.

• the handler is async and the req is returned - fastify does not care about the REQUEST, it will wait res, the REPLY, so your route replies with an empty response..
• in case of errors, the reply should be fulfilled or it will starve
• req.render does not exist https://github.com/fastify/point-of-view so you have unhandled errors somewhere for sure

Here is a cleaned version of the code:

const db = require('playerio-node')
const auth = require('../../../../../index').hashGenerator('Stock')

const index = async (fastify, options) => {
  fastify.get('/pricing', (req, reply) => {
    db.PlayerIO.authenticate(
      'HIDDEN',
      'HIDDEN',
      {
        userId: 'Stock',
        auth
      },
      {},
      (client) => {
        client.bigDB.loadOrCreate('StockItems', 'Stock', function (obj) {
          // ? what if loadOrCreate fails?
          const items = req.config.stockItems.map(item => {
            return {
              name: item.name,
              img: item.img,
              price: item.price,
              stock: obj[item.img] ?? 5
            }
          })

          reply.render('/dynamic/pricing/index.liquid', {
            stockItems: items,
            Chests: req.config.chests
          })
        })
      },
      (error) => {
        reply.send(error)
      }
    )
  })
}