Asynchronous function findOne returns "undefined"

Question

I created a function to check if in my database a user exists according to the sub parameter. I would like my function to give me a true or false value.

Front-end :

......
async function exist(sub) {
  const result = await InfoDataService.get(sub)
  alert(result.sub);
 }      
......

Controller :

// Find a User with sub
exports.findOne = (req, res) => {
  const sub = req.params.sub;
  

  User.findOne({sub})
  .then(data => {
    res.send(data);
  })
  .catch(err => {
    res.status(500).send({
      message: "Error retrieving User with id=" +sub 
    });
  });
};

Route :

module.exports = app => {
  const users = require("../controllers/user.controller.js");

  const router = require("express").Router();


  // Retrieve
  router.get("/:sub", users.findOne);


  app.use('/api/users', router);
};

InfoDataService :

import http from "../http-common.js";


const get = sub => {
  return http.get(`/users/${sub}`);
};

export default {
  get,
};

http-common :

import axios from "axios";


    export default axios.create({
      method: 'GET',
      baseURL: "http://localhost:8080/api",
      
    });

If instead of result.sub I use only result I can retrieve the object, but if I try to access the .sub property I get "undefined".

I noticed another thing that is probably related: the path for post is api/users , while for get it is api/users/:sub . Checking the network I found that the asynchronous function makes the request to api/users/undefined . Where would the error be?

Answer 1

Not sure if User.findOne({sub}) is correct, should maybe rather be a where clause there? { where: sub}