node.js async return value & export module

Question

I am trying to get some data from csv file, then make some magic with them and create an object with this derived data. I created this function by using module.exports I exported it.

var csvtojson = require('csvtojson');

var data = [];

module.exports = function createStock(name){
    var myObj = {};
    csvtojson().fromFile('./csv-raw/'+name+'.csv')
    .then(source => {
        source.forEach(value => {
            var row = {};
            row.Date = value.Date;
            row.Dividend_Yield = value.Dividend_Yield;
            row.Gross_Dividend_Per_Share = value.Gross_Dividend_Per_Share;
            row.Distribution_Rate = value.Distribution_Rate;
            data.push(row);
        });
    })
    .then(() => {
        myObj = {
            name: name,
            data: data,
            summary: {a: Math.random(), b: Math.random(), c: Math.random()}
        };
    })
    .then(() => {
        console.log(myObj)
        return myObj
    })  
}

And import to the route;

const createdStock = require('../../modified');

router.get('/new/:stockName', async (req,res) => {
   var stock = await createdStock(req.params.stockName);
   setTimeout(() => {
       console.log(stock);  
   }, 2000);

(I can see the result of console.log(myObj) inside first file)

(I can not see console.log(stock); inside second file)

I tried to figure out the problem whether stems from async behavior of JS but could find any solution ?

Generally my question is how can I send data that is created inside of .then block to another JS file.

Answer 1

In your createStock function you need to return your call to csvtojson . That will return the Promise making the await work properly. Then you won't need the setTimeout and you can just console.log(stock) .

module.exports = function createStock(name){
  var myObj = {};
  return csvtojson().fromFile('./csv-raw/'+name+'.csv')
  ...
};