Node server response in CSV format

responseCsv.js

const { Parser } = require('json2csv')
//example database model (Modeling MongoDB with Mongoose)
const Log = require('../models/logModel')

const responseCsv = async (req, res) => {
  
  let logs
  try {
    //reading logs from the database
    //append .lean() to get a plain JS object rather than a mongoose document; use less memory
    logs = await Log.find({}, '_id voltage current temperature loggedAt').sort({
      loggedAt: -1,
    }).lean()
    } catch (err) {
    //error because of database reading
    console.log(err)
    res.status(500).json({ message: err.message })
    return
  }

  //csv field labels, the parser will re-arrange you data (logs) into the order below
  const fields = [
    { label: 'time', value: 'loggedAt' },
    { label: 'id', value: '_id' },
    { label: 'voltage', value: 'voltage' },
    { label: 'current', value: 'current' },
    { label: 'temperature', value: 'temperature' },
  ]

  const json2csv = new Parser({ fields: fields })

  try {
    const csv = json2csv.parse(logs)
  } catch (err) {
    //error because of parsing error
    console.log(err)
    res.status(500).json({ message: err.message })
  }
  
  //the filename, can be anything
  res.attachment('data.csv')
  //response with the csv data 
  res.status(200).send(csv)
  return
  
}