const fs = require('fs')
const fsPromises = require('fs/promises');
const readline = require('readline')
const path = require('path')

const targetFilePath = path.join(__dirname, '..', '..', 'data', 'data-target.csv')
const sourceFilePath = path.join(__dirname, '..', '..', 'data', 'data-source.csv')

/**
 * @param {number} index
 */
async function main (index) {
  console.time(`test #${index}`)
  await fsPromises.truncate(targetFilePath)
  const readStream = fs.createReadStream(sourceFilePath)
  const writeStream = fs.createWriteStream(targetFilePath)
  const rl = readline.createInterface({
    input:     readStream,
    crlfDelay: Infinity
  })

  for await (const line of rl) {
    writeStream.write(`${line}\n`)
  }
  console.timeEnd(`test #${index}`)
}

main(10)

file-parser-metrics/src/node on  main [!?] via  v16.11.1 
❯ node parser.js
test #10: 108.873ms