NodeJS : Reading bulk file using stream (ReadLine)

reader.js

const path = require('path')
const fs = require('fs')
const readline = require('readline')
const start = new Date()
const hrstart = process.hrtime()
const file =  path.resolve(__dirname, "log.txt")

fs.stat(file, (err) => {
  if(err === null) {
    let lines = 0 // counter
    let cursor = 0 // current line
    let stop = 0 // 
    let streamExcess = [] // <array>

    const readInterface = readline.createInterface({
      input: fs.createReadStream(file)
    })
    readInterface.on('line', function(line) {
      // counter
      lines++
      if(stop === 1) {
        //console.log('stoped: ',lines)
        streamExcess.push(Promise.resolve(lines))
      } else {
        // current cursor
        // do all stuff here
        // . . .
        
        process.nextTick(() => {
          // Do not forget to delete excess data from the stream after
          // processing it to avoid duplicates & probably memory exhaustion
          streamExcess = [] //delete to save memory
          // reset and resume operation
          // call this after processing the data
          stop = 0
          this.resume()
        })
        
      }
      // mark the current position of the ongoing operation
      cursor = lines
      // pause
      this.pause()
    })

    readInterface.on('pause', function(line) { 
      if(cursor === lines) {
        // current operation
        //console.log('pause',lines) 
        // this will tell that the process already stopped
        // and everything is an excess that should be acumulated
        // Note: Even if you want to stop at the very first result
        // stream would not stop as expected but rather yield few hundred lines 
        // uncomment the //console.log('stoped: ',lines) below the stop condition to see results
        stop = 1
      } 
    })

   readInterface.on('close', function(line) {
    // log execution time
    hrend = process.hrtime(hrstart)
    console.info('Execution time: %dms', (new Date() - start))
    console.info('Execution time (hr): %ds %dms', hrend[0], hrend[1] / 1000000)
   })
      
  } else {
    throw new Error('File not found')
  }
})

// PS: This might be different on your tests but with mine, it was 4x faster than other npm modules.