app.js

const fs = require('fs');
const readline = require('readline');
const stream = require('stream');

const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

function readLines({ input }) {
  const output = new stream.PassThrough({ objectMode: true });
  const rl = readline.createInterface({ input });
  rl.on("line", line => { 
    output.write(line);
  });
  rl.on("close", () => {
    output.push(null);
  }); 
  return output;
}
const input = fs.createReadStream("./hello.txt");

(async () => {
  for await (const line of readLines({ input })) {
    await delay(2322);
    console.log(line);
  }
})();