Read a file line by in node.js

readline.js

const fs = require('fs'); // file system package
const rl = require('readline'); // readline package helps reading data line by line
// create an interface to read the file
const rI = rl.createInterface({
  input: fs.createReadStream('/path/to/file') // your path to file
});
rI.on('line', line => {
  console.log(line); // your line
});

const getFileContent = path =>
  new Promise((resolve, reject) => {
    const lines = [],
      input = fs.createReadStream(path);

    // handle if cann't create a read strem e.g if file not found
    input.on('error', e => {
      reject(e);
    });

    // create a readline interface so that we can read line by line
    const rI = rl.createInterface({
      input
    });

    // listen to event line when a line is read
    rI.on('line', line => {
      lines.push(line);
    })
      // if file read done
      .on('close', () => {
        resolve(lines);
      })
      // if any errors occur while reading line
      .on('error', e => {
        reject(e);
      });
  });

getFileContent('YOUR_PATH_TO_FILE')
  .then(lines => {
    console.log(lines);
  })
  .catch(e => {
    console.log(e);
  });