파일 백업 NodeJS

app.post('/', async (req, res) => {
  const filePath = path.join(__dirname, 'data.txt');
  //backup path with format date to YYYYMM-DD--HH_mm
  const backupPath = path.join(
    __dirname,
    `data-${new Date()
      .toISOString()
      .replace(/:/g, '_')
      .replace(/-/g, '_')
      .replace(/\./g, '_')
      .replace('T', '--')}.txt`
  );

  if (fs.existsSync(filePath)) {
    fs.copyFileSync(filePath, backupPath);
    fs.unlinkSync(filePath);
  }
  fs.writeFileSync(filePath, req.body.note);
  // send the new file content back to the db
  const course = new Course({
    name: req.body.note,
  });
  await course.save();
  res.send('file written');
});