если у вас есть lastModifed
время. Вы можете использовать fs.stats для сравнения
fs.stat(path, (err, data) => {
console.log('check if file/folder last modified date, was it after my last check ');
//I use moment module to compare dates
let previousLMM = moment(lastModifed);
let folderLMM = moment(data.mtime.toISOString());
let res = !(folderLMM.isSame(previousLMM, 'second')); //seconds granularity
return callback (null, res);
});