how to fix this error TypeError [ERR_INVALID_CALLBACK]: Callback must be a function

by

Fs.writeFile() according to the documentation here takes (
file, data[, options]and callback ) params so your code will be like this :

 var fs = require('fs');
 fs.readFile('readMe.txt', 'utf8', function (err, data) {
  fs.writeFile('writeMe.txt', data, function(err, result) {
     if(err) console.log('error', err);
   });
 });

Leave a Comment