Multer does not throw an error when limits: fileSize is exceeded and hangs

I have the following code to handle profile pic uploads. Everything works fine if under the limits: fileSize, but when fileSize is exceeded no error is thrown. Error handling based on https://github.com/expressjs/multer/issues/336. I have a custom disk storage engine. The problem with this is that I cannot send any error message or a response to react frontend.

var storage = ProfileStorage({
  square: true,
  responsive: true,
  greyscale: false,
  quality: 60
});

var limits = {
  //files: 1, // allow only 1 file per request
  fileSize: 100 * 1024
};

var fileFilter = function(req, file, cb) {
  var allowedMimes = ['image/jpeg', 'image/pjpeg', 'image/png', 'image/gif'];

  if (_.includes(allowedMimes, file.mimetype)) {
    cb(null, true);
  } else {
    cb(new Error('Invalid file type. Only jpg, png and gif image files are allowed.'));
  }
};

var upload = multer({
  storage: storage,
  limits: limits,
  fileFilter: fileFilter
});

The post method:

var profileUpload = upload.single('Profiilikuva');

module.exports = app => {
  app.post('/api/profile/save', requireLogin, (req, res) => {
    console.log('Entered profile save');

    profileUpload(req, res, (err) => {
      console.log('Entered profile upload.');
      if (err) {
        console.log('Error from multer: ', err);
        return res.status(400).send(err);
      }

      if (req.file) {
        console.log('Stored file: ', req.file.filename); // Storage engine stores under random filename
      }

      const {firstName, lastName, email, address,
        postalCode, descriptionText, lat, lng } = req.body;

      req.user.profileCompleted = true;
      req.user.firstName = firstName;
      // some more of these...
      req.user.save().then((user) => { 
        console.log('User saved');
        return res.send(user);
      }).catch(err => {
        console.log('Error saving user. ', err);
        return res.status(400).send('Error while saving user information');
      });
    });
  });
};

Log output when uploading 75KB:

Entered profile save
_handleFile called. { fieldname: 'Profiilikuva',
   originalname: '75KB.jpg',
   encoding: '7bit',
   mimetype: 'image/jpeg' }
 Entered profile upload.
 Stored file:  0b3dc28730ecc387115a03b3f860af20_lg.jpg
 User saved

Log output when uploading 190KB:

 Entered profile save
 _handleFile called. { fieldname: 'Profiilikuva',
   originalname: '190KB.jpg',
   encoding: '7bit',
   mimetype: 'image/jpeg' }
_removeFile called

[sainisagar310]

I am also facing the same issue. It doesn’t throw an error when the file limit exceeded.

[beac0n]

“Though I think it is my custom storage engine that messes things up” I am using the google cloud storage engine for buckets.

“Seems the error handling is a bit tricky.” That’s a huge understatement.

I think the issue might have something to do with the file streams. As far as I know, the file streams for writing to the file system have more meta information than, e.g. streams to google storage buckets.