Consume content of the file without saving the file with express.js?

I am writing an application where I have an CVS file upload. I have an CVS parser so from my frontend I can upload the CSV to backend, process it and save it to database. After that I am deleting the file.

I am using multer to accept the file and it get's saved to hard drive, then I can read the file and consume the content of the file and delete the file. All fine and all good there.

I am trying to figure out if there is a way to skip actually saving the file altogether. Is there an easy way of just submitting the file from 'multipart/form-data' form and reading the content directly with express without having to save it on file system?

Just for reference, this is what I have now and it is working as expected

On frontend:

static fileUpload(file) {
  const url = '/api/statement-upload';
  const formData = new FormData();
  formData.append('file', file);
  const config = {
    headers: {
      'content-type': 'multipart/form-data'
    }
  };
  return post(url, formData, config);
}

On my express server I'm using multer and have defined route like this:

import multer from 'multer';

export default function (router) {
  const upload = multer({dest: 'uploads/'});

  router.use('/api/statement-upload', upload.single('file'), (req, res) => {
    cvsParser(req.file.path)
      .then(() => res.json({error: false}))
      .catch(e => res.json({error: e}));
  });

  return router;
};

And in my cvsParser then I have this:

export default function (filePath) {
  let content = fs.readFileSync(filePath, 'binary');  
  fs.unlink(filePath, () => {});

  // do nasty stuff to content and save it gently in the database
}

So in short again, is there a way to do this without having to resort to saving the CSV to file system before I can consume the content of the file?

Is this even possible considering the file encodings, etc, maybe there is no way around using fs?

This is what can be done when you don't want to store the csv in a file system and read the content. In my case, I had to pass the content of csv file as a string to another server (without saving in local system of server).

const multer = require('multer');
const upload = multer({ storage: multer.memoryStorage() })

app.post(
        '/users/bulkUpload',
        upload.single('csvFile'),
        this.usersRoutes.uploadUserData
 );

and in uploadUserData():

uploadUserData = async(
    req: Request,
    res: Response,
    next: any
): Promise<any> => {
    try {
        const options = {
                formData : {
                    'upload': String(req.file.buffer)
                },
                headers: {
                    authorization: req.token,
                    'Content-type': 'multipart/form-data'
                },
                json: true
        };
        const response = await this.http.post.exec(
                '/somePostUrl/',
                options
        );
        return res.status(200).json(response.body);
    }catch (error) {
        return next(error);
    }
}

Here, console.log(String(req.file.buffer)) would show you the content of csv file as a string.

I hope it helps you.