how to set file type and size in multer

var multer = require('multer')
var upload = multer().single('avatar')'/profile', function (req, res) {
upload(req, res, function (err) {
if (err instanceof multer.MulterError) {
// A Multer error occurred when uploading.
} else if (err) {
// An unknown error occurred when uploading.

// Everything went fine.

how to reduce the size of my electron app

You can reduce the electron app size by packaging using electron-builder package.
PicArt is an electronjs app which I developed recently. It is built using reactJS.
Initially when I packaged the app using electron-packager the Window's build size was
around 98 MB.
Then I found this awesome boilerplate electron-react where they configured the
electron-builder to produced optimised build size.
After using those configuration setup, PicArt's build is now around 36 MB.