File uploading with multer and express

gistfile1.txt

const express = require('express');
const router = express.Router();
const multer = require('multer');
const path = require('path');
const debug = require('debug')('myNameSpace');
const ALLOWED_IMAGE_TYPES = ['png', 'jpg', 'gif'];

const publicFilesDestination = path.join('public', 'static', 'uploads', '/');

let fileStorage = multer.diskStorage({
    destination: function (req, file, cb) {
        debug("file path: ", publicFilesDestination);
        cb(null, publicFilesDestination);
    },
    filename: function (req, file, cb) {
        let ext = path.extname(file.originalname).toLowerCase();

        if (ALLOWED_IMAGE_TYPES.indexOf(ext) < 0) {
            return cb('INVALID_FILETYPE');
        }
        let filepath = publicFilesDestination;
        let filename = file.fieldname + '-' + Date.now() + ext;
        debug("renamed file: ", filepath + filename);
        cb(null, filename);
    }
});

let fileHandler = multer({
    storage: fileStorage
});


router.post("/my/route/here", fileHandler.any(), myController.doSomething);