multer uploading multiple files - express

Question

So, I have two properties in my schema. 1) ImageCover (single file) and 2) Images (array of images)
I am using multer's upload.fields method to upload both of these files. when I upload both, it works.But when I try to upload only either of them I am getting error that the other field is not defined. How can I fix this?
1) multer.js
module.exports = () => {
let multer = require('multer')
let myStorage = multer.diskStorage({
destination: (req, file, cb) => {
cb(null, './uploads/')
},
filename: (req, file, cb) => {
cb(null, `${Date.now()}-${file.originalname}`)
}
})
filter = (req, file, cb) => {
let mimeType = file.mimetype.split('/')[0]
if (mimeType !== 'image') {
req.fileError = true
cb(null, false)
} else {
cb(null, true)
}
}
let upload = multer({
storage: myStorage,
fileFilter: filter
})
return upload
}
2) uploading photo file
module.exports = function Check(req) {
if (req.files.images) {
req.body.images = []
let allFiles = req.files.images
allFiles.forEach(file => {
let mimeType = file.mimetype.split('/')[0]
if (mimeType !== 'image') {
fs.unlink(path.join(process.cwd(), 'uploads/'), (err, done) => {
if (err) console.log(err)
})
}
req.body.images.push(file.filename)
})
}
if (req.files.imageCover[0]) {
let file = req.files.imageCover[0]
let mimeType = file.mimetype.split('/')[0]
if (mimeType !== 'image') {
fs.unlink(path.join(process.cwd(), 'uploads/'), (err, done) => {
if (err) console.log(err)
})
}
req.body.imageCover = file.filename
}
}
3) create controller (check is the function that I have exported above)
exports.createTour = (req, res, next) => {
check(req)
if (req.fileError) { return next({ error: 'invalid file format dude' }) }
Tour.create({
...req.body,
owner: req.user._id
}).then(result => {
res.status(201).json({
status: 'success',
total: result.length,
result
})
}).catch(err => next(err))
}
4) Route handler
Router.route('/')
.post(authController.protect,
upload.fields([
{
name: 'imageCover', maxCount: 1,
},
{
name: 'images', maxCount: 10
}
]),
tourController.createTour)
response in postman when I only select images

Answer 1

I think you get this error because you are trying to access first element of array, and array is empty or not defined.
For example:
if (req.files.imageCover[0])
try to refactor to look like this:
if (req.files.hasOwnProperty("imageCover") && req.files.imageCover.length > 0)
you should do validations like this on all places where objects/arrays can be optional