Upload multiple images with node in s3 map problem - node.js

Question

I'm struggling finding a solution to upload two files to s3. I can upload one file with multer and I have learnt how to do it, but when I try to do a map inside all files in the formdata and upload each file, I push into an array each location URL which is the one I save in my database. Then I try to print each url but for my surprise they are print inside the if statement but not when I save it in the database outside the if. Could it be for an asychronous problem?.
Thanks.
tournamentsCtrl.createTournament = async (req, res) => {
var files_upload = []
if (req.files) {
aws.config.setPromisesDependency();
aws.config.update({
accessKeyId: process.env.AWS_ACCESS_KEY_ID,
secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
//region: process.env.REGION
});
const s3 = new aws.S3();
req.files.map((item) => {
var params = {
ACL: 'public-read',
Bucket: process.env.AWS_BUCKET_NAME,
Body: fs.createReadStream(item.path),
Key: `tournament_img/${uuidv4()/* +req.file.originalname */}`
};
await s3.upload(params, (err, data) => {
if (err) {
console.log('Error occured while trying to upload to S3 bucket', err);
}
if (data) {
fs.unlinkSync(item.path); // Empty temp folder
const locationUrl = data.Location;
files_upload.push(locationUrl);
console.log(files_upload)
}
});
});
}
console.log(files_upload)
const new_data = { ...JSON.parse(req.body.values), img_source: files_upload[0], info_url: files_upload[1] }
console.log(new_data)
const newUser = new Tournaments(new_data);
newUser
.save()
.then(user => {
res.json({ message: 'User created successfully', user });
})
.catch(err => {
console.log('Error occured while trying to save to DB');
});
};

Answer 1

If you look at the docs for upload it does not return a promise so you should not call await on it. The default map method is not compatible with async code in this form. You need to either use async.map or wrap the async code in a promise like
return await new Promise((resolve, reject) => {
...
if (data) {
fs.unlinkSync(item.path);
resolve(data.location);
}
}
Your other code has some issues as well. A map function should return a value. If you dont want to return anything you should use foreach.

Answer 2

This is a bad place to ask for code advice but something like the following
function uploadFile(s3, element) {
return new Promise((resolve, reject) => {
let folder;
if (element.fieldname.includes('img')) {
folder = 'club_images'
} else if (element.fieldname.inlcudes('poster')) {
folder = 'poster_tournament'
} else {
folder = 'info_tournament'
}
const params = {
ACL: 'public-read',
Bucket: process.env.AWS_BUCKET_NAME,
Body: fs.createReadStream(element.path),
Key: `${folder + '/' + uuidv4() + element.fieldname}`
};
s3.upload(params, (err, data) => {
if (err) {
return reject(err);
}
if (data) {
return fs.unlink(element.path, err=> {
if(err) {
console.error("Failed to unlink file", element.path);
}
return resolve({[element.fieldname]: data.Location});
}); // Empty temp folder
}
return resolve();
});
})
}
tournamentsCtrl.createTournament = async (req, res) => {
aws.config.setPromisesDependency();
aws.config.update({
accessKeyId: process.env.AWS_ACCESS_KEY_ID,
secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
//region: process.env.REGION
});
const s3 = new aws.S3();
try {
const uploadData = await Promise.all(req.files.map(element => uploadFile(s3, element)));
const returnData = Object.assign({}, ...uploadData);
console.log(Object.assign(JSON.parse(req.body.values), returnData));
} catch(e) {
console.error('Failed to upload file', e);
return res.sendStatus(500);
}
const newUser = new Tournaments(Object.assign(JSON.parse(req.body.values), files_upload));
console.log(newUser)
try {
const user = await newUser.save()
res.json({message: 'User created successfully', user});
} catch(e) {
console.error('Error occured while trying to save to DB');
return res.sendStatus(500);
}
};