AWS S3 Lambda WriteFile from stream - node.js

Question

Using an AWS Lambda, I just want to get an archive (lo.tar.gz) from my s3, copy it to the tmp folder and extract it to the tmp folder.
I have this code in local who work perfectly :
var AWS = require('aws-sdk');
var fs = require('fs');
var targz = require('targz');
var s3 = new AWS.S3({ apiVersion: '2006-03-01' });
var fileStream = fs.createWriteStream('./tmp/lo.tar.gz');
var s3Stream = s3.getObject({ Bucket: 'mybucketname', Key: 'lo.tar.gz' }).createReadStream();
//console.log("Here the last console.log who appear");
// Listen for errors returned by the service
s3Stream.on('error', function (err) {
// NoSuchKey: The specified key does not exist
console.error(err);
});
s3Stream.pipe(fileStream).on('error', function (err) {
// capture any errors that occur when writing data to the file
console.error('File Stream:', err);
}).on('close', function () {
console.log('Stream Done.');
// decompress files from tar.gz archive
targz.decompress({
src: './tmp/lo.tar.gz',
dest: './tmp'
}, function (err) {
if (err) {
console.log(err);
} else {
console.log("Extract Done!");
}
});
});
But when I put it in a lambda, nothing append.
It creates an empty file "lo.tar.gz" in tmp and it closes saying "statut:succeeded" and without any error message ... I put "console.log" between each line and the last to appear is the one I left ("Here the last console.log who appear") ...
Does anyone have any idea why the code is not being executed to the end?
Thank you :D!
EDIT : here the exact code for the lambda (the same with exports.handler) :
var AWS = require('aws-sdk');
var fs = require('fs');
var targz = require('targz');
exports.handler = async (event, context, callback) => {
var s3 = new AWS.S3({ apiVersion: '2006-03-01' });
var fileStream = fs.createWriteStream('./tmp/lo.tar.gz');
var s3Stream = s3.getObject({ Bucket: 'mybucketname', Key: 'lo.tar.gz'
}).createReadStream();
//console.log("Here the last console.log who appear");
// Listen for errors returned by the service
s3Stream.on('error', function (err) {
// NoSuchKey: The specified key does not exist
console.error(err);
});
s3Stream.pipe(fileStream).on('error', function (err) {
// capture any errors that occur when writing data to the file
console.error('File Stream:', err);
}).on('close', function () {
console.log('Stream Done.');
// decompress files from tar.gz archive
targz.decompress({
src: './tmp/lo.tar.gz',
dest: './tmp'
}, function (err) {
if (err) {
console.log(err);
} else {
console.log("Extract Done!");
}
});
});
}