Firebase cloud functions bucket upload no such file or directory - firebase

Question

I'm writing a cloud function that triggers every time a file is uploaded on my default firebase storage bucket and if it's an image it converts it to JPG.
This is the official firebase example:
exports.processTripImage = functions.storage.object().onFinalize((object) => {
const filePath = object.name;
const baseFileName = path.basename(filePath, path.extname(filePath));
const fileDir = path.dirname(filePath);
const JPEGFilePath = path.normalize(path.format({ dir: fileDir, name: baseFileName, ext: JPEG_EXTENSION }));
const tempLocalFile = path.join(os.tmpdir(), filePath);
const tempLocalDir = path.dirname(tempLocalFile);
const tempLocalJPEGFile = path.join(os.tmpdir(), JPEGFilePath);
// Exit if this is triggered on a file that is not an image.
if (!object.contentType.startsWith('image/')) {
console.log('This is not an image.');
return null;
}
// Exit if the image is already a JPEG.
if (object.contentType.startsWith('image/jpeg')) {
console.log('Already a JPEG.');
return null;
}
const bucket = gcs.bucket(object.bucket);
// Create the temp directory where the storage file will be downloaded.
return mkdirp(tempLocalDir).then(() => {
// Download file from bucket.
return bucket.file(filePath).download({ destination: tempLocalFile });
}).then(() => {
console.log('The file has been downloaded to', tempLocalFile);
// Convert the image to JPEG using ImageMagick.
return spawn('convert', [tempLocalFile, tempLocalJPEGFile]);
}).then(() => {
console.log('JPEG image created at', tempLocalJPEGFile);
// Uploading the JPEG image.
return bucket.upload(tempLocalJPEGFile, { destination: JPEGFilePath });
}).then(() => {
console.log('JPEG image uploaded to Storage at', JPEGFilePath);
// Once the image has been converted delete the local files to free up disk space.
fs.unlinkSync(tempLocalJPEGFile);
fs.unlinkSync(tempLocalFile);
return;
});
})
The problem is that it writes the file and convert it correctly but when it tries to upload it back to the bucket it can't find the file in the tmp directory it just created.
My cloud function log: