const formData = new FormData();
formData.append('file', params.file);
formData.append('id', params.fileId);
formData.append('name', params.file.name);

xhr.onreadystatechange = () => handleRequestStateChange(xhr, params);
xhr.open('POST', 'url', true);
xhr.send(formData);

const handleRequestStateChange = (xhr: XMLHttpRequest) => {
    if (xhr.readyState !== 4) {
        return;
    }

    if (xhr.status === 0) {
        console.log('upload failure');
        return;
    }
};

When I upload a file.txt without permission (chmod 000 file.txt) why it log 'upload failure'?