/**
 * Gets the name of parent folder in a url.
 * @param url - URL of a file.
 * @return Name of the parent folder, or the file itself if it has no parent folder.
 */
export function folderName(url: string) {
    let lastSlashIndex = url.lastIndexOf('/');

    if (lastSlashIndex != -1) {
        url = url.slice(0, lastSlashIndex);
    }

    lastSlashIndex = url.lastIndexOf('/');

    if (lastSlashIndex !== -1) {
        url = url.slice(lastSlashIndex + 1);
    }

    return url;
}