function getFileExtension(path) {
  if (typeof path === 'string') {
    var splitPathRe = /^(\/?)([\s\S]*?)((?:\.{1,2}|[^\/]+?)(\.([^\.\/\?]+)))(?:[\/]*|[\?].*)$/i;
    var pathParts = splitPathRe.exec(path);

    if (pathParts) {
      return pathParts.pop().toLowerCase();
    }
  }

  return '';
}