split-filename-regex.mjs

/**
 * Split a file name into its name and extension.
 *
 * // splitFileNameRegex(fileName: string): { name: string; extension: string | undefined }
 * @param {string} fileName The file name to split.
 * @returns {Object} An object with the file name and its extension.
 * @returns {string} name The name of the file.
 * @returns {string | undefined} extension The extension of the file, or undefined if there is no extension.
 */
export default function splitFileNameRegex(fileName) {
  const match = fileName.match(/^(.*?)(?:\.([^.]+))?$/);

  if (!match) {
    return { name: fileName, extension: undefined };
  }

  const [, name, extension] = match;
  return {
    name: name || fileName,
    extension: extension?.toLowerCase(),
  };
}