code: function renameFile(from, to) {
    return new Promise((resolve, reject) => {
      fs.rename(from, to, (err) => {
        if (err) {
          reject(err);
          return;
        }
        resolve(to);
      });
    });
  }
docs: Rename a file to another path
  @param {string} from origin path and filename
  @param {string} to destination path and filename
  @returns {Promise<string>} resolve with the destination filePath