Function appendFileSync

lib/fs.js:2996–3014

* Synchronously appends data to a file. * @param {string | Buffer | URL | number} path * @param {string | Buffer} data * @param {{ * encoding?: string | null; * mode?: number; * flag?: string; * } | string} [options] * @returns {void}

(path, data, options)

 * @returns {void}
 */
function appendFileSync(path, data, options) {
  options = getOptions(options, { encoding: 'utf8', mode: 0o666, flag: 'a' });
  parseFileMode(options.mode, 'mode', 0o666);

  const h = vfsState.handlers;
  if (h !== null) {
    const result = h.appendFileSync(path, data, options);
    if (result !== undefined) return;
  }

  // Don't make changes directly on options object
  options = copyObject(options);

  // Force append behavior when using a supplied file descriptor
  if (!options.flag || isFd(path))
    options.flag = 'a';

  fs.writeFileSync(path, data, options);
}

/**
 * Watches for the changes on `filename`.