Function normalizeEncoding

lib/internal/util.js:258–261

* Move the "slow cases" to a separate function to make sure this function gets * inlined properly. That prioritizes the common case. * @param {unknown} enc * @returns {string | undefined} Returns undefined if there is no match.

(enc)

 * @returns {string | undefined} Returns undefined if there is no match.
 */
function normalizeEncoding(enc) {
  if (enc == null || enc === 'utf8' || enc === 'utf-8') return 'utf8';
  return slowCases(enc);
}

function slowCases(enc) {
  switch (enc.length) {