Function normalizeReferrerURL

lib/internal/modules/helpers.js:331–350

* Normalize the referrer name as a URL. * If it's a string containing an absolute path or a URL it's normalized as * a URL string. * Otherwise it's returned as undefined. * @param {string | null | undefined} referrerName * @returns {string | undefined}

(referrerName)

 * @returns {string | undefined}
 */
function normalizeReferrerURL(referrerName) {
  if (referrerName === null || referrerName === undefined) {
    return undefined;
  }

  if (typeof referrerName === 'string') {
    if (path.isAbsolute(referrerName)) {
      return pathToFileURL(referrerName).href;
    }

    if (StringPrototypeStartsWith(referrerName, 'file://') ||
    URLCanParse(referrerName)) {
      return referrerName;
    }

    return undefined;
  }

  assert.fail('Unreachable code reached by ' + inspect(referrerName));
}

/**
 * Coerce a URL string to a filename. This is used by the ESM loader