Function parseFileMode

lib/internal/validators.js:73–85

* Parse and validate values that will be converted into mode_t (the S_* * constants). Only valid numbers and octal strings are allowed. They could be * converted to 32-bit unsigned integers or non-negative signed integers in the * C++ land, but any value higher than 0o777 will result in platform-

(value, name, def)

 * @returns {number}
 */
function parseFileMode(value, name, def) {
  value ??= def;
  if (typeof value === 'string') {
    if (RegExpPrototypeExec(octalReg, value) === null) {
      throw new ERR_INVALID_ARG_VALUE(name, value, modeDesc);
    }
    value = NumberParseInt(value, 8);
  }

  validateUint32(value, name);
  // Coerce -0 to +0.
  return value + 0;
}

/**
 * @callback validateInteger