fs-jetpack/lib/utils/mode.js

Better file system API

// Logic for unix file mode operations.

"use strict";

// Converts mode to string 3 characters long.
exports.normalizeFileMode = mode => {
  let modeAsString;
  if (typeof mode === "number") {
    modeAsString = mode.toString(8);
  } else {
    modeAsString = mode;
  }
  return modeAsString.substring(modeAsString.length - 3);
};