code: function ensureDirExists (name) {
    try {
      fs.mkdirSync(path.join(__dirname, name));
    } catch (e) {
      if (e.code !== 'EEXIST') {
        console.log("Error ensuring that node_modules exists");
        process.exit(1);
      }
    }
  }
docs: Ensuring both node_modules (the source one and build one), src and out directories exist