read json file and use data object code example

Example: read json data from file

// consider your file data is something like json string but aving parse issue 
//that means some additional char is there 
fs.readFile(ROLES_FILE, "utf8", (err, data) => {
      if (err) {
        res.status(403).json({});
      }
      const [localScope, action] = scope.split(".");
      const mapper = JSON.parse(data.toString("utf8").replace(/^\uFEFF/, ""));
      const isAllowed = checkRole(mapper, localScope, action, role);
      if (isAllowed) {
        next();
      } else {
        res.status(403).json({});
      }