text: const fs = require("fs");
  
  module.exports = {
      getUser: function (filename) {
          let users = JSON.parse(fs.readFileSync(filename).toString());
          let userDict = {};
          for (let v of users) {
              userDict[v['userNo']] = {
                  name: v['name'],
                  password: v['password'],
              };
          }
          return (id) => id in userDict ? userDict[id] : null;
      }
  };
  