text: const fs = require('fs');
  const path = require('path');
  
  function filterByQuery(query, zookeepers) {
      let filteredResults = zookeepers;
      // Ensure personality traits are saved as an array
      if (query.age) {
          filteredResults = filteredResults.filter((zookeeper) => zookeeper.age === Number(query.age))
      }
      if (query.favoriteAnimal) {
          filteredResults = filteredResults.filter(zookeeper => zookeeper.favoriteAnimal === query.favoriteAnimal);
      }
      if (query.name) {
          filteredResults = filteredResults.filter(zookeeper => zookeeper.name === query.name);
      }
      return filteredResults;
  }
  
  function findById(id, zookeepers) {
      const result = zookeepers.filter(zookeeper => zookeeper.id === id)[0];
      return result;
  }
  
  function createNewZookeeper(body, zookeepers) {
      const zookeeper = body;
      zookeepers.push(zookeeper);
      fs.writeFileSync(
          path.join(__dirname, '../data/zookeepers.json'),
          JSON.stringify({ zookeepers }, null, 2)
      );
      return zookeeper;
  }
  
  function validateZookeeper(zookeeper) {
      if (!zookeeper.name || typeof zookeeper.name !== 'string') {
          return false;
      }
      if (!zookeeper.age || typeof zookeeper.age !== 'number') {
          return false;
      }
      if (!zookeeper.favoriteAnimal || typeof zookeeper.favoriteAnimal !== 'string') {
          return false;
      }
      return true;
  }
  
  module.exports = { filterByQuery, findById, createNewZookeeper, validateZookeeper }