text: const fs = require('fs');
  const path = require('path');
  
  function filterByQuery(query, zookeepers){
      let filteredResults = zookeepers;
      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
  }