hr.gs/mob-frontend

index.js

const { writeFile } = require('fs')

const fetchUsers = () =>
  new Promise(r => {
    setTimeout(() => {
      r([
        {
          name: "amos",
          id: "amos"
        },
        {
          name: "soma",
          id: "soma"
        }
      ]);
    }, 100);
  });

const fetchPets = () =>
  new Promise(r => {
    setTimeout(() => {
      r([
        {
          name: "geof",
          userID: "amos"
        },
        {
          name: "lyla",
          userID: "soma"
        }
      ]);
    }, 100);
  });

function workWithData() {
  console.log("enter");

  return Promise.all([fetchUsers(), fetchPets()])
    .then(([users, pets]) => {
      console.log(`users: ${users} pets: ${pets}`);
      const petsByName = pets.sort((pet1, pet2) =>
        pet1.name < pet2.name ? -1 : pet1.name > pet2.name ? 1 : 0
      );
      const userWithPets = users.map(user => ({
        ...user,
        pets: pets.filter(({ userID }) => user.id === userID)
      }));

      return Promise.all([
        writeFile("sorted-pets.json", JSON.stringify(petsByName), null, (err) => {
          if(err) {
            console.log('error' + err)
          }
        }),
        writeFile("users-with-pets.json", JSON.stringify(userWithPets), null, (err) => {
          if(err) {
            console.log('error' + err)
          }
        })
      ]).catch(error => {
        // handler special case here
      });
    })
    .catch(error => {
      console.log(`error ${error}`);
      // handle network error
    });
}

workWithData();