HackerRank: JavaScript (Basic) on 15th Sep 2020

ChampionsLeagueTeams.js

const https = require('https');

const fetch = (url) => {
  return new Promise((resolve, reject) => {
    https
      .get(url, (resp) => {
        let data = '';

        // A chunk of data has been recieved.
        resp.on('data', (chunk) => {
          data += chunk;
        });

        // The whole response has been received. Print out the result.
        resp.on('end', () => {
          resolve(JSON.parse(data));
        });
      })
      .on('error', (err) => {
        reject(err.message);
      });
  });
};

const getAPIURL = (year, page) => {
  return `https://jsonmock.hackerrank.com/api/football_matches?competition=UEFA%20Champions%20League&year=${year}&page=${page}`;
};

const getFootballMatches = (year, page) => {
  const url = getAPIURL(year, page);
  return new Promise((resolve, reject) => {
    fetch(url)
      .then((jsonRespone) => resolve(jsonRespone))
      .catch((e) => reject(e.message));
  });
};

async function getTeams(year, k) {
  // write your code here
  // API endpoint template: https://jsonmock.hackerrank.com/api/football_matches?competition=UEFA%20Champions%20League&year=<YEAR>&page=<PAGE_NUMBER>
  const matchesPerTeam = {};
  let initialPage = 1;
  let totalPages = 1;
  while (initialPage <= totalPages) {
    const { total_pages, data: matches } = await getFootballMatches(
      year,
      initialPage,
    );

    matches.forEach(({ team1, team2 }) => {
      matchesPerTeam[team1] = (matchesPerTeam[team1] || 0) + 1;
      matchesPerTeam[team2] = (matchesPerTeam[team2] || 0) + 1;
    });
    totalPages = total_pages;
    initialPage += 1;
  }
  return Object.entries(matchesPerTeam)
    .filter(([, numOfMatches]) => numOfMatches >= k)
    .map(([team]) => team)
    .sort();
}

function main(year, k) {
  getTeams(year, k)
    .then((result) => console.log(result))
    .catch((e) => console.error(e.message));
}

main(2015, 6);

NoteStore.js

const VALID_STATES = ['completed', 'active', 'others'];

class NotesStore {
  //add your code here
  constructor() {
    this.notes = [];
  }

  addNote(state, name) {
    if (!name) {
      throw new Error('Name cannot be empty');
    }
    if (!VALID_STATES.includes(state)) {
      throw new Error(`Invalid state ${state}`);
    }
    this.notes.push({ name, state });
  }

  getNotes(state) {
    if (!VALID_STATES.includes(state)) {
      throw new Error(`Invalid state ${state}`);
    }
    return this.notes
      .filter((note) => note.state === state)
      .map((note) => note.name);
  }
}