Hubspot Code Assessment

index.js

const fetch = require('node-fetch');
const dayjs = require('dayjs')

const DATASET_API = "https://candidate.hubteam.com/candidateTest/v3/problem/dataset?userKey=USER_KEY"
const RESULT_API = "https://candidate.hubteam.com/candidateTest/v3/problem/result?userKey=USER_KEY"

const findIdealStartDatePartners = (country, partners) => {
  let partnersByDate = {}
  let mostAvailDate = null
  let maxAttendee = -1

  //Loop through each partner
  partners.forEach((p) => {
    const {
      availableDates
    } = p
    // Filter out all the potential start day and put it under availableDates
    let availDates = availableDates.filter((dateData, index) => {
      return availableDates[index + 1] ===
        dayjs(dateData).add(1, 'day').format("YYYY-MM-DD") //Assume availableDates are sorted
    })
    if (availDates.length > 0) {
      availDates.forEach((date) => {
        //For each start date, add it to partnersByDate and find the most available Date
        partnersByDate[date] = partnersByDate[date] || []
        const partnerCount = partnersByDate[date].push(p)
        if (partnerCount > maxAttendee) {
          mostAvailDate = date
          maxAttendee = partnerCount
        }
      })
    }
  }, [])
  //Return the expected object format
  return {
    "attendeeCount": partnersByDate[mostAvailDate].length,
    "attendees": partnersByDate[mostAvailDate].map((p) => p.email),
    "name": country,
    "startDate": mostAvailDate,
  }
}

(async () => {
  try {
    const data_api_res = await fetch(DATASET_API)
    const result = await data_api_res.json()

    //Group the partner data by country since its all separated calculation
    let groupByCountries = result.partners.reduce((accu, partner) => {
      const {
        country
      } = partner
      accu[country] = accu[country] || []
      accu[country].push(partner)
      return accu
    }, {})

    let countries = []
    for (const [country, partners] of Object.entries(groupByCountries)) {
      countries.push(findIdealStartDatePartners(country, partners))
    }

    const result_api_res = await fetch(RESULT_API, {
      method: 'POST',
      body: JSON.stringify({
        countries
      }),
      headers: {
        'Content-Type': 'application/json'
      },
    })
    const result_api_data = await result_api_res.json()
    console.dir(result_api_data)
  } catch (e) {
    console.error(e)
  }
})();