convertCurrency.js

const convertCurrency = (from, to, amount) => {
  let countries
  return getCountries(to).then((tempCountries) => {
    countries = tempCountries
    return getExchangeRate(from, to)
  }).then((rate) => {
    const exchangedAmount = amount * rate
    return `${amount} ${from} is worth ${exchangedAmount} ${to}. ${to} can be used in the following countries: ${countries.join(', ')}`
  })
}

convertCurrency('CAD', 'USD', 100).then((status) => {
  console.log(status)
})