get-word-frequency.js

function getWordsByFrequency (text) {
  return text
    .replace('\'', '')
    .replace(/\W+/g, ' ')
    .toLowerCase()
    .split(' ')
    .reduce((acc, word) => {
      if (acc[word] === undefined) {
        acc[word] = 1
      } else {
        acc[word] += 1
      }
      return acc
    }, {})
}

function getMaxFromObject (obj) {
  return Object.keys(obj)
    .sort((a, b) => obj[a] > obj[b] ? 1 : -1 )
    .map((word) => ({
      word, count: obj[word]
    }))
}


getMaxFromObject( getWordsByFrequency(foo) )