const hasNoneLetters = (blacklist, phrase) =>  !blacklist.split('').find(b => phrase.includes(b))

const hasNoneLetters = (blacklist, phrase) => {
  const set = new Set(blacklist.toLowerCase());
  return !Array.from(phrase.toLowerCase()).some(c => set.has(c));
}

const checkBlackList = (blacklist, phrase) => {
  let hash = {}
  blacklist = blacklist.toLowerCase()
  
  for (let i = 0; i < blacklist.length; i += 1) {
    hash[blacklist[i]] = hash[blacklist[i]] + 1 || 1
  }
  
  for (let key in hash) {    
    return !!(!phrase.toLowerCase().includes(key))
  }
}