wordy.js

function guess_fits(guess, clue) {
  const guess_freq = frequency(guess)
  const clue_freq = frequency(clue)

  for (const ltr in clue_freq) {
    if (ltr === '?') { continue }
    if (!guess_freq[ltr]) { return false } // Clue has a letter the guess doesn't
    if (guess_freq[ltr] < clue_freq[ltr]) { return false } // Clue has more of these than guess
    guess_freq[ltr] -= clue_freq[ltr]
  }

  let unaccounted_letters = 0
  for (const ltr in guess_freq) { unaccounted_letters += guess_freq[ltr] }
  return clue_freq['?'] === unaccounted_letters
}

function frequency(word) {
  const freq = {}
  word.split('').forEach(ltr => {
    if (freq[ltr]) { freq[ltr]++ }
    else freq[ltr] = 1
  })
  return freq
}

guess_fits('wall', 'awl?') // true
guess_fits('walk', 'awl?') // true, letter only in clue
guess_fits('will', 'awl?') // false, no a
guess_fits('wilt', 'ill?') // false, more l's in clue