Count repeated emojis (badges) with subscript

countBadges.js

const subscriptNumber = (n) => n
  .toString(10)
  .split``
  .map((i) => Number.parseInt(i, 10))
  .map((i) => String.fromCharCode(0x2080 + i))
  .join``

const countBadges = (badges) => Array
  .from(
    [...new Intl.Segmenter().segment(badges)]
      .map((x) => x.segment)
      .reduce(
        (freq, badge) => freq.set(badge, (freq.get(badge) ?? 0) + 1),
        new Map(),
      )
  ).flatMap(
    ([badge, count]) => [badge, count === 1 ? `` : subscriptNumber(count)]
  )
  .join``


countBadges(`🥷🥷🥷👨👨👨👨👨👨🎤🧑‍🧑‍🧒‍🧒🧑‍🧑‍🧒‍🧒👨👨👨👨👨👨`)
// -> `🥷₃👨₁₂🎤🧑‍🧑‍🧒‍🧒₂`