Little ugly function for setting the skin tone on an emoji

emoji_skin_tone.ts

/* HELPERS */

const SKIN_TONE = {
  DARK: '\uD83C\uDFFF',
  MEDIUM_DARK: '\uD83C\uDFFE',
  MEDIUM: '\uD83C\uDFFD',
  MEDIUM_LIGHT: '\uD83C\uDFFC',
  LIGHT: '\uD83C\uDFFB',
  NEUTRAL: ''
};

const VARIATION = '\uFE0F';
const ZWJ = '\u200D';

/* MAIN */

// This assumes a neutral emoji as input

const getEmojiWithSkinTone = ( emoji: string, skinTone: string, isEmojiSkinToneable: ( emoji: string ) => boolean ): string => {

  if ( skinTone === SKIN_TONE.NEUTRAL ) return emoji;

  const emojiWithSkinTone = emoji.split ( ZWJ ).map ( chunk => {

    if ( !isEmojiSkinToneable ( chunk ) ) return chunk;

    return `${chunk}${skinTone}`;

  }).join ( ZWJ );

  const emojiWithoutVariation = emojiWithSkinTone.replaceAll ( `${VARIATION}${skinTone}`, `${skinTone}` );

  return emojiWithoutVariation;

};

/* EXPORT */

export default getEmojiWithSkinTone;
export {SKIN_TONE};