import { getEmojiRegex } from './emojiRegex' // \ufe0f is a variation selector, which seems to appear for some reason in e.g. ™ let NON_EMOJI_REGEX = new RegExp('^[0-9#*™®\ufe0f]+$') // replace emoji in HTML with something else, safely skipping HTML tags export function replaceEmoji (string, replacer) { let output = '' let leftAngleBracketIdx = string.indexOf('<') let currentIdx = 0 let emojiRegex = getEmojiRegex() function safeReplacer (substring) { // emoji regex matches digits and pound sign https://git.io/fpl6J if (substring.match(NON_EMOJI_REGEX)) { return substring } return replacer(substring) } while (leftAngleBracketIdx !== -1) { let substring = string.substring(currentIdx, leftAngleBracketIdx) output += substring.replace(emojiRegex, safeReplacer) let rightAngleBracketIdx = string.indexOf('>', leftAngleBracketIdx + 1) if (rightAngleBracketIdx === -1) { // broken HTML, abort output += string.substring(leftAngleBracketIdx, string.length) return output } output += string.substring(leftAngleBracketIdx, rightAngleBracketIdx) + '>' currentIdx = rightAngleBracketIdx + 1 leftAngleBracketIdx = string.indexOf('<', currentIdx) } output += string.substring(currentIdx, string.length).replace(emojiRegex, safeReplacer) return output }