Fix emojify() by generating a mapping to existing Twemoji files (#5080)

A new rake task emojis:generate downloads a full list of valid
unicode sequences from unicode.org and checks it against existing
Twemoji files, finally generating a map from each sequence to the
existing file (e.g. when there's multiple ways an emoji can be
expressed). The map is dumped into app/javascript/mastodon/emoji_map.json

That file is loaded by emojione_light.js (now a misnomer) which
decorates it further with shortcodes taken from emoji-mart's index.

app/javascript/mastodon/emoji_map.json

@@ -0,0 +1 @@
+{"😀":"1f600","😁":"1f601","😂":"1f602","🤣":"1f923","😃":"1f603","😄":"1f604","😅":"1f605","😆":"1f606","😉":"1f609","😊":"1f60a","😋":"1f60b","😎":"1f60e","😍":"1f60d","😘":"1f618","😗":"1f617","😙":"1f619","😚":"1f61a","☺":"263a","🙂":"1f642","🤗":"1f917","🤩":"1f929","🤔":"1f914","🤨":"1f928","😐":"1f610","😑":"1f611","😶":"1f636","🙄":"1f644","😏":"1f60f","😣":"1f623","😥":"1f625","😮":"1f62e","🤐":"1f910","😯":"1f62f","😪":"1f62a","😫":"1f62b","😴":"1f634","😌":"1f60c","😛":"1f61b","😜":"1f61c","😝":"1f61d","🤤":"1f924","😒":"1f612","😓":"1f613","😔":"1f614","😕":"1f615","🙃":"1f643","🤑":"1f911","😲":"1f632","☹":"2639","🙁":"1f641","😖":"1f616","😞":"1f61e","😟":"1f61f","😤":"1f624","😢":"1f622","😭":"1f62d","😦":"1f626","😧":"1f627","😨":"1f628","😩":"1f629","🤯":"1f92f","😬":"1f62c","😰":"1f630","😱":"1f631","😳":"1f633","🤪":"1f92a","😵":"1f635","😡":"1f621","😠":"1f620","🤬":"1f92c","😷":"1f637","🤒":"1f912","🤕":"1f915","🤢":"1f922","🤮":"1f92e","🤧":"1f927","😇":"1f607","🤠":"1f920","🤡":"1f921","🤥":"1f925","🤫":"1f92b","🤭":"1f92d","🧐":"1f9d0","🤓":"1f913","😈":"1f608","👿":"1f47f","👹":"1f479","👺":"1f47a","💀":"1f480","☠":"2620","👻":"1f47b","👽":"1f47d","👾":"1f47e","🤖":"1f916","💩":"1f4a9","😺":"1f63a","😸":"1f638","😹":"1f639","😻":"1f63b","😼":"1f63c","😽":"1f63d","🙀":"1f640","😿":"1f63f","😾":"1f63e","🙈":"1f648","🙉":"1f649","🙊":"1f64a","👶":"1f476","🧒":"1f9d2","👦":"1f466","👧":"1f467","🧑":"1f9d1","👨":"1f468","👩":"1f469","🧓":"1f9d3","👴":"1f474","👵":"1f475","👮":"1f46e","🕵":"1f575","💂":"1f482","👷":"1f477","🤴":"1f934","👸":"1f478","👳":"1f473","👲":"1f472","🧕":"1f9d5","🧔":"1f9d4","👱":"1f471","🤵":"1f935","👰":"1f470","🤰":"1f930","🤱":"1f931","👼":"1f47c","🎅":"1f385","🤶":"1f936","🧙":"1f9d9","🧚":"1f9da","🧛":"1f9db","🧜":"1f9dc","🧝":"1f9dd","🧞":"1f9de","🧟":"1f9df","🙍":"1f64d","🙎":"1f64e","🙅":"1f645","🙆":"1f646","💁":"1f481","🙋":"1f64b","🙇":"1f647","🤦":"1f926","🤷":"1f937","💆":"1f486","💇":"1f487","🚶":"1f6b6","🏃":"1f3c3","💃":"1f483","🕺":"1f57a","👯":"1f46f","🧖":"1f9d6","🧗":"1f9d7","🧘":"1f9d8","🛀":"1f6c0","🛌":"1f6cc","🕴":"1f574","🗣":"1f5e3","👤":"1f464","👥":"1f465","🤺":"1f93a","🏇":"1f3c7","⛷":"26f7","🏂":"1f3c2","🏌":"1f3cc","🏄":"1f3c4","🚣":"1f6a3","🏊":"1f3ca","⛹":"26f9","🏋":"1f3cb","🚴":"1f6b4","🚵":"1f6b5","🏎":"1f3ce","🏍":"1f3cd","🤸":"1f938","🤼":"1f93c","🤽":"1f93d","🤾":"1f93e","🤹":"1f939","👫":"1f46b","👬":"1f46c","👭":"1f46d","💏":"1f48f","💑":"1f491","👪":"1f46a","🤳":"1f933","💪":"1f4aa","👈":"1f448","👉":"1f449","☝":"261d","👆":"1f446","🖕":"1f595","👇":"1f447","✌":"270c","🤞":"1f91e","🖖":"1f596","🤘":"1f918","🤙":"1f919","🖐":"1f590","✋":"270b","👌":"1f44c","👍":"1f44d","👎":"1f44e","✊":"270a","👊":"1f44a","🤛":"1f91b","🤜":"1f91c","🤚":"1f91a","👋":"1f44b","🤟":"1f91f","✍":"270d","👏":"1f44f","👐":"1f450","🙌":"1f64c","🤲":"1f932","🙏":"1f64f","🤝":"1f91d","💅":"1f485","👂":"1f442","👃":"1f443","👣":"1f463","👀":"1f440","👁":"1f441","🧠":"1f9e0","👅":"1f445","👄":"1f444","💋":"1f48b","💘":"1f498","❤":"2764","💓":"1f493","💔":"1f494","💕":"1f495","💖":"1f496","💗":"1f497","💙":"1f499","💚":"1f49a","💛":"1f49b","🧡":"1f9e1","💜":"1f49c","🖤":"1f5a4","💝":"1f49d","💞":"1f49e","💟":"1f49f","❣":"2763","💌":"1f48c","💤":"1f4a4","💢":"1f4a2","💣":"1f4a3","💥":"1f4a5","💦":"1f4a6","💨":"1f4a8","💫":"1f4ab","💬":"1f4ac","🗨":"1f5e8","🗯":"1f5ef","💭":"1f4ad","🕳":"1f573","👓":"1f453","🕶":"1f576","👔":"1f454","👕":"1f455","👖":"1f456","🧣":"1f9e3","🧤":"1f9e4","🧥":"1f9e5","🧦":"1f9e6","👗":"1f457","👘":"1f458","👙":"1f459","👚":"1f45a","👛":"1f45b","👜":"1f45c","👝":"1f45d","🛍":"1f6cd","🎒":"1f392","👞":"1f45e","👟":"1f45f","👠":"1f460","👡":"1f461","👢":"1f462","👑":"1f451","👒":"1f452","🎩":"1f3a9","🎓":"1f393","🧢":"1f9e2","⛑":"26d1","📿":"1f4ff","💄":"1f484","💍":"1f48d","💎":"1f48e","🐵":"1f435","🐒":"1f412","🦍":"1f98d","🐶":"1f436","🐕":"1f415","🐩":"1f429","🐺":"1f43a","🦊":"1f98a","🐱":"1f431","🐈":"1f408","🦁":"1f981","🐯":"1f42f","🐅":"1f405","🐆":"1f406","🐴":"1f434","🐎":"1f40e","🦄":"1f984","🦓":"1f993","🦌":"1f98c","🐮":"1f42e","🐂":"1f402","🐃":"1f403","🐄":"1f404","🐷":"1f437","🐖":"1f416","🐗":"1f417","🐽":"1f43d","🐏":"1f40f","🐑":"1f411","🐐":"1f410","🐪":"1f42a","🐫":"1f42b","🦒":"1f992","🐘":"1f418","🦏":"1f98f","🐭":"1f42d","🐁":"1f401","🐀":"1f400"Line truncated

app/javascript/mastodon/emojione_light.js

@@ -1,13 +1,38 @@
 // @preval
-// Force tree shaking on emojione by exposing just a subset of its functionality
+// http://www.unicode.org/Public/emoji/5.0/emoji-test.txt
 
-const emojione = require('emojione');
+const emojis         = require('./emoji_map.json');
+const { emojiIndex } = require('emoji-mart');
+const excluded       = ['®', '©', '™'];
+const skins          = ['🏻', '🏼', '🏽', '🏾', '🏿'];
+const shortcodeMap   = {};
 
-const mappedUnicode = emojione.mapUnicodeToShort();
-const excluded = ['®', '©', '™'];
+Object.keys(emojiIndex.emojis).forEach(key => {
+  shortcodeMap[emojiIndex.emojis[key].native] = emojiIndex.emojis[key].id;
+});
 
-module.exports.unicodeMapping = Object.keys(emojione.jsEscapeMap)
-  .filter(c => !excluded.includes(c))
-  .map(unicodeStr => [unicodeStr, mappedUnicode[emojione.jsEscapeMap[unicodeStr]]])
-  .map(([unicodeStr, shortCode]) => ({ [unicodeStr]: [emojione.emojioneList[shortCode].fname.replace(/^0+/g, ''), shortCode.slice(1, shortCode.length - 1)] }))
-  .reduce((x, y) => Object.assign(x, y), { });
+const stripModifiers = unicode => {
+  skins.forEach(tone => {
+    unicode = unicode.replace(tone, '');
+  });
+
+  return unicode;
+};
+
+Object.keys(emojis).forEach(key => {
+  if (excluded.includes(key)) {
+    delete emojis[key];
+    return;
+  }
+
+  const normalizedKey = stripModifiers(key);
+  let shortcode       = shortcodeMap[normalizedKey];
+
+  if (!shortcode) {
+    shortcode = shortcodeMap[normalizedKey + '\uFE0F'];
+  }
+
+  emojis[key] = [emojis[key], shortcode];
+});
+
+module.exports.unicodeMapping = emojis;