Compress and combine emoji data (#5229)

app/javascript/mastodon/features/emoji/emoji_compressed.js

@@ -0,0 +1,90 @@
+// @preval
+// http://www.unicode.org/Public/emoji/5.0/emoji-test.txt
+// This file contains the compressed version of the emoji data from
+// both emoji_map.json and from emoji-mart's emojiIndex and data objects.
+// It's designed to be emitted in an array format to take up less space
+// over the wire.
+
+const { unicodeToFilename } = require('./unicode_to_filename');
+const { unicodeToUnifiedName } = require('./unicode_to_unified_name');
+const emojiMap         = require('./emoji_map.json');
+const { emojiIndex } = require('emoji-mart');
+const emojiMartData = require('emoji-mart/dist/data').default;
+const excluded       = ['®', '©', '™'];
+const skins          = ['🏻', '🏼', '🏽', '🏾', '🏿'];
+const shortcodeMap   = {};
+
+const shortCodesToEmojiData = {};
+const emojisWithoutShortCodes = [];
+
+Object.keys(emojiIndex.emojis).forEach(key => {
+  shortcodeMap[emojiIndex.emojis[key].native] = emojiIndex.emojis[key].id;
+});
+
+const stripModifiers = unicode => {
+  skins.forEach(tone => {
+    unicode = unicode.replace(tone, '');
+  });
+
+  return unicode;
+};
+
+Object.keys(emojiMap).forEach(key => {
+  if (excluded.includes(key)) {
+    delete emojiMap[key];
+    return;
+  }
+
+  const normalizedKey = stripModifiers(key);
+  let shortcode       = shortcodeMap[normalizedKey];
+
+  if (!shortcode) {
+    shortcode = shortcodeMap[normalizedKey + '\uFE0F'];
+  }
+
+  const filename = emojiMap[key];
+
+  const filenameData = [key];
+
+  if (unicodeToFilename(key) !== filename) {
+    // filename can't be derived using unicodeToFilename
+    filenameData.push(filename);
+  }
+
+  if (typeof shortcode === 'undefined') {
+    emojisWithoutShortCodes.push(filenameData);
+  } else {
+    shortCodesToEmojiData[shortcode] = shortCodesToEmojiData[shortcode] || [[]];
+    shortCodesToEmojiData[shortcode][0].push(filenameData);
+  }
+});
+
+Object.keys(emojiIndex.emojis).forEach(key => {
+  const { native } = emojiIndex.emojis[key];
+  const { short_names, search, unified } = emojiMartData.emojis[key];
+  if (short_names[0] !== key) {
+    throw new Error('The compresser expects the first short_code to be the ' +
+      'key. It may need to be rewritten if the emoji change such that this ' +
+      'is no longer the case.');
+  }
+
+  short_names.splice(0, 1); // first short name can be inferred from the key
+
+  const searchData = [native, short_names, search];
+  if (unicodeToUnifiedName(native) !== unified) {
+    // unified name can't be derived from unicodeToUnifiedName
+    searchData.push(unified);
+  }
+
+  shortCodesToEmojiData[key].push(searchData);
+});
+
+// JSON.parse/stringify is to emulate what @preval is doing and avoid any
+// inconsistent behavior in dev mode
+module.exports = JSON.parse(JSON.stringify([
+  shortCodesToEmojiData,
+  emojiMartData.skins,
+  emojiMartData.categories,
+  emojiMartData.short_names,
+  emojisWithoutShortCodes,
+]));