Update emoji list

Update emoji list to include all Unicode 14.0 emojis. GitHub shortcodes
are used, with fallback to Unicode CLDR annotations.

tools/build_emojis.js

@@ -0,0 +1,67 @@
+// Builds static/emoji.json
+// GitHub shortcodes are used, with fallback to Unicode CLDR annotations
+// 
+// curl -o gh-emojis.json https://api.github.com/emojis
+// curl -o emoji-test.txt https://unicode.org/Public/emoji/14.0/emoji-test.txt
+//
+
+const fs = require('fs')
+
+const GH_REGEX = /unicode\/(.*)\.png/
+const CLDR_REGEX = /^(([0-9A-F]+ )+)\s*; ([^\s]+)\s+# [^ ]+ [^ ]+ (.*)/
+
+const emojiFilename = '../static/emoji.json'
+
+const ghEmojis = JSON.parse(fs.readFileSync('gh-emojis.json', 'utf8'))
+const ghEmojiNames = {}
+for (const name in ghEmojis) {
+  const match = GH_REGEX.exec(ghEmojis[name]);
+  if (match) {
+    const char = String.fromCodePoint(...match[1].split('-').map(cp => Number.parseInt(cp, 16)));
+    ghEmojiNames[char] = name;
+  }
+}
+
+function hasSkinToneIndicator(codepoints) {
+  return codepoints.some(cp => cp >= 0x1F3FB && cp <= 0x1F3FF)
+}
+
+const emojis = []
+const cldrDataRaw = fs.readFileSync('./emoji-test.txt', 'utf-8')
+for (const line of cldrDataRaw.split('\n')) {
+  const match = CLDR_REGEX.exec(line)
+  if (match) {
+    const codepoints = match[1].trim().split(' ').map(cp => Number.parseInt(cp, 16));
+    if (hasSkinToneIndicator(codepoints)) continue;
+
+    const char = String.fromCodePoint(...codepoints)
+    if (match[3] === 'fully-qualified') {
+      let slug = match[4].replaceAll(/[^A-Za-z0-9#*]+/g, '_').toLowerCase();
+      emojis.push({
+        keyword: ghEmojiNames[char] ?? slug,
+        value: char,
+      })
+    }
+  }
+}
+
+const collator = new Intl.Collator('en-u-co-emoji')
+
+emojis.sort((a, b) => {
+  return collator.compare(a.value, b.value)
+})
+
+// Add regional indicators
+// This is done after sorting, because Unicode collation would interleave 
+// these with country flags, and that's ugly
+for (let char = 0x1F1E6; char <= 0x1F1FF; char++) {
+  const asciiChar = String.fromCodePoint(char-0x1F1E6+97)
+  emojis.push({
+    keyword: `regional_indicator_${asciiChar}`,
+    value: String.fromCodePoint(char)
+  })
+}
+
+fs.writeFile(emojiFilename, JSON.stringify(emojis, null, 2), 'utf8', (err) => {
+  if (err) console.log('Error writing file', err)
+})