Disallow group names longer than 32 extended graphemes

ts/test-both/util/grapheme_test.ts

@@ -0,0 +1,49 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import { count } from '../../util/grapheme';
+
+describe('grapheme utilities', () => {
+  describe('count', () => {
+    it('returns the number of extended graphemes in a string (not necessarily the length)', () => {
+      // These tests modified [from iOS][0].
+      // [0]: https://github.com/signalapp/Signal-iOS/blob/800930110b0386a4c351716c001940a3e8fac942/Signal/test/util/DisplayableTextFilterTest.swift#L40-L71
+
+      // Plain text
+      assert.strictEqual(count(''), 0);
+      assert.strictEqual(count('boring text'), 11);
+      assert.strictEqual(count('Bokmål'), 6);
+
+      // Emojis
+      assert.strictEqual(count('💩💩💩'), 3);
+      assert.strictEqual(count('👩‍❤️‍👩'), 1);
+      assert.strictEqual(count('🇹🇹🌼🇹🇹🌼🇹🇹'), 5);
+      assert.strictEqual(count('🇹🇹'), 1);
+      assert.strictEqual(count('🇹🇹 '), 2);
+      assert.strictEqual(count('👌🏽👌🏾👌🏿'), 3);
+      assert.strictEqual(count('😍'), 1);
+      assert.strictEqual(count('👩🏽'), 1);
+      assert.strictEqual(count('👾🙇💁🙅🙆🙋🙎🙍'), 8);
+      assert.strictEqual(count('🐵🙈🙉🙊'), 4);
+      assert.strictEqual(count('❤️💔💌💕💞💓💗💖💘💝💟💜💛💚💙'), 15);
+      assert.strictEqual(count('✋🏿💪🏿👐🏿🙌🏿👏🏿🙏🏿'), 6);
+      assert.strictEqual(count('🚾🆒🆓🆕🆖🆗🆙🏧'), 8);
+      assert.strictEqual(count('0️⃣1️⃣2️⃣3️⃣4️⃣5️⃣6️⃣7️⃣8️⃣9️⃣🔟'), 11);
+      assert.strictEqual(count('🇺🇸🇷🇺🇦🇫🇦🇲'), 4);
+      assert.strictEqual(count('🇺🇸🇷🇺🇸 🇦🇫🇦🇲🇸'), 7);
+      assert.strictEqual(count('🇺🇸🇷🇺🇸🇦🇫🇦🇲'), 5);
+      assert.strictEqual(count('🇺🇸🇷🇺🇸🇦'), 3);
+      assert.strictEqual(count('１２３'), 3);
+
+      // Normal diacritic usage
+      assert.strictEqual(count('Příliš žluťoučký kůň úpěl ďábelské ódy.'), 39);
+
+      // Excessive diacritics
+      assert.strictEqual(count('Z͑ͫ̓ͪ̂ͫ̽͏̴̙̤̞͉͚̯̞̠͍A̴̵̜̰͔ͫ͗͢L̠ͨͧͩ͘G̴̻͈͍͔̹̑͗̎̅͛́Ǫ̵̹̻̝̳͂̌̌͘'), 5);
+      assert.strictEqual(count('H҉̸̧͘͠A͢͞V̛̛I̴̸N͏̕͏G҉̵͜͏͢ ̧̧́T̶̛͘͡R̸̵̨̢̀O̷̡U͡҉B̶̛͢͞L̸̸͘͢͟É̸ ̸̛͘͏R͟È͠͞A̸͝Ḑ̕͘͜I̵͘҉͜͞N̷̡̢͠G̴͘͠ ͟͞T͏̢́͡È̀X̕҉̢̀T̢͠?̕͏̢͘͢'), 28);
+      assert.strictEqual(count('L̷̳͔̲͝Ģ̵̮̯̤̩̙͍̬̟͉̹̘̹͍͈̮̦̰̣͟͝O̶̴̮̻̮̗͘͡!̴̷̟͓͓'), 4);
+    });
+  });
+});