Better emoji support in linkify/previews

ts/test-both/util/emoji_test.ts

@@ -0,0 +1,53 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { assert } from 'chai';
+
+import { replaceEmojiWithSpaces, splitByEmoji } from '../../util/emoji';
+
+describe('emoji', () => {
+  describe('replaceEmojiWithSpaces', () => {
+    it('replaces emoji and pictograms with a single space', () => {
+      assert.strictEqual(
+        replaceEmojiWithSpaces('hello🌀🐀🔀😀world'),
+        'hello    world'
+      );
+    });
+
+    it('leaves regular text as it is', () => {
+      assert.strictEqual(
+        replaceEmojiWithSpaces('Привет 嘿 հեյ העלא مرحبا '),
+        'Привет 嘿 հեյ העלא مرحبا '
+      );
+    });
+  });
+
+  describe('splitByEmoji', () => {
+    it('replaces emoji and pictograms with a single space', () => {
+      assert.deepStrictEqual(splitByEmoji('hello😛world😎😛!'), [
+        { type: 'text', value: 'hello' },
+        { type: 'emoji', value: '😛' },
+        { type: 'text', value: 'world' },
+        { type: 'emoji', value: '😎' },
+        { type: 'text', value: '' },
+        { type: 'emoji', value: '😛' },
+        { type: 'text', value: '!' },
+      ]);
+    });
+
+    it('should return empty string after split at the end', () => {
+      assert.deepStrictEqual(splitByEmoji('hello😛'), [
+        { type: 'text', value: 'hello' },
+        { type: 'emoji', value: '😛' },
+        { type: 'text', value: '' },
+      ]);
+    });
+
+    it('should return empty string before the split at the start', () => {
+      assert.deepStrictEqual(splitByEmoji('😛hello'), [
+        { type: 'text', value: '' },
+        { type: 'emoji', value: '😛' },
+        { type: 'text', value: 'hello' },
+      ]);
+    });
+  });
+});