MessageController: return all messages by sent at, not just 1

ts/test-electron/util/MessageController_test.ts

@@ -0,0 +1,56 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import { MessageModel } from '../../models/messages';
+
+import { MessageController } from '../../util/MessageController';
+
+describe('MessageController', () => {
+  describe('filterBySentAt', () => {
+    it('returns an empty iterable if no messages match', () => {
+      const mc = new MessageController();
+
+      assert.isEmpty([...mc.filterBySentAt(123)]);
+    });
+
+    it('returns all messages that match the timestamp', () => {
+      const mc = new MessageController();
+      const message1 = new MessageModel({
+        conversationId: 'xyz',
+        id: 'abc',
+        received_at: 1,
+        sent_at: 1234,
+        timestamp: 9999,
+        type: 'incoming',
+      });
+      const message2 = new MessageModel({
+        conversationId: 'xyz',
+        id: 'def',
+        received_at: 2,
+        sent_at: 1234,
+        timestamp: 9999,
+        type: 'outgoing',
+      });
+      const message3 = new MessageModel({
+        conversationId: 'xyz',
+        id: 'ignored',
+        received_at: 3,
+        sent_at: 5678,
+        timestamp: 9999,
+        type: 'outgoing',
+      });
+      mc.register(message1.id, message1);
+      mc.register(message2.id, message2);
+      // We deliberately register this message twice for testing.
+      mc.register(message2.id, message2);
+      mc.register(message3.id, message3);
+
+      assert.sameMembers([...mc.filterBySentAt(1234)], [message1, message2]);
+
+      mc.unregister(message2.id);
+
+      assert.sameMembers([...mc.filterBySentAt(1234)], [message1]);
+    });
+  });
+});