fix: timer dispose, added widget test

packages/stream_chat_flutter/lib/src/message_input.dart

@@ -318,6 +318,8 @@ class MessageInputState extends State<MessageInput> {
   late DateTime? _cooldownStartedAt;
   int? _timeOut;
 
+  Timer? slowModeTimer;
+
   @override
   void initState() {
     super.initState();
@@ -359,7 +361,7 @@ class MessageInputState extends State<MessageInput> {
           StreamChannel.of(context).channel.cooldown!) {
         _timeOut = StreamChannel.of(context).channel.cooldown! -
             DateTime.now().difference(_cooldownStartedAt!).inSeconds;
-        Timer.periodic(const Duration(seconds: 1), (timer) {
+        slowModeTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
           if (_timeOut == 0) {
             timer.cancel();
           } else {
@@ -2265,6 +2267,7 @@ class MessageInputState extends State<MessageInput> {
     _emojiOverlay?.remove();
     _mentionsOverlay?.remove();
     _keyboardListener?.cancel();
+    slowModeTimer?.cancel();
     super.dispose();
   }
 

packages/stream_chat_flutter/test/src/message_input_test.dart

@@ -69,4 +69,69 @@ void main() {
       expect(find.byKey(const Key('messageInputText')), findsOneWidget);
     },
   );
+
+  testWidgets(
+    'checks message input slow mode',
+    (WidgetTester tester) async {
+      final client = MockClient();
+      final clientState = MockClientState();
+      final channel = MockChannel();
+      final channelState = MockChannelState();
+      final lastMessageAt = DateTime.parse('2020-06-22 12:00:00');
+
+      when(() => client.state).thenReturn(clientState);
+      when(() => clientState.currentUser).thenReturn(OwnUser(id: 'user-id'));
+      when(() => channel.lastMessageAt).thenReturn(lastMessageAt);
+      when(() => channel.state).thenReturn(channelState);
+      when(() => channel.cooldown).thenReturn(10);
+      when(() => channel.cooldownStartedAt).thenReturn(DateTime.now());
+      when(() => channel.client).thenReturn(client);
+      when(() => channel.isMuted).thenReturn(false);
+      when(() => channel.isMutedStream).thenAnswer((i) => Stream.value(false));
+      when(() => channel.extraDataStream).thenAnswer((i) => Stream.value({
+            'name': 'test',
+          }));
+      when(() => channel.extraData).thenReturn({
+        'name': 'test',
+      });
+      when(() => channelState.membersStream).thenAnswer((i) => Stream.value([
+            Member(
+              userId: 'user-id',
+              user: User(id: 'user-id'),
+            )
+          ]));
+      when(() => channelState.members).thenReturn([
+        Member(
+          userId: 'user-id',
+          user: User(id: 'user-id'),
+        ),
+      ]);
+      when(() => channelState.messages).thenReturn([
+        Message(
+          text: 'hello',
+          user: User(id: 'other-user'),
+        )
+      ]);
+      when(() => channelState.messagesStream).thenAnswer((i) => Stream.value([
+            Message(
+              text: 'hello',
+              user: User(id: 'other-user'),
+            )
+          ]));
+
+      await tester.pumpWidget(MaterialApp(
+        home: StreamChat(
+          client: client,
+          child: StreamChannel(
+            channel: channel,
+            child: const Scaffold(
+              body: MessageInput(),
+            ),
+          ),
+        ),
+      ));
+
+      expect(find.text('Slow mode ON'), findsOneWidget);
+    },
+  );
 }