Adding test for file and audio

Author: leandroBorgesFerreira

packages/stream_chat_flutter/test/src/message_input/message_input_test.dart

@@ -373,6 +373,95 @@ void main() {
     },
   );
 
+  testWidgets(
+    'Test that is possible to add a audio message with file attachments too',
+    (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.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'),
+          )
+        ]),
+      );
+
+      final messageInputController = StreamMessageInputController();
+
+      await tester.pumpWidget(MaterialApp(
+        home: StreamChat(
+          client: client,
+          child: StreamChannel(
+            channel: channel,
+            child: Scaffold(
+              body: StreamMessageInput(
+                enableAudioRecord: false,
+                messageInputController: messageInputController,
+              ),
+            ),
+          ),
+        ),
+      ));
+
+      messageInputController.attachments += [
+        Attachment(type: 'audio_recording'),
+        Attachment(type: 'file'),
+      ];
+
+      await tester.pump();
+
+      expect(
+        find.byWidgetPredicate((widget) => widget is AudioPlayerComposeMessage),
+        findsOneWidget,
+      );
+
+      expect(
+        find.byWidgetPredicate((widget) => widget is StreamFileAttachment),
+        findsOneWidget,
+      );
+    },
+  );
+
   testWidgets(
     'Test that start the audio input correctly appears',
     (WidgetTester tester) async {