feat: add transparent background in PinballGame

lib/game/pinball_game.dart

@@ -5,6 +5,7 @@ import 'package:flame/components.dart';
 import 'package:flame/input.dart';
 import 'package:flame_bloc/flame_bloc.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
+import 'package:flutter/material.dart';
 import 'package:pinball/flame/flame.dart';
 import 'package:pinball/game/game.dart';
 import 'package:pinball/gen/assets.gen.dart';
@@ -28,6 +29,9 @@ class PinballGame extends Forge2DGame
   /// Identifier of the play button overlay
   static const playButtonOverlay = 'play_button';
 
+  @override
+  Color backgroundColor() => Colors.transparent;
+
   final PinballTheme theme;
 
   final PinballAudio audio;

test/app/view/app_test.dart

@@ -5,8 +5,10 @@
 // license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
+import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:leaderboard_repository/leaderboard_repository.dart';
+import 'package:mocktail/mocktail.dart';
 import 'package:pinball/app/app.dart';
 import 'package:pinball/game/game.dart';
 import 'package:pinball_audio/pinball_audio.dart';
@@ -21,13 +23,18 @@ void main() {
     setUp(() {
       leaderboardRepository = MockLeaderboardRepository();
       pinballAudio = MockPinballAudio();
+
+      when(pinballAudio.load).thenAnswer((_) => Future.value());
     });
 
     testWidgets('renders PinballGamePage', (tester) async {
       await tester.pumpWidget(
-        App(
-          leaderboardRepository: leaderboardRepository,
-          pinballAudio: pinballAudio,
+        RepositoryProvider<PinballAudio>(
+          create: (_) => pinballAudio,
+          child: App(
+            leaderboardRepository: leaderboardRepository,
+            pinballAudio: pinballAudio,
+          ),
         ),
       );
       expect(find.byType(PinballGamePage), findsOneWidget);

test/helpers/mocks.dart

@@ -72,10 +72,7 @@ class MockComponentSet extends Mock implements ComponentSet {}
 
 class MockDashNestBumper extends Mock implements DashNestBumper {}
 
-class MockPinballAudio extends Mock implements PinballAudio {
-  @override
-  Future<void> load() async {}
-}
+class MockPinballAudio extends Mock implements PinballAudio {}
 
 class MockSparkyTurboChargeSensor extends Mock
     implements SparkyTurboChargeSensor {}