feat: defined DebugGameBallsController

lib/flame/component_controller.dart

@@ -33,7 +33,7 @@ abstract class ComponentController<T extends Component> extends Component {
 /// Mixin that attaches a single [ComponentController] to a [Component].
 mixin Controls<T extends ComponentController> on Component {
   /// The [ComponentController] attached to this [Component].
-  late final T controller;
+  late T controller;
 
   @override
   @mustCallSuper

lib/game/components/controlled_ball.dart

@@ -33,7 +33,7 @@ class ControlledBall extends Ball with Controls<BallController> {
 
   /// [Ball] used in [DebugPinballGame].
   ControlledBall.debug() : super(baseColor: const Color(0xFFFF0000)) {
-    controller = _DebugBallController(this);
+    controller = DebugBallController(this);
   }
 }
 
@@ -57,8 +57,10 @@ class BallController extends ComponentController<Ball>
   }
 }
 
-class _DebugBallController extends BallController {
-  _DebugBallController(Ball<Forge2DGame> component) : super(component);
+/// {@macro ball_controller}
+class DebugBallController extends BallController {
+  /// {@macro ball_controller}
+  DebugBallController(Ball<Forge2DGame> component) : super(component);
 
   @override
   void lost() {

lib/game/pinball_game.dart

@@ -142,7 +142,9 @@ class DebugPinballGame extends PinballGame with TapDetector {
   }) : super(
           theme: theme,
           audio: audio,
-        );
+        ) {
+    controller = _DebugGameBallsController(this);
+  }
 
   @override
   Future<void> onLoad() async {
@@ -174,3 +176,21 @@ class DebugPinballGame extends PinballGame with TapDetector {
     );
   }
 }
+
+class _DebugGameBallsController extends _GameBallsController {
+  _DebugGameBallsController(PinballGame game) : super(game);
+
+  @override
+  bool listenWhen(GameState? previousState, GameState newState) {
+    final noBallsLeft = component
+        .descendants()
+        .whereType<ControlledBall>()
+        .where(
+          (ball) => ball.controller is! DebugBallController,
+        )
+        .isEmpty;
+    final canBallRespawn = newState.balls > 0;
+
+    return noBallsLeft && canBallRespawn;
+  }
+}

test/game/pinball_game_test.dart

@@ -11,11 +11,11 @@ import 'package:pinball_components/pinball_components.dart';
 import '../helpers/helpers.dart';
 
 void main() {
-  group('PinballGame', () {
   TestWidgetsFlutterBinding.ensureInitialized();
   final flameTester = FlameTester(PinballGameTest.new);
   final debugModeFlameTester = FlameTester(DebugPinballGameTest.new);
 
+  group('PinballGame', () {
     // TODO(alestiago): test if [PinballGame] registers
     // [BallScorePointsCallback] once the following issue is resolved:
     // https://github.com/flame-engine/flame/issues/1416
@@ -139,7 +139,9 @@ void main() {
         );
       });
     });
+  });
 
+  group('DebugPinballGame', () {
     debugModeFlameTester.test('adds a ball on tap up', (game) async {
       await game.ready();
 
@@ -159,5 +161,23 @@ void main() {
         equals(previousBalls.length + 1),
       );
     });
+
+    group('controller', () {
+      debugModeFlameTester.test(
+        'ignores debug balls',
+        (game) async {
+          final newState = MockGameState();
+          when(() => newState.balls).thenReturn(2);
+          game.descendants().whereType<Ball>().forEach(game.remove);
+          await game.ready();
+          await game.ensureAdd(ControlledBall.debug());
+
+          expect(
+            game.controller.listenWhen(MockGameState(), newState),
+            isTrue,
+          );
+        },
+      );
+    });
   });
 }