feat: made LaunchedBallControler react to states

lib/game/bloc/game_state.dart

@@ -55,9 +55,6 @@ class GameState extends Equatable {
   /// Determines when the game is over.
   bool get isGameOver => balls == 0;
 
-  /// Determines when the player has only one ball left.
-  bool get isLastBall => balls == 1;
-
   /// Shortcut method to check if the given [i]
   /// is activated.
   bool isLetterActivated(int i) => activatedBonusLetters.contains(i);

lib/game/components/controlled_ball.dart

@@ -1,4 +1,5 @@
 import 'package:flame/components.dart';
+import 'package:flame_bloc/flame_bloc.dart';
 import 'package:flame_forge2d/forge2d_game.dart';
 import 'package:flutter/material.dart';
 import 'package:pinball/flame/flame.dart';
@@ -68,22 +69,34 @@ class BonusBallController extends BallController {
   }
 }
 
+/// {@template launched_ball_controller}
 /// {@macro ball_controller}
+///
+/// A [LaunchedBallController] changes the [GameState.balls] count.
+/// {@endtemplate}
 class LaunchedBallController extends BallController
-    with HasGameRef<PinballGame> {
-  /// {@macro ball_controller}
+    with HasGameRef<PinballGame>, BlocComponent<GameBloc, GameState> {
+  /// {@macro launched_ball_controller}
   LaunchedBallController(Ball<Forge2DGame> ball) : super(ball);
 
+  @override
+  bool listenWhen(GameState? previousState, GameState newState) {
+    return (previousState?.balls ?? 0) < newState.balls;
+  }
+
+  @override
+  void onNewState(GameState state) {
+    super.onNewState(state);
+    component.shouldRemove = true;
+    if (state.balls > 0) gameRef.spawnBall();
+  }
+
   /// Removes the [Ball] from a [PinballGame]; spawning a new [Ball] if
   /// any are left.
   ///
   /// {@macro ball_controller_lost}
   @override
   void lost() {
-    final bloc = gameRef.read<GameBloc>()..add(const BallLost());
-
-    // TODO(alestiago): Consider the use of onNewState instead.
-    final shouldBallRespwan = !bloc.state.isLastBall && !bloc.state.isGameOver;
-    if (shouldBallRespwan) gameRef.spawnBall();
+    gameRef.read<GameBloc>().add(const BallLost());
   }
 }

test/game/components/controlled_ball_test.dart

@@ -39,99 +39,131 @@ void main() {
   });
 
   group('LaunchedBallController', () {
-    group('lost', () {
-      late GameBloc gameBloc;
-      late Ball ball;
-
-      setUp(() {
-        gameBloc = MockGameBloc();
-        ball = Ball(baseColor: const Color(0xFF00FFFF));
-        whenListen(
-          gameBloc,
-          const Stream<GameState>.empty(),
-          initialState: const GameState.initial(),
-        );
-      });
+    late Ball ball;
+    late GameBloc gameBloc;
 
-      final tester = flameBlocTester<PinballGame>(
-        game: PinballGameTest.create,
-        gameBloc: () => gameBloc,
+    setUp(() {
+      ball = Ball(baseColor: const Color(0xFF00FFFF));
+      gameBloc = MockGameBloc();
+      whenListen(
+        gameBloc,
+        const Stream<GameState>.empty(),
+        initialState: const GameState.initial(),
       );
+    });
 
-      tester.testGameWidget(
-        'removes ball',
+    final tester = flameBlocTester<PinballGame>(
+      game: PinballGameTest.create,
+      gameBloc: () => gameBloc,
+    );
+
+    flameTester.testGameWidget(
+      'lost adds BallLost to GameBloc',
+      setUp: (game, tester) async {
+        final controller = LaunchedBallController(ball);
+        await ball.add(controller);
+        await game.add(ball);
+        await game.ready();
+
+        controller.lost();
+      },
+      verify: (game, tester) async {
+        verify(() => gameBloc.add(const BallLost())).called(1);
+      },
+    );
+
+    group('listenWhen', () {
+      flameTester.testGameWidget(
+        'listens when a ball has been lost',
         verify: (game, tester) async {
-          await game.add(ball);
           final controller = LaunchedBallController(ball);
           await ball.add(controller);
+          await game.add(ball);
           await game.ready();
 
-          controller.lost();
-          await game.ready();
+          final previousState = MockGameState();
+          final newState = MockGameState();
+          when(() => previousState.balls).thenReturn(3);
+          when(() => newState.balls).thenReturn(2);
 
-          expect(game.contains(ball), isFalse);
+          expect(controller.listenWhen(previousState, newState), isTrue);
         },
       );
 
-      tester.testGameWidget(
-        'adds BallLost to GameBloc',
+      flameTester.testGameWidget(
+        'does not listen when a ball has not been lost',
         verify: (game, tester) async {
           final controller = LaunchedBallController(ball);
           await ball.add(controller);
           await game.add(ball);
           await game.ready();
 
-          controller.lost();
+          final previousState = MockGameState();
+          final newState = MockGameState();
+          when(() => previousState.balls).thenReturn(3);
+          when(() => newState.balls).thenReturn(3);
 
-          verify(() => gameBloc.add(const BallLost())).called(1);
+          expect(controller.listenWhen(previousState, newState), isTrue);
         },
       );
+    });
+
+    group('onNewState', () {
+      setUp(() {
+        whenListen(
+          gameBloc,
+          const Stream<GameState>.empty(),
+          initialState: const GameState.initial(),
+        );
+      });
 
       tester.testGameWidget(
-        'adds a new ball if the game is not over',
+        'removes ball',
+        setUp: (game, _) => game.ready(),
         verify: (game, tester) async {
           final controller = LaunchedBallController(ball);
-          await ball.add(controller);
           await game.add(ball);
           await game.ready();
 
-          final previousBalls = game.descendants().whereType<Ball>().length;
-          controller.lost();
-          await game.ready();
-          final currentBalls = game.descendants().whereType<Ball>().length;
+          final state = MockGameState();
+          when(() => state.balls).thenReturn(any());
+          controller.onNewState(MockGameState());
 
-          expect(previousBalls, equals(currentBalls));
+          expect(game.contains(ball), isFalse);
         },
       );
 
       tester.testGameWidget(
-        'no ball is added on game over',
-        verify: (game, tester) async {
-          whenListen(
-            gameBloc,
-            const Stream<GameState>.empty(),
-            initialState: const GameState(
-              score: 10,
-              balls: 1,
-              activatedBonusLetters: [],
-              activatedDashNests: {},
-              bonusHistory: [],
-            ),
-          );
+        'spawns a new ball when the ball is not the last one',
+        setUp: (game, tester) async {
           final controller = LaunchedBallController(ball);
-          await ball.add(controller);
           await game.add(ball);
           await game.ready();
 
-          final previousBalls = game.descendants().whereType<Ball>().toList();
-          controller.lost();
+          final state = MockGameState();
+          when(() => state.balls).thenReturn(2);
+
+          controller.onNewState(state);
+        },
+        verify: (game, tester) async {
+          expect(game.contains(ball), isFalse);
+        },
+      );
+
+      tester.testGameWidget(
+        'does not spawn a new ball is the last one',
+        setUp: (game, tester) async {
+          final controller = LaunchedBallController(ball);
+          await game.add(ball);
           await game.ready();
-          final currentBalls = game.descendants().whereType<Ball>().length;
 
-          expect(
-            currentBalls,
-            equals((previousBalls..remove(ball)).length),
-          );
+          final state = MockGameState();
+          when(() => state.balls).thenReturn(1);
+
+          controller.onNewState(state);
+        },
+        verify: (game, tester) async {
+          expect(game.contains(ball), isFalse);
         },
       );
     });