refactor: made ball controller listen to bloc (#116)

* refactor: included BonusBallController

* feat: made LaunchedBallControler react to states

* refactor: removed isLastBall

* fix: solved tests

* fix: solved BonusLetterActivated test

* refactor: used ensureAdd

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';
@@ -28,19 +29,19 @@ class ControlledBall extends Ball with Controls<BallController> {
   ControlledBall.bonus({
     required PinballTheme theme,
   }) : super(baseColor: theme.characterTheme.ballColor) {
-    controller = BallController(this);
+    controller = BonusBallController(this);
   }
 
   /// [Ball] used in [DebugPinballGame].
   ControlledBall.debug() : super(baseColor: const Color(0xFFFF0000)) {
-    controller = BallController(this);
+    controller = BonusBallController(this);
   }
 }
 
 /// {@template ball_controller}
 /// Controller attached to a [Ball] that handles its game related logic.
 /// {@endtemplate}
-class BallController extends ComponentController<Ball> {
+abstract class BallController extends ComponentController<Ball> {
   /// {@macro ball_controller}
   BallController(Ball ball) : super(ball);
 
@@ -50,30 +51,52 @@ class BallController extends ComponentController<Ball> {
   /// Triggered by [BottomWallBallContactCallback] when the [Ball] falls into
   /// a [BottomWall].
   /// {@endtemplate}
-  @mustCallSuper
+  void lost();
+}
+
+/// {@template bonus_ball_controller}
+/// {@macro ball_controller}
+///
+/// A [BonusBallController] doesn't change the [GameState.balls] count.
+/// {@endtemplate}
+class BonusBallController extends BallController {
+  /// {@macro bonus_ball_controller}
+  BonusBallController(Ball<Forge2DGame> component) : super(component);
+
+  @override
   void lost() {
     component.shouldRemove = true;
   }
 }
 
+/// {@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 > 1) gameRef.spawnBall();
+  }
+
   /// Removes the [Ball] from a [PinballGame]; spawning a new [Ball] if
   /// any are left.
   ///
   /// {@macro ball_controller_lost}
   @override
   void lost() {
-    super.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/bloc/game_state_test.dart

@@ -103,38 +103,6 @@ void main() {
       });
     });
 
-    group('isLastBall', () {
-      test(
-        'is true '
-        'when there is only one ball left',
-        () {
-          const gameState = GameState(
-            balls: 1,
-            score: 0,
-            activatedBonusLetters: [],
-            activatedDashNests: {},
-            bonusHistory: [],
-          );
-          expect(gameState.isLastBall, isTrue);
-        },
-      );
-
-      test(
-        'is false '
-        'when there are more balls left',
-        () {
-          const gameState = GameState(
-            balls: 2,
-            score: 0,
-            activatedBonusLetters: [],
-            activatedDashNests: {},
-            bonusHistory: [],
-          );
-          expect(gameState.isLastBall, isFalse);
-        },
-      );
-    });
-
     group('isLetterActivated', () {
       test(
         'is true when the letter is activated',

test/game/components/bonus_word_test.dart

@@ -196,7 +196,7 @@ void main() {
     group('bonus letter activation', () {
       late GameBloc gameBloc;
 
-      final tester = flameBlocTester(
+      final tester = flameBlocTester<PinballGame>(
         // TODO(alestiago): Use TestGame once BonusLetter has controller.
         game: PinballGameTest.create,
         gameBloc: () => gameBloc,
@@ -217,13 +217,8 @@ void main() {
           await game.ready();
           final bonusLetter = game.descendants().whereType<BonusLetter>().first;
 
-          await game.add(bonusLetter);
-          await game.ready();
-
           bonusLetter.activate();
           await game.ready();
-
-          await tester.pump();
         },
         verify: (game, tester) async {
           verify(() => gameBloc.add(const BonusLetterActivated(0))).called(1);

test/game/components/controlled_ball_test.dart

@@ -15,20 +15,26 @@ void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
   final flameTester = FlameTester(PinballGameTest.create);
 
-  group('BallController', () {
+  group('BonusBallController', () {
     late Ball ball;
 
     setUp(() {
       ball = Ball(baseColor: const Color(0xFF00FFFF));
     });
 
+    test('can be instantiated', () {
+      expect(
+        BonusBallController(ball),
+        isA<BonusBallController>(),
+      );
+    });
+
     flameTester.test(
       'lost removes ball',
       (game) async {
         await game.add(ball);
-        final controller = BallController(ball);
-        await ball.add(controller);
-        await game.ready();
+        final controller = BonusBallController(ball);
+        await ball.ensureAdd(controller);
 
         controller.lost();
         await game.ready();
@@ -39,13 +45,20 @@ void main() {
   });
 
   group('LaunchedBallController', () {
-    group('lost', () {
-      late GameBloc gameBloc;
+    test('can be instantiated', () {
+      expect(
+        LaunchedBallController(MockBall()),
+        isA<LaunchedBallController>(),
+      );
+    });
+
+    group('description', () {
       late Ball ball;
+      late GameBloc gameBloc;
 
       setUp(() {
-        gameBloc = MockGameBloc();
         ball = Ball(baseColor: const Color(0xFF00FFFF));
+        gameBloc = MockGameBloc();
         whenListen(
           gameBloc,
           const Stream<GameState>.empty(),
@@ -59,81 +72,126 @@ void main() {
       );
 
       tester.testGameWidget(
-        'removes ball',
-        verify: (game, tester) async {
-          await game.add(ball);
+        'lost adds BallLost to GameBloc',
+        setUp: (game, tester) async {
           final controller = LaunchedBallController(ball);
           await ball.add(controller);
-          await game.ready();
+          await game.ensureAdd(ball);
 
           controller.lost();
-          await game.ready();
-
-          expect(game.contains(ball), isFalse);
         },
-      );
-
-      tester.testGameWidget(
-        'adds BallLost to GameBloc',
         verify: (game, tester) async {
-          final controller = LaunchedBallController(ball);
-          await ball.add(controller);
-          await game.add(ball);
-          await game.ready();
-
-          controller.lost();
-
           verify(() => gameBloc.add(const BallLost())).called(1);
         },
       );
 
-      tester.testGameWidget(
-        'adds a new ball if the game is not over',
-        verify: (game, tester) async {
-          final controller = LaunchedBallController(ball);
-          await ball.add(controller);
-          await game.add(ball);
-          await game.ready();
+      group('listenWhen', () {
+        tester.testGameWidget(
+          'listens when a ball has been lost',
+          setUp: (game, tester) async {
+            final controller = LaunchedBallController(ball);
+
+            await ball.add(controller);
+            await game.ensureAdd(ball);
+          },
+          verify: (game, tester) async {
+            final controller =
+                game.descendants().whereType<LaunchedBallController>().first;
+
+            final previousState = MockGameState();
+            final newState = MockGameState();
+            when(() => previousState.balls).thenReturn(3);
+            when(() => newState.balls).thenReturn(2);
+
+            expect(controller.listenWhen(previousState, newState), isTrue);
+          },
+        );
 
-          final previousBalls = game.descendants().whereType<Ball>().length;
-          controller.lost();
-          await game.ready();
-          final currentBalls = game.descendants().whereType<Ball>().length;
+        tester.testGameWidget(
+          'does not listen when a ball has not been lost',
+          setUp: (game, tester) async {
+            final controller = LaunchedBallController(ball);
+
+            await ball.add(controller);
+            await game.ensureAdd(ball);
+          },
+          verify: (game, tester) async {
+            final controller =
+                game.descendants().whereType<LaunchedBallController>().first;
+
+            final previousState = MockGameState();
+            final newState = MockGameState();
+            when(() => previousState.balls).thenReturn(3);
+            when(() => newState.balls).thenReturn(3);
+
+            expect(controller.listenWhen(previousState, newState), isFalse);
+          },
+        );
+      });
 
-          expect(previousBalls, equals(currentBalls));
-        },
-      );
+      group('onNewState', () {
+        tester.testGameWidget(
+          'removes ball',
+          setUp: (game, tester) async {
+            final controller = LaunchedBallController(ball);
+            await ball.add(controller);
+            await game.ensureAdd(ball);
+
+            final state = MockGameState();
+            when(() => state.balls).thenReturn(1);
+            controller.onNewState(state);
+            await game.ready();
+          },
+          verify: (game, tester) async {
+            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: [],
-            ),
-          );
-          final controller = BallController(ball);
-          await ball.add(controller);
-          await game.add(ball);
-          await game.ready();
+        tester.testGameWidget(
+          '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.ensureAdd(ball);
 
-          final previousBalls = game.descendants().whereType<Ball>().toList();
-          controller.lost();
-          await game.ready();
-          final currentBalls = game.descendants().whereType<Ball>().length;
+            final state = MockGameState();
+            when(() => state.balls).thenReturn(2);
 
-          expect(
-            currentBalls,
-            equals((previousBalls..remove(ball)).length),
-          );
-        },
-      );
+            final previousBalls = game.descendants().whereType<Ball>().toList();
+            controller.onNewState(state);
+            await game.ready();
+
+            final currentBalls = game.descendants().whereType<Ball>();
+
+            expect(currentBalls.contains(ball), isFalse);
+            expect(currentBalls.length, equals(previousBalls.length));
+          },
+        );
+
+        tester.testGameWidget(
+          'does not spawn a new ball is the last one',
+          setUp: (game, tester) async {
+            final controller = LaunchedBallController(ball);
+            await ball.add(controller);
+            await game.ensureAdd(ball);
+
+            final state = MockGameState();
+            when(() => state.balls).thenReturn(1);
+
+            final previousBalls = game.descendants().whereType<Ball>().toList();
+            controller.onNewState(state);
+            await game.ready();
+
+            final currentBalls = game.descendants().whereType<Ball>();
+
+            expect(currentBalls.contains(ball), isFalse);
+            expect(
+              currentBalls.length,
+              equals((previousBalls..remove(ball)).length),
+            );
+          },
+        );
+      });
     });
   });
 }

test/helpers/test_game.dart

@@ -1,6 +1,7 @@
+import 'package:flame_bloc/flame_bloc.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
 
-class TestGame extends Forge2DGame {
+class TestGame extends Forge2DGame with FlameBloc {
   TestGame() {
     images.prefix = '';
   }