refactor: ballsInside private and removed from tests

lib/game/components/ramp_opening.dart

@@ -68,25 +68,24 @@ abstract class RampOpening extends BodyComponent with InitialPosition, Layered {
 class RampOpeningBallContactCallback<Opening extends RampOpening>
     extends ContactCallback<Ball, Opening> {
   /// [Ball]s currently inside the ramp.
-  @visibleForTesting
+  final _ballsInside = <Ball>{};
-  final ballsInside = <Ball>{};
 
   @override
   void begin(Ball ball, Opening opening, Contact _) {
     Layer layer;
 
-    if (!ballsInside.contains(ball)) {
+    if (!_ballsInside.contains(ball)) {
       layer = opening.pathwayLayer;
-      ballsInside.add(ball);
+      _ballsInside.add(ball);
       ball.layer = layer;
     } else {
-      ballsInside.remove(ball);
+      _ballsInside.remove(ball);
     }
   }
 
   @override
   void end(Ball ball, Opening opening, Contact _) {
-    if (!ballsInside.contains(ball)) {
+    if (!_ballsInside.contains(ball)) {
       ball.layer = Layer.board;
     } else {
       // TODO(ruimiguel): change this code. Check what happens with ball that
@@ -100,7 +99,7 @@ class RampOpeningBallContactCallback<Opening extends RampOpening>
 
       if (isBallOutsideOpening) {
         ball.layer = Layer.board;
-        ballsInside.remove(ball);
+        _ballsInside.remove(ball);
       }
     }
   }

test/game/components/ramp_opening_test.dart

@@ -116,13 +116,6 @@ void main() {
   });
 
   group('RampOpeningBallContactCallback', () {
-    test('ballsInside is empty when initialized', () {
-      expect(
-        RampOpeningBallContactCallback<TestRampOpening>().ballsInside,
-        isEmpty,
-      );
-    });
-
     flameTester.test(
         'changes ball layer '
         'when a ball enters upwards into a downward ramp opening',
@@ -146,30 +139,6 @@ void main() {
       verify(() => ball.layer = area.pathwayLayer).called(1);
     });
 
-    flameTester.test(
-        'adds ball to ballsInside '
-        'when a ball enters upwards into a downward oriented ramp',
-        (game) async {
-      final ball = MockBall();
-      final body = MockBody();
-      final area = TestRampOpening(
-        orientation: RampOrientation.down,
-        pathwayLayer: Layer.jetpack,
-      );
-      final callback = TestRampOpeningBallContactCallback();
-
-      when(() => ball.body).thenReturn(body);
-      when(() => body.position).thenReturn(Vector2.zero());
-      when(() => ball.layer).thenReturn(Layer.board);
-
-      await game.ready();
-      await game.ensureAdd(area);
-
-      callback.begin(ball, area, MockContact());
-      expect(callback.ballsInside.length, equals(1));
-      expect(callback.ballsInside.first, ball);
-    });
-
     flameTester.test(
         'changes ball layer '
         'when a ball enters downwards into a upward ramp opening',
@@ -193,59 +162,6 @@ void main() {
       verify(() => ball.layer = area.pathwayLayer).called(1);
     });
 
-    flameTester.test(
-      'adds ball to ballsInside '
-      'when a ball enters downwards into an upward oriented ramp',
-      (game) async {
-        final ball = MockBall();
-        final body = MockBody();
-        final area = TestRampOpening(
-          orientation: RampOrientation.up,
-          pathwayLayer: Layer.jetpack,
-        );
-        final callback = TestRampOpeningBallContactCallback();
-
-        when(() => ball.body).thenReturn(body);
-        when(() => body.position).thenReturn(Vector2.zero());
-        when(() => ball.layer).thenReturn(Layer.board);
-
-        await game.ready();
-        await game.ensureAdd(area);
-
-        callback.begin(ball, area, MockContact());
-        expect(callback.ballsInside.contains(ball), isTrue);
-      },
-    );
-
-    flameTester.test(
-        'removes ball from ballsInside '
-        'when a ball exits from a downward oriented ramp', (game) async {
-      final ball = MockBall();
-      final body = MockBody();
-      final area = TestRampOpening(
-        orientation: RampOrientation.down,
-        pathwayLayer: Layer.jetpack,
-      )..initialPosition = Vector2(0, 10);
-      final callback = TestRampOpeningBallContactCallback();
-
-      when(() => ball.body).thenReturn(body);
-      when(() => body.position).thenReturn(Vector2.zero());
-      when(() => body.linearVelocity).thenReturn(Vector2(0, -1));
-      when(() => ball.layer).thenReturn(Layer.board);
-
-      await game.ready();
-      await game.ensureAdd(area);
-
-      expect(callback.ballsInside.isEmpty, isTrue);
-
-      callback.begin(ball, area, MockContact());
-      expect(callback.ballsInside.length, equals(1));
-      expect(callback.ballsInside.first, ball);
-
-      callback.end(ball, area, MockContact());
-      expect(callback.ballsInside.isEmpty, true);
-    });
-
     flameTester.test(
         'changes ball layer '
         'when a ball exits from a downward oriented ramp', (game) async {
@@ -272,35 +188,6 @@ void main() {
       verify(() => ball.layer = Layer.board);
     });
 
-    flameTester.test(
-        'removes ball from ballsInside '
-        'when a ball exits from a upward oriented ramp', (game) async {
-      final ball = MockBall();
-      final body = MockBody();
-      final area = TestRampOpening(
-        orientation: RampOrientation.up,
-        pathwayLayer: Layer.jetpack,
-      )..initialPosition = Vector2(0, 10);
-      final callback = TestRampOpeningBallContactCallback();
-
-      when(() => ball.body).thenReturn(body);
-      when(() => body.position).thenReturn(Vector2.zero());
-      when(() => body.linearVelocity).thenReturn(Vector2(0, 1));
-      when(() => ball.layer).thenReturn(Layer.board);
-
-      await game.ready();
-      await game.ensureAdd(area);
-
-      expect(callback.ballsInside.isEmpty, isTrue);
-
-      callback.begin(ball, area, MockContact());
-      expect(callback.ballsInside.length, equals(1));
-      expect(callback.ballsInside.first, ball);
-
-      callback.end(ball, area, MockContact());
-      expect(callback.ballsInside.isEmpty, true);
-    });
-
     flameTester.test(
         'changes ball layer '
         'when a ball exits from a upward oriented ramp', (game) async {
@@ -327,39 +214,6 @@ void main() {
       verify(() => ball.layer = Layer.board);
     });
 
-    flameTester.test(
-        'removes added ball from ballsInside '
-        'when a ball enters and exits from ramp', (game) async {
-      final ball = MockBall();
-      final body = MockBody();
-      final area = TestRampOpening(
-        orientation: RampOrientation.down,
-        pathwayLayer: Layer.jetpack,
-      )..initialPosition = Vector2(0, 10);
-      final callback = TestRampOpeningBallContactCallback();
-
-      when(() => ball.body).thenReturn(body);
-      when(() => body.position).thenReturn(Vector2.zero());
-      when(() => body.linearVelocity).thenReturn(Vector2(0, 1));
-      when(() => ball.layer).thenReturn(Layer.board);
-
-      await game.ready();
-      await game.ensureAdd(area);
-
-      expect(callback.ballsInside.isEmpty, isTrue);
-
-      callback.begin(ball, area, MockContact());
-      expect(callback.ballsInside.length, equals(1));
-      expect(callback.ballsInside.first, ball);
-
-      callback.end(ball, area, MockContact());
-      expect(callback.ballsInside.length, equals(1));
-      expect(callback.ballsInside.first, ball);
-
-      callback.begin(ball, area, MockContact());
-      expect(callback.ballsInside.isEmpty, isTrue);
-    });
-
     flameTester.test(
         'change ball layer between pathwayLayer and again to Layer.board '
         'when a ball enters and exits from ramp', (game) async {