feat: pr suggestions

lib/game/components/wall.dart

@@ -3,32 +3,16 @@
 import 'package:flame_forge2d/flame_forge2d.dart';
 import 'package:pinball/game/components/components.dart';
 
-class BallWallContactCallback extends ContactCallback<Ball, Wall> {
-  @override
-  void begin(Ball ball, Wall wall, Contact contact) {
-    if (wall.type == WallType.bottom) {
-      ball
-        ..ballLost()
-        ..shouldRemove = true;
-    }
-  }
-
-  @override
-  void end(_, __, ___) {}
-}
-
 enum WallType {
-  top,
-  bottom,
-  left,
-  right,
+  fatal,
+  passive,
 }
 
 class Wall extends BodyComponent {
   Wall({
-    required this.type,
     required this.start,
     required this.end,
+    this.type = WallType.passive,
   });
 
   factory Wall.bottom(Forge2DGame game) {
@@ -36,7 +20,7 @@ class Wall extends BodyComponent {
     final bottomLeft = Vector2(0, bottomRight.y);
 
     return Wall(
-      type: WallType.bottom,
+      type: WallType.fatal,
       start: bottomRight,
       end: bottomLeft,
     );
@@ -62,3 +46,17 @@ class Wall extends BodyComponent {
     return world.createBody(bodyDef)..createFixture(fixtureDef);
   }
 }
+
+class BallWallContactCallback extends ContactCallback<Ball, Wall> {
+  @override
+  void begin(Ball ball, Wall wall, Contact contact) {
+    if (wall.type == WallType.fatal) {
+      ball
+        ..ballLost()
+        ..shouldRemove = true;
+    }
+  }
+
+  @override
+  void end(_, __, ___) {}
+}

test/game/components/wall_test.dart

@@ -14,13 +14,13 @@ void main() {
   group('Wall', () {
     group('BallWallContactCallback', () {
       test(
-        'removes the ball on begin contact when the wall is a bottom one',
+        'removes the ball on begin contact when the wall is a fatal one',
         () {
           final game = MockPinballGame();
           final wall = MockWall();
           final ball = MockBall();
 
-          when(() => wall.type).thenReturn(WallType.bottom);
+          when(() => wall.type).thenReturn(WallType.fatal);
           when(() => ball.gameRef).thenReturn(game);
 
           BallWallContactCallback()
@@ -39,7 +39,6 @@ void main() {
       'loads correctly',
       (game) async {
         final wall = Wall(
-          type: WallType.bottom,
           start: Vector2.zero(),
           end: Vector2(100, 0),
         );
@@ -54,7 +53,6 @@ void main() {
         'positions correctly',
         (game) async {
           final wall = Wall(
-            type: WallType.top,
             start: Vector2.zero(),
             end: Vector2(100, 0),
           );
@@ -69,7 +67,6 @@ void main() {
         'is static',
         (game) async {
           final wall = Wall(
-            type: WallType.top,
             start: Vector2.zero(),
             end: Vector2(100, 0),
           );
@@ -85,7 +82,6 @@ void main() {
         'exists',
         (game) async {
           final wall = Wall(
-            type: WallType.top,
             start: Vector2.zero(),
             end: Vector2(100, 0),
           );
@@ -99,7 +95,6 @@ void main() {
         'has restitution equals 0',
         (game) async {
           final wall = Wall(
-            type: WallType.top,
             start: Vector2.zero(),
             end: Vector2(100, 0),
           );
@@ -114,7 +109,6 @@ void main() {
         'has friction',
         (game) async {
           final wall = Wall(
-            type: WallType.top,
             start: Vector2.zero(),
             end: Vector2(100, 0),
           );