feat: made InitialPosition position the body

lib/game/components/ball.dart

@@ -40,7 +40,6 @@ class Ball extends BodyComponent<PinballGame> with InitialPosition {
 
     final bodyDef = BodyDef()
       ..userData = this
-      ..position = initialPosition
       ..type = BodyType.dynamic;
 
     return world.createBody(bodyDef)..createFixture(fixtureDef);

lib/game/components/baseboard.dart

@@ -58,7 +58,6 @@ class Baseboard extends BodyComponent with InitialPosition {
     const angle = math.pi / 7;
 
     final bodyDef = BodyDef()
-      ..position = initialPosition
       ..type = BodyType.static
       ..angle = _side.isLeft ? -angle : angle;
 

lib/game/components/bonus_word.dart

@@ -130,7 +130,6 @@ class BonusLetter extends BodyComponent<PinballGame>
 
     final bodyDef = BodyDef()
       ..userData = this
-      ..position = initialPosition
       ..type = BodyType.static;
 
     return world.createBody(bodyDef)..createFixture(fixtureDef);

lib/game/components/flipper.dart

@@ -190,9 +190,7 @@ class Flipper extends BodyComponent with KeyboardHandler, InitialPosition {
   Body createBody() {
     final bodyDef = BodyDef()
       ..gravityScale = 0
-      ..type = BodyType.dynamic
-      ..position = initialPosition;
-
+      ..type = BodyType.dynamic;
     final body = world.createBody(bodyDef);
     _createFixtureDefs().forEach(body.createFixture);
 

lib/game/components/initial_position.dart

@@ -9,9 +9,6 @@ mixin InitialPosition<T extends Forge2DGame> on BodyComponent<T> {
   @override
   Future<void> onLoad() async {
     await super.onLoad();
-    assert(
-      body.position == initialPosition,
-      'Body position is not equal to initial position.',
-    );
+    body.position.setFrom(initialPosition);
   }
 }

lib/game/components/joint_anchor.dart

@@ -22,8 +22,6 @@ class JointAnchor extends BodyComponent with InitialPosition {
 
   @override
   Body createBody() {
-    final bodyDef = BodyDef()..position = initialPosition;
-
-    return world.createBody(bodyDef);
+    return world.createBody(BodyDef());
   }
 }

lib/game/components/pathway.dart

@@ -148,10 +148,7 @@ class Pathway extends BodyComponent with InitialPosition {
 
   @override
   Body createBody() {
-    final bodyDef = BodyDef()
-      ..type = BodyType.static
-      ..position = initialPosition;
-
+    final bodyDef = BodyDef()..type = BodyType.static;
     final body = world.createBody(bodyDef);
     for (final path in _paths) {
       final chain = ChainShape()

lib/game/components/plunger.dart

@@ -26,7 +26,6 @@ class Plunger extends BodyComponent with KeyboardHandler, InitialPosition {
 
     final bodyDef = BodyDef()
       ..userData = this
-      ..position = initialPosition
       ..type = BodyType.dynamic
       ..gravityScale = 0;
 

lib/game/components/round_bumper.dart

@@ -27,9 +27,7 @@ class RoundBumper extends BodyComponent with ScorePoints, InitialPosition {
 
     final fixtureDef = FixtureDef(shape)..restitution = 1;
 
-    final bodyDef = BodyDef()
-      ..position = initialPosition
-      ..type = BodyType.static;
+    final bodyDef = BodyDef()..type = BodyType.static;
 
     return world.createBody(bodyDef)..createFixture(fixtureDef);
   }

lib/game/components/sling_shot.dart

@@ -83,8 +83,7 @@ class SlingShot extends BodyComponent with InitialPosition {
 
   @override
   Body createBody() {
-    final bodyDef = BodyDef()..position = initialPosition;
-    final body = world.createBody(bodyDef);
+    final body = world.createBody(BodyDef());
     _createFixtureDefs().forEach(body.createFixture);
 
     return body;

test/game/components/initial_position_test.dart

@@ -12,13 +12,6 @@ class TestBodyComponent extends BodyComponent with InitialPosition {
   }
 }
 
-class TestPositionedBodyComponent extends BodyComponent with InitialPosition {
-  @override
-  Body createBody() {
-    return world.createBody(BodyDef()..position = initialPosition);
-  }
-}
-
 void main() {
   final flameTester = FlameTester(Forge2DGame.new);
   group('InitialPosition', () {
@@ -35,32 +28,11 @@ void main() {
       );
     });
 
-    flameTester.test(
-      'returns normally '
-      'when the body sets the position to initial position',
-      (game) async {
-        final component = TestPositionedBodyComponent()
-          ..initialPosition = Vector2.zero();
-
-        await expectLater(
-          () async => game.ensureAdd(component),
-          returnsNormally,
-        );
-      },
-    );
-
-    flameTester.test(
-      'throws AssertionError '
-      'when not setting initialPosition to body',
-      (game) async {
-        final component = TestBodyComponent()..initialPosition = Vector2.zero();
-        await game.ensureAdd(component);
-
-        await expectLater(
-          () async => game.ensureAdd(component),
-          throwsAssertionError,
-        );
-      },
-    );
+    flameTester.test('positions correctly', (game) async {
+      final position = Vector2.all(10);
+      final component = TestBodyComponent()..initialPosition = position;
+      await game.ensureAdd(component);
+      expect(component.body.position, equals(position));
+    });
   });
 }