feat: included board tests

test/game/components/board_test.dart

@@ -0,0 +1,69 @@
+// ignore_for_file: cascade_invocations
+
+import 'package:flame_forge2d/flame_forge2d.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pinball/game/game.dart';
+
+import '../../helpers/helpers.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  final flameTester = FlameTester(Forge2DGame.new);
+
+  group('BottomGroup', () {
+    flameTester.test(
+      'loads correctly',
+      (game) async {
+        final bottomGroup = BottomGroup(position: Vector2.zero(), spacing: 0);
+        await game.ready();
+        await game.add(bottomGroup);
+
+        expect(game.contains(bottomGroup), isTrue);
+      },
+    );
+
+    group('children', () {
+      // TODO(alestiago): Make tests pass.
+      flameTester.test(
+        'has one left flipper',
+        (game) async {
+          final bottomGroup = BottomGroup(position: Vector2.zero(), spacing: 0);
+          await game.ready();
+          await game.add(bottomGroup);
+
+          final leftFlippers = bottomGroup.findNestedChildren<Flipper>(
+            condition: (flipper) => flipper.side.isLeft,
+          );
+          expect(leftFlippers.length, equals(1));
+        },
+      );
+
+      flameTester.test(
+        'has one right flipper',
+        (game) async {
+          final bottomGroup = BottomGroup(position: Vector2.zero(), spacing: 0);
+          await game.ready();
+          await game.add(bottomGroup);
+
+          final leftFlippers = bottomGroup.findNestedChildren<Flipper>(
+            condition: (flipper) => flipper.side.isRight,
+          );
+          expect(leftFlippers.length, equals(1));
+        },
+      );
+
+      flameTester.test(
+        'has two Baseboards',
+        (game) async {
+          final bottomGroup = BottomGroup(position: Vector2.zero(), spacing: 0);
+          await game.ready();
+          await game.add(bottomGroup);
+
+          final leftFlippers = bottomGroup.findNestedChildren<Baseboard>();
+          expect(leftFlippers.length, equals(2));
+        },
+      );
+    });
+  });
+}

test/helpers/extensions.dart

@@ -1,3 +1,4 @@
+import 'package:flame/components.dart';
 import 'package:pinball/game/game.dart';
 import 'package:pinball_theme/pinball_theme.dart';
 
@@ -20,3 +21,41 @@ extension DebugPinballGameTest on DebugPinballGame {
         ),
       );
 }
+
+extension ComponentX on Component {
+  T findNestedChild<T extends Component>({
+    bool Function(T)? condition,
+  }) {
+    T? nestedChild;
+    propagateToChildren<T>((child) {
+      final foundChild = (condition ?? (_) => true)(child);
+      if (foundChild) {
+        nestedChild = child;
+      }
+
+      return !foundChild;
+    });
+
+    if (nestedChild == null) {
+      throw Exception('No child of type $T found.');
+    } else {
+      return nestedChild!;
+    }
+  }
+
+  List<T> findNestedChildren<T extends Component>({
+    bool Function(T)? condition,
+  }) {
+    final nestedChildren = <T>[];
+    propagateToChildren<T>((child) {
+      final foundChild = (condition ?? (_) => true)(child);
+      if (foundChild) {
+        nestedChildren.add(child);
+      }
+
+      return true;
+    });
+
+    return nestedChildren;
+  }
+}