feat: CharacterSelectionPage opens how to play dialog

lib/theme/view/character_selection_page.dart

@@ -2,8 +2,8 @@
 
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
-import 'package:pinball/game/game.dart';
 import 'package:pinball/l10n/l10n.dart';
+import 'package:pinball/start_game/start_game.dart';
 import 'package:pinball/theme/theme.dart';
 import 'package:pinball_theme/pinball_theme.dart';
 
@@ -46,11 +46,13 @@ class CharacterSelectionView extends StatelessWidget {
             const _CharacterSelectionGridView(),
             const SizedBox(height: 20),
             TextButton(
-              onPressed: () => Navigator.of(context).push<void>(
-                PinballGamePage.route(
-                  theme: context.read<ThemeCubit>().state.theme,
-                ),
-              ),
+              onPressed: () {
+                Navigator.of(context).pop();
+                showDialog<void>(
+                  context: context,
+                  builder: (_) => const HowToPlayDialog(),
+                );
+              },
               child: Text(l10n.start),
             ),
           ],

test/theme/view/character_selection_page_test.dart

@@ -4,6 +4,7 @@ import 'package:bloc_test/bloc_test.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockingjay/mockingjay.dart';
+import 'package:pinball/start_game/start_game.dart';
 import 'package:pinball/theme/theme.dart';
 import 'package:pinball_theme/pinball_theme.dart';
 
@@ -82,20 +83,17 @@ void main() {
       verify(() => themeCubit.characterSelected(SparkyTheme())).called(1);
     });
 
-    testWidgets('navigates to PinballGamePage when start is tapped',
+    testWidgets('is showing how to play dialog when start is tapped',
         (tester) async {
-      final navigator = MockNavigator();
-      when(() => navigator.push<void>(any())).thenAnswer((_) async {});
-
       await tester.pumpApp(
         CharacterSelectionView(),
         themeCubit: themeCubit,
-        navigator: navigator,
       );
       await tester.ensureVisible(find.byType(TextButton));
       await tester.tap(find.byType(TextButton));
+      await tester.pumpAndSettle();
 
-      verify(() => navigator.push<void>(any())).called(1);
+      expect(find.byType(HowToPlayDialog), findsOneWidget);
     });
   });