test: Add tests for WorldRoute

Author: spydon

packages/flame/test/components/world_route_test.dart

@@ -0,0 +1,112 @@
+import 'package:flame/components.dart';
+import 'package:flame/game.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+class _TestWorld1 extends World {
+  int value = 0;
+}
+
+class _TestWorld2 extends World {}
+
+void main() {
+  group('WorldRoute', () {
+    testWidgets('can set a new world', (tester) async {
+      final router = RouterComponent(
+        initialRoute: '/',
+        routes: {
+          '/': Route(Component.new),
+          '/world': WorldRoute(_TestWorld1.new),
+        },
+      );
+      final game = FlameGame(children: [router]);
+      await tester.pumpWidget(GameWidget(game: game));
+      await tester.pump();
+      await tester.pump();
+      expect(router.currentRoute.name, '/');
+      expect(game.world, isNot(isA<_TestWorld1>));
+
+      router.pushNamed('/world');
+      await tester.pump();
+      expect(router.currentRoute.name, '/world');
+      expect(game.world, isA<_TestWorld1>());
+    });
+
+    testWidgets('changes back to previous world on pop', (tester) async {
+      final router = RouterComponent(
+        initialRoute: '/world1',
+        routes: {
+          '/world1': WorldRoute(_TestWorld1.new),
+          '/world2': WorldRoute(_TestWorld2.new),
+        },
+      );
+      final game = FlameGame(children: [router]);
+      await tester.pumpWidget(GameWidget(game: game));
+      await tester.pump();
+      await tester.pump();
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+
+      router.pushNamed('/world2');
+      expect(router.currentRoute.name, '/world2');
+      expect(game.world, isA<_TestWorld2>());
+
+      router.pop();
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+    });
+
+    testWidgets('retains the state of the world', (tester) async {
+      final router = RouterComponent(
+        initialRoute: '/world1',
+        routes: {
+          '/world1': WorldRoute(_TestWorld1.new),
+          '/world2': WorldRoute(_TestWorld2.new),
+        },
+      );
+      final game = FlameGame(children: [router]);
+      await tester.pumpWidget(GameWidget(game: game));
+      await tester.pump();
+      await tester.pump();
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+      expect((game.world as _TestWorld1).value, isZero);
+      (game.world as _TestWorld1).value = 1;
+
+      router.pushReplacementNamed('/world2');
+      expect(router.currentRoute.name, '/world2');
+      expect(game.world, isA<_TestWorld2>());
+
+      router.pushReplacementNamed('/world1');
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+      expect((game.world as _TestWorld1).value, 1);
+    });
+
+    testWidgets('does not retain the state of world', (tester) async {
+      final router = RouterComponent(
+        initialRoute: '/world1',
+        routes: {
+          '/world1': WorldRoute(_TestWorld1.new, maintainState: false),
+          '/world2': WorldRoute(_TestWorld2.new),
+        },
+      );
+      final game = FlameGame(children: [router]);
+      await tester.pumpWidget(GameWidget(game: game));
+      await tester.pump();
+      await tester.pump();
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+      expect((game.world as _TestWorld1).value, isZero);
+      (game.world as _TestWorld1).value = 1;
+
+      router.pushReplacementNamed('/world2');
+      expect(router.currentRoute.name, '/world2');
+      expect(game.world, isA<_TestWorld2>());
+
+      router.pushReplacementNamed('/world1');
+      expect(router.currentRoute.name, '/world1');
+      expect(game.world, isA<_TestWorld1>());
+      expect((game.world as _TestWorld1).value, isZero);
+    });
+  });
+}