3.1 Architektur Decrement

lib/src/features/counter/presentation/counter.controller.dart

@@ -13,4 +13,11 @@ class CounterController {
     counterModel.value += 1;
     counterRepository.updateCounter(counterModel: counterModel);
   }
+
+  Future<void> decrement() async {
+    if (counterModel.value > 0) {
+      counterModel.value -= 1;
+      counterRepository.updateCounter(counterModel: counterModel);
+    }
+  }
 }

lib/src/features/counter/presentation/counter.page.dart

@@ -24,6 +24,12 @@ class _CounterPageState extends State<CounterPage> {
     });
   }
 
+  void _decrementCounter() {
+    setState(() {
+      counterController.decrement();
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -44,10 +50,21 @@ class _CounterPageState extends State<CounterPage> {
           ],
         ),
       ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
+      floatingActionButton: Column(
+        mainAxisAlignment: MainAxisAlignment.end,
+        children: [
+          FloatingActionButton(
+            onPressed: _incrementCounter,
+            tooltip: 'Increment',
+            child: const Icon(Icons.add),
+          ),
+          const SizedBox(height: 10),
+          FloatingActionButton(
+            onPressed: _decrementCounter,
+            tooltip: 'Decrement',
+            child: const Icon(Icons.remove),
+          ),
+        ],
       ),
     );
   }

test/widget_test.dart

@@ -12,24 +12,69 @@ import 'package:counter_workshop/src/features/counter/data/repositories/counter.
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+const _desktopSize = Size(1024, 768);
+
 void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
-    // Build our app and trigger a frame.
-    await tester.pumpWidget(
-      App(counterRepository: CounterRepository(counterApi: CounterFakeApi(), counterDatabase: CounterDatabase())),
-      const Duration(milliseconds: 300), // Because of FakeApi delay
-    );
-
-    // Verify that our counter starts at 0.
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-
-    // Tap the '+' icon and trigger a frame.
-    await tester.tap(find.byIcon(Icons.add));
-    await tester.pumpAndSettle(const Duration(milliseconds: 300)); // Because of FakeApi delay
-
-    // Verify that our counter has incremented.
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
+  group('Counter Buttons Tests', () {
+    // Test Inceptors
+    setUpAll(() async {
+      final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+      binding.window.physicalSizeTestValue = _desktopSize;
+    });
+    setUp(() async {});
+    tearDownAll(() async {});
+    tearDown(() async {});
+
+    testWidgets('Counter increments smoke test', (WidgetTester tester) async {
+      // Build our app and trigger a frame.
+      await tester.pumpWidget(
+        App(counterRepository: CounterRepository(counterApi: CounterFakeApi(), counterDatabase: CounterDatabase())),
+        const Duration(milliseconds: 300), // Because of FakeApi delay
+      );
+
+      // Verify that our counter starts at 0.
+      expect(find.text('0'), findsOneWidget);
+      expect(find.text('1'), findsNothing);
+
+      // Tap the '+' icon and trigger a frame.
+      await tester.tap(find.byIcon(Icons.add));
+      await tester.pumpAndSettle(const Duration(milliseconds: 300)); // Because of FakeApi delay
+
+      // Verify that our counter has incremented.
+      expect(find.text('0'), findsNothing);
+      expect(find.text('1'), findsOneWidget);
+    });
+    testWidgets('Counter decrements smoke test', (WidgetTester tester) async {
+      // Build our app and trigger a frame.
+      await tester.pumpWidget(
+        App(counterRepository: CounterRepository(counterApi: CounterFakeApi(), counterDatabase: CounterDatabase())),
+        const Duration(milliseconds: 300), // Because of FakeApi delay
+      );
+
+      // Verify that our counter starts at 0.
+      expect(find.text('0'), findsOneWidget);
+      expect(find.text('1'), findsNothing);
+
+      // Tap the '-' icon and trigger a frame.
+      await tester.tap(find.byTooltip('Decrement'));
+      await tester.pumpAndSettle();
+      await tester.pumpAndSettle(const Duration(milliseconds: 300)); // Because of FakeApi delay
+
+      // Verify that our counter does not decremented.
+      expect(find.text('-1'), findsNothing);
+      expect(find.text('0'), findsOneWidget);
+
+      await tester.tap(find.byIcon(Icons.add));
+      await tester.pumpAndSettle(const Duration(milliseconds: 300)); // Because of FakeApi delay
+      // Verify that our counter has incremented.
+      expect(find.text('0'), findsNothing);
+      expect(find.text('1'), findsOneWidget);
+
+      await tester.tap(find.byIcon(Icons.remove));
+      await tester.pumpAndSettle(const Duration(milliseconds: 300)); // Because of FakeApi delay
+      // Verify that our counter has decremented.
+      expect(find.text('1'), findsNothing);
+      expect(find.text('0'), findsOneWidget);
+    });
   });
 }