Testing sample (#500)

testing_app/test/home_test.dart

@@ -0,0 +1,69 @@
+// Copyright 2020 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
+import 'package:testing_app/models/favorites.dart';
+import 'package:testing_app/screens/home.dart';
+
+Widget createHomeScreen() => ChangeNotifierProvider<Favorites>(
+      create: (context) => Favorites(),
+      child: MaterialApp(
+        home: HomePage(),
+      ),
+    );
+
+void main() {
+  group('Home Page Widget Tests', () {
+    testWidgets('Testing if ListView shows up', (tester) async {
+      await tester.pumpWidget(createHomeScreen());
+
+      // Verify if ListView shows up.
+      expect(find.byType(ListView), findsOneWidget);
+    });
+
+    testWidgets('Testing Scrolling', (tester) async {
+      await tester.pumpWidget(createHomeScreen());
+
+      // Check if "Item 0" is present on the screen.
+      expect(find.text('Item 0'), findsOneWidget);
+
+      // Fling i.e scroll down.
+      await tester.fling(find.byType(ListView), Offset(0, -200), 3000);
+      await tester.pumpAndSettle();
+
+      // Check if "Item 0" disappeared.
+      expect(find.text('Item 0'), findsNothing);
+    });
+
+    testWidgets('Testing IconButtons', (tester) async {
+      await tester.pumpWidget(createHomeScreen());
+
+      // Check if any solid favorite icon is present.
+      expect(find.byIcon(Icons.favorite), findsNothing);
+
+      // Tap the first item's icon to add it to favorites.
+      await tester.tap(find.byIcon(Icons.favorite_border).first);
+      await tester.pumpAndSettle(Duration(seconds: 1));
+
+      // Verify if the appropriate message is shown.
+      expect(find.text('Added to favorites.'), findsOneWidget);
+
+      // Check if any solid favorite icon shows up.
+      expect(find.byIcon(Icons.favorite), findsWidgets);
+
+      // Tap the first item's icon which has filled icon to
+      // remove it from favorites.
+      await tester.tap(find.byIcon(Icons.favorite).first);
+      await tester.pumpAndSettle(Duration(seconds: 1));
+
+      // Verify if the appropriate message is shown.
+      expect(find.text('Removed from favorites.'), findsOneWidget);
+
+      // Check if the filled icon changes back to bordered icon.
+      expect(find.byIcon(Icons.favorite), findsNothing);
+    });
+  });
+}