test: Add widget tests for OnboardingScreen.

Author: BURG3R5

test/presentation/login/login_test.dart

@@ -5,7 +5,7 @@ import 'package:codephile/presentation/login/bloc/login_bloc.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void blocTests() {
-  group('LoginBloc - ', () {
+  group('LoginBloc -', () {
     setUpAll(ApiService.init);
 
     test('emits correct initial state', () {
@@ -25,7 +25,7 @@ void blocTests() {
       );
     });
 
-    group('toggles - ', () {
+    group('toggles -', () {
       blocTest<LoginBloc, LoginState>(
         'obscure password',
         build: () => LoginBloc(),
@@ -51,7 +51,7 @@ void blocTests() {
       );
     });
 
-    group('text fields - ', () {
+    group('text fields -', () {
       blocTest<LoginBloc, LoginState>(
         'tracks focus correctly',
         build: () => LoginBloc(),
@@ -111,7 +111,7 @@ void blocTests() {
       expect(bloc.state.isLoginButtonActive(), false);
     });
 
-    group('forgot password dialog - ', () {
+    group('forgot password dialog -', () {
       blocTest<LoginBloc, LoginState>(
         'opens dialog',
         build: () => LoginBloc(),
@@ -144,7 +144,7 @@ void blocTests() {
       );
     });
 
-    group('submit - ', () {
+    group('submit -', () {
       blocTest<LoginBloc, LoginState>(
         'does nothing if fields are empty',
         build: () => LoginBloc(),

test/presentation/onboarding/onboarding_test.dart

@@ -0,0 +1,71 @@
+import 'package:card_swiper/card_swiper.dart';
+import 'package:codephile/presentation/onboarding/onboarding_screen.dart';
+import 'package:codephile/presentation/onboarding/widgets/onboarding_widgets.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../utils/pump_screen.dart';
+
+void widgetTests() {
+  group('OnboardingScreen -', () {
+    testWidgets('contains sub-widgets', (tester) async {
+      await pumpScreen(tester, () => OnboardingScreen());
+
+      expect(find.byType(BackgroundDecoration), findsOneWidget);
+      expect(find.byType(NextButton), findsOneWidget);
+      expect(find.byType(Swiper), findsOneWidget);
+      expect(find.byType(OnboardingPage), findsOneWidget);
+
+      /// The [PaginationDots] widget does not show up as anything special in
+      /// the widget tree because of the idiosyncrasies of the package author.
+      /// Hence this roundabout way of testing whether the widget is present.
+      expect(
+        find.byWidgetPredicate(
+          (widget) => widget is Align && widget.child is Row,
+        ),
+        findsOneWidget,
+      );
+    });
+
+    testWidgets("contains first feature's data", (tester) async {
+      await pumpScreen(tester, () => OnboardingScreen());
+
+      expect(find.text(pages[0].title), findsOneWidget);
+      expect(find.text(pages[0].description), findsOneWidget);
+      expect(
+        find.byWidgetPredicate(
+          (widget) =>
+              widget is Image &&
+              widget.image is AssetImage &&
+              (widget.image as AssetImage).assetName == pages[0].asset,
+        ),
+        findsOneWidget,
+      );
+    });
+
+    testWidgets('pressing NextButton takes user to next page', (tester) async {
+      await pumpScreen(tester, () => OnboardingScreen());
+
+      for (var i = 0; i < pages.length; i++) {
+        // Finds i^th feature's data
+        expect(find.text(pages[i].title), findsOneWidget);
+        expect(find.text(pages[i].description), findsOneWidget);
+        expect(
+          find.byWidgetPredicate(
+            (widget) =>
+                widget is Image &&
+                widget.image is AssetImage &&
+                (widget.image as AssetImage).assetName == pages[i].asset,
+          ),
+          findsOneWidget,
+        );
+
+        await tester.tap(find.byType(NextButton));
+        await tester.pumpAndSettle();
+      }
+
+      // TODO(BURG3R5): Uncomment the next line when a HomeScreen widget has been created.
+      // expect(find.byType(HomeScreen), findsOneWidget);
+    });
+  });
+}

test/presentation/widget_test.dart

@@ -1 +1,5 @@
-void main() {}
+import 'onboarding/onboarding_test.dart' as onboarding;
+
+void main() {
+  onboarding.widgetTests();
+}

test/utils/pump_screen.dart

@@ -0,0 +1,27 @@
+import 'package:codephile/presentation/core/router.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_screenutil/flutter_screenutil.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:get/get.dart';
+
+/// Pumps a screen, wrapping it with the necessary configuration widgets.
+Future<void> pumpScreen(WidgetTester tester, Widget Function() screen) async {
+  await tester.pumpWidget(
+    ScreenUtilInit(
+      designSize: const Size(360, 640),
+      builder: () {
+        return GetMaterialApp(
+          builder: (context, widget) {
+            ScreenUtil.setContext(context);
+            return MediaQuery(
+              data: MediaQuery.of(context).copyWith(textScaleFactor: 1),
+              child: widget!,
+            );
+          },
+          onGenerateRoute: AppRouter.generateRoute,
+          home: screen(),
+        );
+      },
+    ),
+  );
+}