Update unit, widget, integration tests

ecommerce_app/integration_test/purchase_flow_test.dart

@@ -15,15 +15,17 @@ void main() {
     await r.cart.addToCart();
     await r.cart.openCart();
     r.cart.expectFindNCartItems(1);
-    await r.closePage();
-    // sign in
-    await r.openPopupMenu();
-    await r.auth.openEmailPasswordSignInScreen();
+    // checkout
+    await r.checkout.startCheckout();
     await r.auth.signInWithEmailAndPassword();
-    r.products.expectFindAllProductCards();
-    // check cart again (to verify cart synchronization)
-    await r.cart.openCart();
     r.cart.expectFindNCartItems(1);
+    await r.checkout.startPayment();
+    // when a payment is complete, user is taken to the orders page
+    r.orders.expectFindNOrders(1);
+    await r.closePage(); // close orders page
+    // check that cart is now empty
+    await r.cart.openCart();
+    r.cart.expectFindZeroCartItems();
     await r.closePage();
     // sign out
     await r.openPopupMenu();

ecommerce_app/lib/src/features/checkout/application/fake_checkout_service.dart

@@ -26,26 +26,30 @@ class FakeCheckoutService {
     final uid = authRepository.currentUser!.uid;
     // 1. Get the cart object
     final cart = await remoteCartRepository.fetchCart(uid);
-    final total = _totalPrice(cart);
-    // * If we want to make this code more testable, a DateTime builder
-    // * should be injected as a dependency
-    final orderDate = DateTime.now();
-    // * The orderId is a unique string that could be generated with the UUID
-    // * package. Since this is a fake service, we just derive it from the date.
-    final orderId = orderDate.toIso8601String();
-    // 2. Create an order
-    final order = Order(
-      id: orderId,
-      userId: uid,
-      items: cart.items,
-      orderStatus: OrderStatus.confirmed,
-      orderDate: orderDate,
-      total: total,
-    );
-    // 3. Save it using the repository
-    await ordersRepository.addOrder(uid, order);
-    // 4. Empty the cart
-    await remoteCartRepository.setCart(uid, const Cart());
+    if (cart.items.isNotEmpty) {
+      final total = _totalPrice(cart);
+      // * If we want to make this code more testable, a DateTime builder
+      // * should be injected as a dependency
+      final orderDate = DateTime.now();
+      // * The orderId is a unique string that could be generated with the UUID
+      // * package. Since this is a fake service, we just derive it from the date.
+      final orderId = orderDate.toIso8601String();
+      // 2. Create an order
+      final order = Order(
+        id: orderId,
+        userId: uid,
+        items: cart.items,
+        orderStatus: OrderStatus.confirmed,
+        orderDate: orderDate,
+        total: total,
+      );
+      // 3. Save it using the repository
+      await ordersRepository.addOrder(uid, order);
+      // 4. Empty the cart
+      await remoteCartRepository.setCart(uid, const Cart());
+    } else {
+      throw StateError('Can\'t place an order if the cart is empty');
+    }
   }
 
   // Helper method to calculate the total price

ecommerce_app/test/src/features/authentication/auth_robot.dart

@@ -69,6 +69,13 @@ class AuthRobot {
     await tester.enterText(passwordField, password);
   }
 
+  void expectEmailAndPasswordFieldsFound() {
+    final emailField = find.byKey(EmailPasswordSignInScreen.emailKey);
+    expect(emailField, findsOneWidget);
+    final passwordField = find.byKey(EmailPasswordSignInScreen.passwordKey);
+    expect(passwordField, findsOneWidget);
+  }
+
   void expectCreateAccountButtonFound() {
     final dialogTitle = find.text('Create an account');
     expect(dialogTitle, findsOneWidget);

ecommerce_app/test/src/features/checkout/application/fake_checkout_service_test.dart

@@ -0,0 +1,92 @@
+import 'package:ecommerce_app/src/features/authentication/data/fake_auth_repository.dart';
+import 'package:ecommerce_app/src/features/authentication/domain/app_user.dart';
+import 'package:ecommerce_app/src/features/cart/data/remote/remote_cart_repository.dart';
+import 'package:ecommerce_app/src/features/cart/domain/cart.dart';
+import 'package:ecommerce_app/src/features/checkout/application/fake_checkout_service.dart';
+import 'package:ecommerce_app/src/features/orders/data/fake_orders_repository.dart';
+import 'package:ecommerce_app/src/features/orders/domain/order.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+
+import '../../../mocks.dart';
+
+void main() {
+  const testUser = AppUser(uid: 'abc');
+  setUpAll(() {
+    // needed for MockOrdersRepository
+    registerFallbackValue(Order(
+      id: '1',
+      userId: testUser.uid,
+      items: {'1': 1},
+      orderStatus: OrderStatus.confirmed,
+      orderDate: DateTime(2022, 7, 13),
+      total: 15,
+    ));
+    // needed for MockRemoteCartRepository
+    registerFallbackValue(const Cart());
+  });
+
+  late MockAuthRepository authRepository;
+  late MockRemoteCartRepository remoteCartRepository;
+  late MockOrdersRepository ordersRepository;
+  setUp(() {
+    authRepository = MockAuthRepository();
+    remoteCartRepository = MockRemoteCartRepository();
+    ordersRepository = MockOrdersRepository();
+  });
+
+  FakeCheckoutService makeCheckoutService() {
+    final container = ProviderContainer(
+      overrides: [
+        authRepositoryProvider.overrideWithValue(authRepository),
+        remoteCartRepositoryProvider.overrideWithValue(remoteCartRepository),
+        ordersRepositoryProvider.overrideWithValue(ordersRepository),
+      ],
+    );
+    addTearDown(container.dispose);
+    return container.read(checkoutServiceProvider);
+  }
+
+  group('placeOrder', () {
+    test('null user, throws', () async {
+      // setup
+      when(() => authRepository.currentUser).thenReturn(null);
+      final checkoutService = makeCheckoutService();
+      // run
+      expect(checkoutService.placeOrder, throwsA(isA<TypeError>()));
+    });
+
+    test('empty cart, throws', () async {
+      // setup
+      when(() => authRepository.currentUser).thenReturn(testUser);
+      when(() => remoteCartRepository.fetchCart(testUser.uid)).thenAnswer(
+        (_) => Future.value(const Cart()),
+      );
+      final checkoutService = makeCheckoutService();
+      // run
+      expect(checkoutService.placeOrder, throwsStateError);
+    });
+
+    test('non-empty cart, creates order', () async {
+      // setup
+      when(() => authRepository.currentUser).thenReturn(testUser);
+      when(() => remoteCartRepository.fetchCart(testUser.uid)).thenAnswer(
+        (_) => Future.value(const Cart({'1': 1})),
+      );
+      when(() => ordersRepository.addOrder(testUser.uid, any())).thenAnswer(
+        (_) => Future.value(),
+      );
+      when(() => remoteCartRepository.setCart(testUser.uid, const Cart()))
+          .thenAnswer(
+        (_) => Future.value(),
+      );
+      final checkoutService = makeCheckoutService();
+      // run
+      await checkoutService.placeOrder();
+      // verify
+      verify(() => ordersRepository.addOrder(testUser.uid, any())).called(1);
+      verify(() => remoteCartRepository.setCart(testUser.uid, const Cart()));
+    });
+  });
+}

ecommerce_app/test/src/features/checkout/checkout_robot.dart

@@ -0,0 +1,26 @@
+import 'package:flutter_test/flutter_test.dart';
+
+class CheckoutRobot {
+  CheckoutRobot(this.tester);
+  final WidgetTester tester;
+
+  Future<void> startCheckout() async {
+    final finder = find.text('Checkout');
+    expect(finder, findsOneWidget);
+    await tester.tap(finder);
+    await tester.pumpAndSettle();
+  }
+
+  // payment
+  Future<void> startPayment() async {
+    final finder = find.text('Pay');
+    expect(finder, findsOneWidget);
+    await tester.tap(finder);
+    await tester.pumpAndSettle();
+  }
+
+  void expectPayButtonFound() {
+    final finder = find.text('Pay');
+    expect(finder, findsOneWidget);
+  }
+}

ecommerce_app/test/src/features/checkout/presentation/checkout_screen/checkout_screen_test.dart

@@ -0,0 +1,35 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../../../robot.dart';
+
+void main() {
+  testWidgets('checkout when not previously signed in', (tester) async {
+    final r = Robot(tester);
+    await r.pumpMyApp();
+    // add a product and start checkout
+    await r.products.selectProduct();
+    await r.cart.addToCart();
+    await r.cart.openCart();
+    await r.checkout.startCheckout();
+    // sign in from checkout screen
+    r.auth.expectEmailAndPasswordFieldsFound();
+    await r.auth.signInWithEmailAndPassword();
+    // check that we move to the payment page
+    r.checkout.expectPayButtonFound();
+  });
+
+  testWidgets('checkout when previously signed in', (tester) async {
+    final r = Robot(tester);
+    await r.pumpMyApp();
+    // sign in first
+    await r.auth.openEmailPasswordSignInScreen();
+    await r.auth.signInWithEmailAndPassword();
+    // then add a product and start checkout
+    await r.products.selectProduct();
+    await r.cart.addToCart();
+    await r.cart.openCart();
+    await r.checkout.startCheckout();
+    // expect that we see the payment page right away
+    r.checkout.expectPayButtonFound();
+  });
+}

ecommerce_app/test/src/features/checkout/presentation/payment/payment_button_controller_test.dart

@@ -0,0 +1,53 @@
+import 'package:ecommerce_app/src/features/checkout/presentation/payment/payment_button_controller.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+
+import '../../../../mocks.dart';
+
+void main() {
+  group('pay', () {
+    test('success', () async {
+      // setup
+      final checkoutService = MockCheckoutService();
+      when(() => checkoutService.placeOrder()).thenAnswer(
+        (_) => Future.value(null),
+      );
+      final controller =
+          PaymentButtonController(checkoutService: checkoutService);
+      // run & verify
+      expectLater(
+        controller.stream,
+        emitsInOrder([
+          const AsyncLoading<void>(),
+          const AsyncData<void>(null),
+        ]),
+      );
+      await controller.pay();
+    });
+
+    test('failure', () async {
+      // setup
+      final checkoutService = MockCheckoutService();
+      when(() => checkoutService.placeOrder()).thenThrow(
+        Exception('Card declined'),
+      );
+      final controller =
+          PaymentButtonController(checkoutService: checkoutService);
+      // run & verify
+      expectLater(
+        controller.stream,
+        emitsInOrder([
+          const AsyncLoading<void>(),
+          predicate<AsyncValue<void>>(
+            (value) {
+              expect(value.hasError, true);
+              return true;
+            },
+          ),
+        ]),
+      );
+      await controller.pay();
+    });
+  });
+}

ecommerce_app/test/src/features/orders/orders_robot.dart

@@ -0,0 +1,17 @@
+import 'package:ecommerce_app/src/features/orders/presentation/orders_list/order_card.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+class OrdersRobot {
+  OrdersRobot(this.tester);
+  final WidgetTester tester;
+
+  void expectFindZeroOrders() {
+    final finder = find.byType(OrderCard);
+    expect(finder, findsNothing);
+  }
+
+  void expectFindNOrders(int count) {
+    final finder = find.byType(OrderCard);
+    expect(finder, findsNWidgets(count));
+  }
+}

ecommerce_app/test/src/features/purchase_flow_test.dart

@@ -13,15 +13,17 @@ void main() {
     await r.cart.addToCart();
     await r.cart.openCart();
     r.cart.expectFindNCartItems(1);
-    await r.closePage();
-    // sign in
-    await r.openPopupMenu();
-    await r.auth.openEmailPasswordSignInScreen();
+    // checkout
+    await r.checkout.startCheckout();
     await r.auth.signInWithEmailAndPassword();
-    r.products.expectFindAllProductCards();
-    // check cart again (to verify cart synchronization)
-    await r.cart.openCart();
     r.cart.expectFindNCartItems(1);
+    await r.checkout.startPayment();
+    // when a payment is complete, user is taken to the orders page
+    r.orders.expectFindNOrders(1);
+    await r.closePage(); // close orders page
+    // check that cart is now empty
+    await r.cart.openCart();
+    r.cart.expectFindZeroCartItems();
     await r.closePage();
     // sign out
     await r.openPopupMenu();

ecommerce_app/test/src/mocks.dart

@@ -2,6 +2,8 @@ import 'package:ecommerce_app/src/features/authentication/data/fake_auth_reposit
 import 'package:ecommerce_app/src/features/cart/application/cart_service.dart';
 import 'package:ecommerce_app/src/features/cart/data/local/local_cart_repository.dart';
 import 'package:ecommerce_app/src/features/cart/data/remote/remote_cart_repository.dart';
+import 'package:ecommerce_app/src/features/checkout/application/fake_checkout_service.dart';
+import 'package:ecommerce_app/src/features/orders/data/fake_orders_repository.dart';
 import 'package:ecommerce_app/src/features/products/data/fake_products_repository.dart';
 import 'package:mocktail/mocktail.dart';
 
@@ -14,3 +16,7 @@ class MockLocalCartRepository extends Mock implements LocalCartRepository {}
 class MockCartService extends Mock implements CartService {}
 
 class MockProductsRepository extends Mock implements FakeProductsRepository {}
+
+class MockOrdersRepository extends Mock implements FakeOrdersRepository {}
+
+class MockCheckoutService extends Mock implements FakeCheckoutService {}

ecommerce_app/test/src/robot.dart

@@ -12,6 +12,8 @@ import 'package:flutter_test/flutter_test.dart';
 
 import 'features/authentication/auth_robot.dart';
 import 'features/cart/cart_robot.dart';
+import 'features/checkout/checkout_robot.dart';
+import 'features/orders/orders_robot.dart';
 import 'features/products/products_robot.dart';
 import 'goldens/golden_robot.dart';
 
@@ -20,11 +22,15 @@ class Robot {
       : auth = AuthRobot(tester),
         products = ProductsRobot(tester),
         cart = CartRobot(tester),
+        checkout = CheckoutRobot(tester),
+        orders = OrdersRobot(tester),
         golden = GoldenRobot(tester);
   final WidgetTester tester;
   final AuthRobot auth;
   final ProductsRobot products;
   final CartRobot cart;
+  final CheckoutRobot checkout;
+  final OrdersRobot orders;
   final GoldenRobot golden;
 
   Future<void> pumpMyApp() async {