Starter project for section 8 (#14)

* Update MutableCart extension, add corresponding tests * Use dateFormatterProvider and currencyFormatterProvider rather than global formatters * Set addDelay to false for faster loading * Add FakeLocalCartRepository and FakeRemoteCartRepository * Cleanup LocalCartRepository, RemoteCartRepository * Update MutableCart extension and tests * Updated to latest package versions * Improved documentation # Conflicts: # ecommerce_app/pubspec.lock # ecommerce_app/pubspec.yaml
bizz84 · Nov 16, 2023 · e59f92d · e59f92d
1 parent 8e0cdff
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diff --git a/ecommerce_app/lib/src/features/cart/data/local/fake_local_cart_repository.dart b/ecommerce_app/lib/src/features/cart/data/local/fake_local_cart_repository.dart
@@ -0,0 +1,23 @@
+import 'package:ecommerce_app/src/features/cart/data/local/local_cart_repository.dart';
+import 'package:ecommerce_app/src/features/cart/domain/cart.dart';
+import 'package:ecommerce_app/src/utils/delay.dart';
+import 'package:ecommerce_app/src/utils/in_memory_store.dart';
+
+class FakeLocalCartRepository implements LocalCartRepository {
+  FakeLocalCartRepository({this.addDelay = true});
+  final bool addDelay;
+
+  final _cart = InMemoryStore<Cart>(const Cart());
+
+  @override
+  Future<Cart> fetchCart() => Future.value(_cart.value);
+
+  @override
+  Stream<Cart> watchCart() => _cart.stream;
+
+  @override
+  Future<void> setCart(Cart cart) async {
+    await delay(addDelay);
+    _cart.value = cart;
+  }
+}
diff --git a/ecommerce_app/lib/src/features/cart/data/local/local_cart_repository.dart b/ecommerce_app/lib/src/features/cart/data/local/local_cart_repository.dart
@@ -0,0 +1,16 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:ecommerce_app/src/features/cart/domain/cart.dart';
+
+/// API for reading, watching and writing local cart data (guest user)
+abstract class LocalCartRepository {
+  Future<Cart> fetchCart();
+
+  Stream<Cart> watchCart();
+
+  Future<void> setCart(Cart cart);
+}
+
+final localCartRepositoryProvider = Provider<LocalCartRepository>((ref) {
+  // * Override this in the main method
+  throw UnimplementedError();
+});
diff --git a/ecommerce_app/lib/src/features/cart/data/remote/fake_remote_cart_repository.dart b/ecommerce_app/lib/src/features/cart/data/remote/fake_remote_cart_repository.dart
@@ -0,0 +1,35 @@
+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/utils/delay.dart';
+import 'package:ecommerce_app/src/utils/in_memory_store.dart';
+
+class FakeRemoteCartRepository implements RemoteCartRepository {
+  FakeRemoteCartRepository({this.addDelay = true});
+  final bool addDelay;
+
+  /// An InMemoryStore containing the shopping cart data for all users, where:
+  /// key: uid of the user
+  /// value: Cart of that user
+  final _carts = InMemoryStore<Map<String, Cart>>({});
+
+  @override
+  Future<Cart> fetchCart(String uid) {
+    return Future.value(_carts.value[uid] ?? const Cart());
+  }
+
+  @override
+  Stream<Cart> watchCart(String uid) {
+    return _carts.stream.map((cartData) => cartData[uid] ?? const Cart());
+  }
+
+  @override
+  Future<void> setCart(String uid, Cart cart) async {
+    await delay(addDelay);
+    // First, get the current carts data for all users
+    final carts = _carts.value;
+    // Then, set the cart for the given uid
+    carts[uid] = cart;
+    // Finally, update the carts data (will emit a new value)
+    _carts.value = carts;
+  }
+}
diff --git a/ecommerce_app/lib/src/features/cart/data/remote/remote_cart_repository.dart b/ecommerce_app/lib/src/features/cart/data/remote/remote_cart_repository.dart
@@ -0,0 +1,17 @@
+import 'package:ecommerce_app/src/features/cart/data/remote/fake_remote_cart_repository.dart';
+import 'package:ecommerce_app/src/features/cart/domain/cart.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+/// API for reading, watching and writing cart data for a specific user ID
+abstract class RemoteCartRepository {
+  Future<Cart> fetchCart(String uid);
+
+  Stream<Cart> watchCart(String uid);
+
+  Future<void> setCart(String uid, Cart cart);
+}
+
+final remoteCartRepositoryProvider = Provider<RemoteCartRepository>((ref) {
+  // TODO: replace with "real" remote cart repository
+  return FakeRemoteCartRepository();
+});
diff --git a/ecommerce_app/lib/src/features/cart/domain/mutable_cart.dart b/ecommerce_app/lib/src/features/cart/domain/mutable_cart.dart
@@ -4,45 +4,48 @@ import 'package:ecommerce_app/src/features/products/domain/product.dart';
 
 /// Helper extension used to mutate the items in the shopping cart.
 extension MutableCart on Cart {
+  /// add an item to the cart by *overriding* the quantity if it already exists
+  Cart setItem(Item item) {
+    final copy = Map<ProductID, int>.from(items);
+    copy[item.productId] = item.quantity;
+    return Cart(copy);
+  }
+
+  /// add an item to the cart by *updating* the quantity if it already exists
   Cart addItem(Item item) {
     final copy = Map<ProductID, int>.from(items);
-    if (copy.containsKey(item.productId)) {
-      copy[item.productId] = item.quantity + copy[item.productId]!;
-    } else {
-      copy[item.productId] = item.quantity;
-    }
+    // * update item quantity. Read this for more details:
+    // * https://codewithandrea.com/tips/dart-map-update-method/
+    copy.update(
+      item.productId,
+      // if there is already a value, update it by adding the item quantity
+      (value) => item.quantity + value,
+      // otherwise, add the item with the given quantity
+      ifAbsent: () => item.quantity,
+    );
     return Cart(copy);
   }
 
+  /// add a list of items to the cart by *updating* the quantities of items that
+  /// already exist
   Cart addItems(List<Item> itemsToAdd) {
     final copy = Map<ProductID, int>.from(items);
     for (var item in itemsToAdd) {
-      if (copy.containsKey(item.productId)) {
-        copy[item.productId] = item.quantity + copy[item.productId]!;
-      } else {
-        copy[item.productId] = item.quantity;
-      }
+      copy.update(
+        item.productId,
+        // if there is already a value, update it by adding the item quantity
+        (value) => item.quantity + value,
+        // otherwise, add the item with the given quantity
+        ifAbsent: () => item.quantity,
+      );
     }
     return Cart(copy);
   }
 
+  /// if an item with the given productId is found, remove it
   Cart removeItemById(ProductID productId) {
     final copy = Map<ProductID, int>.from(items);
     copy.remove(productId);
     return Cart(copy);
   }
-
-  Cart updateItemIfExists(Item item) {
-    if (items.containsKey(item.productId)) {
-      final copy = Map<ProductID, int>.from(items);
-      copy[item.productId] = item.quantity;
-      return Cart(copy);
-    } else {
-      return this;
-    }
-  }
-
-  Cart clear() {
-    return const Cart();
-  }
 }
diff --git a/ecommerce_app/lib/src/features/cart/presentation/cart_total/cart_total_text.dart b/ecommerce_app/lib/src/features/cart/presentation/cart_total/cart_total_text.dart
@@ -1,16 +1,17 @@
 import 'package:ecommerce_app/src/utils/currency_formatter.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 /// Text widget for showing the total price of the cart
-class CartTotalText extends StatelessWidget {
+class CartTotalText extends ConsumerWidget {
   const CartTotalText({super.key});
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
     // TODO: Read from data source
     const cartTotal = 104.0;
-    // TODO: Inject formatter
-    final totalFormatted = kCurrencyFormatter.format(cartTotal);
+    final totalFormatted =
+        ref.watch(currencyFormatterProvider).format(cartTotal);
     return Text(
       'Total: $totalFormatted',
       style: Theme.of(context).textTheme.headlineSmall,

diff --git a/ecommerce_app/lib/src/features/cart/presentation/shopping_cart/shopping_cart_item.dart b/ecommerce_app/lib/src/features/cart/presentation/shopping_cart/shopping_cart_item.dart
@@ -4,6 +4,7 @@ import 'package:ecommerce_app/src/common_widgets/alert_dialogs.dart';
 import 'package:ecommerce_app/src/common_widgets/async_value_widget.dart';
 import 'package:ecommerce_app/src/features/products/data/fake_products_repository.dart';
 import 'package:ecommerce_app/src/localization/string_hardcoded.dart';
+import 'package:ecommerce_app/src/utils/currency_formatter.dart';
 import 'package:flutter/material.dart';
 import 'package:ecommerce_app/src/common_widgets/custom_image.dart';
 import 'package:ecommerce_app/src/common_widgets/item_quantity_selector.dart';
@@ -12,7 +13,6 @@ import 'package:ecommerce_app/src/constants/app_sizes.dart';
 import 'package:ecommerce_app/src/features/cart/domain/item.dart';
 import 'package:ecommerce_app/src/features/products/domain/product.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:intl/intl.dart';
 
 /// Shows a shopping cart item (or loading/error UI if needed)
 class ShoppingCartItem extends ConsumerWidget {
@@ -54,7 +54,7 @@ class ShoppingCartItem extends ConsumerWidget {
 }
 
 /// Shows a shopping cart item for a given product
-class ShoppingCartItemContents extends StatelessWidget {
+class ShoppingCartItemContents extends ConsumerWidget {
   const ShoppingCartItemContents({
     super.key,
     required this.product,
@@ -71,10 +71,9 @@ class ShoppingCartItemContents extends StatelessWidget {
   static Key deleteKey(int index) => Key('delete-$index');
 
   @override
-  Widget build(BuildContext context) {
-    // TODO: error handling
-    // TODO: Inject formatter
-    final priceFormatted = NumberFormat.simpleCurrency().format(product.price);
+  Widget build(BuildContext context, WidgetRef ref) {
+    final priceFormatted =
+        ref.watch(currencyFormatterProvider).format(product.price);
     return ResponsiveTwoColumnLayout(
       startFlex: 1,
       endFlex: 2,
@@ -90,28 +89,10 @@ class ShoppingCartItemContents extends StatelessWidget {
           gapH24,
           isEditable
               // show the quantity selector and a delete button
-              ? Row(
-                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                  children: [
-                    ItemQuantitySelector(
-                      quantity: item.quantity,
-                      maxQuantity: min(product.availableQuantity, 10),
-                      itemIndex: itemIndex,
-                      // TODO: Implement onChanged
-                      onChanged: (value) {
-                        showNotImplementedAlertDialog(context: context);
-                      },
-                    ),
-                    IconButton(
-                      key: deleteKey(itemIndex),
-                      icon: Icon(Icons.delete, color: Colors.red[700]),
-                      // TODO: Implement onPressed
-                      onPressed: () {
-                        showNotImplementedAlertDialog(context: context);
-                      },
-                    ),
-                    const Spacer(),
-                  ],
+              ? EditOrRemoveItemWidget(
+                  product: product,
+                  item: item,
+                  itemIndex: itemIndex,
                 )
               // else, show the quantity as a read-only label
               : Padding(
@@ -125,3 +106,46 @@ class ShoppingCartItemContents extends StatelessWidget {
     );
   }
 }
+
+// custom widget to show the quantity selector and a delete button
+class EditOrRemoveItemWidget extends ConsumerWidget {
+  const EditOrRemoveItemWidget({
+    super.key,
+    required this.product,
+    required this.item,
+    required this.itemIndex,
+  });
+  final Product product;
+  final Item item;
+  final int itemIndex;
+
+  // * Keys for testing using find.byKey()
+  static Key deleteKey(int index) => Key('delete-$index');
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Row(
+      mainAxisAlignment: MainAxisAlignment.spaceBetween,
+      children: [
+        ItemQuantitySelector(
+          quantity: item.quantity,
+          maxQuantity: min(product.availableQuantity, 10),
+          itemIndex: itemIndex,
+          // TODO: Implement onChanged
+          onChanged: (value) {
+            showNotImplementedAlertDialog(context: context);
+          },
+        ),
+        IconButton(
+          key: deleteKey(itemIndex),
+          icon: Icon(Icons.delete, color: Colors.red[700]),
+          // TODO: Implement onPressed
+          onPressed: () {
+            showNotImplementedAlertDialog(context: context);
+          },
+        ),
+        const Spacer(),
+      ],
+    );
+  }
+}
diff --git a/ecommerce_app/lib/src/features/cart/presentation/shopping_cart/shopping_cart_screen.dart b/ecommerce_app/lib/src/features/cart/presentation/shopping_cart/shopping_cart_screen.dart
@@ -14,6 +14,7 @@ class ShoppingCartScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    // TODO: error handling
     // TODO: Read from data source
     const cartItemsList = [
       Item(

diff --git a/ecommerce_app/lib/src/features/orders/presentation/orders_list/order_card.dart b/ecommerce_app/lib/src/features/orders/presentation/orders_list/order_card.dart
@@ -7,6 +7,7 @@ import 'package:ecommerce_app/src/features/cart/domain/item.dart';
 import 'package:ecommerce_app/src/features/orders/domain/order.dart';
 import 'package:ecommerce_app/src/utils/currency_formatter.dart';
 import 'package:ecommerce_app/src/utils/date_formatter.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 /// Shows all the details for a given order
 class OrderCard extends StatelessWidget {
@@ -35,16 +36,16 @@ class OrderCard extends StatelessWidget {
 /// Order header showing the following:
 /// - Total order amount
 /// - Order date
-class OrderHeader extends StatelessWidget {
+class OrderHeader extends ConsumerWidget {
   const OrderHeader({super.key, required this.order});
   final Order order;
 
   @override
-  Widget build(BuildContext context) {
-    // TODO: Inject currency formatter
-    final totalFormatted = kCurrencyFormatter.format(order.total);
-    // TODO: Inject date formatter
-    final dateFormatted = kDateFormatter.format(order.orderDate);
+  Widget build(BuildContext context, WidgetRef ref) {
+    final totalFormatted =
+        ref.watch(currencyFormatterProvider).format(order.total);
+    final dateFormatted =
+        ref.watch(dateFormatterProvider).format(order.orderDate);
     return Container(
       color: Colors.grey[200],
       padding: const EdgeInsets.all(Sizes.p16),

diff --git a/ecommerce_app/lib/src/features/products/data/fake_products_repository.dart b/ecommerce_app/lib/src/features/products/data/fake_products_repository.dart
@@ -40,7 +40,8 @@ class FakeProductsRepository {
 }
 
 final productsRepositoryProvider = Provider<FakeProductsRepository>((ref) {
-  return FakeProductsRepository();
+  // * Set addDelay to false for faster loading
+  return FakeProductsRepository(addDelay: false);
 });
 
 final productsListStreamProvider =

diff --git a/ecommerce_app/lib/src/features/products/presentation/home_app_bar/shopping_cart_icon.dart b/ecommerce_app/lib/src/features/products/presentation/home_app_bar/shopping_cart_icon.dart
@@ -1,17 +1,18 @@
 import 'package:ecommerce_app/src/routing/app_router.dart';
 import 'package:flutter/material.dart';
 import 'package:ecommerce_app/src/constants/app_sizes.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 
 /// Shopping cart icon with items count badge
-class ShoppingCartIcon extends StatelessWidget {
+class ShoppingCartIcon extends ConsumerWidget {
   const ShoppingCartIcon({super.key});
 
   // * Keys for testing using find.byKey()
   static const shoppingCartIconKey = Key('shopping-cart');
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
     // TODO: Read from data source
     const cartItemsCount = 3;
     return Stack(