Add new items to the top of the Cart

Author: staskus

WooCommerce/Classes/POS/ViewModels/CartViewModel.swift

@@ -45,7 +45,7 @@ final class CartViewModel: CartViewModelProtocol {
 
     func addItemToCart(_ item: POSItem) {
         let cartItem = CartItem(id: UUID(), item: item, quantity: 1)
-        itemsInCart.append(cartItem)
+        itemsInCart.insert(cartItem, at: 0)
 
         analytics.track(.pointOfSaleAddItemToCart)
     }

WooCommerce/WooCommerceTests/POS/ViewModels/CartViewModelTests.swift

@@ -43,7 +43,7 @@ final class CartViewModelTests: XCTestCase {
         sut.submitCart()
     }
 
-    func test_cart_when_addItemToCart_is_invoked_then_adds_item_to_cart() {
+    func test_addItemToCart_then_cart_is_not_empty() {
         // Given
         XCTAssertTrue(sut.itemsInCart.isEmpty, "Initial state")
         let item = Self.makeItem()
@@ -55,6 +55,19 @@ final class CartViewModelTests: XCTestCase {
         XCTAssertTrue(sut.itemsInCart.isNotEmpty)
     }
 
+    func test_addItemToCart_when_multiple_items_added_then_latest_item_is_first() {
+        // Given
+        XCTAssertTrue(sut.itemsInCart.isEmpty, "Initial state")
+        let items = [Self.makeItem(), Self.makeItem(), Self.makeItem()]
+
+        // When
+        items.forEach(sut.addItemToCart)
+
+        // Then
+        XCTAssertEqual(sut.itemsInCart.map(\.item.itemID), items.reversed().map(\.itemID))
+        XCTAssertNotEqual(sut.itemsInCart.map(\.item.itemID), items.map(\.itemID))
+    }
+
     func test_removeItemFromCart() {
         /* TODO:
          https://github.com/woocommerce/woocommerce-ios/issues/13209