[Woo POS] Coupons: Disallow adding duplicate coupons to cart

WooCommerce/Classes/POS/Models/Cart.swift

@@ -49,7 +49,7 @@ extension Cart {
         case .variableParentProduct:
             return
         case .coupon(let coupon):
-            let couponItem = Cart.CouponItem(id: UUID(), code: coupon.code, summary: coupon.summary)
+            let couponItem = Cart.CouponItem(id: coupon.id, code: coupon.code, summary: coupon.summary)
             coupons.insert(couponItem, at: coupons.startIndex)
         }
     }

WooCommerce/Classes/POS/Presentation/Item Selector/POSItemActionHandler.swift

@@ -29,6 +29,15 @@ extension POSItemActionHandler {
             break
         }
     }
+
+    func shouldSkipDuplicate(_ item: POSItem, itemListType: ItemListType, posModel: PointOfSaleAggregateModelProtocol) -> Bool {
+        switch itemListType {
+        case .coupons:
+            return posModel.cart.coupons.contains(where: { $0.id == item.id })
+        default:
+            return false
+        }
+    }
 }
 
 /// Standard handler for handling item taps without any special context
@@ -45,8 +54,10 @@ final class StandardPOSItemActionHandler: POSItemActionHandler {
     }
 
     func handleTap(_ item: POSItem) {
+        if shouldSkipDuplicate(item, itemListType: itemListType, posModel: posModel) {
+            return
+        }
         posModel.addToCart(item)
-
         trackTapAnalytics(for: item, itemListType: itemListType, using: analytics)
     }
 }
@@ -70,6 +81,9 @@ final class SearchResultItemActionHandler: POSItemActionHandler {
     }
 
     func handleTap(_ item: POSItem) {
+        if shouldSkipDuplicate(item, itemListType: itemListType, posModel: posModel) {
+            return
+        }
         posModel.saveSearchTerm(searchTerm, for: itemListType.itemType)
 
         posModel.addToCart(item)

WooCommerce/WooCommerceTests/POS/Models/PointOfSaleAggregateModelTests.swift

@@ -243,14 +243,7 @@ struct PointOfSaleAggregateModelTests {
         }
 
         @available(iOS 17.0, *)
-        @Test(.disabled(
-            """
-            This test doesn't currently work; analytics extensions are not thread-safe,
-            and using the MainActor means the assert happens too early. I don't think
-            we want the addToCart to be async, but that would be one way to fix it.
-            """))
-        func addToCart_tracks_analytics_event() async throws {
-            // Given
+        @Test func addToCart_when_attempt_to_add_duplicated_coupon_then_does_not_add_it_to_cart() {
             let sut = PointOfSaleAggregateModel(itemsController: MockPointOfSaleItemsController(),
                                                 purchasableItemsSearchController: MockPointOfSalePurchasableItemsSearchController(),
                                                 couponsController: MockPointOfSaleCouponsController(),
@@ -261,14 +254,14 @@ struct PointOfSaleAggregateModelTests {
                                                 collectOrderPaymentAnalyticsTracker: MockPOSCollectOrderPaymentAnalyticsTracker(),
                                                 searchHistoryService: MockPOSSearchHistoryService(),
                                                 popularItemsController: MockPointOfSalePopularItemsController())
-            let item = makePurchasableItem()
+            let coupon = makeCouponItem(code: "DISCOUNT!")
 
             // When
-            sut.addToCart(item)
+            sut.addToCart(coupon)
+            sut.addToCart(coupon)
 
             // Then
-            let event = try #require(analyticsProvider.receivedEvents.first)
-            #expect(event == "item_added_to_cart")
+            #expect(sut.cart.coupons.count == 1)
         }
     }