Update coupon lines on POSOrderService

Author: staskus

Yosemite/Yosemite/Tools/POS/POSOrderService.swift

@@ -41,12 +41,12 @@ public final class POSOrderService: POSOrderServiceProtocol {
         let initialOrder: Order = posOrder ?? OrderFactory.newOrder(currency: currency)
             .copy(siteID: siteID,
                   status: .autoDraft)
-        let order = updateOrder(initialOrder, cartItems: cart.items).sanitizingLocalItems()
+        let order = updateOrder(initialOrder, cart: cart).sanitizingLocalItems()
         let syncedOrder: Order
         if posOrder != nil {
-            syncedOrder = try await ordersRemote.updatePOSOrder(siteID: siteID, order: order, fields: [.items])
+            syncedOrder = try await ordersRemote.updatePOSOrder(siteID: siteID, order: order, fields: [.items, .couponLines])
         } else {
-            syncedOrder = try await ordersRemote.createPOSOrder(siteID: siteID, order: order, fields: [.items, .status, .currency])
+            syncedOrder = try await ordersRemote.createPOSOrder(siteID: siteID, order: order, fields: [.items, .status, .currency, .couponLines])
         }
         return syncedOrder
     }
@@ -82,17 +82,39 @@ private struct POSOrderSyncProductType: OrderSyncProductTypeProtocol, Hashable {
 }
 
 private extension POSOrderService {
-    func updateOrder(_ order: Order, cartItems: [POSCartItem]) -> Order {
+    func updateOrder(_ order: Order, cart: POSCart) -> Order {
         // Removes all existing items by setting quantity to 0.
         let itemsToRemove = order.items.compactMap {
             Self.removalProductInput(item: $0)
         }
 
         // Adds items from the latest cart grouping by item.
-        let itemsToAdd = cartItems.createGroupedOrderSyncProductInputs().values
+        let itemsToAdd = cart.items.createGroupedOrderSyncProductInputs().values
         let itemsToSync = itemsToRemove + itemsToAdd
 
-        return ProductInputTransformer.updateMultipleItems(with: itemsToSync, on: order, shouldUpdateOrDeleteZeroQuantities: .update)
+        var order = ProductInputTransformer.updateMultipleItems(with: itemsToSync, on: order, shouldUpdateOrDeleteZeroQuantities: .update)
+        order = updateCoupons(cart.coupons, on: order)
+
+        return order
+    }
+
+    func updateCoupons(_ coupons: [POSCartCouponItem], on order: Order) -> Order {
+        // Get coupon codes from cart
+        let cartCouponCodes = Set(coupons.map { $0.code })
+
+        // Keep existing coupons that are still in the cart
+        let remainingCoupons = order.coupons.filter { orderCoupon in
+            cartCouponCodes.contains(orderCoupon.code)
+        }
+
+        // Find new coupons that need to be added (in cart but not in order)
+        let existingCouponCodes = Set(order.coupons.map { $0.code })
+        let newCoupons = coupons
+            .filter { !existingCouponCodes.contains($0.code) }
+            .map { OrderFactory.newOrderCouponLine(code: $0.code) }
+
+        // Update order with remaining + new coupons
+        return order.copy(coupons: remainingCoupons + newCoupons)
     }
 
     /// Creates a new `OrderSyncProductInput` type meant to remove an existing item from `OrderSynchronizer`

Yosemite/YosemiteTests/Tools/POS/POSOrderServiceTests.swift

@@ -135,6 +135,101 @@ struct POSOrderServiceTests {
             item.productID == 102 && item.quantity == 5
         }), "Item for product 102 should be added")
     }
+
+    @Test func syncOrder_after_adding_coupon_to_cart_adds_it_to_the_order() async throws {
+        // Given
+        let orderItems = [OrderItem.fake().copy(itemID: 1, name: "Item 1", productID: 100, quantity: 1)]
+        let order = Order.fake().copy(siteID: 123, orderID: 456, items: orderItems, coupons: [])
+
+        // When
+        let cart = POSCart(
+            items: [makePOSCartItem(productID: 100, quantity: 1)],
+            coupons: [.init(code: "SAVE10")]
+        )
+        _ = try await sut.syncOrder(cart: cart, order: order, currency: .USD)
+
+        // Then
+        let updatedOrderCoupons = try #require(mockOrdersRemote.spyUpdatePOSOrder?.coupons)
+        #expect(updatedOrderCoupons.count == 1)
+        #expect(updatedOrderCoupons.first?.code == "SAVE10")
+    }
+
+    @Test func syncOrder_after_removing_coupon_from_cart_removes_it_from_the_order() async throws {
+        // Given
+        let orderItems = [OrderItem.fake().copy(itemID: 1, name: "Item 1", productID: 100, quantity: 1)]
+        let existingCoupons = [OrderCouponLine.fake().copy(code: "SAVE10")]
+        let order = Order.fake().copy(siteID: 123, orderID: 456, items: orderItems, coupons: existingCoupons)
+
+        // When
+        let cart = POSCart(
+            items: [makePOSCartItem(productID: 100, quantity: 1)],
+            coupons: [] // Empty coupons in cart
+        )
+        _ = try await sut.syncOrder(cart: cart, order: order, currency: .USD)
+
+        // Then
+        let updatedOrderCoupons = try #require(mockOrdersRemote.spyUpdatePOSOrder?.coupons)
+        #expect(updatedOrderCoupons.isEmpty)
+    }
+
+    @Test func syncOrder_with_multiple_coupons_handles_mixed_changes() async throws {
+        // Given
+        let orderItems = [OrderItem.fake().copy(itemID: 1, name: "Item 1", productID: 100, quantity: 1)]
+        let existingCoupons = [
+            OrderCouponLine.fake().copy(code: "REMOVE1"),
+            OrderCouponLine.fake().copy(code: "KEEP1"),
+            OrderCouponLine.fake().copy(code: "REMOVE2")
+        ]
+        let order = Order.fake().copy(siteID: 123, orderID: 456, items: orderItems, coupons: existingCoupons)
+
+        // When
+        let cart = POSCart(
+            items: [makePOSCartItem(productID: 100, quantity: 1)],
+            coupons: [
+                .init(code: "KEEP1"),
+                .init(code: "NEW1"),
+                .init(code: "NEW2")
+            ]
+        )
+        _ = try await sut.syncOrder(cart: cart, order: order, currency: .USD)
+
+        // Then
+        let updatedOrderCoupons = try #require(mockOrdersRemote.spyUpdatePOSOrder?.coupons)
+
+        // Verify kept coupon
+        #expect(updatedOrderCoupons.contains(where: { $0.code == "KEEP1" }))
+
+        // Verify removed coupons
+        #expect(!updatedOrderCoupons.contains(where: { $0.code == "REMOVE1" }))
+        #expect(!updatedOrderCoupons.contains(where: { $0.code == "REMOVE2" }))
+
+        // Verify new coupons
+        #expect(updatedOrderCoupons.contains(where: { $0.code == "NEW1" }))
+        #expect(updatedOrderCoupons.contains(where: { $0.code == "NEW2" }))
+
+        // Verify total count
+        #expect(updatedOrderCoupons.count == 3)
+    }
+
+    @Test func syncOrder_with_unchanged_coupons_preserves_existing_coupon_data() async throws {
+        // Given
+        let orderItems = [OrderItem.fake().copy(itemID: 1, name: "Item 1", productID: 100, quantity: 1)]
+        let existingCoupon = OrderCouponLine.fake().copy(code: "KEEP1", discount: "10.00")
+        let order = Order.fake().copy(siteID: 123, orderID: 456, items: orderItems, coupons: [existingCoupon])
+
+        // When
+        let cart = POSCart(
+            items: [makePOSCartItem(productID: 100, quantity: 1)],
+            coupons: [.init(code: "KEEP1")] // Same coupon in cart
+        )
+        _ = try await sut.syncOrder(cart: cart, order: order, currency: .USD)
+
+        // Then
+        let updatedOrderCoupons = try #require(mockOrdersRemote.spyUpdatePOSOrder?.coupons)
+        #expect(updatedOrderCoupons.count == 1)
+        #expect(updatedOrderCoupons.first?.code == "KEEP1")
+        #expect(updatedOrderCoupons.first?.discount == "10.00", "Existing coupon data should be preserved")
+    }
 }
 
 private func makePOSCartItem(