fix: remove tax fields from cart queries unless its prepare for completion

Samples/MobileBuyIntegration/MobileBuyIntegration.xcodeproj/project.pbxproj

@@ -502,6 +502,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_ENTITLEMENTS = MobileBuyIntegration/MobileBuyIntegration.entitlements;
+				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_TEAM = A7XGC83MZE;
@@ -520,6 +521,7 @@
 				MARKETING_VERSION = 1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = com.shopify.example.MobileBuyIntegration;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
@@ -532,6 +534,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_ENTITLEMENTS = MobileBuyIntegration/MobileBuyIntegration.entitlements;
+				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_TEAM = A7XGC83MZE;
@@ -551,6 +554,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = com.shopify.example.MobileBuyIntegration;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";

Samples/MobileBuyIntegration/MobileBuyIntegration/ApplePay/ApplePayHandler.swift

@@ -103,26 +103,16 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
             print(CartManager.Errors.invariant(message: "Shipping method identifier is nil"))
             return PKPaymentRequestShippingMethodUpdate(
                 paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
-                    cart: CartManager.shared.cart,
                     shippingMethod: nil
                 )
             )
         }
 
         do {
-            _ = try await CartManager.shared.performCartSelectedDeliveryOptionsUpdate(
+            try await CartManager.shared.performCartSelectedDeliveryOptionsUpdate(
                 deliveryOptionHandle: identifier
             )
 
-            let cart = try await CartManager.shared.performCartPrepareForCompletion()
-
-            let paymentRequestShippingContactUpdate = PKPaymentRequestShippingMethodUpdate(
-                paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
-                    cart: cart,
-                    shippingMethod: shippingMethod
-                )
-            )
-            return paymentRequestShippingContactUpdate
         } catch {
             print(
                 CartManager.Errors.apiErrors(
@@ -131,10 +121,19 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
                     "Check response from cartSelectedDeliveryOptionsUpdate or cartPrepareForCompletion \(error)"
                 )
             )
+        }
 
+        do {
+            try await CartManager.shared.performCartPrepareForCompletion()
+
+            return PKPaymentRequestShippingMethodUpdate(
+                paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
+                    shippingMethod: shippingMethod
+                )
+            )
+        } catch {
             return PKPaymentRequestShippingMethodUpdate(
                 paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
-                    cart: CartManager.shared.cart,
                     shippingMethod: nil
                 )
             )
@@ -146,7 +145,7 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
         didSelectShippingContact contact: PKContact
     ) async -> PKPaymentRequestShippingContactUpdate {
         do {
-            _ = try await CartManager.shared.performBuyerIdentityUpdate(
+            try await CartManager.shared.performCartBuyerIdentityUpdate(
                 contact: contact,
                 partial: true
             )
@@ -155,12 +154,11 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
                 firstDeliveryGroup: CartManager.shared.cart?.deliveryGroups.nodes.first
             )
 
-            _ = try await CartManager.shared.performCartPrepareForCompletion()
+            try await CartManager.shared.performCartPrepareForCompletion()
 
             return PKPaymentRequestShippingContactUpdate(
                 errors: [],
                 paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
-                    cart: CartManager.shared.cart,
                     shippingMethod: nil
                 ),
                 shippingMethods: shippingMethods
@@ -170,7 +168,6 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
             return PKPaymentRequestShippingContactUpdate(
                 errors: [error],
                 paymentSummaryItems: PassKitFactory.shared.createPaymentSummaryItems(
-                    cart: CartManager.shared.cart,
                     shippingMethod: nil
                 ),
                 shippingMethods: []
@@ -185,29 +182,26 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
         /**
          * Apply validations that make sense for your business requirements
          */
-        guard
-            let shippingContact = payment.shippingContact,
-            payment.shippingContact?.postalAddress?.isoCountryCode == "US"
-        else {
+        guard let shippingContact = payment.shippingContact else {
             paymentStatus = .failure
             return PassKitFactory.shared.createPKPaymentUSAdressError()
         }
 
-        guard
-            let emailAddress = shippingContact.emailAddress,
-            emailAddress.isEmpty == false
-        else {
-            paymentStatus = .failure
-            return PassKitFactory.shared.createPKPaymentEmailError()
-        }
-
+        /**
+         * (Optional) If the user is a guest and you haven't set an email on buyerIdentity
+         * update the buyerIdentity with the shippingContact.email
+         */
         if appConfiguration.useVaultedState == false {
-            /**
-             * (Optional) If the user is a guest and you haven't set an email on buyerIdentity
-             * update the buyerIdentity with the shippingContact.email
-             */
+            guard
+                let emailAddress = shippingContact.emailAddress,
+                emailAddress.isEmpty == false
+            else {
+                paymentStatus = .failure
+                return PassKitFactory.shared.createPKPaymentEmailError()
+            }
+
             do {
-                _ = try await CartManager.shared.performBuyerIdentityUpdate(
+                try await CartManager.shared.performCartBuyerIdentityUpdate(
                     contact: shippingContact,
                     partial: true
                 )
@@ -219,14 +213,17 @@ extension ApplePayHandler: PKPaymentAuthorizationControllerDelegate {
         }
 
         do {
-            _ = try await CartManager.shared.performCartPaymentUpdate(payment: payment)
+            try await CartManager.shared.performCartPrepareForCompletion()
+            sleep(1)
+            try await CartManager.shared.performCartPaymentUpdate(payment: payment)
         } catch {
             print("[didAuthorizePayment][performCartPaymentUpdate][failure] \(error)")
             paymentStatus = .failure
             return PKPaymentAuthorizationResult(status: .failure, errors: [error])
         }
 
         do {
+            sleep(1)
             let response = try await CartManager.shared.performCartSubmitForCompletion()
             CartManager.shared.redirectUrl = response.redirectUrl
             paymentStatus = .success

Samples/MobileBuyIntegration/MobileBuyIntegration/ApplePay/PassKitFactory.swift

@@ -69,13 +69,15 @@ class PassKitFactory {
             )
         }
 
-        paymentSummaryItems.append(
-            .init(
-                label: "Tax",
-                amount: NSDecimalNumber(decimal: cart.cost.totalTaxAmount?.amount ?? 0),
-                type: .final
+        if let tax = CartManager.shared.totalTaxAmount {
+            paymentSummaryItems.append(
+                .init(
+                    label: "Tax",
+                    amount: NSDecimalNumber(decimal: tax),
+                    type: .final
+                )
             )
-        )
+        }
 
         paymentSummaryItems.append(
             .init(
@@ -134,9 +136,9 @@ class PassKitFactory {
     }
 
     public func createPaymentSummaryItems(
-        cart: Storefront.Cart?, shippingMethod: PKShippingMethod?
+        shippingMethod: PKShippingMethod?
     ) -> [PKPaymentSummaryItem] {
-        guard let cart, !cart.lines.nodes.isEmpty else {
+        guard let cart = CartManager.shared.cart, !cart.lines.nodes.isEmpty else {
             return []
         }
 
@@ -165,11 +167,11 @@ class PassKitFactory {
         }
 
         // Null and 0 mean different things
-        if let amount = cart.cost.totalTaxAmount?.amount {
+        if let tax = CartManager.shared.totalTaxAmount {
             paymentSummaryItems.append(
                 .init(
                     label: "Tax",
-                    amount: NSDecimalNumber(decimal: amount),
+                    amount: NSDecimalNumber(decimal: tax),
                     type: .final
                 )
             )

Samples/MobileBuyIntegration/MobileBuyIntegration/CartManager.swift

@@ -40,6 +40,16 @@ class CartManager: ObservableObject {
     public var redirectUrl: URL?
 
     @Published var cart: Storefront.Cart?
+    /**
+     * Represents the cart's total tax amount (`cart.totalTaxAmount.amount`).
+     *
+     * This property is handled separately from the main cart object because:
+     * 1. The BuySDK throws errors when accessing unrequested properties
+     * 2. `totalTaxAmount` is deprecated in most cart operations (only available in `prepareForCompletion`)
+     *
+     * By isolating this property, we avoid SDK errors while maintaining access to tax data when needed.
+     */
+    @Published var totalTaxAmount: Decimal?
     @Published var isDirty: Bool = false
 
     // MARK: Initializers
@@ -68,7 +78,7 @@ class CartManager: ObservableObject {
      * Creates cart if no cart.id present, or adds line items to pre-existing cart
      * Non-idempotent - subsequent calls for existing cartLine items will increase quantity by 1
      */
-    func performCartLinesAdd(variant: GraphQL.ID) async throws -> Storefront.Cart {
+    @discardableResult func performCartLinesAdd(variant: GraphQL.ID) async throws -> Storefront.Cart {
         guard let cartId = cart?.id else {
             return try await performCartCreate(items: [variant])
         }
@@ -80,7 +90,7 @@ class CartManager: ObservableObject {
         ) {
             $0.cartLinesAdd(cartId: cartId, lines: lines) {
                 $0.cart { $0.cartManagerFragment() }
-                  .userErrors { $0.code().message() }
+                    .userErrors { $0.code().message() }
             }
         }
 
@@ -151,14 +161,13 @@ class CartManager: ObservableObject {
         }
     }
 
-    func performBuyerIdentityUpdate(
+    @discardableResult func performCartBuyerIdentityUpdate(
         contact: PKContact,
         partial _: Bool
     ) async throws -> Storefront.Cart {
         guard let cartId = cart?.id else {
             throw Errors.invariant(message: "cart.id should be defined")
         }
-
         guard let address = contact.postalAddress else {
             throw Errors.invariant(message: "contact.postalAddress is nil")
         }
@@ -252,7 +261,7 @@ class CartManager: ObservableObject {
         }
     }
 
-    func performCartSelectedDeliveryOptionsUpdate(
+    @discardableResult func performCartSelectedDeliveryOptionsUpdate(
         deliveryOptionHandle: String
     ) async throws -> Storefront.Cart {
         guard let cartId = cart?.id else {
@@ -312,7 +321,7 @@ class CartManager: ObservableObject {
         }
     }
 
-    func performCartPaymentUpdate(
+    @discardableResult func performCartPaymentUpdate(
         payment: PKPayment // REFACTOR: this method should just receive the decoded payment token
     ) async throws -> Storefront.Cart {
         guard let cartId = cart?.id else {
@@ -344,7 +353,7 @@ class CartManager: ObservableObject {
 
         let mutation = Storefront.buildMutation(inContext: CartManager.ContextDirective) {
             $0.cartPaymentUpdate(cartId: cartId, payment: paymentInput) {
-                $0.cart { $0.cartManagerFragment() }
+                $0.cart { $0.cartPrepareForCompletionFragment() }
                     .userErrors {
                         $0.code().message()
                     }
@@ -376,7 +385,7 @@ class CartManager: ObservableObject {
         }
     }
 
-    func performCartPrepareForCompletion() async throws -> Storefront.Cart {
+    @discardableResult func performCartPrepareForCompletion() async throws -> Storefront.Cart {
         guard let cartId = cart?.id else {
             throw Errors.invariant(message: "cart.id should be defined")
         }
@@ -386,10 +395,10 @@ class CartManager: ObservableObject {
         ) {
             $0.cartPrepareForCompletion(cartId: cartId) {
                 $0.result {
-                    $0.onCartStatusReady { $0.cart { $0.cartManagerFragment() } }
+                    $0.onCartStatusReady { $0.cart { $0.cartPrepareForCompletionFragment() } }
                     $0.onCartThrottled { $0.pollAfter() }
                     $0.onCartStatusNotReady {
-                        $0.cart { $0.cartManagerFragment() }
+                        $0.cart { $0.cartPrepareForCompletionFragment() }
                             .errors { $0.code().message() }
                     }
                 }.userErrors { $0.code().message() }
@@ -410,17 +419,27 @@ class CartManager: ObservableObject {
 
             guard
                 let result = payload.result as? Storefront.CartStatusReady,
-                let cart = result.cart
+                let cartWithResolvedPendingTerms = result.cart
             else {
                 throw Errors.invariant(
                     message: "CartPrepareForCompletionResult is not CartStatusReady")
             }
 
             DispatchQueue.main.async {
-                self.cart = cart
+                self.cart = cartWithResolvedPendingTerms
+                /**
+                 * IMPORTANT: Special handling for `totalTaxAmount`:
+                 * - Deprecated field on cart, except from `cartPrepareForCompletion` mutation
+                 * - Not included in standard cart fragments used by other mutations
+                 * - Accessing `self.cart.cost.totalTaxAmount` will throw if cart was set by other mutations
+                 * - Store separately to preserve the value when cart is updated by subsequent mutations
+                 */
+                if let tax = cartWithResolvedPendingTerms.cost.totalTaxAmount?.amount {
+                    self.totalTaxAmount = tax
+                }
             }
 
-            return cart
+            return cartWithResolvedPendingTerms
         } catch {
             throw Errors.apiErrors(requestName: "cartSubmitForCompletion", message: "\(error)")
         }
@@ -435,7 +454,11 @@ class CartManager: ObservableObject {
             $0.cartSubmitForCompletion(cartId: cartId, attemptToken: UUID().uuidString) {
                 $0.result {
                     $0.onSubmitSuccess { $0.redirectUrl() }
-                    $0.onSubmitFailed { $0.checkoutUrl() }
+                    $0.onSubmitFailed {
+                        $0.checkoutUrl().errors {
+                            $0.code().message()
+                        }
+                    }
                     $0.onSubmitAlreadyAccepted { $0.attemptId() }
                     $0.onSubmitThrottled { $0.pollAfter() }
                 }