Graceful degradation with Webview reuse

.swiftlint.yml

@@ -1,5 +1,6 @@
 disabled_rules:
   - line_length
+  - file_length
 
 opt_in_rules:
   - array_init
@@ -18,6 +19,9 @@ opt_in_rules:
   - modifier_order
   - overridden_super_call
   - toggle_bool
+  - switch_case_alignment:
+    indented_cases: false
+  - fallthrough
 
 nesting:
   type_level:

Samples/MobileBuyIntegration/.swiftlint.yml

@@ -18,6 +18,9 @@ opt_in_rules:
   - modifier_order
   - overridden_super_call
   - toggle_bool
+  - switch_case_alignment:
+    indented_cases: false
+  - fallthrough
 
 nesting:
   type_level:

Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift

@@ -133,6 +133,7 @@ class CartViewController: UIViewController, UITableViewDelegate, UITableViewData
 
 	@IBAction private func presentCheckout() {
 		guard let url = CartManager.shared.cart?.checkoutUrl else { return }
+
 		ShopifyCheckoutSheetKit.present(checkout: url, from: self, delegate: self)
 	}
 
@@ -197,8 +198,11 @@ extension CartViewController: CheckoutDelegate {
 			errorMessage = message
 		}
 
-		print(#function, error)
-		forceCloseCheckout(errorMessage)
+		print(errorMessage, "Recoverable: \(error.isRecoverable)")
+
+		if !error.isRecoverable {
+			forceCloseCheckout(errorMessage)
+		}
 	}
 
 	private func handleCheckoutUnavailable(_ message: String, _ code: CheckoutUnavailable) {

Sources/ShopifyCheckoutSheetKit/CheckoutBridge.swift

@@ -31,11 +31,17 @@ enum BridgeError: Swift.Error {
 enum CheckoutBridge {
 	static let schemaVersion = "8.1"
 	static let messageHandler = "mobileCheckoutSdk"
+	internal static let userAgent = "ShopifyCheckoutSDK/\(ShopifyCheckoutSheetKit.version)"
 	internal static var logger: ProductionLogger = InternalLogger()
 
 	static var applicationName: String {
 		let theme = ShopifyCheckoutSheetKit.configuration.colorScheme.rawValue
-		return "ShopifyCheckoutSDK/\(ShopifyCheckoutSheetKit.version) (\(schemaVersion);\(theme);standard)"
+		return "\(userAgent) (\(schemaVersion);\(theme);standard)"
+	}
+
+	static var recoveryAgent: String {
+		let theme = ShopifyCheckoutSheetKit.configuration.colorScheme.rawValue
+		return "\(userAgent) (noconnect;\(theme);standard_recovery)"
 	}
 
 	static func instrument(_ webView: WKWebView, _ instrumentation: InstrumentationPayload) {
@@ -119,7 +125,7 @@ extension CheckoutBridge {
 					self = .checkoutComplete(event: checkoutCompletedEvent)
 				} catch {
 					logger.logError(error, "Error decoding CheckoutCompletedEvent")
-					self = .checkoutComplete(event: emptyCheckoutCompletedEvent)
+					self = .checkoutComplete(event: createEmptyCheckoutCompletedEvent())
 				}
 			case "error":
 				let errorDecoder = CheckoutErrorEventDecoder()

Sources/ShopifyCheckoutSheetKit/CheckoutCompletedEvent.swift

@@ -21,8 +21,6 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-// swiftlint:disable identifier_name
-
 import Foundation
 
 public struct CheckoutCompletedEvent: Codable {
@@ -52,9 +50,11 @@ extension CheckoutCompletedEvent {
 
 	public struct CartLineImage: Codable {
 		public let altText: String?
+		// swiftlint:disable identifier_name
 		public let lg: String
 		public let md: String
 		public let sm: String
+		// swiftlint:enable identifier_name
 	}
 
 	public struct CartLine: Codable {
@@ -115,38 +115,38 @@ extension CheckoutCompletedEvent {
 	}
 }
 
-// swiftlint:enable identifier_name
-
-internal let emptyCheckoutCompletedEvent = CheckoutCompletedEvent(
-	orderDetails: CheckoutCompletedEvent.OrderDetails(
-		billingAddress: CheckoutCompletedEvent.Address(
-			address1: nil,
-			address2: nil,
-			city: nil,
-			countryCode: nil,
-			firstName: nil,
-			lastName: nil,
-			name: nil,
-			phone: nil,
-			postalCode: nil,
-			referenceId: nil,
-			zoneCode: nil
-		),
-		cart: CheckoutCompletedEvent.CartInfo(
-			lines: [],
-			price: CheckoutCompletedEvent.Price(
-				discounts: nil,
-				shipping: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
-				subtotal: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
-				taxes: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
-				total: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil)
+internal func createEmptyCheckoutCompletedEvent(id: String? = "") -> CheckoutCompletedEvent {
+	return CheckoutCompletedEvent(
+		orderDetails: CheckoutCompletedEvent.OrderDetails(
+			billingAddress: CheckoutCompletedEvent.Address(
+				address1: nil,
+				address2: nil,
+				city: nil,
+				countryCode: nil,
+				firstName: nil,
+				lastName: nil,
+				name: nil,
+				phone: nil,
+				postalCode: nil,
+				referenceId: nil,
+				zoneCode: nil
+			),
+			cart: CheckoutCompletedEvent.CartInfo(
+				lines: [],
+				price: CheckoutCompletedEvent.Price(
+					discounts: nil,
+					shipping: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
+					subtotal: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
+					taxes: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil),
+					total: CheckoutCompletedEvent.Money(amount: nil, currencyCode: nil)
+				),
+				token: ""
 			),
-			token: ""
-		),
-		deliveries: nil,
-		email: nil,
-		id: "",
-		paymentMethods: nil,
-		phone: nil
+			deliveries: nil,
+			email: nil,
+			id: id ?? "",
+			paymentMethods: nil,
+			phone: nil
+		)
 	)
-)
+}

Sources/ShopifyCheckoutSheetKit/CheckoutCompletedEventDecoder.swift

@@ -28,7 +28,7 @@ class CheckoutCompletedEventDecoder {
 		let messageBody = try container.decode(String.self, forKey: .body)
 
 		guard let data = messageBody.data(using: .utf8) else {
-			return emptyCheckoutCompletedEvent
+			return createEmptyCheckoutCompletedEvent()
 		}
 
 		return try JSONDecoder().decode(CheckoutCompletedEvent.self, from: data)

Sources/ShopifyCheckoutSheetKit/CheckoutDelegate.swift

@@ -35,6 +35,9 @@ public protocol CheckoutDelegate: AnyObject {
 	/// Tells the delegate that the checkout encoutered one or more errors.
 	func checkoutDidFail(error: CheckoutError)
 
+	/// Tells the delegate that checkout has encountered an error and the return value will determine if it is handled with a fallback
+	func shouldRecoverFromError(error: CheckoutError) -> Bool
+
     /// Tells te delegate that the buyer clicked a link
 	/// This includes email address or telephone number via `mailto:` or `tel:` or `http` links directed outside the application.
 	func checkoutDidClickLink(url: URL)
@@ -56,6 +59,10 @@ extension CheckoutDelegate {
 		throw error
 	}
 
+	public func shouldRecoverFromError(error: CheckoutError) -> Bool {
+		return error.isRecoverable
+	}
+
 	private func handleUrl(_ url: URL) {
 		if UIApplication.shared.canOpenURL(url) {
 			UIApplication.shared.open(url)

Sources/ShopifyCheckoutSheetKit/CheckoutError.swift

@@ -60,8 +60,8 @@ public enum CheckoutError: Swift.Error {
 	/// if the issue persists, it is recommended to open a bug report in http://github.com/Shopify/checkout-sheet-kit-swift
 	case sdkError(underlying: Swift.Error, recoverable: Bool = true)
 
-	/// Issued when the provided checkout URL results in an error related to shop being on checkout.liquid.
-	/// The SDK only supports stores migrated for extensibility.
+	/// Issued when the storefront configuration has caused an error.
+	/// Note that the Checkout Sheet Kit only supports stores migrated for extensibility.
 	case configurationError(message: String, code: CheckoutErrorCode, recoverable: Bool = false)
 
 	/// Issued when checkout has encountered a unrecoverable error (for example server side error)
@@ -72,6 +72,17 @@ public enum CheckoutError: Swift.Error {
 	/// This may happen when the user has paused on checkout for a long period (hours) and then attempted to proceed again with the same checkout url
 	/// In event of checkoutExpired, a new checkout url will need to be generated
 	case checkoutExpired(message: String, code: CheckoutErrorCode, recoverable: Bool = false)
+
+	public var isRecoverable: Bool {
+        switch self {
+		case .authenticationError(_, _, let recoverable),
+			.checkoutExpired(_, _, let recoverable),
+			.checkoutUnavailable(_, _, let recoverable),
+			.configurationError(_, _, let recoverable),
+			.sdkError(_, let recoverable):
+			return recoverable
+		}
+    }
 }
 
 internal enum CheckoutErrorGroup: String, Codable {