improvement Enable library evolution (#1482)

## Summary
- Adds default implementation for protocol `@_spi` properties
- Adds tests to guarantee `assertionFailure` on unimplemented protocol
conformance
- Fixes unrelated warnings
- Adds a [github
workflow](https://github.com/Adyen/adyen-ios/actions/workflows/test_library_evolution.yml)
that ensures the compatibility with `BUILD_LIBRARY_FOR_DISTRIBUTION=YES`

See: #1354

.github/workflows/test_library_evolution.yml

@@ -0,0 +1,35 @@
+name: 📚 Library Evolution Compatibility
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  push:
+    branches:
+      - develop
+
+jobs:
+
+  build:
+    name: Verify
+    runs-on: macos-13-xl
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: n1hility/cancel-previous-runs@v3
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Select latest Xcode
+      uses: maxim-lobanov/setup-xcode@v1
+      with:
+        xcode-version: '14.3'
+
+    - name: "xcodebuild clean archive BUILD_LIBRARY_FOR_DISTRIBUTION=YES"
+      run: |
+        xcodebuild -version
+        xcodebuild clean archive -project "${project}" -scheme "${scheme}" ${params} -destination "${destination}" | xcpretty --utf --color && exit ${PIPESTATUS[0]}
+      env:
+        project: 'Adyen.xcodeproj'
+        params: '-archivePath "archives/Adyen-iphoneos.xcarchive" -skipPackagePluginValidation SKIP_INSTALL=NO BUILD_LIBRARY_FOR_DISTRIBUTION=YES'
+        scheme: 'Adyen'
+        destination: 'generic/platform=iOS'

Adyen/Core/APIClient/APIContext.swift

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2022 Adyen N.V.
+// Copyright (c) 2023 Adyen N.V.
 //
 // This file is open source and available under the MIT license. See the LICENSE file for more info.
 //
@@ -11,7 +11,6 @@ import Foundation
 public protocol AdyenContextAware: AnyObject {
 
     /// The context object for this component.
-    @_spi(AdyenInternal)
     var context: AdyenContext { get }
 }
 

Adyen/Core/Core Protocols/Details.swift

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2022 Adyen N.V.
+// Copyright (c) 2023 Adyen N.V.
 //
 // This file is open source and available under the MIT license. See the LICENSE file for more info.
 //
@@ -16,5 +16,27 @@ public protocol PaymentMethodDetails: Details {
     var checkoutAttemptId: String? { get set }
 }
 
+public extension PaymentMethodDetails {
+
+    /// This default implementation has to be provided to be able to build with `BUILD_LIBRARY_FOR_DISTRIBUTION` enabled
+    ///
+    /// - Warning: Access will cause an failure in debug mode to assure the correct implementation of the `PaymentMethodDetails` protocol
+    @_spi(AdyenInternal)
+    var checkoutAttemptId: String? {
+        get {
+            AdyenAssertion.assertionFailure(
+                message: "`@_spi(AdyenInternal) var checkoutAttemptId: String?` needs to be provided on `\(String(describing: Self.self))`"
+            )
+
+            return "do-not-track"
+        }
+        set {
+            AdyenAssertion.assertionFailure(
+                message: "`@_spi(AdyenInternal) var checkoutAttemptId: String?` needs to be provided on `\(String(describing: Self.self))`"
+            )
+        }
+    }
+}
+
 /// Contains additional details that were retrieved to complete a payment.
 public protocol AdditionalDetails: Details {}

Adyen/Core/Core Protocols/PaymentMethod.swift

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2022 Adyen N.V.
+// Copyright (c) 2023 Adyen N.V.
 //
 // This file is open source and available under the MIT license. See the LICENSE file for more info.
 //
@@ -30,6 +30,21 @@ public protocol PaymentMethod: Decodable {
     func buildComponent(using builder: PaymentComponentBuilder) -> PaymentComponent?
 }
 
+public extension PaymentMethod {
+
+    /// This default implementation has to be provided to be able to build with `BUILD_LIBRARY_FOR_DISTRIBUTION` enabled
+    ///
+    /// - Warning: Access will cause an failure in debug mode to assure the correct implementation of the `PaymentMethod` protocol
+    @_spi(AdyenInternal)
+    func buildComponent(using builder: PaymentComponentBuilder) -> PaymentComponent? {
+        AdyenAssertion.assertionFailure(
+            message: "`@_spi(AdyenInternal) \(#function)` needs to be implemented on `\(String(describing: Self.self))`"
+        )
+
+        return nil
+    }
+}
+
 /// A protocol to define any partial payment method such as gift cards, `MealVoucher` etc.
 public protocol PartialPaymentMethod: PaymentMethod {}
 

Tests/Adyen Tests/Core/PaymentMethodTests.swift

@@ -12,6 +12,11 @@ class PaymentMethodTests: XCTestCase {
 
     var paymentMethods: PaymentMethods!
 
+    override func tearDown() {
+        super.tearDown()
+        AdyenAssertion.listener = nil
+    }
+
     override func setUpWithError() throws {
         paymentMethods = try getPaymentMethods()
     }
@@ -896,6 +901,30 @@ class PaymentMethodTests: XCTestCase {
         XCTAssertEqual(paymentMethod.bankAccountNumber, "123456789")
     }
 
+    // MARK: - PaymentMethodDetails
+
+    func testMissingImplementationPaymentMethodDetails() throws {
+
+        class DummyPaymentMethodDetails: PaymentMethodDetails {}
+
+        var dummy = DummyPaymentMethodDetails()
+
+        let expectation = expectation(description: "Access expectation")
+        expectation.expectedFulfillmentCount = 2
+
+        AdyenAssertion.listener = { assertion in
+            XCTAssertEqual(assertion, "`@_spi(AdyenInternal) var checkoutAttemptId: String?` needs to be provided on `DummyPaymentMethodDetails`")
+            expectation.fulfill()
+        }
+
+        // set
+        dummy.checkoutAttemptId = ""
+        // get
+        let _ = dummy.checkoutAttemptId
+
+        wait(for: [expectation], timeout: 1)
+    }
+
     // MARK: - Accessibility
 
     func testPaymentMethodTypeName() throws {

Tests/Card Tests/CardComponentTests.swift

@@ -983,7 +983,7 @@ class CardComponentTests: XCTestCase {
 
         let supportedCardLogosItemId = "AdyenCard.CardComponent.numberContainerItem.supportedCardLogosItem"
 
-        var supportedCardLogosItem: FormCardLogosItemView = try XCTUnwrap(sut.viewController.view.findView(with: supportedCardLogosItemId))
+        let supportedCardLogosItem: FormCardLogosItemView = try XCTUnwrap(sut.viewController.view.findView(with: supportedCardLogosItemId))
         XCTAssertFalse(supportedCardLogosItem.isHidden)
 
         // Valid input

Tests/DropIn Tests/ComponentManagerTests.swift

@@ -77,6 +77,7 @@ class ComponentManagerTests: XCTestCase {
     }
 
     override func tearDownWithError() throws {
+        AdyenAssertion.listener = nil
         presentationDelegate = nil
         context = nil
         configuration = nil
@@ -464,6 +465,40 @@ class ComponentManagerTests: XCTestCase {
         XCTAssertFalse(achComponent.configuration.showsBillingAddress)
         XCTAssertEqual(achComponent.configuration.billingAddressCountryCodes, ["US", "UK"])
     }
+
+    func testMissingImplementationBuildComponent() throws {
+
+        struct DummyPaymentMethod: PaymentMethod {
+            var type: PaymentMethodType = .achDirectDebit
+            var name: String = ""
+            var merchantProvidedDisplayInformation: MerchantCustomDisplayInformation? = nil
+
+            init() {}
+            init(from decoder: Decoder) throws {}
+        }
+
+        var dummy = DummyPaymentMethod()
+
+        let expectation = expectation(description: "Access expectation")
+        expectation.expectedFulfillmentCount = 1
+
+        AdyenAssertion.listener = { assertion in
+            XCTAssertEqual(assertion, "`@_spi(AdyenInternal) buildComponent(using:)` needs to be implemented on `DummyPaymentMethod`")
+            expectation.fulfill()
+        }
+
+        let componentManager = ComponentManager(
+            paymentMethods: .init(regular: [], stored: []),
+            context: Dummy.context,
+            configuration: .init(),
+            order: nil,
+            presentationDelegate: presentationDelegate
+        )
+
+        let _ = dummy.buildComponent(using: componentManager)
+
+        wait(for: [expectation], timeout: 1)
+    }
 
     // MARK: - Private