Localization: Phase 2 - public API

[atmamont]

Summary

✅ Phase 0 — #2463
✅ Phase 1 — Internalize legacy localization API
➡️ Phase 2 — Introduce the new public contract
Phase 3 — Wire provider resolution into card flow
Phase 4 — Unsupported locale warnings
Phase 5 — Final confidence pass for card alpha scope

This change completes Phase 2 of the custom localization feature by introducing the new Android-aligned public localization contract: CheckoutLocalizationKey, CheckoutLocalizationProvider, and CheckoutConfiguration.localizationProvider(_).

The provider is propagated generically through CheckoutComponentBuilder into checkout component configurations, with demo usage and focused unit coverage added.

Note: I cannot make internal public struct LocalizationKey to become package yet, as it causes a massive amount of downstream dependencies changes.

Ticket

COSDK-1097

Checklist

• Tested changes locally
• Added/updated unit tests
• Verified against acceptance criteria

[gemini-code-assist]

Code Review

This pull request introduces a custom localization framework for the Adyen SDK, allowing developers to override default UI strings via a new CheckoutLocalizationProvider protocol. The implementation includes the definition of public and internal localization keys, updates to various component configurations to propagate the provider, and an adapter for cross-module compatibility. Unit tests and a demo implementation are also provided. Review feedback highlights a potential runtime risk due to enum mapping and suggests using CaseIterable to ensure exhaustive synchronization between modules.

[github-actions]

ℹ️ No baseline data found for 'feature/cosdk-1097-ios-v6-custom-localization-develop'.

Framework	Size
AdyenComponents.framework	2821 KB
AdyenActions.framework	2411 KB
AdyenDropIn.framework	1329 KB
AdyenDelegatedAuthentication.framework	98 KB
AdyenAuthentication.framework	347 KB
AdyenWeChatPay.framework	266 KB
AdyenUI.framework	3357 KB
AdyenCardScanner.framework	699 KB
AdyenEncryption.framework	508 KB
AdyenSession.framework	753 KB
AdyenTwint.framework	282 KB
AdyenWeChatPayInternal.framework	4135 KB
AdyenCheckout.framework	2036 KB
AdyenCashAppPay.framework	1781 KB
AdyenCard.framework	1736 KB
TwintSDK.framework	97 KB
Adyen3DS2.framework	919 KB
Adyen.framework	5109 KB
total	28684 KB

[atmamont]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces the CheckoutLocalizationProvider protocol and CheckoutLocalizationKey enum to facilitate custom localization across checkout components. The localizationProvider property was added to multiple configuration objects, including those for Card, 3DS2, Twint, ACH, and BLIK, and integrated into the CheckoutComponentBuilder for propagation. Unit tests and a demo implementation were also provided. Feedback suggests explicitly defining snake_case raw values for the localization keys to align with the Android SDK and updating the configuration setter to accept optional values for consistency.

[github-actions]

👀 3 public changes detected

Comparing feature/cosdk-1097-ios-v6-custom-localization-phase2 to feature/cosdk-1097-ios-v6-custom-localization-develop

❇️	3 Additions

---

Adyen

❇️ Added

public protocol CheckoutLocalizationProvider {
  func localizedString(
    _ key: Adyen.CheckoutLocalizationKey,
    locale: Foundation.Locale
  ) -> Swift.String?
}

public struct CheckoutLocalizationKey: Swift.Hashable {
  public func hash(into hasher: inout Swift.Hasher) -> Swift.Void
  public static func ==(
    lhs: Adyen.CheckoutLocalizationKey,
    rhs: Adyen.CheckoutLocalizationKey
  ) -> Swift.Bool
  public static let awaitLoading: Adyen.CheckoutLocalizationKey { get }
  public static let blikCode: Adyen.CheckoutLocalizationKey { get }
  public static let blikCodeHint: Adyen.CheckoutLocalizationKey { get }
  public static let blikCodeInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let blikHelperText: Adyen.CheckoutLocalizationKey { get }
  public static let cardDualBrandSelectorDescription: Adyen.CheckoutLocalizationKey { get }
  public static let cardDualBrandSelectorTitle: Adyen.CheckoutLocalizationKey { get }
  public static let cardExpiryDate: Adyen.CheckoutLocalizationKey { get }
  public static let cardExpiryDateHint: Adyen.CheckoutLocalizationKey { get }
  public static let cardExpiryDateInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let cardExpiryDateInvalidTooFarInTheFuture: Adyen.CheckoutLocalizationKey { get }
  public static let cardExpiryDateInvalidTooOld: Adyen.CheckoutLocalizationKey { get }
  public static let cardHolderName: Adyen.CheckoutLocalizationKey { get }
  public static let cardHolderNameInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let cardNumber: Adyen.CheckoutLocalizationKey { get }
  public static let cardNumberInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let cardNumberInvalidUnsupportedBrand: Adyen.CheckoutLocalizationKey { get }
  public static let cardSecurityCode: Adyen.CheckoutLocalizationKey { get }
  public static let cardSecurityCodeHint3Digits: Adyen.CheckoutLocalizationKey { get }
  public static let cardSecurityCodeHint4Digits: Adyen.CheckoutLocalizationKey { get }
  public static let cardSecurityCodeInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let cardSocialSecurityNumber: Adyen.CheckoutLocalizationKey { get }
  public static let cardSocialSecurityNumberInvalid: Adyen.CheckoutLocalizationKey { get }
  public static let cardStorePaymentMethod: Adyen.CheckoutLocalizationKey { get }
  public static let dropInManageFavoritesCardsSectionTitle: Adyen.CheckoutLocalizationKey { get }
  public static let dropInManageFavoritesOthersSectionTitle: Adyen.CheckoutLocalizationKey { get }
  public static let dropInManageFavoritesRemove: Adyen.CheckoutLocalizationKey { get }
  public static let dropInManageFavoritesRemoveConfirmation: Adyen.CheckoutLocalizationKey { get }
  public static let dropInManageFavoritesTitle: Adyen.CheckoutLocalizationKey { get }
  public static let dropInOtherPaymentMethods: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodCardDescription: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodListDescription: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodListFavoritesSectionAction: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodListFavoritesSectionTitle: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodListOptionsSectionTitle: Adyen.CheckoutLocalizationKey { get }
  public static let dropInPaymentMethodListOptionsTitleWithFavorites: Adyen.CheckoutLocalizationKey { get }
  public static let generalBack: Adyen.CheckoutLocalizationKey { get }
  public static let generalCancel: Adyen.CheckoutLocalizationKey { get }
  public static let generalClose: Adyen.CheckoutLocalizationKey { get }
  public static let generalOptional: Adyen.CheckoutLocalizationKey { get }
  public static let generalSearchHint: Adyen.CheckoutLocalizationKey { get }
  public static let mbwayCountryCode: Adyen.CheckoutLocalizationKey { get }
  public static let mbwayInvalidPhoneNumber: Adyen.CheckoutLocalizationKey { get }
  public static let mbwayPhoneNumber: Adyen.CheckoutLocalizationKey { get }
  public var hashValue: Swift.Int { get }
}

AdyenCheckout

CheckoutConfiguration

❇️ Added

public func localizationProvider(_ localizationProvider: any Adyen.CheckoutLocalizationProvider) -> AdyenCheckout.CheckoutConfiguration

---

Analyzed targets: Adyen, AdyenActions, AdyenCard, AdyenCardScanner, AdyenCashAppPay, AdyenCheckout, AdyenComponents, AdyenDelegatedAuthentication, AdyenDropIn, AdyenEncryption, AdyenSession, AdyenSwiftUI, AdyenTwint, AdyenUI, AdyenWeChatPay