fix(storage): restore legacy userdefaults keys and suites for v11 compatibility

AppCheckCore/Sources/AppAttestProvider/Storage/AppCheckCoreAppAttestKeyIDStorage.swift

@@ -25,18 +25,21 @@ public protocol AppCheckCoreAppAttestKeyIDStorageProtocol: NSObjectProtocol {
   @objc func getAppAttestKeyID() async throws -> String?
 }
 
-private let kKeyIDStorageDefaultsSuiteName = "com.firebase.AppCheckCoreAppAttestKeyIDStorage"
-
 @objc(GACAppAttestKeyIDStorage)
 public class AppCheckCoreAppAttestKeyIDStorage: NSObject,
   AppCheckCoreAppAttestKeyIDStorageProtocol {
+  /// Suite name for the app attest key ID in UserDefaults.
+  /// Do not rename: retains the "GAC" prefix for compatibility with existing stored data from v11
+  /// or lower.
+  static let keyIDStorageDefaultsSuiteName = "com.firebase.GACAppAttestKeyIDStorage"
+
   private let keySuffix: String
   private let userDefaults: GULUserDefaults
 
   @objc(initWithKeySuffix:)
   public init(keySuffix: String) {
     self.keySuffix = keySuffix
-    userDefaults = GULUserDefaults(suiteName: kKeyIDStorageDefaultsSuiteName)
+    userDefaults = GULUserDefaults(suiteName: Self.keyIDStorageDefaultsSuiteName)
     super.init()
   }
 

AppCheckCore/Sources/DebugProvider/AppCheckCoreDebugProvider.swift

@@ -25,12 +25,20 @@ import Foundation
 
 private let kDebugTokenEnvKey = "AppCheckDebugToken"
 private let kFirebaseDebugTokenEnvKey = "FIRAAppCheckDebugToken"
-private let kDebugTokenUserDefaultsKey = "AppCheckCoreDebugToken"
-private let kDebugTokenRegisteredUserDefaultsKey = "AppCheckCoreDebugTokenRegistered"
 
 @objc(GACAppCheckDebugProvider)
 @objcMembers
 public class AppCheckCoreDebugProvider: NSObject, AppCheckCoreProvider {
+  /// Storage key for the debug token in UserDefaults.
+  /// Do not rename: retains the "GAC" prefix for compatibility with existing stored data from v11
+  /// or lower.
+  static let debugTokenUserDefaultsKey = "GACAppCheckDebugToken"
+
+  /// Storage key prefix for registered debug tokens in UserDefaults.
+  /// Do not rename: retains the "GAC" prefix for compatibility with existing stored data from v11
+  /// or lower.
+  static let debugTokenRegisteredUserDefaultsKeyPrefix = "GACAppCheckDebugTokenRegistered"
+
   private let apiService: AppCheckCoreDebugProviderAPIServiceProtocol
   private let debugTokenEnvValue: String?
   private let registeredUserDefaultsKey: String
@@ -156,11 +164,11 @@ public class AppCheckCoreDebugProvider: NSObject, AppCheckCoreProvider {
   }
 
   private static func localDebugToken() -> String {
-    if let token = GULUserDefaults.standard().string(forKey: kDebugTokenUserDefaultsKey) {
+    if let token = GULUserDefaults.standard().string(forKey: debugTokenUserDefaultsKey) {
       return token
     } else {
       let token = UUID().uuidString
-      GULUserDefaults.standard().setObject(token, forKey: kDebugTokenUserDefaultsKey)
+      GULUserDefaults.standard().setObject(token, forKey: debugTokenUserDefaultsKey)
       return token
     }
   }
@@ -172,7 +180,7 @@ public class AppCheckCoreDebugProvider: NSObject, AppCheckCoreProvider {
     if safeResourceName.isEmpty {
       safeResourceName = "default"
     }
-    return "\(kDebugTokenRegisteredUserDefaultsKey)_\(safeServiceName)_\(safeResourceName)"
+    return "\(debugTokenRegisteredUserDefaultsKeyPrefix)_\(safeServiceName)_\(safeResourceName)"
   }
 
   private static func environmentVariableDebugToken(registeredUserDefaultsKey: String,

AppCheckCore/Tests/Unit/AppAttestProvider/Storage/AppCheckCoreAppAttestKeyIDStorageTests.swift

@@ -54,6 +54,46 @@ class AppCheckCoreAppAttestKeyIDStorageTests: XCTestCase {
     XCTAssertNil(setKeyID)
   }
 
+  // IMMUTABLE TEST: Do not edit, update, or remove under any circumstance.
+  // This test locks in an immutable backwards compatibility contract with App Check 11.
+  // If this test fails, revert changes to the implementation instead of modifying this test.
+  func testKeyIDStorageDefaultsSuiteName_MatchesContract() {
+    XCTAssertEqual(
+      AppCheckCoreAppAttestKeyIDStorage.keyIDStorageDefaultsSuiteName,
+      "com.firebase.GACAppAttestKeyIDStorage",
+      "Suite name mismatch breaks App Check 11 migration compatibility."
+    )
+  }
+
+  func testGetAppAttestKeyID_CompatibilityWithLegacyGACStorage() async throws {
+    let legacySuiteName = AppCheckCoreAppAttestKeyIDStorage.keyIDStorageDefaultsSuiteName
+    let legacyDefaults = try XCTUnwrap(UserDefaults(suiteName: legacySuiteName))
+    let legacyKey = "app_attest_keyID.\(keySuffix!)"
+    let expectedKeyID = "legacy_test_key_id"
+    legacyDefaults.set(expectedKeyID, forKey: legacyKey)
+    defer {
+      legacyDefaults.removeObject(forKey: legacyKey)
+    }
+
+    let retrievedKeyID = try await storage.getAppAttestKeyID()
+    XCTAssertEqual(retrievedKeyID, expectedKeyID)
+  }
+
+  func testSetAppAttestKeyID_CompatibilityWithLegacyGACStorage() async throws {
+    let legacySuiteName = AppCheckCoreAppAttestKeyIDStorage.keyIDStorageDefaultsSuiteName
+    let legacyDefaults = try XCTUnwrap(UserDefaults(suiteName: legacySuiteName))
+    let legacyKey = "app_attest_keyID.\(keySuffix!)"
+    let newKeyID = "new_test_key_id"
+    defer {
+      legacyDefaults.removeObject(forKey: legacyKey)
+    }
+
+    _ = try await storage.setAppAttestKeyID(newKeyID)
+
+    let storedValue = legacyDefaults.string(forKey: legacyKey)
+    XCTAssertEqual(storedValue, newKeyID)
+  }
+
   func testGetAppAttestKeyID_WhenAppAttestKeyIDNotFoundError() async {
     do {
       _ = try await storage.getAppAttestKeyID()

AppCheckCore/Tests/Unit/DebugProvider/AppCheckCoreDebugProviderTests.swift

@@ -47,8 +47,9 @@ class MockAppCheckDebugProviderAPIService: NSObject, AppCheckCoreDebugProviderAP
 class AppCheckCoreDebugProviderTests: XCTestCase {
   let kDebugTokenEnvKey = "AppCheckDebugToken"
   let kFirebaseDebugTokenEnvKey = "FIRAAppCheckDebugToken"
-  let kDebugTokenUserDefaultsKey = "AppCheckCoreDebugToken"
-  let kDebugTokenRegisteredUserDefaultsKey = "AppCheckCoreDebugTokenRegistered"
+  let kDebugTokenUserDefaultsKey = AppCheckCoreDebugProvider.debugTokenUserDefaultsKey
+  let kDebugTokenRegisteredUserDefaultsKey = AppCheckCoreDebugProvider
+    .debugTokenRegisteredUserDefaultsKeyPrefix
 
   var provider: AppCheckCoreDebugProvider!
   var fakeAPIService: MockAppCheckDebugProviderAPIService!
@@ -71,6 +72,67 @@ class AppCheckCoreDebugProviderTests: XCTestCase {
 
   // MARK: - Debug token generating/storing
 
+  // IMMUTABLE TEST: Do not edit, update, or remove under any circumstance.
+  // This test locks in an immutable backwards compatibility contract with App Check 11.
+  // If this test fails, revert changes to the implementation instead of modifying this test.
+  func testDebugTokenUserDefaultsKeys_MatchContract() {
+    XCTAssertEqual(
+      AppCheckCoreDebugProvider.debugTokenUserDefaultsKey,
+      "GACAppCheckDebugToken",
+      "Debug token key mismatch breaks App Check 11 migration compatibility."
+    )
+    XCTAssertEqual(
+      AppCheckCoreDebugProvider.debugTokenRegisteredUserDefaultsKeyPrefix,
+      "GACAppCheckDebugTokenRegistered",
+      "Registered token key prefix mismatch breaks App Check 11 migration compatibility."
+    )
+  }
+
+  func testLegacyDebugTokenCompatibility() {
+    let legacyKey = kDebugTokenUserDefaultsKey
+    let legacyToken = "legacy_stored_debug_token"
+    UserDefaults.standard.set(legacyToken, forKey: legacyKey)
+    defer {
+      UserDefaults.standard.removeObject(forKey: legacyKey)
+    }
+
+    let debugProvider = AppCheckCoreDebugProvider(
+      apiService: fakeAPIService,
+      serviceName: "test-service",
+      resourceName: "projects/test-project/apps/test-app",
+      environment: [:]
+    )
+
+    XCTAssertEqual(
+      debugProvider.currentDebugToken(),
+      legacyToken,
+      "Debug token mismatch breaks App Check 11 migration compatibility."
+    )
+  }
+
+  func testSetDebugToken_CompatibilityWithLegacyGACStorage() {
+    let legacyKey = kDebugTokenUserDefaultsKey
+    UserDefaults.standard.removeObject(forKey: legacyKey)
+    defer {
+      UserDefaults.standard.removeObject(forKey: legacyKey)
+    }
+
+    let debugProvider = AppCheckCoreDebugProvider(
+      apiService: fakeAPIService,
+      serviceName: "test-service",
+      resourceName: "projects/test-project/apps/test-app",
+      environment: [:]
+    )
+
+    let generatedToken = debugProvider.currentDebugToken()
+    let storedLegacyValue = UserDefaults.standard.string(forKey: legacyKey)
+    XCTAssertEqual(
+      storedLegacyValue,
+      generatedToken,
+      "Generated debug token was not stored under legacy key."
+    )
+  }
+
   func testCurrentTokenWhenEnvironmentVariableSetAndTokenStored() {
     UserDefaults.standard.set("stored token", forKey: kDebugTokenUserDefaultsKey)
     let envToken = "env token"