Add support for FirebaseAppCheck APIs (#61)

Author: marcprux

Sources/SkipFirebaseAppCheck/Skip/skip.yml

@@ -10,3 +10,5 @@ build:
     - block: 'dependencies'
       contents:
         - 'implementation("com.google.firebase:firebase-appcheck")'
+        - 'implementation("com.google.firebase:firebase-appcheck-debug")'
+        - 'implementation("com.google.firebase:firebase-appcheck-playintegrity")'

Sources/SkipFirebaseAppCheck/SkipFirebaseAppCheck.swift

@@ -1,26 +1,158 @@
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 #if !SKIP_BRIDGE
 #if SKIP
+import Foundation
 import SkipFirebaseCore
 import kotlinx.coroutines.tasks.await
 
 // https://firebase.google.com/docs/reference/swift/firebaseappcheck/api/reference/Classes/AppCheck
 // https://firebase.google.com/docs/reference/android/com/google/firebase/appcheck/FirebaseAppCheck
 
 public final class AppCheck {
-    public let appcheck: com.google.firebase.appcheck.FirebaseAppCheck
+    public let platformValue: com.google.firebase.appcheck.FirebaseAppCheck
 
-    public init(appcheck: com.google.firebase.appcheck.FirebaseAppCheck) {
-        self.appcheck = appcheck
+    public init(platformValue: com.google.firebase.appcheck.FirebaseAppCheck) {
+        self.platformValue = platformValue
     }
 
     public static func appCheck() -> AppCheck {
-        AppCheck(appcheck: com.google.firebase.appcheck.FirebaseAppCheck.getInstance())
+        AppCheck(platformValue: com.google.firebase.appcheck.FirebaseAppCheck.getInstance())
     }
 
     public static func appCheck(app: FirebaseApp) -> AppCheck {
-        AppCheck(appcheck: com.google.firebase.appcheck.FirebaseAppCheck.getInstance(app.app))
+        AppCheck(platformValue: com.google.firebase.appcheck.FirebaseAppCheck.getInstance(app.app))
+    }
+
+    /// Sets the provider factory for App Check.
+    /// On iOS this is a static method; on Android it calls `installAppCheckProviderFactory` on the instance.
+    public static func setAppCheckProviderFactory(_ factory: AppCheckProviderFactory?) {
+        guard let factory = factory else { return }
+        com.google.firebase.appcheck.FirebaseAppCheck.getInstance().installAppCheckProviderFactory(factory.platformValue)
+    }
+
+    /// Requests a Firebase App Check token.
+    /// - Parameter forcingRefresh: If `true`, forces a token refresh even if the cached token is still valid.
+    /// - Returns: An `AppCheckToken` containing the token string and expiration date.
+    public func token(forcingRefresh: Bool) async throws -> AppCheckToken {
+        let result = platformValue.getAppCheckToken(forcingRefresh).await()
+        return AppCheckToken(platformValue: result)
+    }
+
+    /// Requests a limited-use Firebase App Check token for server-side replay protection.
+    /// - Returns: An `AppCheckToken` containing the token string and expiration date.
+    public func limitedUseToken() async throws -> AppCheckToken {
+        let result = platformValue.getLimitedUseAppCheckToken().await()
+        return AppCheckToken(platformValue: result)
+    }
+
+    /// Controls whether the App Check SDK automatically refreshes the token when needed.
+    public var isTokenAutoRefreshEnabled: Bool {
+        // Android only exposes a setter; store and return the last set value
+        get { _isTokenAutoRefreshEnabled }
+        set {
+            _isTokenAutoRefreshEnabled = newValue
+            platformValue.setTokenAutoRefreshEnabled(newValue)
+        }
+    }
+    private var _isTokenAutoRefreshEnabled: Bool = false
+
+    /// The notification name posted when the App Check token changes.
+    /// On Android this is backed by `AppCheckListener`.
+    // SKIP @nobridge // no support for bridging notifications yet
+    public static let appCheckTokenDidChangeNotification = Notification.Name("AppCheckAppCheckTokenDidChangeNotification")
+
+    /// Adds a listener that is called when the App Check token changes.
+    /// - Parameter listener: A closure called with the updated `AppCheckToken`.
+    /// - Returns: An opaque listener handle that can be passed to `removeTokenChangeListener`.
+    public func addTokenChangeListener(_ listener: @escaping (AppCheckToken) -> Void) -> AppCheckListenerHandle {
+        let androidListener = com.google.firebase.appcheck.FirebaseAppCheck.AppCheckListener { token in
+            let wrapped = AppCheckToken(platformValue: token)
+            listener(wrapped)
+            NotificationCenter.default.post(
+                name: AppCheck.appCheckTokenDidChangeNotification,
+                object: self,
+                userInfo: [AppCheckTokenNotificationKey: wrapped]
+            )
+        }
+        platformValue.addAppCheckListener(androidListener)
+        return AppCheckListenerHandle(platformValue: androidListener)
+    }
+
+    /// Removes a previously added token change listener.
+    public func removeTokenChangeListener(_ handle: AppCheckListenerHandle) {
+        platformValue.removeAppCheckListener(handle.platformValue)
+    }
+}
+
+// MARK: - AppCheckToken
+
+/// A token returned by the App Check service, containing the token string and its expiration.
+public final class AppCheckToken {
+    public let platformValue: com.google.firebase.appcheck.AppCheckToken
+
+    public init(platformValue: com.google.firebase.appcheck.AppCheckToken) {
+        self.platformValue = platformValue
+    }
+
+    /// The token string to include in requests to your backend.
+    public var token: String {
+        platformValue.getToken()
+    }
+
+    /// The expiration date of this token.
+    public var expirationDate: Date {
+        Date(timeIntervalSince1970: Double(platformValue.getExpireTimeMillis()) / 1000.0)
     }
 }
+
+/// Key for retrieving the `AppCheckToken` from the `userInfo` dictionary of an `appCheckTokenDidChangeNotification`.
+public let AppCheckTokenNotificationKey = "AppCheckTokenNotificationKey"
+
+// MARK: - AppCheckListenerHandle
+
+/// An opaque handle for a registered token change listener.
+public class AppCheckListenerHandle {
+    public let platformValue: com.google.firebase.appcheck.FirebaseAppCheck.AppCheckListener
+
+    public init(platformValue: com.google.firebase.appcheck.FirebaseAppCheck.AppCheckListener) {
+        self.platformValue = platformValue
+    }
+}
+
+// MARK: - AppCheckProviderFactory
+
+/// A wrapper around the Android `AppCheckProviderFactory` that matches the Swift `AppCheckProviderFactory` protocol.
+public class AppCheckProviderFactory {
+    public let platformValue: com.google.firebase.appcheck.AppCheckProviderFactory
+
+    public init(platformValue: com.google.firebase.appcheck.AppCheckProviderFactory) {
+        self.platformValue = platformValue
+    }
+}
+
+// MARK: - AppCheckDebugProviderFactory
+
+/// A factory that creates debug App Check providers, useful for testing.
+/// On iOS this is `AppCheckDebugProviderFactory`; on Android it is `DebugAppCheckProviderFactory`.
+public class AppCheckDebugProviderFactory: AppCheckProviderFactory {
+    public init() {
+        super.init(platformValue: com.google.firebase.appcheck.debug.DebugAppCheckProviderFactory.getInstance())
+    }
+}
+
+// MARK: - AppCheckError
+
+/// Error codes for App Check operations, matching the Swift `AppCheckErrorCode` enum.
+public enum AppCheckErrorCode: Int {
+    case unknown = 0
+    case serverUnreachable = 1
+    case invalidConfiguration = 2
+    case keychain = 3
+    case unsupported = 4
+}
+
+/// The error domain for App Check errors.
+public let AppCheckErrorDomain = "FIRAppCheckErrorDomain"
+
 #endif
 #endif

Tests/SkipFirebaseAppCheckTests/SkipFirebaseAppCheckTests.swift

@@ -15,7 +15,25 @@ let logger: Logger = Logger(subsystem: "SkipFirebaseAppCheckTests", category: "T
 @MainActor final class SkipFirebaseAppCheckTests: XCTestCase {
     func testSkipFirebaseAppCheckTests() async throws {
         if false {
-            let _: AppCheck = AppCheck.appCheck()
+            let appCheck: AppCheck = AppCheck.appCheck()
+            //let _: AppCheck = AppCheck.appCheck(app: FirebaseApp.app()!)
+
+            // Provider factory
+            let debugFactory = AppCheckDebugProviderFactory()
+            AppCheck.setAppCheckProviderFactory(debugFactory)
+
+            // Token retrieval
+            let token: AppCheckToken = try await appCheck.token(forcingRefresh: false)
+            let _: String = token.token
+            let _: Date = token.expirationDate
+
+            // Limited-use token
+            let limitedToken: AppCheckToken = try await appCheck.limitedUseToken()
+            let _: String = limitedToken.token
+
+            // Auto-refresh
+            appCheck.isTokenAutoRefreshEnabled = true
+            let _: Bool = appCheck.isTokenAutoRefreshEnabled
         }
     }
 }