[Auth] More Swift 6 progress (#14867)

Co-authored-by: Morgan Chen <morganchen12@gmail.com>

Author: ncooke3

FirebaseAuth/Sources/Swift/AuthProvider/PhoneAuthProvider.swift

@@ -15,11 +15,13 @@
 import FirebaseCore
 import Foundation
 
+// TODO(Swift 6 Breaking): Make checked Sendable.
+
 /// A concrete implementation of `AuthProvider` for phone auth providers.
 ///
 /// This class is available on iOS only.
 @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
-@objc(FIRPhoneAuthProvider) open class PhoneAuthProvider: NSObject {
+@objc(FIRPhoneAuthProvider) open class PhoneAuthProvider: NSObject, @unchecked Sendable {
   /// A string constant identifying the phone identity provider.
   @objc public static let id = "phone"
   private static let recaptchaVersion = "RECAPTCHA_ENTERPRISE"
@@ -56,7 +58,7 @@ import Foundation
     @objc(verifyPhoneNumber:UIDelegate:completion:)
     open func verifyPhoneNumber(_ phoneNumber: String,
                                 uiDelegate: AuthUIDelegate? = nil,
-                                completion: ((_: String?, _: Error?) -> Void)?) {
+                                completion: (@MainActor (String?, Error?) -> Void)?) {
       verifyPhoneNumber(phoneNumber,
                         uiDelegate: uiDelegate,
                         multiFactorSession: nil,
@@ -75,21 +77,17 @@ import Foundation
     open func verifyPhoneNumber(_ phoneNumber: String,
                                 uiDelegate: AuthUIDelegate? = nil,
                                 multiFactorSession: MultiFactorSession? = nil,
-                                completion: ((_: String?, _: Error?) -> Void)?) {
+                                completion: (@MainActor (String?, Error?) -> Void)?) {
       Task {
         do {
           let verificationID = try await verifyPhoneNumber(
             phoneNumber,
             uiDelegate: uiDelegate,
             multiFactorSession: multiFactorSession
           )
-          await MainActor.run {
-            completion?(verificationID, nil)
-          }
+          await completion?(verificationID, nil)
         } catch {
-          await MainActor.run {
-            completion?(nil, error)
-          }
+          await completion?(nil, error)
         }
       }
     }
@@ -135,7 +133,7 @@ import Foundation
     open func verifyPhoneNumber(with multiFactorInfo: PhoneMultiFactorInfo,
                                 uiDelegate: AuthUIDelegate? = nil,
                                 multiFactorSession: MultiFactorSession?,
-                                completion: ((_: String?, _: Error?) -> Void)?) {
+                                completion: ((String?, Error?) -> Void)?) {
       Task {
         do {
           let verificationID = try await verifyPhoneNumber(
@@ -641,7 +639,6 @@ import Foundation
     private let auth: Auth
     private let callbackScheme: String
     private let usingClientIDScheme: Bool
-    private var recaptchaVerifier: AuthRecaptchaVerifier?
 
     init(auth: Auth) {
       self.auth = auth
@@ -662,7 +659,6 @@ import Foundation
         return
       }
       callbackScheme = ""
-      recaptchaVerifier = AuthRecaptchaVerifier.shared(auth: auth)
     }
 
     private let kAuthTypeVerifyApp = "verifyApp"

FirebaseAuth/Sources/Swift/MultiFactor/MultiFactorInfo.swift

@@ -14,13 +14,15 @@
 
 import Foundation
 
+// TODO(Swift 6 Breaking): Make checked Sendable.
+
 #if os(iOS)
   extension MultiFactorInfo: NSSecureCoding {}
 
   /// Safe public structure used to represent a second factor entity from a client perspective.
   ///
   /// This class is available on iOS only.
-  @objc(FIRMultiFactorInfo) open class MultiFactorInfo: NSObject {
+  @objc(FIRMultiFactorInfo) open class MultiFactorInfo: NSObject, @unchecked Sendable {
     /// The multi-factor enrollment ID.
     @objc(UID) public let uid: String
 

FirebaseAuth/Sources/Swift/MultiFactor/MultiFactorSession.swift

@@ -27,33 +27,46 @@ import Foundation
   @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
   @objc(FIRMultiFactorSession) open class MultiFactorSession: NSObject {
     /// The ID token for an enroll flow. This has to be retrieved after recent authentication.
-    var idToken: String?
+    let idToken: String?
 
     /// The pending credential after an enrolled second factor user signs in successfully with the
     /// first factor.
-    var mfaPendingCredential: String?
+    let mfaPendingCredential: String?
+
+    /// Current user object.
+    let currentUser: User?
 
     /// Multi factor info for the current user.
     var multiFactorInfo: MultiFactorInfo?
 
-    /// Current user object.
-    var currentUser: User?
-
     class func session(for user: User?) -> MultiFactorSession {
       let currentUser = user ?? Auth.auth().currentUser
       guard let currentUser else {
         fatalError("Internal Auth Error: missing user for multifactor auth")
       }
-      return .init(idToken: currentUser.tokenService.accessToken, currentUser: currentUser)
+      return .init(
+        idToken: currentUser.tokenService.accessToken,
+        mfaPendingCredential: nil,
+        multiFactorInfo: nil,
+        currentUser: currentUser
+      )
     }
 
-    init(idToken: String?, currentUser: User) {
-      self.idToken = idToken
-      self.currentUser = currentUser
+    convenience init(mfaCredential: String?) {
+      self.init(
+        idToken: nil,
+        mfaPendingCredential: mfaCredential,
+        multiFactorInfo: nil,
+        currentUser: nil
+      )
     }
 
-    init(mfaCredential: String?) {
-      mfaPendingCredential = mfaCredential
+    private init(idToken: String?, mfaPendingCredential: String?, multiFactorInfo: MultiFactorInfo?,
+                 currentUser: User?) {
+      self.idToken = idToken
+      self.mfaPendingCredential = mfaPendingCredential
+      self.multiFactorInfo = multiFactorInfo
+      self.currentUser = currentUser
     }
   }
 

FirebaseAuth/Sources/Swift/MultiFactor/Phone/PhoneMultiFactorInfo.swift

@@ -14,14 +14,17 @@
 
 import Foundation
 
+// TODO(Swift 6 Breaking): Make checked Sendable.
+
 #if os(iOS)
 
   /// Extends the MultiFactorInfo class for phone number second factors.
   ///
   /// The identifier of this second factor is "phone".
   ///
   /// This class is available on iOS only.
-  @objc(FIRPhoneMultiFactorInfo) open class PhoneMultiFactorInfo: MultiFactorInfo {
+  @objc(FIRPhoneMultiFactorInfo) open class PhoneMultiFactorInfo: MultiFactorInfo,
+    @unchecked Sendable {
     /// The string identifier for using phone as a second factor.
     @objc(FIRPhoneMultiFactorID) public static let PhoneMultiFactorID = "phone"
 

FirebaseAuth/Sources/Swift/MultiFactor/TOTP/TOTPMultiFactorInfo.swift

@@ -14,14 +14,17 @@
 
 import Foundation
 
+// TODO(Swift 6 Breaking): Make checked Sendable. Also, does this need
+// to be public?
+
 #if os(iOS)
 
   /// Extends the MultiFactorInfo class for time based one-time password second factors.
   ///
   /// The identifier of this second factor is "totp".
   ///
   /// This class is available on iOS only.
-  class TOTPMultiFactorInfo: MultiFactorInfo {
+  class TOTPMultiFactorInfo: MultiFactorInfo, @unchecked Sendable {
     /// Initialize the AuthProtoMFAEnrollment instance with proto.
     /// - Parameter proto: AuthProtoMFAEnrollment proto object.
     init(proto: AuthProtoMFAEnrollment) {