auto link accounts

Author: russellwheatley

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Services/AuthService.swift

@@ -14,17 +14,6 @@ public protocol PhoneAuthProviderProtocol {
   @MainActor func verifyPhoneNumber(phoneNumber: String) async throws -> String
 }
 
-public enum AuthenticationProvider {
-  case email
-  case google
-}
-
-public enum AuthenticationOperationType: String {
-  case signIn
-  case signUp
-  case deleteAccount
-}
-
 public enum AuthenticationState {
   case unauthenticated
   case authenticating
@@ -153,17 +142,32 @@ public final class AuthService {
     updateAuthenticationState()
   }
 
-  public func signIn(with credentials: AuthCredential) async throws {
+  public func linkAccounts(credentials credentials: AuthCredential) async throws {
     authenticationState = .authenticating
     do {
-      try await auth.signIn(with: credentials)
+      try await currentUser?.link(with: credentials)
       updateAuthenticationState()
     } catch {
       authenticationState = .unauthenticated
       throw error
     }
   }
 
+  public func signIn(credentials credentials: AuthCredential) async throws {
+    authenticationState = .authenticating
+    if currentUser?.isAnonymous == true, configuration.shouldAutoUpgradeAnonymousUsers {
+      try await linkAccounts(credentials: credentials)
+    } else {
+      do {
+        try await auth.signIn(with: credentials)
+        updateAuthenticationState()
+      } catch {
+        authenticationState = .unauthenticated
+        throw error
+      }
+    }
+  }
+
   func sendEmailVerification() async throws {
     if currentUser != nil {
       do {
@@ -181,11 +185,12 @@ public final class AuthService {
 public extension AuthService {
   func signIn(withEmail email: String, password: String) async throws {
     let credential = EmailAuthProvider.credential(withEmail: email, password: password)
-    try await auth.signIn(with: credential)
+    try await signIn(credentials: credential)
   }
 
   func createUser(withEmail email: String, password: String) async throws {
     authenticationState = .authenticating
+
     do {
       try await auth.createUser(withEmail: email, password: password)
       updateAuthenticationState()
@@ -252,7 +257,7 @@ public extension AuthService {
       }
       let credential = try await safeGoogleProvider.signInWithGoogle(clientID: clientID)
 
-      try await signIn(with: credential)
+      try await signIn(credentials: credential)
       updateAuthenticationState()
     } catch {
       authenticationState = .unauthenticated
@@ -269,7 +274,7 @@ public extension AuthService {
     do {
       let credential = try await safeFacebookProvider
         .signInWithFacebook(isLimitedLogin: limitedLogin)
-      try await signIn(with: credential)
+      try await signIn(credentials: credential)
       updateAuthenticationState()
     } catch {
       authenticationState = .unauthenticated
@@ -290,7 +295,7 @@ public extension AuthService {
     do {
       let credential = PhoneAuthProvider.provider()
         .credential(withVerificationID: verificationID, verificationCode: verificationCode)
-      try await signIn(with: credential)
+      try await signIn(credentials: credential)
       updateAuthenticationState()
     } catch {
       authenticationState = .unauthenticated

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Views/EmailAuthView.swift

@@ -4,6 +4,7 @@
 //
 //  Created by Russell Wheatley on 20/03/2025.
 //
+import FirebaseAuth
 import SwiftUI
 
 private enum FocusableField: Hashable {
@@ -36,10 +37,19 @@ public struct EmailAuthView {
   private func signInWithEmailPassword() async {
     do {
       try await authService.signIn(withEmail: email, password: password)
-    } catch {
-      errorMessage = authService.string.localizedErrorMessage(
-        for: error
-      )
+    } catch let error as NSError {
+      switch AuthErrorCode(rawValue: error.code) {
+      case .credentialAlreadyInUse:
+        // TODO: - how are we handling this?
+        if let updatedCredential = error
+          .userInfo[AuthErrorUserInfoUpdatedCredentialKey] as? AuthCredential {
+          // user ought to merge accounts on their backend here
+        }
+      default:
+        errorMessage = authService.string.localizedErrorMessage(
+          for: error
+        )
+      }
     }
   }
 

samples/swiftui/FirebaseSwiftUIExample/FirebaseSwiftUIExample/FirebaseSwiftUIExampleApp.swift

@@ -78,13 +78,18 @@ struct ContentView: View {
   let authService: AuthService
 
   init() {
+    // Auth.auth().signInAnonymously()
+
     let actionCodeSettings = ActionCodeSettings()
     actionCodeSettings.handleCodeInApp = true
     actionCodeSettings
       .url = URL(string: "https://flutterfire-e2e-tests.firebaseapp.com")
     actionCodeSettings.linkDomain = "flutterfire-e2e-tests.firebaseapp.com"
     actionCodeSettings.setIOSBundleID(Bundle.main.bundleIdentifier!)
-    let configuration = AuthConfiguration(emailLinkSignInActionCodeSettings: actionCodeSettings)
+    let configuration = AuthConfiguration(
+      shouldAutoUpgradeAnonymousUsers: true,
+      emailLinkSignInActionCodeSettings: actionCodeSettings
+    )
     let facebookProvider = FacebookProviderSwift()
     let phoneAuthProvider = PhoneAuthProviderSwift()
     authService = AuthService(