Game center auth (#12359)

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/Assets.xcassets/Auth Provider Icons/Contents.json

@@ -1,6 +1,6 @@
 {
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
+}

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/Assets.xcassets/Auth Provider Icons/Game Center.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "gamecontroller.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/AuthenticationExample.entitlements

@@ -10,6 +10,8 @@
 	</array>
 	<key>com.apple.developer.associated-domains</key>
 	<array/>
+	<key>com.apple.developer.game-center</key>
+	<true/>
 	<key>keychain-access-groups</key>
 	<array>
 		<string>$(AppIdentifierPrefix)com.google.firebase.auth.keychainGroup1</string>

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/Models/AuthMenu.swift

@@ -24,6 +24,7 @@ enum AuthMenu: String {
   case gitHub = "github.com"
   case yahoo = "yahoo.com"
   case facebook = "facebook.com"
+  case gameCenter = "gc.apple.com"
   case emailPassword = "password"
   case passwordless = "emailLink"
   case phoneNumber = "phone"
@@ -54,6 +55,8 @@ enum AuthMenu: String {
       return "Yahoo"
     case .facebook:
       return "Facebook"
+    case .gameCenter:
+      return "Game Center"
     case .emailPassword:
       return "Email & Password Login"
     case .passwordless:
@@ -91,6 +94,8 @@ enum AuthMenu: String {
       self = .yahoo
     case "Facebook":
       self = .facebook
+    case "Game Center":
+      self = .gameCenter
     case "Email & Password Login":
       self = .emailPassword
     case "Email Link/Passwordless":
@@ -114,7 +119,7 @@ enum AuthMenu: String {
 
 extension AuthMenu: DataSourceProvidable {
   private static var providers: [AuthMenu] {
-    [.google, .apple, .twitter, .microsoft, .gitHub, .yahoo, .facebook]
+    [.google, .apple, .twitter, .microsoft, .gitHub, .yahoo, .facebook, .gameCenter]
   }
 
   static var settingsSection: Section {

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/ViewControllers/AccountLinkingViewController.swift

@@ -14,6 +14,7 @@
 
 import FirebaseAuth
 import FirebaseCore
+import GameKit
 import UIKit
 
 // For Account Linking with Sign in with Google.
@@ -93,6 +94,9 @@ class AccountLinkingViewController: UIViewController, DataSourceProviderDelegate
     case .twitter, .microsoft, .gitHub, .yahoo:
       performOAuthAccountLink(for: provider)
 
+    case .gameCenter:
+      performGameCenterAccountLink()
+
     case .emailPassword:
       performEmailPasswordAccountLink()
 
@@ -233,6 +237,35 @@ class AccountLinkingViewController: UIViewController, DataSourceProviderDelegate
     }
   }
 
+  private func performGameCenterAccountLink() {
+    // Step 1: Ensure Game Center Authentication
+    guard GKLocalPlayer.local.isAuthenticated else {
+      print("Error: Player not authenticated with Game Center.")
+      return
+    }
+
+    // Step 2: Get Game Center Credential for Linking
+    GameCenterAuthProvider.getCredential { credential, error in
+      if let error = error {
+        print("Error getting Game Center credential: \(error.localizedDescription)")
+        return
+      }
+
+      guard let credential = credential else {
+        print("Error: Missing Game Center credential")
+        return
+      }
+
+      // Step 3: Link Credential with Current Firebase User
+      Auth.auth().currentUser?.link(with: credential) { authResult, error in
+        if let error = error {
+          print("Error linking Game Center to Firebase: \(error.localizedDescription)")
+          return
+        }
+      }
+    }
+  }
+
   // MARK: - Email & Password Login Account Linking 🔥
 
   private func performEmailPasswordAccountLink() {

FirebaseAuth/Tests/SampleSwift/AuthenticationExample/ViewControllers/AuthViewController.swift

@@ -18,6 +18,7 @@ import FirebaseAuth
 
 // [START auth_import]
 import FirebaseCore
+import GameKit
 
 // For Sign in with Google
 // [START google_import]
@@ -71,6 +72,9 @@ class AuthViewController: UIViewController, DataSourceProviderDelegate {
     case .twitter, .microsoft, .gitHub, .yahoo:
       performOAuthLoginFlow(for: provider)
 
+    case .gameCenter:
+      performGameCenterLoginFlow()
+
     case .emailPassword:
       performDemoEmailPasswordLoginFlow()
 
@@ -210,6 +214,42 @@ class AuthViewController: UIViewController, DataSourceProviderDelegate {
     }
   }
 
+  private func performGameCenterLoginFlow() {
+    // Step 1: System Game Center Login
+    GKLocalPlayer.local.authenticateHandler = { viewController, error in
+      if let error = error {
+        // Handle Game Center login error
+        print("Error logging into Game Center: \(error.localizedDescription)")
+      } else if let authViewController = viewController {
+        // Present Game Center login UI if needed
+        self.present(authViewController, animated: true)
+      } else {
+        // Game Center login successful, proceed to Firebase
+        self.linkGameCenterToFirebase()
+      }
+    }
+  }
+
+  // Step 2: Link to Firebase
+  private func linkGameCenterToFirebase() {
+    GameCenterAuthProvider.getCredential { credential, error in
+      if let error = error {
+        // Handle Firebase credential retrieval error
+        print("Error getting Game Center credential: \(error.localizedDescription)")
+      } else if let credential = credential {
+        Auth.auth().signIn(with: credential) { authResult, error in
+          if let error = error {
+            // Handle Firebase sign-in error
+            print("Error signing into Firebase with Game Center: \(error.localizedDescription)")
+          } else {
+            // Firebase sign-in successful
+            print("Successfully linked Game Center to Firebase")
+          }
+        }
+      }
+    }
+  }
+
   private func performDemoEmailPasswordLoginFlow() {
     let loginController = LoginController()
     loginController.delegate = self

FirebaseAuth/Tests/SampleSwift/AuthenticationExampleUITests/AuthenticationExampleUITests.swift

@@ -36,11 +36,6 @@ class AuthenticationExampleUITests: XCTestCase {
     XCTAssertTrue(app.navigationBars["Firebase Auth"].exists)
   }
 
-  func testAuthOptions() {
-    // There are 15 sign in methods, each with its own cell
-    XCTAssertEqual(app.tables.cells.count, 15)
-  }
-
   func testAuthAnonymously() {
     app.staticTexts["Anonymous Authentication"].tap()