refactor(auth)!: align Google auth provider helpers

Author: russellwheatley

.github/scripts/compare-types/configs/auth.ts

@@ -165,11 +165,6 @@ const config: PackageConfig = {
       reason:
         'Native provider flows resolve immediately with a UserCredential instead of following the browser redirect contract used by the firebase-js-sdk.',
     },
-    {
-      name: 'GoogleAuthProvider',
-      reason:
-        'RN Firebase now exposes the firebase-js-sdk static fields and OAuthCredential return type, but its native helper class still omits credentialFromResult/credentialFromError helpers because native provider results do not expose web credential extraction.',
-    },
     {
       name: 'OAuthProvider',
       reason:

packages/auth/e2e/provider.e2e.js

@@ -178,6 +178,13 @@ describe('auth() -> Providers', function () {
           firebase.auth.GoogleAuthProvider.PROVIDER_ID.should.equal('google.com');
         });
       });
+
+      describe('credential extraction helpers', function () {
+        it('should return null for native provider results and errors', function () {
+          should.equal(firebase.auth.GoogleAuthProvider.credentialFromResult({}), null);
+          should.equal(firebase.auth.GoogleAuthProvider.credentialFromError({}), null);
+        });
+      });
     });
 
     describe('OAuthProvider', function () {
@@ -626,6 +633,15 @@ describe('auth() -> Providers', function () {
           GoogleAuthProvider.PROVIDER_ID.should.equal('google.com');
         });
       });
+
+      describe('credential extraction helpers', function () {
+        it('should return null for native provider results and errors', function () {
+          const { GoogleAuthProvider } = authModular;
+
+          should.equal(GoogleAuthProvider.credentialFromResult({}), null);
+          should.equal(GoogleAuthProvider.credentialFromError({}), null);
+        });
+      });
     });
 
     describe('OAuthProvider', function () {

packages/auth/lib/providers/GoogleAuthProvider.ts

@@ -15,7 +15,10 @@
  *
  */
 
-import type { OAuthCredential } from '../types/auth';
+import type { AuthError, OAuthCredential, UserCredential } from '../types/auth';
+
+// Keep the SDK helper signature name while mapping to RNFB's native auth error type.
+type FirebaseError = AuthError;
 
 const providerId = 'google.com' as const;
 
@@ -54,4 +57,12 @@ export default class GoogleAuthProvider {
       },
     };
   }
+
+  static credentialFromResult(_userCredential: UserCredential): OAuthCredential | null {
+    return null;
+  }
+
+  static credentialFromError(_error: FirebaseError): OAuthCredential | null {
+    return null;
+  }
 }

packages/auth/type-test.ts

@@ -168,6 +168,12 @@ const githubCredentialFromError: OAuthCredential | null = GithubAuthProvider.cre
   {} as AuthError,
 );
 const googleCredential: OAuthCredential = GoogleAuthProvider.credential('google-id-token', null);
+const googleCredentialFromResult: OAuthCredential | null = GoogleAuthProvider.credentialFromResult(
+  {} as UserCredential,
+);
+const googleCredentialFromError: OAuthCredential | null = GoogleAuthProvider.credentialFromError(
+  {} as AuthError,
+);
 const twitterCredential: OAuthCredential = TwitterAuthProvider.credential(
   'twitter-token',
   'twitter-secret',
@@ -191,6 +197,8 @@ console.log(githubCredential.accessToken);
 console.log(githubCredentialFromResult?.accessToken);
 console.log(githubCredentialFromError?.accessToken);
 console.log(googleCredential.idToken);
+console.log(googleCredentialFromResult?.idToken);
+console.log(googleCredentialFromError?.idToken);
 console.log(twitterCredential.accessToken);
 console.log(
   ActionCodeOperation.VERIFY_EMAIL,