Throw UnsupportedOperationException in FirebaseAuthInterop getUid for regionalAuth

Author: mansisampat

packages/auth/src/core/auth/firebase_internal.test.ts

@@ -326,4 +326,13 @@ describe('core/auth/firebase_internal - Regional Firebase Auth', () => {
       expect(await regionalAuthInternal.getToken()).to.eql(null);
     });
   });
+
+  context('getUid', () => {
+    it('returns null if currentUser is undefined', () => {
+      expect(() => regionalAuthInternal.getUid()).to.throw(
+        FirebaseError,
+        'auth/operation-not-allowed'
+      );
+    });
+  });
 });

packages/auth/src/core/auth/firebase_internal.ts

@@ -36,6 +36,7 @@ export class AuthInterop implements FirebaseAuthInternal {
 
   getUid(): string | null {
     this.assertAuthConfigured();
+    this.assertRegionalAuthConfigured();
     return this.auth.currentUser?.uid || null;
   }
 
@@ -90,6 +91,13 @@ export class AuthInterop implements FirebaseAuthInternal {
     );
   }
 
+
+  private assertRegionalAuthConfigured(): void {
+    _assert(
+      !this.auth.tenantConfig,
+      AuthErrorCode.OPERATION_NOT_ALLOWED);
+  }
+
   private updateProactiveRefresh(): void {
     if (this.internalListeners.size > 0) {
       this.auth._startProactiveRefresh();