updateUser() from GoTrue returns a UserResponse. The UserResponse doesn't contain an error parameter

[JaseElder]

Describe the bug
in updateUser(), updating the user with the same password as current will generate an error: {errorMessage: type 'Null' is not a subtype of type 'UserResponse' in type cast} because in this case it doesn't return a UserResponse

To Reproduce
Steps to reproduce the behavior:

1. call

  final userResponse = await _supabase.auth.updateUser(
        UserAttributes(password: newPassword),
      );

where newPassword == old password.

Expected behavior
I would expect an exception to be thrown, rather than a generic null error.

Version (please complete the following information):
On Linux/macOS

❯ dart pub deps | grep -E "supabase|gotrue|postgrest|storage_client|realtime_client|functions_client"
├── brick_offline_first_with_supabase 1.3.0
│   ├── brick_supabase...
│   └── supabase...
├── brick_offline_first_with_supabase_build 1.1.0
│   ├── brick_offline_first_with_supabase...
│   ├── brick_supabase...
│   ├── brick_supabase_generators 1.2.0
│   │   ├── brick_supabase...
├── brick_supabase 1.4.1+1
│   └── supabase 2.9.2
│       ├── functions_client 2.4.4
│       ├── gotrue 2.15.0
│       ├── postgrest 2.5.0
│       ├── realtime_client 2.5.3
│       ├── storage_client 2.4.1
├── supabase_flutter 2.10.2
│   ├── supabase...

Additional context
Add any other context about the problem here.

[grdsdev]

Hi @JaseElder,

Thanks for reporting this issue! I've looked into it and found that we do have an integration test for this exact scenario (updating a user with the same password), and it's working as expected - the test confirms that an AuthException with ErrorCode.samePassword should be thrown.

However, I wasn't able to reproduce the type cast error you're experiencing. To help us investigate further, could you please provide:

1. A minimal reproducible example - A complete code snippet that demonstrates the issue, including:

   • How you're initializing the Supabase client
   • The exact code that triggers the error
   • Any relevant configuration

2. The full error stack trace - This will help us identify exactly where the type cast is failing

3. The actual response from the backend - If possible, could you log or share what the response object contains when the error occurs? You could add a debug log right before line 734 in updateUser:

   final response = await _fetch.request('/user', RequestMethodType.put, options: options);
   print('Response: $response'); // Add this
   final userResponse = UserResponse.fromJson(response);

4. Backend version - What version of Supabase Auth/GoTrue are you using on the backend?

5. Any custom error handling or interceptors - Are you using any custom HTTP clients or error handling that might affect the response?

The expected behavior is that when you try to update with the same password, the backend should return an error response (non-2xx status code), which should be caught by our error handling and throw an AuthApiException with ErrorCode.samePassword. If you're seeing a type cast error instead, it suggests the response format might be different than expected, or there's an edge case we haven't accounted for.

Once we have a reproducible example, we can fix the issue!