ManyToMany relation detach without ids broken after 12.9.0 upgrade

[MatasElectronics]

Laravel Version

12.9.0

PHP Version

8.3.20

Database Driver & Version

sqlite

Description

As of Laravel 12.9.0 the functionality to detach all pivot records on a ManyToMany relation by calling detach without any ids is broken when using a custom pivot model.

The commit 99e1ceb seems to be the problem, where changes have been made to fix pivot model events being fired.

What would happen before is that the && ! empty($ids) call below would cause the else clause to be performed, where a simple delete of all pivot rows would be performed:

But in 12.9.0 this has been changed to only check $this->using, and as we are using a custom pivot model, we got to the detachUsingCustomClass method.

Inside that method there is no check if $ids is empty, so we end up in the foreach ($this->parse($ids) as $id) line, but $ids is empty, so nothing will be deleted.

Steps To Reproduce

1. Create a new Laravel project
2. Create a Role model and migration
3. Create a RoleUser pivot model.
4. Setup the BelongsToMany relation without ->using(RoleUser::class)
5. Write a simple test that creates a User and Role and attach them.
6. Now call $user->roles()->detach() and you'll see the pivot record will be deleted.
7. Now add ->using(RoleUser::class) to the BelongsToMany relation.
8. Run the test again, and you'll see the pivot record is not deleted.

[adzchappers]

Just had this issue with a failing test due to this, came here to add a issue/pr.

->sync([]) can be a temporary workaround.

[npbtrac]

I have been facing the same issues. Just remove all the unnecessary usages of $guarded or $fillable in Pivot classes then everything should be fine.

e.g. you may want to do this

[macropay-solutions]

Cause: #55026