Fix json encode null

[datlechin]

Fix json encode null in php8.3

Fixes #0000

Changes proposed in this pull request:

Reviewers should focus on:

Screenshot

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).

Required changes:

• Related Flarum core extension PR's: (Omit this section if irrelevant)

[DavideIadeluca]

I'm fine with this, but I think it would make sense to simplify the surrounding logic a little while already at it:

public function handle(SettingsRepositoryInterface $settings, Dispatcher $dispatcher)
{
    $autoAssignGroups = $settings->get('fof-gamification.autoAssignedGroups');
    
    // If the setting is missing or empty, or if the subject user is an admin, we can skip this job
    if (empty($autoAssignGroups) || $this->user->isAdmin()) {
        return;
    }

    $entries = json_decode($autoAssignGroups, true);
..
}

[DavideIadeluca]

Thanks @datlechin!

[luceos]

@DavideIadeluca if you want to do an optimization, although just a slight one, stop early instead of accessing the settings repository first (which you then don't need for an admin):

        if ($this->user->isAdmin()) return;

        return json_decode(
                $settings->get('fof-gamification.autoAssignGroups', '[]'),
                true
        );

[DavideIadeluca]

@DavideIadeluca if you want to do an optimization, although just a slight one, stop early instead of accessing the settings repository first (which you then don't need for an admin):

        if ($this->user->isAdmin()) return;

        return json_decode(
                $settings->get('fof-gamification.autoAssignGroups', '[]'),
                true
        );

Yeah right, makes sense. @datlechin Can you please use the suggestion of @luceos instead? 🙏