nullValues doesn't work with ->withMeta

[michaelstoffer]

• Laravel Version: 8.40
• Nova Version: 3.29.0
• PHP Version: 8.0.9
• Database Driver & Version:
• Operating System and Version: macOS Catalina 10.15.7
• Browser type and version: Chrome 92.0.4515.159

Description:

I am using a Nova KeyValue field and trying to add pre-populated keys in for the user so all they can do is fill out values. Below is the example of code that I have. I would expect that by setting a null value to '{"title":""}', that it would see this and interpret a null value there. When I dd($value); within nullValues, it never fires which is telling me that it isn't using nullValues at all.

    KeyValue::make('Properties')
        ->nullable()
        ->nullValues(function ($value) {
            dd($value); // This isn't firing.
            return $value == '' || $value == 'null' || (int)$value === 0 || $value == '{"title":""}';
        })
        ->rules('json')
        ->hideFromIndex()
        ->withMeta([
            'value' => $this->properties ?? [
            'title' => '',
        ]
    ])
    ->disableEditingKeys()
    ->disableDeletingRows()