Panel prepareFields can cause the disappearance of fields when the numeric keys are mismatched due to array_filter

[Tarpsvo]

• Laravel Version: 9.48
• Nova Version: 4.21.0
• PHP Version: 8.1

Description:

When you have conditional fields inside a Panel (ie array_filter([somethingIsEnabled() ? Text::make('Whatever') : null]), the panel can cause the disappearance of multiple fields as the numeric keys will become messed up and merging will break.

Detailed steps to reproduce the issue on a fresh Nova installation:

Create a resource with the following fields:

 public function fields(NovaRequest $request)
{
    return [
        Text::make('Name'),

        Panel::make('Twost', array_filter([
            null,
            Text::make('Content'),
        ])),

        Text::make('Where have I gone?'),
    ];
}

And this will happen:

Remove the null from inside the panel and this will show:

Proposed fix

I suggest using ->values()->toArray() instead of ->all() inside Panel's prepareFields() function. I would even go as far as to call ->filter() on the field collection before the rejection statement.

[crynobone]

We have no plan to support null as valid options, as for now you should be able to do the following:

Panel::make('Twost', collect([
    somethingIsEnabled() ? Text::make('Whatever') : null,
    Text::make('Content'),
])->values()->all()),

[crynobone]

In 4.22.0 you can do the following:

Panel::make('Twost', [
    $this->mergeWhen(somethingIsEnabled(), [
        Text::make('Whatever'),
    ]),
    Text::make('Content'),
]),