thats-me/backend/app/Http/Requests/UpdateSettingsRequest.php

<?php

namespace App\Http\Requests;

use App\Support\SettingsSchema;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Validator;

class UpdateSettingsRequest extends FormRequest
{
    public function authorize(): bool
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
     */
    public function rules(): array
    {
        return SettingsSchema::rules();
    }

    /**
     * Reject keys the schema does not know about instead of persisting them.
     *
     * @return array<int, callable>
     */
    public function after(): array
    {
        return [
            function (Validator $validator): void {
                $this->rejectUnknownKeys(
                    $validator,
                    'settings',
                    (array) $this->input('settings', []),
                    SettingsSchema::allowedKeys(),
                );

                $floatingLines = $this->input('settings.floatingLines');

                if (is_array($floatingLines)) {
                    $this->rejectUnknownKeys(
                        $validator,
                        'settings.floatingLines',
                        $floatingLines,
                        SettingsSchema::allowedFloatingLineKeys(),
                    );
                }
            },
        ];
    }

    /**
     * @param  array<string, mixed>  $given
     * @param  array<int, string>  $allowed
     */
    private function rejectUnknownKeys(
        Validator $validator,
        string $attribute,
        array $given,
        array $allowed,
    ): void {
        $unknown = array_diff(array_keys($given), $allowed);

        if ($unknown === []) {
            return;
        }

        $validator->errors()->add(
            $attribute,
            'Unknown settings keys: '.implode(', ', array_map('strval', $unknown)).'.',
        );
    }
}