Integrity constraint violation on a nullable field with sqlite testing

I am trying again to get some test set up, but starting to remember why i gave up on them in the past.

I am using PEST, along with laravel modules set up,

PHPunit.xml is set with the following:

 <env name="DB_CONNECTION" value="sqlite"/>
        <env name="DB_DATABASE" value=":memory:"/>

PEST.PHP (note it was suggested to add the foreign keys configuration here and im assuming the uses TestCase, and refreshDatabase is something i set up a while ago to avoid having to type it in every file.

<?php


/*
|--------------------------------------------------------------------------
| Test Case
|--------------------------------------------------------------------------
|
| The closure you provide to your test functions is always bound to a specific PHPUnit test
| case class. By default, that class is "PHPUnit\Framework\TestCase". Of course, you may
| need to change it using the "uses()" function to bind a different classes or traits.
|
*/

use Illuminate\Support\Facades\DB;

uses(Tests\TestCase::class)->in(
    'Feature',
    __DIR__.'/../Modules/*/Tests/Feature',
);

uses(Illuminate\Foundation\Testing\RefreshDatabase::class)->in(
    'Feature',
    __DIR__.'/../Modules/*/Tests/Feature',
);
beforeEach(function () {
    // Enable foreign key support in SQLite for testing.
    DB::statement('PRAGMA foreign_keys=ON;');
});
/*
|--------------------------------------------------------------------------
| Expectations
|--------------------------------------------------------------------------
|
| When you're writing tests, you often need to check that values meet certain conditions. The
| "expect()" function gives you access to a set of "expectations" methods that you can use
| to assert different things. Of course, you may extend the Expectation API at any time.
|
*/

expect()->extend('toBeOne', function () {
    return $this->toBe(1);
});

/*
|--------------------------------------------------------------------------
| Functions
|--------------------------------------------------------------------------
|
| While Pest is very powerful out-of-the-box, you may have some testing code specific to your
| project that you don't want to repeat in every file. Here you can also expose helpers as
| global functions to help you to reduce the number of lines of code in your test files.
|
*/

function something()
{
    // ..
}

TestCase.php doesnt have much in it. not even sure if pest.php is actually being referenced to be honest.

<?php

namespace Tests;

use Illuminate\Foundation\Testing\TestCase as BaseTestCase;
use Illuminate\Support\Facades\DB;

abstract class TestCase extends BaseTestCase
{
    use CreatesApplication;
}

And the actual test case. I probably had an AI make this as i dont know what Im doing. But i am getting the integrity violation on the first creation of a parent category cause it doesnt like my parent_id being null. Php storm is also not recognizing the assert functions. So what do i have to do to make this allow my null foreign id.

here's the column in question: $table->foreignId('parent_id')->nullable()->constrained('tags') ->cascadeOnDelete();

use Modules\Hobbies\Models\Hobby;
use Modules\Site\Models\Tag;


use function Pest\Laravel\get;
use function Pest\Laravel\assertSee;
use function Pest\Laravel\assertViewHas;


it('displays top-level categories and asserts there are three hobbies in subcategories',
    function () {
       
        // Create a parent category
        $parentCategory = Tag::factory()->create([
            'tag'       => 'Parent Category',
            'tag_type'  => 1,
            'parent_id' => null,
        ]);

        // Create three child categories
        $childCategories = Tag::factory()->count(3)->create([
            'tag'       => 'Child Category',
            'tag_type'  => 1,
            'parent_id' => $parentCategory->id,
        ]);

        // Assign a hobby to each child category
        foreach ($childCategories as $category) {
            Hobby::factory()->create()->categories()->attach($category->id);
        }

        // Hit the browse route
        $response = $this->get('/browse');

        // Assert that only top-level categories are displayed
        $response->assertSee($parentCategory->tag);
        foreach ($childCategories as $category) {
            $response->assertDontSee($category->tag);
        }

        // Assert that there are three hobbies displayed
        // You'll need to modify this to match your actual view data
        $response->assertViewHas('hobbies', function ($hobbies) {
            return count($hobbies) === 3;
        });
    });