How to adjust the number of objects created in Sequence (Laravel 8)

Question

I'm trying to create 30 news items using Seeder and Factory. But I need to create 10 news items with non-null field value published_at(Carbon) and other news items with random values ​​(Carbon/NULL).

In the documentation, I saw an example of this, which created 5 records with the value admin (Y), and another 5 records with the value admin(N).

User::factory()
    ->count(10)
    ->state(new Sequence(
        ['admin' => 'Y'],
        ['admin' => 'N'],
        ))
        ->create();

So far I'm using this code but I can't figure out how to add the number of records with a specific parameter value published_at. For example, use Carbon for 10 items and NULL for 20 items.

/**ArticleSeeder*/
Article::factory()
    ->count(30)
    ->state(new Sequence([
        'published_at' => Factory::create()->dateTimeBetween(
            now()->startOfMonth(),
            now()->endOfMonth()
        ),
    ]))
    ->create();

Answer 1

In a sequence closure, you have access to the $index property, which contains the number of iterations through the sequence so far.

The following is the simplest logic you can use to achieve your desired results.

Article::factory()
->count(30)
->sequence(fn ($sequence) => [
    'published_at' => $sequence->index < 10
                      ?  Factory::create()->dateTimeBetween(
                             now()->startOfMonth(),
                             now()->endOfMonth()
                         );
                      : null
])
->create();