Is recycle method from factory random?

[Barbapapazes]

Hello 👋,

There is something I'm not understanding with the recycle method.

$emoji = Emoji::all();

$posts = Post::factory()
    ->count(50)
    ->create();

$users = User::factory()
    ->count(50)
    ->create();

$reactions = Reaction::factory()
    ->count(500)
    ->recycle([$posts, $emoji, $users])
    ->create();

With the following code, I expect that the first reaction to be post=1, emoji=1, user=1, then post=1, emoji=1, user=2 (or something like this but at the end, a predictable sequence where the recycle loop over small collections).

But, I've this in my database:

Which is clearly not a predictable sequence.

My issue is that I have the following SQL rule:

$table->unique(['post_id', 'emoji_id', 'user_id']);

And the randomness cause SQL unique constraint to fail during seeding.

   Illuminate\Database\UniqueConstraintViolationException 

  SQLSTATE[23000]: Integrity constraint violation: 19 UNIQUE constraint failed: reactions.post_id, reactions.emoji_id, reactions.user_id (Connection: sqlite, SQL: insert into "reactions" ("post_id", "emoji_id", "user_id", "updated_at", "created_at") values (17, 4, 38, 2024-10-04 07:57:32, 2024-10-04 07:57:32))

How could I solve this issue?

[markunsworth]

Yes, it looks like the models are taken at random from the recycle collections in the factory.

public function getRandomRecycledModel($modelClassName)
{
    return $this->recycle->get($modelClassName)?->random();
}

I think creating models where unique constraints are necessary is a fairly common use case, i tend to code around it in the seeders by generating a Sequence that I know is correct and passing that in but it feels like the factory should/could handle this.

I'd propose that the recycle method was extended to allow something like a useOnce flag or perhaps a recycleOnce method was added for passing in models, so that when a model is used inside the factory it's popped off the recycle collection internally.