Laravel model relationship belongsTo with associate() gives infinite loop toArray() - php

Question

I hope someone may help me with the issue I have for a long time, but only now I'm posting it.
The project I'm working on uses models with nested relationships. Just to simplify the context of the issue, let's imagine a parent with many children model relation: hasMany and belongsTo.
I usually create new instances and fill the properties then I relate them by hand using setRelation() and associate() methods (because I like to retrieve the relationships using parent-to-child and child-to-parent methods).
But infinite loops arises after I call toArray() (among many other model methods that traverse its relations).
The question is: Am I doing the right thing caling setRelation and associate for model relationship? If not, how would I retrieve $model->children()/$model->parent() relation?
I'm using Laravel Framework 7.14.1 with PHPUnit 8.5.5 and PHP 7.4.4 (cli)
Here a Unit test:
<?php
namespace Tests\Unit;
use PHPUnit\Framework\TestCase;
use Illuminate\Database\Eloquent\Model;
class Team extends Model {
protected $fillable = ['name'];
public function players()
{
return $this->hasMany(Player::class);
}
}
class Player extends Model {
protected $fillable = ['name'];
public function team()
{
return $this->belongsTo(Team::class);
}
}
class CircularReferencesTest extends TestCase
{
public function testCircularReference(): void
{
// new instances
$team = app(Team::class)->fill(['name' => 'team name']);
$player = app(Player::class)->fill(['name' => 'player name']);
// set relations
$team->setRelation('players', collect([$player]));
$player->team()->associate($team);
dd($team->toArray(), $player->toArray()); // ERROR: Segmentation fault (core dumped).
// dd($team->push()); // push calls save() method recursively #see https://laravel.com/docs/7.x/eloquent-relationships#the-push-method
dd($team, $player);
}
}
I'm calling by:
./vendor/phpunit/phpunit/phpunit --stop-on-failure --colors=always ./tests/Unit/CircularReferencesTest.php

Answer 1

according to this
you can't create a relationship between 2 models that are not already represented in the database.
at least one of the models must be saved in advance, in order to create the relationship.
this is the first issue in your code ...
second one:
setting relation of one side is more than enough.. why you set the relation from the other side?
i mean:
one of those two line is enough:
$team->setRelation('players', collect([$player]));
$player->team()->associate($team);
i prefer using 'associate' method is more clearer ...