Inconsistent Data being associate on belongsTo - php

Question

I am creating a feature test on one to many relationship. I just have a simple one to many relation with a proper setup base on the Laravel documentation. My test goes like this.
/** #test */
public function it_attach_containers()
{
$this->withoutExceptionHandling();
$vendor = factory(Vendor::class)->create();
$containersCount = 30;
$containers = factory(Container::class, $containersCount)->create();
$user = factory(User::class)->create();
$attributes = [
'vendor' => $vendor->id,
'ordered' => null,
'deployed' => null,
'last_contact' => null,
'containers' => $containers->pluck('name')
];
$response = $this->actingAs($user, 'api')
->withHeaders([
'X-Requested-With' => 'XMLHttpRequest'
])
->json('POST', '/api/deployments', $attributes);
$deployment = Deployment::find($containers[0]->id);
$this->assertInstanceOf(Deployment::class, $deployment);
$this->assertCount($containersCount, $deployment->containers()->get());
$this->assertDatabaseHas('deployments', [
'vendor' => $vendor->id,
'ordered' => null,
'deployed' => null,
'last_contact' => null
]);
}
The relation I have is a one to many relationship. A one deployment has many container. The code below is how I associate relation..
public function associateDeployment(Deployment $deployment, $data)
{
foreach ($data['containers'] as $containerName) {
$container = Container::where('name', $containerName)->first();
if (!$container) {
$container = Container::create([
'name' => $containerName,
'status' => true
]);
}
if (is_null($container->deployment_id)) {
$container->deployment()->associate($deployment);
$container->save();
}
}
}
The result on my test is really weird. sometimes it pass but sometimes not. I notice that the issue occur on the assertCount. as you can see on my test. it assert if the containers is 30. but mostly it didnt go up to 30. its about 25-29.. then sometimes it pass. what do you think is the problem?

Answer 1

I think the bug is the following line:
$deployment = Deployment::find($containers[0]->id);
Here you are fetching a deployment record by using container id. Instead use the following code:
$deployment = Deployment::find($containers[0]->deployment_id);