using first() in laravel fractal - laravel

Question

I want to transform on the first item of Contacts and here is my code
public function includeContact(Customer $customer)
{
return $this->item($customer->contacts()->first(), new ContactTransformer);
}
but it's not working and I get this error :
Type error: Argument 1 passed to
App\Transformers\ContactTransformer::transform() must be an instance
of App\Models\Contact, null given, called in
*\vendor\league\fractal\src\Scope.php
on line 407
Edited
Here is ContactTransformer
namespace App\Transformers;
use App\Models\Contact;
use League\Fractal\TransformerAbstract;
class ContactTransformer extends TransformerAbstract
{
public function transform(Contact $contact)
{
return [
'value' => $contact->value,
'type' => $contact->communication->title,
'icon' => $contact->communication->icon
];
}
}
Here is CustomerTransformer
class CustomerTransformer extends TransformerAbstract
{
protected $availableIncludes = ['contacts', 'contact'];
public function transform(Customer $customer)
{
return [
'id' => $customer->id,
'name'=>$customer->name,
'status' => $customer->status,
'tags' => $customer->tags->pluck('name'),
'created_at' => Verta::instance($customer->created_at)->format('Y/n/j'),
];
}
public function includeContacts(Customer $customer)
{
return $this->collection($customer->contacts, new ContactTransformer);
}
public function includeContact(Customer $customer)
{
return $this->collection($customer->contacts, new ContactTransformer);
}
}

Answer 1

It's because some of your customers don't have contacts. Looks at your ContactTransformer class on transform() method, it should receive instance of Contact. If you give that method null, of course it'll fail.
Then, you need to have like so,
class ContactTransformer extends TransformerAbstract
{
public function transform(Contact $contact = null)
{
if (is_null($contact)) return null;
return [
'value' => $contact->value,
'type' => $contact->communication->title,
'icon' => $contact->communication->icon
];
}
}