snipe-it/tests/unit/LocationTest.php

<?php
namespace Tests\Unit;

use App\Models\Location;
use Tests\Unit\BaseTest;
use Illuminate\Database\Eloquent\Factories\Factory;
use Tests\TestCase;

class LocationTest extends BaseTest
{
    /**
     * @var \UnitTester
     */
    protected $tester;

    public function testPassesIfNotSelfParent()
    {
        $this->createValidLocation(['id' => 10]);

        $a = Location::factory()->make([
            'name' => 'Test Location',
            'id' => 1,
            'parent_id' => 10,
        ]);

        $this->assertTrue($a->isValid());
    }

    public function testFailsIfSelfParent()
    {
        $a = Location::factory()->make([
            'name' => 'Test Location',
            'id' => 1,
            'parent_id' => 1,
        ]);

        $this->assertFalse($a->isValid());
        $this->assertStringContainsString(trans('validation.non_circular', ['attribute' => 'parent id']), $a->getErrors());
    }
}