How do unit tests work?

Question

PHPUnit

How do unit tests work? (particularly php) If I cause an error in the code, the tests do not show this.
Example:
Test:

public function testFindAll(): void
    {
        self::bootKernel();
        $repository = static::$kernel->getContainer()->get(PropertyInMemoryRepository::class);

        $this->assertInstanceOf(PropertyCollection::class, $repository->findAll(1, 1, 1));

        $count = $repository->findAll(1, 1, 1)->count();

        $this->assertSame(3, $count);
    }

PropertyInMemoryRepository:

public function findAll(int $groupId, int $page, int $limit, array $filters = []): PropertyCollection
    {
        $propertyCollection = new PropertyCollection();

        foreach ($this->propertyCollection as $property) {
            if ($property->getGroupIdValue() === $groupId) {
                $propertyCollection->append($property);
            }
        }

        return $propertyCollection;
    }

The line in the controller with the triggered error :

$dProperties = $this->propertyRepository->findAll($this->getUser()->getGroupId(), 'string', $limit, $filters);

At the exit I have Job succeeded

Answer 1

The error is that you are passing a string as the second argument in the controller?
If yes, then it will catch the controller test , not the findAll method, that test will not know by any magic that you will be passing invalid arguments somewhere else.