Integration or unit test - laravel

Question

It is not quite clear to me when I should use integrations and unit test
If I want to test the following code without making any http requests, should I use an integration test or unit ?
When a thread is created, the activity is recorded and an email event is fired
ThreadObserver extends Observer
{
public function created(Thread $thread)
{
Activity::record($thead);
event(new ThreadWasCreated($thread);
}
}
class RecordsActivityTest
{
public function it_records_the_acitivty_when_a_thread_is_created()
{
Thread::factory()->create();
$this->assertDatabaseHas('activities', […]);
}
}
Another example, I want to test that give a query it returns the expected results .
class Search
{
public function __construct(protected Index $index)
{
}
public function handle($query)
{
$this->index->search($query);
// more code
}
}
class SearchTest
{
public function it_returns_the_expected_result()
{
$search = new Search(new Index);
$results = $search->handle(“some query”);
$this->assertEquals(“some
Data”);
}
}
Do I need a unit test, to test the Search class or an integration test because it is dependent on another class ?

Answer 1

The first example, I'd most likely write an integration test, but instead of testing if the database has a value, I'd just mock the event https://laravel.com/docs/8.x/mocking#event-fake and assert that the event was dispatched.
The second example however, it could go either way. You can write a unit test and just mock everything OR, you could write an integration test so you can use the Laravel helpers, specifically the https://laravel.com/docs/8.x/mocking#http-fake if you're testing an API, otherwise mockery if you're testing and SDK for example.