Tests

The library is designed to be easily testable. We provide you with a few helpers to make testing easier and some tips on how to test your application.

Aggregate Unit Tests

The aggregates can also be tested very well. You can test whether certain events have been recorded or whether the state is set up correctly when the aggregate is set up again via the events.

use PHPUnit\Framework\TestCase;

final class ProfileTest extends TestCase
{
    public function testCreateProfile(): void
    {
        $id = ProfileId::generate();
        $profile = Profile::createProfile($id, Email::fromString('[email protected]'));

        self::assertEquals(
            $profile->releaseEvents(),
            [
                new ProfileCreated($id, Email::fromString('[email protected]')),
            ],
        );

        self::assertEquals('[email protected]', $profile->email()->toString());
    }
}

You can also prepare the aggregate with events to a specific state. And then test whether the aggregate behaves as expected.

use PHPUnit\Framework\TestCase;

final class ProfileTest extends TestCase
{
    public function testChangeName(): void
    {
        $id = ProfileId::generate();

        $profile = Profile::createFromEvents([
            new ProfileCreated($id, Email::fromString('[email protected]')),
        ]);

        $profile->changeEmail(Email::fromString('[email protected]'));

        self::assertEquals(
            $profile->releaseEvents(),
            [
                new EmailChanged(Email::fromString('[email protected]')),
            ],
        );

        self::assertEquals('[email protected]', $profile->email()->toString());
    }
}

Tests with DateTime

You should not instantiate the DateTimeImmutable directly in the aggregate. Instead, you should pass a Clock to the aggregate and use this to get the current time. This allows you to test the aggregate with a fixed time.

use Patchlevel\EventSourcing\Clock\FrozenClock;
use PHPUnit\Framework\TestCase;

final class ProfileTest extends TestCase
{
    public function testCreateProfile(): void
    {
        $clock = new FrozenClock(new DateTimeImmutable('2021-01-01 00:00:00'));

        $profile = Profile::createProfile(
            ProfileId::generate(),
            Email::fromString('[email protected]'),
            $clock,
        );

        $clock->sleep(10);

        $profile->changeEmail(Email::fromString('[email protected]'));
    }
}

Note

You can find out more about the clock here.

Tip

You can use the FreezeClock in you integration tests to test the time-based behavior of your application.

Tests with UUID

Uuids are randomly generated and can be a problem in tests. If you want deterministic tests, you can use the IncrementalRamseyUuidFactory from the library.

use Patchlevel\EventSourcing\Test\IncrementalRamseyUuidFactory;
use PHPUnit\Framework\TestCase;
use Ramsey\Uuid\Uuid;

final class ProfileTest extends TestCase
{
    public function setUp(): void
    {
        Uuid::setFactory(new IncrementalRamseyUuidFactory());
    }

    public function testCreateProfile(): void
    {
        $id1 = ProfileId::generate(); // 10000000-7000-0000-0000-000000000001
        $id2 = ProfileId::generate(); // 10000000-7000-0000-0000-000000000002
    }
}

Warning

The IncrementalRamseyUuidFactory is only for testing purposes and supports only the version 7 what is used by the library.