This is the documentation for
v3 but the latest version is
v7
.
You can switch versions in the menu on the left/at the top.
Check your current version with the following command:
composer show spatie/laravel-event-sourcing
In the test suite of your application you probably also want to write some tests to check if an aggregate works correctly. The package contains some handy methods to help you.
Imagine you have an AccountAggregateRoot
that handles adding and subtract an amount for a bank account. The account has a limit of -$5000.
use Spatie\EventSourcing\AggregateRoots\AggregateRoot;
class AccountAggregateRoot extends AggregateRoot
{
/** @var int */
private $balance = 0;
/** @var int */
private $accountLimit = -5000;
public function createAccount(string $name, string $userId)
{
$this->recordThat(new AccountCreated($name, $userId));
return $this;
}
public function addMoney(int $amount)
{
$this->recordThat(new MoneyAdded($amount));
return $this;
}
protected function applyMoneyAdded(MoneyAdded $event)
{
$this->balance += $event->amount;
}
public function subtractMoney(int $amount)
{
$this->hasSufficientFundsToSubtractAmount($amount)
? $this->recordThat(new MoneySubtracted($amount))
: $this->recordThat(new AccountLimitHit($amount));
}
protected function applyMoneySubtracted(MoneySubtracted $event)
{
$this->balance -= $event->amount;
}
private function hasSufficientFundsToSubtractAmount(int $amount): bool
{
return $this->balance - $amount >= $this->accountLimit;
}
}
Let's now test that rule that an account cannot go beyond its limit.
// in a PHPUnit test
/** @test */
public function it_can_subtract_money()
{
AccountAggregateRoot::fake()
->given([new AccountCreated('Luke'), new MoneySubtracted(4999)])
->when(function (AccountAggregate $accountAggregate) {
$accountAggregate->subtractMoney(1);
})
->assertRecorded(new MoneySubtracted(1))
->assertNotRecorded(AccountLimitHit::class);
}
/** @test */
public function it_will_not_make_subtractions_that_would_go_below_the_account_limit()
{
AccountAggregateRoot::fake()
->given([new AccountCreated('Luke'), new MoneySubtracted(4999)])
->when(function (AccountAggregate $accountAggregate) {
$accountAggregate->subtractMoney(2);
})
->assertRecorded(new AccountLimitHit(2))
->assertNotRecorded(MoneySubtracted::class);
}
The given
and assertRecorded
methods can accept a single event instances or an array with event instances. assertNotRecorded
can also accept an array of class names.
If you don't expect any events to be recorded you can use assertNothingRecorded
.
##Disabling dispatching events
When calling the given
method the aggregate will fire of events for your projector and reactor to react to. If you don't want events being dispatched. Simply use the Event
facade's fake
method before your test executes.
\Illuminate\Support\Facades\Event::fake();
If you would prefer to disable Projectors reacting to events whilst retaining Event
functionality simply use the Projectionist
facade's withoutEventHandlers
method before your test executes.
\Spatie\EventSourcing\Facades\Projectionist::withoutEventHandlers();