Merge pull request #687 from patchlevel/use-reflection-for-child-prop…

…erty

Use reflection for accessing child aggregates, add test case which covers private child aggregates

baseline.xml

@@ -251,6 +251,11 @@
       <code><![CDATA[PersonalInformation]]></code>
     </PropertyNotSetInConstructor>
   </file>
+  <file src="tests/Integration/ChildAggregate/Views.php">
+    <PropertyNotSetInConstructor>
+      <code><![CDATA[Views]]></code>
+    </PropertyNotSetInConstructor>
+  </file>
   <file src="tests/Integration/PersonalData/PersonalDataTest.php">
     <MixedArgument>
       <code><![CDATA[$row['payload']]]></code>

src/Aggregate/AggregateRootAttributeBehaviour.php

@@ -49,9 +49,11 @@ protected function apply(object $event): void
         if (count($parts) === 2) {
             [$property, $method] = $parts;
 
-            /** @var ChildAggregate $child */
-            $child = $this->$property;
-            $child->$method($event);
+            $child = $this->getChildAggregateByPropertyName($property);
+
+            if ($child !== null) {
+                $child->$method($event);
+            }
         } else {
             $this->$method($event);
         }
@@ -65,17 +67,31 @@ private function passRecorderToChildAggregates(): void
         $metadata = static::metadata();
         $this->recorder ??= $this->recordThat(...);
 
-        foreach ($metadata->childAggregates as $property) {
-            if (!isset($this->{$property})) {
+        foreach ($metadata->childAggregates as $propertyName) {
+            $child = $this->getChildAggregateByPropertyName($propertyName);
+
+            if ($child === null) {
                 continue;
             }
 
-            /** @var ChildAggregate $child */
-            $child = $this->{$property};
             $child->setRecorder($this->recorder);
         }
     }
 
+    private function getChildAggregateByPropertyName(string $propertyName): ChildAggregate|null
+    {
+        $reflectionProperty = new ReflectionProperty($this::class, $propertyName);
+
+        if (!$reflectionProperty->isInitialized($this)) {
+            return null;
+        }
+
+        /** @var ChildAggregate|null $child */
+        $child = $reflectionProperty->getValue($this);
+
+        return $child;
+    }
+
     public function aggregateRootId(): AggregateRootId
     {
         if ($this->cachedAggregateRootId instanceof AggregateRootId) {

tests/Integration/ChildAggregate/ChildAggregateIntegrationTest.php

@@ -75,6 +75,7 @@ public function testSuccessful(): void
         $profileId = ProfileId::generate();
         $profile = Profile::create($profileId, 'John');
         $profile->changeName('Snow');
+        $profile->trackView();
         $repository->save($profile);
 
         $result = $this->connection->fetchAssociative(
@@ -92,8 +93,9 @@ public function testSuccessful(): void
 
         self::assertInstanceOf(Profile::class, $profile);
         self::assertEquals($profileId, $profile->aggregateRootId());
-        self::assertSame(2, $profile->playhead());
+        self::assertSame(3, $profile->playhead());
         self::assertSame('Snow', $profile->name());
+        self::assertSame(1, $profile->views());
     }
 
     public function testSnapshot(): void
@@ -154,13 +156,15 @@ public function testSnapshot(): void
         $profile = $repository->load($profileId);
 
         $profile->changeName('Snow');
+        $profile->trackView();
         $repository->save($profile);
 
         $profile = $repository->load($profileId);
 
         self::assertInstanceOf(Profile::class, $profile);
         self::assertEquals($profileId, $profile->aggregateRootId());
-        self::assertSame(2, $profile->playhead());
+        self::assertSame(3, $profile->playhead());
         self::assertSame('Snow', $profile->name());
+        self::assertSame(1, $profile->views());
     }
 }

tests/Integration/ChildAggregate/Events/ViewTracked.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Integration\ChildAggregate\Events;
+
+use Patchlevel\EventSourcing\Attribute\Event;
+
+#[Event('profile.view_tracked')]
+final class ViewTracked
+{
+    public function __construct()
+    {
+    }
+}

tests/Integration/ChildAggregate/Profile.php

@@ -22,6 +22,9 @@ final class Profile extends BasicAggregateRoot
     #[ChildAggregate]
     protected PersonalInformation $personalInformation;
 
+    #[ChildAggregate]
+    private Views $views;
+
     public static function create(ProfileId $id, string $name): self
     {
         $self = new self();
@@ -35,15 +38,26 @@ protected function applyProfileCreated(ProfileCreated $event): void
     {
         $this->id = $event->profileId;
         $this->personalInformation = new PersonalInformation($event->name);
+        $this->views = new Views();
     }
 
     public function name(): string
     {
         return $this->personalInformation->name();
     }
 
+    public function views(): int
+    {
+        return $this->views->views();
+    }
+
     public function changeName(string $name): void
     {
         $this->personalInformation->changeName($name);
     }
+
+    public function trackView(): void
+    {
+        $this->views->trackView();
+    }
 }

tests/Integration/ChildAggregate/Views.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Integration\ChildAggregate;
+
+use Patchlevel\EventSourcing\Aggregate\BasicChildAggregate;
+use Patchlevel\EventSourcing\Attribute\Apply;
+use Patchlevel\EventSourcing\Tests\Integration\ChildAggregate\Events\ViewTracked;
+
+final class Views extends BasicChildAggregate
+{
+    public function __construct(private int $views = 0)
+    {
+    }
+
+    #[Apply(ViewTracked::class)]
+    public function applyNameChanged(ViewTracked $event): void
+    {
+        $this->views++;
+    }
+
+    public function views(): int
+    {
+        return $this->views;
+    }
+
+    public function trackView(): void
+    {
+        $this->recordThat(new ViewTracked());
+    }
+}