Add support for extracting other identities from Message headers

src/Messages/MessageInflection.php

@@ -9,6 +9,7 @@
 use EventSauce\EventSourcing\AggregateRootId;
 use EventSauce\EventSourcing\ClassNameInflector;
 use EventSauce\EventSourcing\Message;
+use Whrc\Model\Common\Identity\Identity;
 
 final readonly class MessageInflection
 {
@@ -25,12 +26,12 @@ public function __construct(private ClassNameInflector $classNameInflector)
      */
     public function extractAggregateRootId(Message $message, ?string $identityType = null): AggregateRootId
     {
-        /** @var class-string<AggregateRootIdAware>|null $aggregateRootTypeString */
+        /** @var class-string<AggregateRootIdAware<T>>|null $aggregateRootTypeString */
         $aggregateRootTypeString = $message->aggregateRootType();
 
         !is_null($aggregateRootTypeString) || throw new \LogicException('Expected $message to have an aggregate root type.');
 
-        /** @phpstan-var class-string<AggregateRootIdAware> $aggregateRootType */
+        /** @phpstan-var class-string<AggregateRootIdAware<T>> $aggregateRootType */
         $aggregateRootType = $this->classNameInflector->typeToClassName($aggregateRootTypeString);
 
         if (!in_array(AggregateRootIdAware::class, class_implements($aggregateRootType) ?: [])) {
@@ -50,4 +51,37 @@ public function extractAggregateRootId(Message $message, ?string $identityType =
 
         return $value;
     }
+
+    /**
+     * @template T of Identity
+     *
+     * @param class-string<T> $identityType
+     *
+     * @phpstan-return T|AggregateRootId|null $value
+     */
+    public function extractOptionalIdentityFromHeader(Message $message, string $identityType, string $headerName): ?AggregateRootId
+    {
+        return IdentityInflection::toObject(
+            $identityType,
+            $message->header($headerName)
+        );
+    }
+
+    /**
+     * @template T of Identity
+     *
+     * @param class-string<T> $identityType
+     *
+     * @phpstan-return T|AggregateRootId $value
+     */
+    public function extractIdentityFromHeader(Message $message, string $identityType, string $headerName): AggregateRootId
+    {
+        $value = $this->extractOptionalIdentityFromHeader($message, $identityType, $headerName);
+
+        if (is_null($value)) {
+            throw new \RuntimeException('Expected $message to have an identity');
+        }
+
+        return $value;
+    }
 }