Header as Interface

deptrac.yaml

@@ -41,10 +41,6 @@ deptrac:
       collectors:
         - type: directory
           value: src/Metadata/Event/.*
-    - name: MetadataMessage
-      collectors:
-        - type: directory
-          value: src/Metadata/Message/.*
     - name: MetadataSubscriber
       collectors:
         - type: directory
@@ -60,8 +56,6 @@ deptrac:
               value: MetadataAggregate
             - type: layer
               value: MetadataEvent
-            - type: layer
-              value: MetadataMessage
             - type: layer
               value: MetadataSubscriber
     - name: Pipeline
@@ -96,6 +90,7 @@ deptrac:
   ruleset:
     Aggregate:
       - Attribute
+      - Message
       - MetadataAggregate
     Attribute:
     Clock:
@@ -117,8 +112,9 @@ deptrac:
       - Attribute
       - Message
     Message:
-      - MetadataMessage
-      - Serializer
+      - Aggregate
+      - Debug
+      - Store
     Metadata:
     MetadataAggregate:
       - Aggregate
@@ -127,9 +123,6 @@ deptrac:
     MetadataEvent:
       - Attribute
       - Metadata
-    MetadataMessage:
-      - Attribute
-      - Metadata
     MetadataSubscriber:
       - Attribute
       - Metadata

docs/pages/getting_started.md

@@ -297,12 +297,10 @@ $projectionConnection = DriverManager::getConnection([
 $mailer = /* your own mailer */;
 
 $serializer = DefaultEventSerializer::createFromPaths(['src/Domain/Hotel/Event']);
-$aggregateRegistry = (new AttributeAggregateRootRegistryFactory)->create(['src/Domain/Hotel']);
 
 $eventStore = new DoctrineDbalStore(
     $connection,
     $serializer,
-    $aggregateRegistry,
 );
 
 $hotelProjector = new HotelProjector($projectionConnection);

src/Aggregate/AggregateHeader.php

@@ -5,20 +5,45 @@
 namespace Patchlevel\EventSourcing\Aggregate;
 
 use DateTimeImmutable;
-use Patchlevel\EventSourcing\Attribute\Header;
-use Patchlevel\Hydrator\Normalizer\DateTimeImmutableNormalizer;
+use Patchlevel\EventSourcing\Message\Header;
 
-/** @psalm-immutable */
-#[Header('aggregate')]
-final class AggregateHeader
+/**
+ * @template-implements Header<array{aggregateName: string, aggregateId: string, playhead: int, recordedOn: string}>
+ * @psalm-immutable
+ */
+final class AggregateHeader implements Header
 {
     /** @param positive-int $playhead */
     public function __construct(
         public readonly string $aggregateName,
         public readonly string $aggregateId,
         public readonly int $playhead,
-        #[DateTimeImmutableNormalizer]
         public readonly DateTimeImmutable $recordedOn,
     ) {
     }
+
+    public static function name(): string
+    {
+        return 'aggregate';
+    }
+
+    public static function fromJsonSerialize(array $data): static
+    {
+        return new self(
+            $data['aggregateName'],
+            $data['aggregateId'],
+            $data['playhead'],
+            new DateTimeImmutable($data['recordedOn']),
+        );
+    }
+
+    public function jsonSerialize(): array
+    {
+        return [
+            'aggregateName' => $this->aggregateName,
+            'aggregateId' => $this->aggregateId,
+            'playhead' => $this->playhead,
+            'recordedOn' => $this->recordedOn->format(DateTimeImmutable::ATOM),
+        ];
+    }
 }

src/Console/Command/ShowAggregateCommand.php

@@ -6,7 +6,6 @@
 
 use Patchlevel\EventSourcing\Console\InputHelper;
 use Patchlevel\EventSourcing\Console\OutputStyle;
-use Patchlevel\EventSourcing\Message\Serializer\HeadersSerializer;
 use Patchlevel\EventSourcing\Metadata\AggregateRoot\AggregateRootRegistry;
 use Patchlevel\EventSourcing\Serializer\EventSerializer;
 use Patchlevel\EventSourcing\Store\Criteria;
@@ -31,7 +30,6 @@ final class ShowAggregateCommand extends Command
     public function __construct(
         private readonly Store $store,
         private readonly EventSerializer $eventSerializer,
-        private readonly HeadersSerializer $headersSerializer,
         private readonly AggregateRootRegistry $aggregateRootRegistry,
     ) {
         parent::__construct();
@@ -78,7 +76,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         $hasMessage = false;
         foreach ($stream as $message) {
             $hasMessage = true;
-            $console->message($this->eventSerializer, $this->headersSerializer, $message);
+            $console->message($this->eventSerializer, $message);
         }
 
         $stream->close();

src/Console/Command/ShowCommand.php

@@ -6,7 +6,6 @@
 
 use Patchlevel\EventSourcing\Console\InputHelper;
 use Patchlevel\EventSourcing\Console\OutputStyle;
-use Patchlevel\EventSourcing\Message\Serializer\HeadersSerializer;
 use Patchlevel\EventSourcing\Serializer\EventSerializer;
 use Patchlevel\EventSourcing\Store\Store;
 use Symfony\Component\Console\Attribute\AsCommand;
@@ -26,7 +25,6 @@ final class ShowCommand extends Command
     public function __construct(
         private readonly Store $store,
         private readonly EventSerializer $eventSerializer,
-        private readonly HeadersSerializer $headersSerializer,
     ) {
         parent::__construct();
     }
@@ -74,7 +72,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                     break 2;
                 }
 
-                $console->message($this->eventSerializer, $this->headersSerializer, $message);
+                $console->message($this->eventSerializer, $message);
 
                 $stream->next();
 

src/Console/Command/WatchCommand.php

@@ -6,7 +6,6 @@
 
 use Patchlevel\EventSourcing\Console\InputHelper;
 use Patchlevel\EventSourcing\Console\OutputStyle;
-use Patchlevel\EventSourcing\Message\Serializer\HeadersSerializer;
 use Patchlevel\EventSourcing\Serializer\EventSerializer;
 use Patchlevel\EventSourcing\Store\Criteria;
 use Patchlevel\EventSourcing\Store\Store;
@@ -26,7 +25,6 @@ final class WatchCommand extends Command
     public function __construct(
         private readonly Store $store,
         private readonly EventSerializer $eventSerializer,
-        private readonly HeadersSerializer $headersSerializer,
     ) {
         parent::__construct();
     }
@@ -76,7 +74,7 @@ function () use ($console, &$index, $aggregate, $aggregateId): void {
                 );
 
                 foreach ($stream as $message) {
-                    $console->message($this->eventSerializer, $this->headersSerializer, $message);
+                    $console->message($this->eventSerializer, $message);
                     $index = $stream->index();
                 }
 

src/Console/OutputStyle.php

@@ -5,21 +5,23 @@
 namespace Patchlevel\EventSourcing\Console;
 
 use Patchlevel\EventSourcing\Message\Message;
-use Patchlevel\EventSourcing\Message\Serializer\HeadersSerializer;
 use Patchlevel\EventSourcing\Serializer\Encoder\Encoder;
 use Patchlevel\EventSourcing\Serializer\EventSerializer;
 use Symfony\Component\Console\Style\SymfonyStyle;
 use Throwable;
 
 use function array_keys;
 use function array_values;
+use function json_encode;
 use function sprintf;
 
+use const JSON_PRETTY_PRINT;
+use const JSON_THROW_ON_ERROR;
+
 final class OutputStyle extends SymfonyStyle
 {
     public function message(
         EventSerializer $eventSerializer,
-        HeadersSerializer $headersSerializer,
         Message $message,
     ): void {
         $event = $message->event();
@@ -42,25 +44,12 @@
             return;
         }
 
-        try {
-            $headers = $headersSerializer->serialize($message->headers(), [Encoder::OPTION_PRETTY_PRINT => true]);
-        } catch (Throwable $error) {
-            $this->error(
-                sprintf(
-                    'Error while serializing headers: %s',
-                    $error->getMessage(),
-                ),
-            );
-
-            if ($this->isVeryVerbose()) {
-                $this->throwable($error);
-            }
-
-            return;
+        foreach ($message->headers() as $header) {
+            $headers[$header::name()] = json_encode($header, JSON_THROW_ON_ERROR | JSON_PRETTY_PRINT);
         }
 
         $this->title($data->name);
         $this->horizontalTable(array_keys($headers), [array_values($headers)]);
         $this->block($data->payload);
     }
 

src/Debug/Trace/TraceHeader.php

@@ -4,15 +4,35 @@
 
 namespace Patchlevel\EventSourcing\Debug\Trace;
 
-use Patchlevel\EventSourcing\Attribute\Header;
+use Patchlevel\EventSourcing\Message\Header;
 
-/** @experimental */
-#[Header('trace')]
-final class TraceHeader
+/**
+ * @experimental
+ * @template-implements Header<array{traces: list<array{name: string, category: string}>}>
+ * @psalm-immutable
+ */
+final class TraceHeader implements Header
 {
     /** @param list<array{name: string, category: string}> $traces */
     public function __construct(
         public readonly array $traces,
     ) {
     }
+
+    public static function name(): string
+    {
+        return 'trace';
+    }
+
+    public static function fromJsonSerialize(array $data): static
+    {
+        return new self($data['traces']);
+    }
+
+    public function jsonSerialize(): array
+    {
+        return [
+            'traces' => $this->traces,
+        ];
+    }
 }

src/Message/Header.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Message;
+
+use JsonSerializable;
+
+/**
+ * @psalm-immutable
+ * @template T of array
+ */
+interface Header extends JsonSerializable
+{
+    public static function name(): string;
+
+    /** @param T $data */
+    public static function fromJsonSerialize(array $data): static;
+
+    /** @return T */
+    public function jsonSerialize(): array;
+}

src/Metadata/Message/HeaderClassNotRegistered.php → src/Message/HeaderClassNotRegistered.php

@@ -2,13 +2,13 @@
 
 declare(strict_types=1);
 
-namespace Patchlevel\EventSourcing\Metadata\Message;
+namespace Patchlevel\EventSourcing\Message;
 
-use Patchlevel\EventSourcing\Metadata\MetadataException;
+use RuntimeException;
 
 use function sprintf;
 
-final class HeaderClassNotRegistered extends MetadataException
+final class HeaderClassNotRegistered extends RuntimeException
 {
     public function __construct(string $headerClass)
     {

src/Metadata/Message/HeaderNameNotRegistered.php → src/Message/HeaderNameNotRegistered.php

@@ -2,13 +2,13 @@
 
 declare(strict_types=1);
 
-namespace Patchlevel\EventSourcing\Metadata\Message;
+namespace Patchlevel\EventSourcing\Message;
 
-use Patchlevel\EventSourcing\Metadata\MetadataException;
+use RuntimeException;
 
 use function sprintf;
 
-final class HeaderNameNotRegistered extends MetadataException
+final class HeaderNameNotRegistered extends RuntimeException
 {
     public function __construct(string $name)
     {

src/Message/Message.php

@@ -15,7 +15,7 @@
  */
 final class Message
 {
-    /** @var array<class-string, object> */
+    /** @var array<class-string, Header> */
     private array $headers = [];
 
     /** @param T $event */
@@ -36,7 +36,7 @@
         return new self($event);
     }
 
-    /** @param iterable<object> $headers */
+    /** @param iterable<Header> $headers */
     public static function createWithHeaders(object $event, iterable $headers): self
     {
         return self::create($event)->withHeaders($headers);
@@ -55,7 +55,7 @@
      *
      * @throws HeaderNotFound
      *
-     * @template H1 of object
+     * @template H1 of Header
      */
     public function header(string $name): object
     {
@@ -73,18 +73,18 @@
     public function withHeader(object $header): self
     {
         $message = clone $this;
         $message->headers[$header::class] = $header;
 
         return $message;
     }
 
-    /** @return list<object> */
+    /** @return list<Header> */
     public function headers(): array
     {
         return array_values($this->headers);
     }
 
-    /** @param iterable<object> $headers */
+    /** @param iterable<Header> $headers */
     public function withHeaders(iterable $headers): self
     {
         $message = clone $this;