[backend] stabilise codebase

server/src/MessageHandler/SignalCreatedMessageHandler.php

@@ -7,30 +7,32 @@ namespace App\MessageHandler;
 use App\Message\SignalCreatedMessage;
 use App\Repository\SignalRepository;
 use App\Service\SignalSnapshotBuilder;
-use DateTimeImmutable;
-use DateTimeZone;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\DependencyInjection\Attribute\Autowire;
 use Symfony\Component\Mercure\HubInterface;
 use Symfony\Component\Mercure\Update;
 use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+use Symfony\Component\Serializer\Exception\ExceptionInterface;
+use Symfony\Component\Serializer\SerializerInterface;
 use Throwable;
-use function json_encode;
-use const JSON_THROW_ON_ERROR;
 
 #[AsMessageHandler]
-final class SignalCreatedMessageHandler
+final readonly class SignalCreatedMessageHandler
 {
     public function __construct(
-        private readonly SignalRepository $signals,
-        private readonly SignalSnapshotBuilder $snapshotBuilder,
-        private readonly HubInterface $hub,
-        #[Autowire('%app.signal_stream_topic%')] private readonly string $topic,
-        #[Autowire('%app.signal_snapshot_limit%')] private readonly int $snapshotLimit,
-        private readonly ?LoggerInterface $logger = null,
+        private SignalRepository $signals,
+        private SignalSnapshotBuilder $snapshotBuilder,
+        private HubInterface $hub,
+        private SerializerInterface $serializer,
+        private LoggerInterface $logger,
+        #[Autowire('%app.signal_stream_topic%')] private string $topic,
+        #[Autowire('%app.signal_snapshot_limit%')] private int $snapshotLimit,
     ) {
     }
 
+    /**
+     * @throws ExceptionInterface
+     */
     public function __invoke(SignalCreatedMessage $message): void
     {
         $recentSignals = $this->signals->findRecent($this->snapshotLimit);
@@ -43,21 +45,17 @@ final class SignalCreatedMessageHandler
                 'density' => $snapshot['density'],
                 'latestByUser' => $snapshot['latestByUser'],
                 'totals' => $snapshot['totals'],
-                'updatedAt' => (new DateTimeImmutable('now', new DateTimeZone('UTC')))->format(DATE_ATOM),
+                'updatedAt' => new \DateTimeImmutable('now', new \DateTimeZone('UTC'))->format(DATE_ATOM),
             ],
         ];
 
-        $data = json_encode($payload, JSON_THROW_ON_ERROR);
-
-        $update = new Update(
-            topics: $this->topic,
-            data: $data,
-        );
+        $data = $this->serializer->serialize($payload, 'json');
+        $update = new Update(topics: $this->topic, data: $data);
 
         try {
             $this->hub->publish($update);
         } catch (Throwable $exception) {
-            $this->logger?->error('Failed to publish signal update to Mercure.', [
+            $this->logger->error('Failed to publish signal update to Mercure.', [
                 'exception' => $exception,
             ]);
         }