Fix bug with non serializing recursive departure

config/packages/jms_serializer.yaml

@@ -1,4 +1,8 @@
 jms_serializer:
+    default_context:
+        serialization:
+            serialize_null: true
+
     visitors:
         xml_serialization:
             format_output: '%kernel.debug%'

resources/ts/components/picker.ts

@@ -42,7 +42,7 @@ export class PickerStopComponent extends Vue {
             [lines => lines.length > 2,   ([first]) => `${first.symbol}…`],
         );
 
-        return unique(this.stop.destinations || [], destination => destination.stop.name).map(compactLines);
+        return unique(this.stop.destinations || [], destination => destination.stop && destination.stop.name).map(compactLines);
     }
 }
 

src/Handler/Database/WithDestinationsDatabaseHandler.php

@@ -7,6 +7,7 @@ use App\Event\PostProcessEvent;
 use App\Handler\PostProcessingHandler;
 use App\Model\Destination;
 use App\Model\Stop;
+use App\Service\CacheableConverter;
 use App\Service\Converter;
 use App\Service\IdUtils;
 use Doctrine\ORM\EntityManagerInterface;
@@ -25,6 +26,11 @@ class WithDestinationsDatabaseHandler implements PostProcessingHandler
         $this->em = $entityManager;
         $this->converter = $converter;
         $this->id = $id;
+
+        if ($this->converter instanceof CacheableConverter) {
+            $this->converter = clone $this->converter;
+            $this->converter->flushCache();
+        }
     }
 
     public function postProcess(PostProcessEvent $event)

src/Service/AggregateConverter.php

@@ -3,8 +3,9 @@
 namespace App\Service;
 
 use Tightenco\Collect\Support\Collection;
+use function Kadet\Functional\Predicates\instance;
 
-class AggregateConverter implements Converter
+class AggregateConverter implements Converter, CacheableConverter
 {
     private $converters;
 
@@ -42,4 +43,22 @@ class AggregateConverter implements Converter
     {
         return clone $this->converters;
     }
+
+    public function flushCache()
+    {
+        $this
+            ->converters
+            ->filter(instance(CacheableConverter::class))
+            ->each(function (CacheableConverter $converter) {
+                $converter->flushCache();
+            })
+        ;
+    }
+
+    public function __clone()
+    {
+        $this->converters = $this->converters->map(function ($object) {
+            return clone $object;
+        });
+    }
 }

src/Service/SerializerContextFactory.php

@@ -23,7 +23,7 @@ final class SerializerContextFactory
 
     public function create($subject, array $groups = ['Default'])
     {
-        return SerializationContext::create()->setGroups($this->groups($subject, $groups));
+        return SerializationContext::create()->setSerializeNull(true)->setGroups($this->groups($subject, $groups));
     }
 
     private function groups($subject, array $groups)