Double check for xdraft before creating new draft

Author: silverbackdan

features/publishable/publishable.feature

@@ -219,7 +219,8 @@ Feature: Access to unpublished/draft resources should be configurable
   @loginAdmin
   Scenario: As a user with draft access, when I update a published resource with a draft resource available, it should update and return the draft resource.
     Given there is a published resource with a draft set to publish at "2999-12-31T23:59:59+00:00"
-    When I send a "PUT" request to the resource "publishable_draft" with body:
+    And I add "Content-Type" header equal to "application/merge-patch+json"
+    When I send a "PATCH" request to the resource "publishable_published" with body:
     """
     {
         "reference": "updated"
@@ -229,6 +230,20 @@ Feature: Access to unpublished/draft resources should be configurable
     And the JSON node "publishedAt" should be equal to "2999-12-31T23:59:59+00:00"
     And the JSON node "reference" should be equal to "updated"
 
+  @loginAdmin
+  Scenario: As a user with draft access, when I update a published with no draft, it should update and return a draft resource.
+    Given there is a publishable resource set to publish at "1970-12-31T23:59:59+00:00"
+    And I add "Content-Type" header equal to "application/merge-patch+json"
+    When I send a "PATCH" request to the resource "publishable_published" with body:
+    """
+    {
+        "reference": "updated_again"
+    }
+    """
+    Then the response status code should be 200
+    And the JSON node "publishedAt" should be null
+    And the JSON node "reference" should be equal to "updated_again"
+
   @loginAdmin
   Scenario Outline: As a user with draft access, when I update a published resource with a publication date in the past (or now), it should be ignored.
     Given there is a publishable resource set to publish at "1970-12-31T23:59:59+00:00"

src/Serializer/Normalizer/PublishableNormalizer.php

@@ -82,6 +82,7 @@ public function normalize($object, $format = null, array $context = []): float|a
         $resourceMetadata->setPublishable($isPublished);
 
         $type = $object::class;
+
         $configuration = $this->publishableStatusChecker->getAttributeReader()->getConfiguration($type);
         $em = $this->getManagerFromType($type);
         $classMetadata = $this->getClassMetadataInfo($em, $type);
@@ -171,7 +172,16 @@ public function denormalize($data, $type, $format = null, array $context = []):
         }
 
         // Any field has been modified: create a draft
-        $draft = $this->createDraft($object, $configuration, $type);
+        // if we sent 2 simultaneous requests then the initial sql query will have got the live version even if there is a draft now, so let's re-check before creating
+        $em = $this->getManagerFromType($type);
+        $em->refresh($object);
+        $configuration = $this->publishableStatusChecker->getAttributeReader()->getConfiguration($type);
+        $em = $this->getManagerFromType($type);
+        $classMetadata = $this->getClassMetadataInfo($em, $type);
+        $draft = $classMetadata->getFieldValue($object, $configuration->reverseAssociationName);
+        if (!$draft) {
+            $draft = $this->createDraft($object, $configuration, $type);
+        }
         $context[AbstractNormalizer::OBJECT_TO_POPULATE] = $draft;
 
         return $this->denormalizer->denormalize($data, $type, $format, $context);
@@ -244,6 +254,9 @@ public function createDraft(object $object, Publishable $configuration, string $
         // Add draft object to UnitOfWork
         $em->persist($draft);
 
+        // todo: perhaps we need to flush here so if we get another request before flushed, we do not get a duplicate key sql error trying to create a draft when one already exists
+        $em->flush($draft);
+
         // Clear the cache of the published resource because it should now also return an associated draft
         $event = new ResourceChangedEvent($object, 'updated');
         $this->eventDispatcher->dispatch($event);