Finalize entity query support

Author: mxr576

src/Entity/Query/Query.php

@@ -86,26 +86,51 @@ public function execute() {
     // result because this function gets called.
     $all_records = $this->getFromStorage();
 
-    // @todo Proper entity query support that is aligned with the implementation
-    //   in \Drupal\Core\Entity\Query\Sql\Query::prepare() can be only added
-    //   if the following Entity API module issue is solved.
+    // Be consistent with \Drupal\Core\Entity\Query\Sql\Query::prepare().
+    // Add and fire special entity query tags.
+    // @todo This fix can be only merged after the fix in the following issue
+    //   is available in a tagged release of entity.module.
     //   https://www.drupal.org/project/entity/issues/3332956
+    //   The minimum required entity.module version also MUST be bumped as part
+    //   of this fix.
     //   (Having a fix for a similar Group module issue is a nice to have,
     //   https://www.drupal.org/project/group/issues/3332963.)
+    $this->addTag('entity_query');
+    $this->addTag('entity_query_' . $this->entityTypeId);
+
     if ($this->accessCheck) {
+      // We do not just add a tag but ensure that only those Apigee entities
+      // are returned that the entity access API grants view access.
+      // (Storage level filtering is not available or way too limited.)
+      $this->addTag($this->entityTypeId . '_access');
+
       // Read meta-data from query, if provided.
       if (!$account = $this->getMetaData('account')) {
-        // @todo DI dependency.
         $account = \Drupal::currentUser();
       }
+
       $cacheability = CacheableMetadata::createFromRenderArray([]);
-      $all_records = array_filter($all_records, static function (EntityInterface $entity) use ($cacheability, $account) {
+      $viewable_entity_ids = array_reduce($all_records, static function (array $carry, EntityInterface $entity) use ($cacheability, $account) {
         // Bubble up cacheability information even from a revoked access result.
         $result = $entity->access('view', $account, TRUE);
         $cacheability->addCacheableDependency($result);
-        return $result->isAllowed();
-      });
-      // @todo DI dependencies.
+        if ($result->isAllowed()) {
+          $carry[] = $entity->id();
+        }
+        return $carry;
+      }, []);
+
+      // We deliberately add conditions to the original entity query instead
+      // of pre-filtering all records because query conditions are visible
+      // in hook_query_TAG_alter() implementations for downstream developers.
+      if (empty($viewable_entity_ids)) {
+        // Add an always false condition. A persisted entity's primary id
+        // cannot be null.
+        $this->condition->notExists($this->entityType->getKey('id'));
+      }
+      else {
+        $this->condition->condition($this->entityType->getKey('id'), $viewable_entity_ids, 'IN');
+      }
       /** @var \Symfony\Component\HttpFoundation\Request $request */
       $request = \Drupal::requestStack()->getCurrentRequest();
       $renderer = \Drupal::service('renderer');
@@ -116,6 +141,12 @@ public function execute() {
       }
     }
 
+    $hooks = ['query'];
+    foreach ($this->alterTags as $tag => $value) {
+      $hooks[] = 'query_' . $tag;
+    }
+    \Drupal::moduleHandler()->alter($hooks, $this);
+
     $filter = $this->condition->compile($this);
     $result = array_filter($all_records, $filter);