fix(entity_definition): Add test coverage a minor fixes for entiy definition data producers

src/GraphQL/Execution/ExecutionResult.php

@@ -9,4 +9,16 @@
 class ExecutionResult extends LibraryExecutionResult implements CacheableDependencyInterface {
   use RefinableCacheableDependencyTrait;
 
+  /**
+   * PHP Serialization: skip some class members when serializing during tests.
+   */
+  public function __sleep(): array {
+    // PHPUnit error: Fatal error: Uncaught Exception: Serialization of
+    // 'Closure' is not allowed.
+    // Remove some closure-containing members before serializing.
+    $vars = get_object_vars($this);
+    unset($vars['extensions']);
+    return array_keys($vars);
+  }
+
 }

src/Plugin/GraphQL/DataProducer/EntityDefinition/Fields.php

@@ -2,7 +2,7 @@
 
 namespace Drupal\graphql\Plugin\GraphQL\DataProducer\EntityDefinition;
 
-use Drupal\Core\Entity\ContentEntityType;
+use Drupal\Core\Entity\ContentEntityTypeInterface;
 use Drupal\Core\Entity\EntityFieldManager;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\EntityTypeManager;
@@ -121,24 +121,22 @@ public function resolve(
     ?array $field_types_context = NULL,
     FieldContext $field_context
   ): \Iterator {
-    $entity_definition->getBundleEntityType();
-    if ($entity_definition instanceof ContentEntityType) {
+
+    if ($entity_definition instanceof ContentEntityTypeInterface) {
+      $entity_type_id = $entity_definition->id();
       if ($bundle_context) {
         $key = $bundle_context['key'];
-        $id = $entity_definition->id();
-        $fields = $this->entityFieldManager->getFieldDefinitions($id, $key);
+        $fields = $this->entityFieldManager->getFieldDefinitions($entity_type_id, $key);
 
         // Set entity form default display as context.
-        $entity_id = $id . '.' . $key . '.default';
-        /** @var \Drupal\Core\Config\Entity\ConfigEntityStorage $form_display_context */
+        $form_display_id = $entity_type_id . '.' . $key . '.default';
         $form_display_context = $this->entityTypeManager
           ->getStorage('entity_form_display')
-          ->load($entity_id);
+          ->load($form_display_id);
         $field_context->setContextValue('entity_form_display', $form_display_context);
       }
       else {
-        $id = $entity_definition->id();
-        $fields = $this->entityFieldManager->getFieldDefinitions($id, $id);
+        $fields = $this->entityFieldManager->getFieldDefinitions($entity_type_id, $entity_type_id);
       }
 
       if ($field_types_context) {

src/Plugin/GraphQL/DataProducer/EntityDefinition/Fields/Multiple.php

@@ -3,6 +3,7 @@
 namespace Drupal\graphql\Plugin\GraphQL\DataProducer\EntityDefinition\Fields;
 
 use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;
 
 /**
@@ -34,6 +35,9 @@ class Multiple extends DataProducerPluginBase {
    *   If the field contains multiple values or just single value.
    */
   public function resolve(FieldDefinitionInterface $entity_definition_field): bool {
+    if ($entity_definition_field instanceof FieldStorageDefinitionInterface) {
+      return $entity_definition_field->isMultiple();
+    }
     return $entity_definition_field->isList();
   }
 

src/Plugin/GraphQL/DataProducer/EntityDefinition/Fields/Reference.php

@@ -2,10 +2,7 @@
 
 namespace Drupal\graphql\Plugin\GraphQL\DataProducer\EntityDefinition\Fields;
 
-use Drupal\Core\Field\BaseFieldDefinition;
-use Drupal\Core\Field\Entity\BaseFieldOverride;
 use Drupal\Core\Field\FieldDefinitionInterface;
-use Drupal\field\Entity\FieldConfig;
 use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;
 
 /**
@@ -37,36 +34,7 @@ class Reference extends DataProducerPluginBase {
    *   If the field is referencing entities (is the entity reference type).
    */
   public function resolve(FieldDefinitionInterface $entity_definition_field): bool {
-    if ($entity_definition_field instanceof BaseFieldDefinition) {
-      /** @var \Drupal\Core\Field\BaseFieldDefinition $entity_definition_field */
-      if ($entity_definition_field->getType() === 'entity_reference') {
-        return TRUE;
-      }
-      else {
-        return FALSE;
-      }
-    }
-    elseif ($entity_definition_field instanceof FieldConfig) {
-      /** @var \Drupal\field\Entity\FieldConfig $entity_definition_field */
-      if ($entity_definition_field->getType() === 'entity_reference') {
-        return TRUE;
-      }
-      else {
-        return FALSE;
-      }
-    }
-    elseif ($entity_definition_field instanceof BaseFieldOverride) {
-      /** @var \Drupal\field\Entity\FieldConfig $entity_definition_field */
-      if ($entity_definition_field->getType() === 'entity_reference') {
-        return TRUE;
-      }
-      else {
-        return FALSE;
-      }
-    }
-    else {
-      return FALSE;
-    }
+    return $entity_definition_field->getType() === 'entity_reference';
   }
 
 }