Issue #3174924 by joachim, xjm, smustgrave, sourabhjain, ranjith_kumar_k_u,...

Issue #3174924 by joachim, xjm, smustgrave, sourabhjain, ranjith_kumar_k_u, kiwimind, catch, bnjmnm: Throw a better exception when a reference field can't find the target entity type

core/lib/Drupal/Core/Field/FieldItemInterface.php

@@ -84,6 +84,9 @@ public static function mainPropertyName();
    *     stored in SQL. Also, the possible usage is limited, as you cannot
    *     specify another field as related, only existing SQL tables,
    *     such as {taxonomy_term_data}.
+   *
+   * @throws \Drupal\Core\Field\FieldException
+   *   Throws an exception if the schema is invalid.
    */
   public static function schema(FieldStorageDefinitionInterface $field_definition);
 

core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php

@@ -6,6 +6,7 @@
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Entity\ContentEntityStorageInterface;
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Entity\TypedData\EntityDataDefinition;
@@ -121,7 +122,16 @@ public static function mainPropertyName() {
    */
   public static function schema(FieldStorageDefinitionInterface $field_definition) {
     $target_type = $field_definition->getSetting('target_type');
-    $target_type_info = \Drupal::entityTypeManager()->getDefinition($target_type);
+    try {
+      $target_type_info = \Drupal::entityTypeManager()->getDefinition($target_type);
+    }
+    catch (PluginNotFoundException $e) {
+      throw new FieldException(sprintf("Field '%s' on entity type '%s' references a target entity type '%s' which does not exist.",
+        $field_definition->getName(),
+        $field_definition->getTargetEntityTypeId(),
+        $target_type
+      ));
+    }
     $properties = static::propertyDefinitions($field_definition)['target_id'];
     if ($target_type_info->entityClassImplements(FieldableEntityInterface::class) && $properties->getDataType() === 'integer') {
       $columns = [

core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php

@@ -6,6 +6,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageException;
 use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\Core\Field\FieldException;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
@@ -368,6 +369,26 @@ protected function assertUserRoleAutocreate(EntityInterface $entity, callable $s
     $this->assertEquals($entity->user_role->target_id, $role->id());
   }
 
+  /**
+   * Tests exception thrown with a missing target entity type.
+   */
+  public function testTargetEntityTypeMissing() {
+    // Setup a test entity type with an entity reference field to an entity type
+    // that doesn't exist.
+    $definitions = [
+      'bad_reference' => BaseFieldDefinition::create('entity_reference')
+        ->setSetting('target_type', 'made_up_entity_type')
+        ->setSetting('handler', 'default'),
+    ];
+    $this->state->set('entity_test.additional_base_field_definitions', $definitions);
+    $this->entityTypeManager->clearCachedDefinitions();
+
+    $this->expectException(FieldException::class);
+    $this->expectExceptionMessage("Field 'bad_reference' on entity type 'entity_test' references a target entity type 'made_up_entity_type' which does not exist.");
+
+    $this->installEntitySchema('entity_test');
+  }
+
   /**
    * Tests that the target entity is not unnecessarily loaded.
    */