Add bundle and delta to field label in diff interface.

Closes #3487580

src/DiffEntityParser.php

@@ -7,6 +7,7 @@ namespace Drupal\diff;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\ImmutableConfig;
 use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
 use Drupal\Core\Language\LanguageInterface;
 
 /**
@@ -16,6 +17,7 @@ class DiffEntityParser {
 
   protected ImmutableConfig $config;
   protected ImmutableConfig $pluginsConfig;
+  protected EntityTypeBundleInfoInterface $entityTypeBundleInfo;
 
   /**
    * Constructs a DiffEntityParser object.
@@ -23,9 +25,11 @@ class DiffEntityParser {
   public function __construct(
     protected DiffBuilderManager $diffBuilderManager,
     ConfigFactoryInterface $config_factory,
+    EntityTypeBundleInfoInterface $entityTypeBundleInfo,
   ) {
     $this->config = $config_factory->get('diff.settings');
     $this->pluginsConfig = $config_factory->get('diff.plugins');
+    $this->entityTypeBundleInfo = $entityTypeBundleInfo;
   }
 
   /**
@@ -65,11 +69,19 @@ class DiffEntityParser {
         // Create the array with the fields of the entity. Recursive if the
         // field contains entities.
         if ($plugin instanceof FieldReferenceInterface) {
+          $bundle_info = $this->entityTypeBundleInfo->getAllBundleInfo();
+          $delta = 1;
           foreach ($plugin->getEntitiesToDiff($field_items) as $reference_entity) {
             foreach ($this->parseEntity($reference_entity) as $key => $build) {
               $result[$key] = $build;
-              $result[$key]['label'] = $field_items->getFieldDefinition()->getLabel() . ' > ' . $result[$key]['label'];
+              $result[$key]['label'] = \sprintf('%s > %s[%d] > %s',
+                $field_items->getFieldDefinition()->getLabel(),
+                $bundle_info[$reference_entity->getEntityTypeId()][$reference_entity->bundle()]['label'] ?? $reference_entity->bundle(),
+                $delta,
+                $result[$key]['label'],
+              );
             }
+            $delta++;
           }
         }
         else {