Add stubs for daterange field type

stubs/Drupal/datetime_range/Plugin/Field/FieldType/DateRangeItem.stub

@@ -0,0 +1,17 @@
+<?php
+
+namespace Drupal\datetime_range\Plugin\Field\FieldType;
+
+use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
+
+/**
+ * @property-read null $date
+ *   Even though this extends DateTimeItem, the date property does not actually
+ *   exist. It is not possible to undo a property definition.
+ * @property-read ?\Drupal\Core\Datetime\DrupalDateTime $start_date
+ * @property ?string $end_value
+ * @property-read ?\Drupal\Core\Datetime\DrupalDateTime $end_date
+ */
+class DateRangeItem extends DateTimeItem {
+
+}

tests/src/Type/data/field-types.php

@@ -19,6 +19,7 @@
 use Drupal\Core\Field\Plugin\Field\FieldType\UriItem;
 use Drupal\Core\Field\Plugin\Field\FieldType\UuidItem;
 use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
+use Drupal\datetime_range\Plugin\Field\FieldType\DateRangeItem;
 use Drupal\file\Plugin\Field\FieldType\FileItem;
 use Drupal\file\Plugin\Field\FieldType\FileUriItem;
 use Drupal\link\Plugin\Field\FieldType\LinkItem;
@@ -145,6 +146,15 @@
 assertType('string|null', $datetime_field->value);
 assertType('Drupal\Core\Datetime\DrupalDateTime|null', $datetime_field->date);
 
+// DateRangeItem.
+$daterange_field = $node->get('field_daterange')->first();
+assert($daterange_field instanceof DateRangeItem);
+assertType(DateRangeItem::class, $daterange_field);
+assertType('string|null', $daterange_field->value);
+assertType('\Drupal\Core\Datetime\DrupalDateTime|null', $daterange_field->start_date);
+assertType('string|null', $daterange_field->end_value);
+assertType('\Drupal\Core\Datetime\DrupalDateTime|null', $daterange_field->end_date);
+
 // FileItem.
 $file_field = $node->get('field_file')->first();
 assert($file_field instanceof FileItem);