feat(query): add parent id joining query

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Spamercz

doc/02-query-objects.md

@@ -344,6 +344,16 @@ new \Spameri\ElasticQuery\Query\Boosting(
 
 Queries that traverse parent/child or join relationships.
 
+##### ParentId Query
+Match children that belong to a parent with a known id.
+- Class: `\Spameri\ElasticQuery\Query\ParentId`
+- [Documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-parent-id-query.html)
+- [Implementation](https://github.com/Spameri/ElasticQuery/blob/master/src/Query/ParentId.php)
+
+```php
+new \Spameri\ElasticQuery\Query\ParentId(type: 'comment', id: '1');
+```
+
 ##### HasParent Query
 Match children whose parent matches the inner query.
 - Class: `\Spameri\ElasticQuery\Query\HasParent`

src/Query/ParentId.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Spameri\ElasticQuery\Query;
+
+/**
+ * @see https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-parent-id-query.html
+ */
+class ParentId implements \Spameri\ElasticQuery\Query\LeafQueryInterface
+{
+
+	public function __construct(
+		private string $type,
+		private string $id,
+		private bool|null $ignoreUnmapped = null,
+	)
+	{
+	}
+
+
+	public function key(): string
+	{
+		return 'parent_id_' . $this->type . '_' . $this->id;
+	}
+
+
+	/**
+	 * @return array<string, array<string, mixed>>
+	 */
+	public function toArray(): array
+	{
+		$body = [
+			'type' => $this->type,
+			'id' => $this->id,
+		];
+
+		if ($this->ignoreUnmapped !== null) {
+			$body['ignore_unmapped'] = $this->ignoreUnmapped;
+		}
+
+		return [
+			'parent_id' => $body,
+		];
+	}
+
+}

tests/SpameriTests/ElasticQuery/Query/ParentId.phpt

@@ -0,0 +1,58 @@
+<?php declare(strict_types = 1);
+
+namespace SpameriTests\ElasticQuery\Query;
+
+require_once __DIR__ . '/../../bootstrap.php';
+
+
+class ParentId extends \Tester\TestCase
+{
+
+	private const INDEX = 'spameri_test_query_parent_id';
+
+
+	public function setUp(): void
+	{
+		$ch = \curl_init();
+		\curl_setopt($ch, \CURLOPT_URL, \ELASTICSEARCH_HOST . '/' . self::INDEX);
+		\curl_setopt($ch, \CURLOPT_RETURNTRANSFER, 1);
+		\curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'PUT');
+		\curl_setopt($ch, \CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
+
+		\curl_exec($ch);
+	}
+
+
+	public function testToArray(): void
+	{
+		$parentId = new \Spameri\ElasticQuery\Query\ParentId(type: 'comment', id: '1');
+
+		$array = $parentId->toArray();
+
+		\Tester\Assert::same('comment', $array['parent_id']['type']);
+		\Tester\Assert::same('1', $array['parent_id']['id']);
+	}
+
+
+	public function testKey(): void
+	{
+		$parentId = new \Spameri\ElasticQuery\Query\ParentId('comment', '1');
+
+		\Tester\Assert::same('parent_id_comment_1', $parentId->key());
+	}
+
+
+	public function tearDown(): void
+	{
+		$ch = \curl_init();
+		\curl_setopt($ch, \CURLOPT_URL, \ELASTICSEARCH_HOST . '/' . self::INDEX);
+		\curl_setopt($ch, \CURLOPT_RETURNTRANSFER, 1);
+		\curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'DELETE');
+		\curl_setopt($ch, \CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
+
+		\curl_exec($ch);
+	}
+
+}
+
+(new ParentId())->run();