Mark DOMNamedNodeMap as taking a covariant DOMNode

stubs/dom.stub

@@ -1,6 +1,6 @@
 <?php
 
-class DOMDocument
+class DOMDocument extends DOMNode
 {
 
 	/** @var DOMDocumentType|null */
@@ -29,7 +29,16 @@ class DOMDocument
 
 class DOMNode
 {
+	/**
+	 * @readonly
+	 * @var DOMNamedNodeMap<DOMAttr>|null
+	 */
+	public $attributes;
 
+	/**
+	 * @phpstan-assert-if-true DOMNamedNodeMap<DOMAttr> $this->attributes
+	 */
+	public function hasAttributes(): bool {}
 }
 
 class DOMElement extends DOMNode
@@ -38,6 +47,12 @@ class DOMElement extends DOMNode
 	/** @var DOMDocument */
 	public $ownerDocument;
 
+	/**
+	 * @readonly
+	 * @var DOMNamedNodeMap<DOMAttr>
+	 */
+	public $attributes;
+
 	/**
 	 * @param string $name
 	 * @return DOMNodeList<DOMElement>
@@ -50,7 +65,6 @@ class DOMElement extends DOMNode
 	 * @return DOMNodeList<DOMElement>
 	 */
 	public function getElementsByTagNameNS ($namespaceURI, $localName) {}
-
 }
 
 /**
@@ -82,47 +96,47 @@ class DOMXPath
 
 }
 
-class DOMAttr
+class DOMAttr extends DOMNode
 {
 
 	/** @var DOMDocument */
 	public $ownerDocument;
 
 }
 
-class DOMCharacterData
+class DOMCharacterData extends DOMNode
 {
 
 	/** @var DOMDocument */
 	public $ownerDocument;
 
 }
 
-class DOMDocumentType
+class DOMDocumentType extends DOMNode
 {
 
 	/** @var DOMDocument */
 	public $ownerDocument;
 
 }
 
-class DOMEntity
+class DOMEntity extends DOMNode
 {
 
 	/** @var DOMDocument */
 	public $ownerDocument;
 
 }
 
-class DOMNotation
+class DOMNotation extends DOMNode
 {
 
 	/** @var DOMDocument */
 	public $ownerDocument;
 
 }
 
-class DOMProcessingInstruction
+class DOMProcessingInstruction extends DOMNode
 {
 
 	/** @var DOMDocument */
@@ -141,14 +155,35 @@ class DOMProcessingInstruction
 }
 
 /**
+ * @template-covariant TNode as DOMNode
+ * @implements Traversable<string, TNode>
+ * @implements IteratorAggregate<int, TNode>
  * @property-read int $length
  */
-class DOMNamedNodeMap
+class DOMNamedNodeMap implements Traversable, IteratorAggregate, Countable
 {
 
+    /**
+     * @return (TNode | null)
+     */
+    public function getNamedItem(string $qualifiedName)
+    {
+    }
+    /**
+     * @return (TNode | null)
+     */
+    public function getNamedItemNS(?string $namespace, string $localName)
+    {
+    }
+    /**
+     * @return (TNode | null)
+     */
+    public function item(int $index)
+    {
+    }
 }
 
-class DOMText
+class DOMText extends DOMCharacterData
 {
 
 	/** @var string */

tests/PHPStan/Analyser/nsrt/DOMLegacyNamedNodeNap.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace DOMLegacyNamedNodeMap;
+
+use DOMAttr;
+use DOMElement;
+use DOMNode;
+use DOMNamedNodeMap;
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+	public function basic_node(DOMNode $node): void {
+		if ($node->hasAttributes()) {
+			assertType('DOMNamedNodeMap<DOMAttr>', $node->attributes);
+		} else {
+			assertType('null', $node->attributes);
+		}
+	}
+
+	public function element_node(DOMElement $element): void
+	{
+		assertType('DOMNamedNodeMap<DOMAttr>', $element->attributes);
+		if ($element->hasAttribute('class')) {
+			$attribute = $element->getAttributeNode('class');
+			assertType(DOMAttr::class, $attribute);
+			assertType('string', $attribute->value);
+		} else {
+			$attribute = $element->getAttributeNode('class');
+			assertType('false', $attribute);
+		}
+	}
+
+	public function element_node_attribute_fetch_via_attributes_property(DOMElement $element): void
+	{
+		assertType('DOMNamedNodeMap<DOMAttr>', $element->attributes);
+		if ($element->hasAttribute('class')) {
+			$attribute = $element->attributes->getNamedItem('class');
+			if ($attribute === null) {
+				return;
+			}
+			assertType(DOMAttr::class, $attribute);
+			assertType('string', $attribute->value);
+		}
+	}
+}

tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php

@@ -957,4 +957,12 @@ public function testTraitMixin(): void
 		$this->analyse([__DIR__ . '/data/trait-mixin.php'], []);
 	}
 
+	public function testDomExtensionLegacyTemplateNodes(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkUnionTypes = true;
+		$this->checkDynamicProperties = true;
+		$this->analyse([__DIR__ . '/data/dom-legacy-ext-template-nodes.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/dom-legacy-ext-template-nodes.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace DOMNodeStubsAccessProperties;
+
+function basic_node(\DOMNode $node): void {
+	var_dump($node->attributes);
+}
+
+function element_node(\DOMElement $element): void
+{
+	if ($element->hasAttribute('class')) {
+		$attribute = $element->getAttributeNode('class');
+		echo $attribute->value;
+	}
+}
+
+function element_node_attribute_fetch_via_attributes_property(\DOMElement $element): void
+{
+	$attribute = $element->attributes->getNamedItem('class');
+	if ($attribute === null) {
+		return;
+	}
+	echo $attribute->value;
+}
+
+function element_node_attribute_fetch_via_getAttributeNode(\DOMElement $element): void
+{
+	$attribute = $element->getAttributeNode('class');
+	if ($attribute === null) {
+		return;
+	}
+	echo $attribute->value;
+}