Support for promoted properties rules on AST level

Author: ondrejmirtes

composer.json

@@ -23,7 +23,7 @@
 		"nette/utils": "^3.1.3",
 		"nikic/php-parser": "4.10.2",
 		"ondram/ci-detector": "^3.4.0",
-		"ondrejmirtes/better-reflection": "4.3.40",
+		"ondrejmirtes/better-reflection": "4.3.41",
 		"phpdocumentor/reflection-docblock": "4.3.4",
 		"phpstan/php-8-stubs": "^0.1.6",
 		"phpstan/phpdoc-parser": "^0.4.9",

composer.lock

@@ -458,6 +458,27 @@ private function processStmtNode(
 				$isFinal
 			);
 
+			if ($stmt->name->toLowerString() === '__construct') {
+				foreach ($stmt->params as $param) {
+					if ($param->flags === 0) {
+						continue;
+					}
+
+					if (!$param->var instanceof Variable || !is_string($param->var->name)) {
+						throw new \PHPStan\ShouldNotHappenException();
+					}
+					$nodeCallback(new ClassPropertyNode(
+						$param->var->name,
+						$param->flags,
+						$param->type,
+						$param->default,
+						null, // todo
+						true,
+						$param
+					), $methodScope);
+				}
+			}
+
 			if ($stmt->getAttribute('virtual', false) === false) {
 				$nodeCallback(new InClassMethodNode($stmt), $methodScope);
 			}
@@ -595,6 +616,7 @@ private function processStmtNode(
 						$stmt->type,
 						$prop->default,
 						$docComment !== null ? $docComment->getText() : null,
+						false,
 						$prop
 					),
 					$scope

src/Analyser/NodeScopeResolver.php

@@ -25,6 +25,8 @@ class ClassPropertyNode extends NodeAbstract implements VirtualNode
 
 	private ?string $phpDoc;
 
+	private bool $isPromoted;
+
 	/**
 	 * @param int $flags
 	 * @param Identifier|Name|NullableType|UnionType|null $type
@@ -37,6 +39,7 @@ public function __construct(
 		$type,
 		?Expr $default,
 		?string $phpDoc,
+		bool $isPromoted,
 		Node $originalNode
 	)
 	{
@@ -45,6 +48,7 @@ public function __construct(
 		$this->flags = $flags;
 		$this->type = $type;
 		$this->default = $default;
+		$this->isPromoted = $isPromoted;
 		$this->phpDoc = $phpDoc;
 	}
 
@@ -63,6 +67,11 @@ public function getDefault(): ?Expr
 		return $this->default;
 	}
 
+	public function isPromoted(): bool
+	{
+		return $this->isPromoted;
+	}
+
 	public function getPhpDoc(): ?string
 	{
 		return $this->phpDoc;

src/Node/ClassPropertyNode.php

@@ -9,6 +9,7 @@
 use PhpParser\Node\Expr\PropertyFetch;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\StaticPropertyFetch;
+use PhpParser\Node\Identifier;
 use PHPStan\Analyser\Scope;
 use PHPStan\Node\Constant\ClassConstantFetch;
 use PHPStan\Node\Property\PropertyRead;
@@ -119,6 +120,12 @@ private function gatherNodes(\PhpParser\Node $node, Scope $scope): void
 		}
 		if ($node instanceof ClassPropertyNode && !$scope->isInTrait()) {
 			$this->properties[] = $node;
+			if ($node->isPromoted()) {
+				$this->propertyUsages[] = new PropertyWrite(
+					new PropertyFetch(new Expr\Variable('this'), new Identifier($node->getName())),
+					$scope
+				);
+			}
 			return;
 		}
 		if ($node instanceof \PhpParser\Node\Stmt\ClassMethod && !$scope->isInTrait()) {

src/Node/ClassStatementsGatherer.php

@@ -155,4 +155,20 @@ public function testBug3636(): void
 		]);
 	}
 
+	public function testPromotedProperties(): void
+	{
+		if (!self::$useStaticReflectionProvider && PHP_VERSION_ID < 80000) {
+			$this->markTestSkipped('Test requires PHP 8.0.');
+		}
+
+		$this->alwaysWrittenTags = [];
+		$this->alwaysReadTags = [];
+		$this->analyse([__DIR__ . '/data/unused-private-promoted-property.php'], [
+			[
+				'Property UnusedPrivatePromotedProperty\Foo::$lorem is never read, only written.',
+				12,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/DeadCode/UnusedPrivatePropertyRuleTest.php

@@ -0,0 +1,20 @@
+<?php // lint >= 8.0
+
+namespace UnusedPrivatePromotedProperty;
+
+class Foo
+{
+
+	public function __construct(
+		public $foo,
+		protected $bar,
+		private $baz,
+		private $lorem
+	) { }
+
+	public function getBaz()
+	{
+		return $this->baz;
+	}
+
+}