Virtual property cannot be uninitialized

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -2633,7 +2633,7 @@ public function hasPropertyNativeType($propertyFetch): bool
 			return false;
 		}
 
-		return !$propertyReflection->getNativeType() instanceof MixedType;
+		return $propertyReflection->hasNativeType();
 	}
 
 	private function getTypeFromArrayDimFetch(

src/Node/ClassPropertiesNode.php

@@ -131,6 +131,9 @@ public function getUninitializedProperties(
 			$is = TrinaryLogic::createFromBoolean($property->isPromoted() && !$property->isPromotedFromTrait());
 			if (!$is->yes() && $classReflection->hasNativeProperty($property->getName())) {
 				$propertyReflection = $classReflection->getNativeProperty($property->getName());
+				if ($propertyReflection->isVirtual()->yes()) {
+					continue;
+				}
 
 				foreach ($extensions as $extension) {
 					if (!$extension->isInitialized($propertyReflection, $property->getName())) {

src/Rules/IssetCheck.php

@@ -7,7 +7,6 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Properties\PropertyDescriptor;
 use PHPStan\Rules\Properties\PropertyReflectionFinder;
-use PHPStan\Type\MixedType;
 use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
 use PHPStan\Type\VerbosityLevel;
@@ -143,8 +142,7 @@ public function check(Expr $expr, Scope $scope, string $operatorDescription, str
 				return null;
 			}
 
-			$nativeType = $propertyReflection->getNativeType();
-			if (!$nativeType instanceof MixedType) {
+			if ($propertyReflection->hasNativeType() && !$propertyReflection->isVirtual()->yes()) {
 				if (!$scope->hasExpressionType($expr)->yes()) {
 					if ($expr instanceof Node\Expr\PropertyFetch) {
 						return $this->checkUndefined($expr->var, $scope, $operatorDescription, $identifier);

src/Rules/Properties/DefaultValueTypesAssignedToPropertiesRule.php

@@ -8,7 +8,6 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\Rules\RuleLevelHelper;
-use PHPStan\Type\MixedType;
 use PHPStan\Type\VerbosityLevel;
 use function sprintf;
 
@@ -38,7 +37,7 @@ public function processNode(Node $node, Scope $scope): array
 
 		$propertyReflection = $classReflection->getNativeProperty($node->getName());
 		$propertyType = $propertyReflection->getWritableType();
-		if ($propertyReflection->getNativeType() instanceof MixedType) {
+		if (!$propertyReflection->hasNativeType()) {
 			if ($default instanceof Node\Expr\ConstFetch && $default->name->toLowerString() === 'null') {
 				return [];
 			}

tests/PHPStan/Rules/Properties/UninitializedPropertyRuleTest.php

@@ -226,4 +226,13 @@ public function testBug12336(): void
 		$this->analyse([__DIR__ . '/data/bug-12336.php'], []);
 	}
 
+	public function testBug12547(): void
+	{
+		if (PHP_VERSION_ID < 80400) {
+			$this->markTestSkipped('Test requires PHP 8.4.');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-12547.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/bug-12547.php

@@ -0,0 +1,11 @@
+<?php // lint >= 8.4
+
+declare(strict_types = 1);
+
+namespace Bug12547;
+
+class Example {
+	public \DateTimeImmutable $noon {
+		get => new \DateTimeImmutable('12:00');
+	}
+}

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -449,4 +449,19 @@ public function testBug10064(): void
 		$this->analyse([__DIR__ . '/data/bug-10064.php'], []);
 	}
 
+	public function testVirtualProperty(): void
+	{
+		if (PHP_VERSION_ID < 80400) {
+			$this->markTestSkipped('Test requires PHP 8.4.');
+		}
+
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/isset-virtual-property.php'], [
+			[
+				'Property IssetVirtualProperty\Example::$noon (DateTimeImmutable) in isset() is not nullable.',
+				16,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/isset-virtual-property.php

@@ -0,0 +1,23 @@
+<?php // lint >= 8.4
+
+namespace IssetVirtualProperty;
+
+class Example {
+	public \DateTimeImmutable $noon {
+		get => new \DateTimeImmutable('12:00');
+	}
+
+	public ?\DateTimeImmutable $nullableNoon {
+		get => new \DateTimeImmutable('12:00');
+	}
+
+	public function doFoo(): void
+	{
+		if (isset($this->noon)) {
+
+		}
+		if (isset($this->nullableNoon)) {
+
+		}
+	}
+}