@readonly property allows private mutation

src/PhpDoc/PhpDocNodeResolver.php

@@ -454,7 +454,7 @@ public function resolveIsImpure(PhpDocNode $phpDocNode): bool
 
 	public function resolveIsReadOnly(PhpDocNode $phpDocNode): bool
 	{
-		foreach (['@readonly', '@psalm-readonly', '@phpstan-readonly', '@psalm-readonly-allow-private-mutation'] as $tagName) {
+		foreach (['@readonly', '@psalm-readonly', '@phpstan-readonly', '@phpstan-readonly-allow-private-mutation', '@psalm-readonly-allow-private-mutation'] as $tagName) {
 			$tags = $phpDocNode->getTagsByName($tagName);
 
 			if (count($tags) > 0) {
@@ -505,4 +505,17 @@ private function shouldSkipType(string $tagName, Type $type): bool
 		return $this->unresolvableTypeHelper->containsUnresolvableType($type);
 	}
 
+	public function resolveAllowPrivateMutation(PhpDocNode $phpDocNode): bool
+	{
+		foreach (['@phpstan-readonly-allow-private-mutation', '@phpstan-allow-private-mutation', '@psalm-readonly-allow-private-mutation', '@psalm-allow-private-mutation'] as $tagName) {
+			$tags = $phpDocNode->getTagsByName($tagName);
+
+			if (count($tags) > 0) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 }

src/PhpDoc/ResolvedPhpDocBlock.php

@@ -100,6 +100,8 @@ class ResolvedPhpDocBlock
 
 	private ?bool $isImmutable = null;
 
+	private ?bool $isAllowedPrivateMutation = null;
+
 	private ?bool $hasConsistentConstructor = null;
 
 	private ?bool $acceptsNamedArguments = null;
@@ -162,6 +164,8 @@ public static function createEmpty(): self
 		$self->isFinal = false;
 		$self->isPure = null;
 		$self->isReadOnly = false;
+		$self->isImmutable = false;
+		$self->isAllowedPrivateMutation = false;
 		$self->hasConsistentConstructor = false;
 		$self->acceptsNamedArguments = true;
 
@@ -211,6 +215,8 @@ public function merge(array $parents, array $parentPhpDocBlocks): self
 		$result->isFinal = $this->isFinal();
 		$result->isPure = $this->isPure();
 		$result->isReadOnly = $this->isReadOnly();
+		$result->isImmutable = $this->isImmutable();
+		$result->isAllowedPrivateMutation = $this->isAllowedPrivateMutation();
 		$result->hasConsistentConstructor = $this->hasConsistentConstructor();
 		$result->acceptsNamedArguments = $acceptsNamedArguments;
 
@@ -593,6 +599,17 @@ public function isImmutable(): bool
 		return $this->isImmutable;
 	}
 
+	public function isAllowedPrivateMutation(): bool
+	{
+		if ($this->isAllowedPrivateMutation === null) {
+			$this->isAllowedPrivateMutation = $this->phpDocNodeResolver->resolveAllowPrivateMutation(
+				$this->phpDocNode,
+			);
+		}
+
+		return $this->isAllowedPrivateMutation;
+	}
+
 	/**
 	 * @param array<string|int, VarTag> $varTags
 	 * @param array<int, self> $parents

src/Reflection/Php/PhpClassReflectionExtension.php

@@ -214,14 +214,15 @@ private function createProperty(
 					$types[] = $value;
 				}
 
-				return new PhpPropertyReflection($declaringClassReflection, null, null, TypeCombinator::union(...$types), $classReflection->getNativeReflection()->getProperty($propertyName), null, false, false, false);
+				return new PhpPropertyReflection($declaringClassReflection, null, null, TypeCombinator::union(...$types), $classReflection->getNativeReflection()->getProperty($propertyName), null, false, false, false, false);
 			}
 		}
 
 		$deprecatedDescription = null;
 		$isDeprecated = false;
 		$isInternal = false;
 		$isReadOnlyByPhpDoc = $classReflection->isImmutable();
+		$isAllowedPrivateMutation = false;
 
 		if (
 			$includingAnnotations
@@ -297,6 +298,7 @@ private function createProperty(
 			$isDeprecated = $resolvedPhpDoc->isDeprecated();
 			$isInternal = $resolvedPhpDoc->isInternal();
 			$isReadOnlyByPhpDoc = $isReadOnlyByPhpDoc || $resolvedPhpDoc->isReadOnly();
+			$isAllowedPrivateMutation = $resolvedPhpDoc->isAllowedPrivateMutation();
 		}
 
 		if ($phpDocType === null) {
@@ -361,6 +363,7 @@ private function createProperty(
 			$isDeprecated,
 			$isInternal,
 			$isReadOnlyByPhpDoc,
+			$isAllowedPrivateMutation,
 		);
 	}
 

src/Reflection/Php/PhpPropertyReflection.php

@@ -31,6 +31,7 @@ public function __construct(
 		private bool $isDeprecated,
 		private bool $isInternal,
 		private bool $isReadOnlyByPhpDoc,
+		private bool $isAllowedPrivateMutation,
 	)
 	{
 	}
@@ -169,6 +170,11 @@ public function isInternal(): TrinaryLogic
 		return TrinaryLogic::createFromBoolean($this->isInternal);
 	}
 
+	public function isAllowedPrivateMutation(): bool
+	{
+		return $this->isAllowedPrivateMutation;
+	}
+
 	public function getNativeReflection(): ReflectionProperty
 	{
 		return $this->reflection;

src/Rules/Properties/ReadOnlyByPhpDocPropertyAssignRule.php

@@ -83,6 +83,10 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
+			if ($nativeReflection->isAllowedPrivateMutation()) {
+				continue;
+			}
+
 			$errors[] = RuleErrorBuilder::message(sprintf('@readonly property %s::$%s is assigned outside of the constructor.', $declaringClass->getDisplayName(), $propertyReflection->getName()))->build();
 		}
 

tests/PHPStan/Rules/Properties/ReadOnlyByPhpDocPropertyAssignRuleTest.php

@@ -32,10 +32,6 @@ public function testRule(): void
 				'@readonly property ReadonlyPropertyAssignPhpDoc\Foo::$foo is assigned outside of the constructor.',
 				40,
 			],
-			[
-				'@readonly property ReadonlyPropertyAssignPhpDoc\Foo::$psalm is assigned outside of the constructor.',
-				41,
-			],
 			[
 				'@readonly property ReadonlyPropertyAssignPhpDoc\Foo::$bar is assigned outside of its declaring class.',
 				53,

tests/PHPStan/Rules/Properties/data/readonly-assign-phpdoc.php

@@ -38,7 +38,7 @@ public function __construct(int $foo)
 	public function setFoo(int $foo): void
 	{
 		$this->foo = $foo; // setter - report
-		$this->psalm = $foo; // setter - report, but Psalm allowed private mutation
+		$this->psalm = $foo; // do not report -allowed private mutation
 	}
 
 }