Fix static method expression invalidation on "maybe pure" methods

Author: takaram

src/Analyser/NodeScopeResolver.php

@@ -291,6 +291,8 @@ public function __construct(
 		private readonly bool $implicitThrows,
 		#[AutowiredParameter]
 		private readonly bool $treatPhpDocTypesAsCertain,
+		#[AutowiredParameter]
+		private readonly bool $rememberPossiblyImpureFunctionValues,
 	)
 	{
 		$earlyTerminatingMethodNames = [];
@@ -3215,11 +3217,13 @@ function (MutatingScope $scope) use ($stmt, $expr, $nodeCallback, $context, $sto
 			$scope = $result->getScope();
 
 			if ($methodReflection !== null) {
-				$hasSideEffects = $methodReflection->hasSideEffects()->yes();
-				if ($hasSideEffects || $methodReflection->getName() === '__construct') {
+				$shouldInvalidateExpr = $this->rememberPossiblyImpureFunctionValues
+					? $methodReflection->hasSideEffects()->yes()
+					: !$methodReflection->hasSideEffects()->no();
+				if ($shouldInvalidateExpr || $methodReflection->getName() === '__construct') {
 					$this->callNodeCallback($nodeCallback, new InvalidateExprNode($normalizedExpr->var), $scope, $storage);
 					$scope = $scope->invalidateExpression($normalizedExpr->var, true, $methodReflection->getDeclaringClass());
-					if ($hasSideEffects) {
+					if ($shouldInvalidateExpr) {
 						$scope = $scope->invalidateStaticMembers($normalizedExpr->var);
 					}
 				}

src/Testing/RuleTestCase.php

@@ -119,6 +119,7 @@ protected function createNodeScopeResolver(): NodeScopeResolver
 			[],
 			self::getContainer()->getParameter('exceptions')['implicitThrows'],
 			$this->shouldTreatPhpDocTypesAsCertain(),
+			self::getContainer()->getParameter('rememberPossiblyImpureFunctionValues'),
 		);
 	}
 

src/Testing/TypeInferenceTestCase.php

@@ -94,6 +94,7 @@ protected static function createNodeScopeResolver(): NodeScopeResolver
 			static::getEarlyTerminatingFunctionCalls(),
 			$container->getParameter('exceptions')['implicitThrows'],
 			$container->getParameter('treatPhpDocTypesAsCertain'),
+			$container->getParameter('rememberPossiblyImpureFunctionValues'),
 		);
 	}
 

tests/PHPStan/Analyser/AnalyserTest.php

@@ -835,6 +835,7 @@ private function createAnalyser(): Analyser
 			[],
 			true,
 			$this->shouldTreatPhpDocTypesAsCertain(),
+			true,
 		);
 		$lexer = new Lexer();
 		$fileAnalyser = new FileAnalyser(

tests/PHPStan/Analyser/Fiber/FiberNodeScopeResolverRuleTest.php

@@ -139,6 +139,7 @@ protected function createNodeScopeResolver(): NodeScopeResolver
 			[],
 			self::getContainer()->getParameter('exceptions')['implicitThrows'],
 			$this->shouldTreatPhpDocTypesAsCertain(),
+			self::getContainer()->getParameter('rememberPossiblyImpureFunctionValues'),
 		);
 	}
 

tests/PHPStan/Analyser/Fiber/FiberNodeScopeResolverTest.php

@@ -72,6 +72,7 @@ protected static function createNodeScopeResolver(): NodeScopeResolver
 			static::getEarlyTerminatingFunctionCalls(),
 			$container->getParameter('exceptions')['implicitThrows'],
 			$container->getParameter('treatPhpDocTypesAsCertain'),
+			$container->getParameter('rememberPossiblyImpureFunctionValues'),
 		);
 	}
 

tests/PHPStan/Analyser/data/do-not-remember-possibly-impure-function-values.php

@@ -6,6 +6,7 @@
 
 class Foo
 {
+	private static int $counter = 0;
 
 	/** @phpstan-pure */
 	public function pure(): int
@@ -24,6 +25,12 @@ public function impure(): int
 		return rand(0, 1);
 	}
 
+	/** @phpstan-pure */
+	public static function getCounter(): int
+	{
+		return self::$counter;
+	}
+
 	public function test(): void
 	{
 		if ($this->pure() === 1) {
@@ -39,6 +46,24 @@ public function test(): void
 		}
 	}
 
+	public function testStatic(): void
+	{
+		if (self::getCounter() === 1) {
+			$this->pure();
+			assertType('1', self::getCounter());
+		}
+
+		if (self::getCounter() === 1) {
+			$this->maybePure();
+			assertType('int', self::getCounter());
+		}
+
+		if (self::getCounter() === 1) {
+			$this->impure();
+			assertType('int', self::getCounter());
+		}
+	}
+
 }
 
 class FooStatic

tests/PHPStan/Analyser/nsrt/remember-possibly-impure-function-values.php

@@ -6,6 +6,7 @@
 
 class Foo
 {
+	private static int $counter = 0;
 
 	/** @phpstan-pure */
 	public function pure(): int
@@ -24,6 +25,11 @@ public function impure(): int
 		return rand(0, 1);
 	}
 
+	public static function getCounter(): int
+	{
+		return self::$counter;
+	}
+
 	public function test(): void
 	{
 		if ($this->pure() === 1) {
@@ -39,6 +45,24 @@ public function test(): void
 		}
 	}
 
+	public function testStatic(): void
+	{
+		if (self::getCounter() === 1) {
+			$this->pure();
+			assertType('1', self::getCounter());
+		}
+
+		if (self::getCounter() === 1) {
+			$this->maybePure();
+			assertType('1', self::getCounter());
+		}
+
+		if (self::getCounter() === 1) {
+			$this->impure();
+			assertType('int', self::getCounter());
+		}
+	}
+
 }
 
 class FooStatic