Fix

Author: VincentLanglet

src/Analyser/NodeScopeResolver.php

@@ -7093,6 +7093,15 @@ public function getPhpDocs(Scope $scope, Node\FunctionLike|Node\Stmt\Property $n
 			$varTags = $resolvedPhpDoc->getVarTags();
 		}
 
+		if ($isPure === null && $scope->isInClass()) {
+			$classResolvedPhpDoc = $scope->getClassReflection()->getResolvedPhpDoc();
+			if ($classResolvedPhpDoc !== null && $classResolvedPhpDoc->areAllMethodsPure()) {
+				$isPure = true;
+			} elseif ($classResolvedPhpDoc !== null && $classResolvedPhpDoc->areAllMethodsImpure()) {
+				$isPure = false;
+			}
+		}
+
 		return [$templateTypeMap, $phpDocParameterTypes, $phpDocImmediatelyInvokedCallableParameters, $phpDocClosureThisTypeParameters, $phpDocReturnType, $phpDocThrowType, $deprecatedDescription, $isDeprecated, $isInternal, $isFinal, $isPure, $acceptsNamedArguments, $isReadOnly, $docComment, $asserts, $selfOutType, $phpDocParameterOutTypes, $varTags, $isAllowedPrivateMutation];
 	}