From e1b48d4141903f83e36a361b78e2ecf0d50f203a Mon Sep 17 00:00:00 2001
From: QDenka <a@bigf.at>
Date: Sun, 8 Feb 2026 09:35:06 +0000
Subject: [PATCH] Skip ClosureToArrowFunctionRector when closure has @var
 docblock

Arrow functions do not support inline @var annotations for type
narrowing. Previously, the rule only skipped conversion when the
@var type was more specific than the native type. However, type
comparison can fail with generics (e.g. Builder<Team> vs Builder),
causing unintended conversion that breaks PHPStan type narrowing.

Now the rule skips conversion whenever a @var tag is present on
the return statement, regardless of type comparison.

Fixes rectorphp/rector#9637
---
 ..._closure_with_var_docblock_generic.php.inc | 16 ++++++++++
 .../Fixture/with_equal_var_doc_type.php.inc   | 15 ----------
 .../ClosureArrowFunctionAnalyzer.php          | 29 ++-----------------
 3 files changed, 19 insertions(+), 41 deletions(-)
 create mode 100644 rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_closure_with_var_docblock_generic.php.inc

diff --git a/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_closure_with_var_docblock_generic.php.inc b/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_closure_with_var_docblock_generic.php.inc
new file mode 100644
index 00000000000..7fcb85b2eba
--- /dev/null
+++ b/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_closure_with_var_docblock_generic.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\Tests\Php74\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class SkipClosureWithVarDocblockGeneric
+{
+    public function run()
+    {
+        $fn = function (object $query) {
+            /** @var \ArrayObject<int, string> $query */
+            return $query->count();
+        };
+    }
+}
+
+?>
diff --git a/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/with_equal_var_doc_type.php.inc b/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/with_equal_var_doc_type.php.inc
index d21f587edd5..27e647dd63a 100644
--- a/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/with_equal_var_doc_type.php.inc
+++ b/rules-tests/Php74/Rector/Closure/ClosureToArrowFunctionRector/Fixture/with_equal_var_doc_type.php.inc
@@ -14,18 +14,3 @@ class WithEqualVarDocType
 }
 
 ?>
------
-<?php
-
-namespace Rector\Tests\Php74\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
-
-class WithEqualVarDocType
-{
-    public function run()
-    {
-        /** @var string $var */
-        fn(string $var) => $var;
-    }
-}
-
-?>
diff --git a/rules/Php74/NodeAnalyzer/ClosureArrowFunctionAnalyzer.php b/rules/Php74/NodeAnalyzer/ClosureArrowFunctionAnalyzer.php
index d6b4ea2c86c..c1687c5d592 100644
--- a/rules/Php74/NodeAnalyzer/ClosureArrowFunctionAnalyzer.php
+++ b/rules/Php74/NodeAnalyzer/ClosureArrowFunctionAnalyzer.php
@@ -12,11 +12,9 @@
 use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Stmt\Return_;
 use PHPStan\PhpDocParser\Ast\PhpDoc\VarTagValueNode;
-use PHPStan\Type\MixedType;
 use Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfo;
 use Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfoFactory;
 use Rector\NodeAnalyzer\CompactFuncCallAnalyzer;
-use Rector\NodeTypeResolver\NodeTypeResolver;
 use Rector\PhpParser\Comparing\NodeComparator;
 use Rector\PhpParser\Node\BetterNodeFinder;
 use Rector\Util\ArrayChecker;
@@ -28,7 +26,6 @@ public function __construct(
         private NodeComparator $nodeComparator,
         private ArrayChecker $arrayChecker,
         private PhpDocInfoFactory $phpDocInfoFactory,
-        private NodeTypeResolver $nodeTypeResolver,
         private CompactFuncCallAnalyzer $compactFuncCallAnalyzer
     ) {
     }
@@ -92,7 +89,8 @@ function (Node $node) use ($variables): bool {
     }
 
     /**
-     * Ensure @var doc usage with more specific type on purpose to be skipped
+     * Ensure @var doc usage to be skipped, as arrow functions do not support
+     * inline @var annotations for type narrowing (e.g. generic types like Builder<Team>)
      */
     private function shouldSkipMoreSpecificTypeWithVarDoc(Return_ $return, Expr $expr): bool
     {
@@ -103,29 +101,8 @@ private function shouldSkipMoreSpecificTypeWithVarDoc(Return_ $return, Expr $exp
         }
 
         $varTagValueNode = $phpDocInfo->getVarTagValueNode();
-        if (! $varTagValueNode instanceof VarTagValueNode) {
-            return false;
-        }
-
-        $varType = $phpDocInfo->getVarType();
-        if ($varType instanceof MixedType) {
-            return false;
-        }
-
-        $variableName = ltrim($varTagValueNode->variableName, '$');
-        $variable = $this->betterNodeFinder->findFirst(
-            $expr,
-            static fn (Node $node): bool => $node instanceof Variable && $node->name === $variableName
-        );
-
-        if (! $variable instanceof Variable) {
-            return false;
-        }
-
-        $nativeVariableType = $this->nodeTypeResolver->getNativeType($variable);
 
-        // not equal with native type means more specific type
-        return ! $nativeVariableType->equals($varType);
+        return $varTagValueNode instanceof VarTagValueNode;
     }
 
     private function shouldSkipForUsedReferencedValue(Closure $closure): bool