From a82a18edd366575db60151880ca44f1a8c2a0120 Mon Sep 17 00:00:00 2001
From: Simon Podlipsky <simon@podlipsky.net>
Date: Wed, 12 Jan 2022 16:43:53 +0100
Subject: [PATCH] Prevent UnionTypes rule from removing `@param static` in
 favor fo `self`-typed $argument (#1667)

---
 .../TypeComparator/TypeComparator.php         | 15 +++++++++
 .../Fixture/param_self_return_static.php.inc  | 31 +++++++++++++++++++
 .../Fixture/skip_static_param.php.inc         | 13 ++++++++
 3 files changed, 59 insertions(+)
 create mode 100644 rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/param_self_return_static.php.inc
 create mode 100644 rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/skip_static_param.php.inc

diff --git a/packages/NodeTypeResolver/TypeComparator/TypeComparator.php b/packages/NodeTypeResolver/TypeComparator/TypeComparator.php
index 37c8779dd0e..11e3acbab56 100644
--- a/packages/NodeTypeResolver/TypeComparator/TypeComparator.php
+++ b/packages/NodeTypeResolver/TypeComparator/TypeComparator.php
@@ -6,6 +6,7 @@
 
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
+use PHPStan\PhpDocParser\Ast\PhpDoc\ParamTagValueNode;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
 use PHPStan\Reflection\ClassReflection;
 use PHPStan\Type\ArrayType;
@@ -15,15 +16,18 @@
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
+use PHPStan\Type\StaticType;
 use PHPStan\Type\ThisType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\UnionType;
+use Rector\BetterPhpDocParser\ValueObject\PhpDocAttributeKey;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Rector\NodeTypeResolver\PHPStan\Type\TypeFactory;
 use Rector\NodeTypeResolver\PHPStan\TypeHasher;
 use Rector\StaticTypeMapper\StaticTypeMapper;
 use Rector\StaticTypeMapper\ValueObject\Type\AliasedObjectType;
+use Rector\StaticTypeMapper\ValueObject\Type\SelfStaticType;
 use Rector\TypeDeclaration\TypeNormalizer;
 
 final class TypeComparator
@@ -96,6 +100,10 @@ public function arePhpParserAndPhpStanPhpDocTypesEqual(
             return false;
         }
 
+        if ($this->isTypeSelfAndDocParamTypeStatic($phpStanDocType, $phpParserNodeType, $phpStanDocTypeNode)) {
+            return false;
+        }
+
         // special case for non-final $this/self compare; in case of interface/abstract class, it can be another $this
         if ($phpStanDocType instanceof ThisType && $phpParserNodeType instanceof ThisType) {
             $scope = $node->getAttribute(AttributeKey::SCOPE);
@@ -247,4 +255,11 @@ private function normalizeConstantBooleanType(Type $type): Type
             return $callable($type);
         });
     }
+
+    private function isTypeSelfAndDocParamTypeStatic(Type $phpStanDocType, Type $phpParserNodeType, TypeNode $phpStanDocTypeNode) : bool
+    {
+        return $phpStanDocType instanceof StaticType
+            && $phpParserNodeType instanceof ThisType
+            && $phpStanDocTypeNode->getAttribute(PhpDocAttributeKey::PARENT) instanceof ParamTagValueNode;
+    }
 }
diff --git a/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/param_self_return_static.php.inc b/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/param_self_return_static.php.inc
new file mode 100644
index 00000000000..8bea600b770
--- /dev/null
+++ b/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/param_self_return_static.php.inc
@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\Tests\Php80\Rector\FunctionLike\UnionTypesRector\Fixture;
+
+class ParamSelfReturnStatic
+{
+    /**
+     * @param self $arg
+     * @return static
+     */
+    public function go(self $arg): static
+    {
+        return $this;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\Php80\Rector\FunctionLike\UnionTypesRector\Fixture;
+
+class ParamSelfReturnStatic
+{
+    public function go(self $arg): static
+    {
+        return $this;
+    }
+}
+
+?>
diff --git a/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/skip_static_param.php.inc b/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/skip_static_param.php.inc
new file mode 100644
index 00000000000..b4ac51d5a4b
--- /dev/null
+++ b/rules-tests/Php80/Rector/FunctionLike/UnionTypesRector/Fixture/skip_static_param.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\Php80\Rector\FunctionLike\UnionTypesRector\Fixture;
+
+class SkipStaticParam
+{
+    /**
+     * @param static $arg
+     */
+    public function go(self $arg1)
+    {
+    }
+}