[CodingStyle] Handle Nullable Type and under intanceof for RemoveUnusedAliasRector (#784)

phpstan.neon

@@ -550,3 +550,5 @@ parameters:
             message: '#Parameter \#2 \$length of function str_split expects int<1, max\>, int given#'
             paths:
                 - rules/Php74/Rector/LNumber/AddLiteralSeparatorToNumberRector.php
+
+        - '#^Cognitive complexity for "Rector\\CodingStyle\\Naming\\NameRenamer\:\:renameNameNode\(\)" is 12, keep it under 9$#'

rules-tests/CodingStyle/Rector/Use_/RemoveUnusedAliasRector/Fixture/nullable_alias.php.inc

@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel as BaseKernel;
+
+class SomeClass
+{
+    public function run(?BaseKernel $baseKernel)
+    {
+        $anotherBaseKernel = $baseKernel ?? new BaseKernel();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel;
+
+class SomeClass
+{
+    public function run(?AbstractKernel $baseKernel)
+    {
+        $anotherBaseKernel = $baseKernel ?? new AbstractKernel();
+    }
+}
+
+?>

rules-tests/CodingStyle/Rector/Use_/RemoveUnusedAliasRector/Fixture/under_intanceof.php.inc

@@ -0,0 +1,33 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel as BaseKernel;
+
+class UnderInstanceOf
+{
+    public function run(?BaseKernel $baseKernel)
+    {
+        if ($baseKernel instanceof BaseKernel) {
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\Tests\CodingStyle\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel;
+
+class UnderInstanceOf
+{
+    public function run(?AbstractKernel $baseKernel)
+    {
+        if ($baseKernel instanceof AbstractKernel) {
+        }
+    }
+}
+
+?>

rules/CodingStyle/Naming/NameRenamer.php

@@ -5,10 +5,12 @@ declare(strict_types=1);
 namespace Rector\CodingStyle\Naming;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr\Instanceof_;
 use PhpParser\Node\Expr\New_;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Identifier;
 use PhpParser\Node\Name;
+use PhpParser\Node\NullableType;
 use PhpParser\Node\Param;
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\Node\Stmt\ClassMethod;
@@ -65,9 +67,41 @@ final class NameRenamer
             if ($parentNode instanceof UnionType) {
                 $this->renameUnionType($lastName, $parentNode, $usedName);
             }
+
+            if ($parentNode instanceof NullableType) {
+                $this->renameNullableType($lastName, $parentNode, $usedName);
+            }
+
+            if ($parentNode instanceof Instanceof_) {
+                $this->renameInInstanceOf($lastName, $parentNode, $usedName);
+            }
         }
     }
 
+    private function renameInInstanceOf(
+        string $lastName,
+        Instanceof_ $instanceof,
+        Name | Identifier $usedNameNode
+    ): void {
+        if (! $this->nodeNameResolver->areNamesEqual($instanceof->class, $usedNameNode)) {
+            return;
+        }
+
+        $instanceof->class = new Name($lastName);
+    }
+
+    private function renameNullableType(
+        string $lastName,
+        NullableType $nullableType,
+        Name | Identifier $usedNameNode
+    ): void {
+        if (! $this->nodeNameResolver->areNamesEqual($nullableType->type, $usedNameNode)) {
+            return;
+        }
+
+        $nullableType->type = new Name($lastName);
+    }
+
     private function renameTraitUse(string $lastName, TraitUse $traitUse, Name | Identifier $usedNameNode): void
     {
         foreach ($traitUse->traits as $key => $traitName) {