[DeadCode][CodeQuality] Handle use RemoveDeadInstanceOfRector + SwitchNegatedTernaryRector with if instanceof check (#201)

Co-authored-by: Robin Richtsfeld <robin.richtsfeld@gmail.com>

rules/DeadCode/Rector/If_/RemoveDeadInstanceOfRector.php

@@ -67,7 +67,7 @@ CODE_SAMPLE
 
     /**
      * @param If_ $node
-     * @return null|Stmt[]|If_
+     * @return null|If_
      */
     public function refactor(Node $node)
     {
@@ -93,10 +93,7 @@ CODE_SAMPLE
         return $node;
     }
 
-    /**
-     * @return Stmt[]|null
-     */
-    private function processMayDeadInstanceOf(If_ $if, Instanceof_ $instanceof): ?array
+    private function processMayDeadInstanceOf(If_ $if, Instanceof_ $instanceof): ?If_
     {
         $classType = $this->nodeTypeResolver->resolve($instanceof->class);
         $exprType = $this->nodeTypeResolver->resolve($instanceof->expr);
@@ -108,10 +105,10 @@ CODE_SAMPLE
         }
 
         if ($if->cond === $instanceof) {
-            return $if->stmts;
+            $this->addNodesBeforeNode($if->stmts, $if);
         }
 
         $this->removeNode($if);
-        return null;
+        return $if;
     }
 }

tests/Issues/Issue6480/Fixture/fixture.php.inc

@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Core\Tests\Issues\Issue6480\Fixture;
+
+class Fixture
+{
+    function test(Foo $foo, mixed $bar): void {
+        if ($foo instanceof Foo) {
+            var_dump(!empty($bar) ? $bar : null);
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Core\Tests\Issues\Issue6480\Fixture;
+
+class Fixture
+{
+    function test(Foo $foo, mixed $bar): void {
+        var_dump(empty($bar) ? null : $bar);
+    }
+}
+
+?>

tests/Issues/Issue6480/NegatedTernaryInsideDeadInstanceTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Core\Tests\Issues\Issue6480;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+/**
+ * @see https://github.com/rectorphp/rector/issues/6480
+ */
+final class NegatedTernaryInsideDeadInstanceTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    /**
+     * @return Iterator<SmartFileInfo>
+     */
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

tests/Issues/Issue6480/config/configured_rule.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\CodeQuality\Rector\Ternary\SwitchNegatedTernaryRector;
+use Rector\DeadCode\Rector\If_\RemoveDeadInstanceOfRector;
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+
+return static function (ContainerConfigurator $containerConfigurator): void {
+    $services = $containerConfigurator->services();
+    $services->set(RemoveDeadInstanceOfRector::class);
+    $services->set(SwitchNegatedTernaryRector::class);
+};