Run post rectors after the rules reach a fixed point, so no rule sees an imported short name

src/Application/FileProcessor.php

@@ -58,21 +58,30 @@ public function processFile(File $file, Configuration $configuration): FileProce
 
         $fileHasChanged = false;
         $filePath = $file->getFilePath();
+        $rulesReachedFixedPoint = false;
 
         do {
             $file->changeHasChanged(false);
 
             // every rule and post rector records a line change when it mutates the AST
             $changeCountBeforePass = count($file->getRectorWithLineChanges());
 
-            // 1. change nodes with Rector Rules
-            $newStmts = $this->rectorNodeTraverser->traverse($file->getNewStmts(), $file);
+            // 1. change nodes with Rector Rules, until they reach a fixed point
+            if ($rulesReachedFixedPoint) {
+                $newStmts = $file->getNewStmts();
+            } else {
+                $newStmts = $this->rectorNodeTraverser->traverse($file->getNewStmts(), $file);
+                $rulesReachedFixedPoint = count($file->getRectorWithLineChanges()) === $changeCountBeforePass;
+            }
 
-            // 2. apply post rectors
-            $postNewStmts = $this->postFileProcessor->traverse($newStmts, $file);
+            // 2. apply post rectors after the rules: a rule in a next pass would resolve
+            // a short name they import against the global namespace
+            if ($rulesReachedFixedPoint) {
+                $newStmts = $this->postFileProcessor->traverse($newStmts, $file);
+            }
 
             // 3. this is needed for new tokens added in "afterTraverse()"
-            $file->changeNewStmts($postNewStmts);
+            $file->changeNewStmts($newStmts);
 
             // file never changed and this pass changed nothing: the print would just reproduce the
             // original content, so skip the expensive format-preserving print entirely.
@@ -86,9 +95,14 @@ public function processFile(File $file, Configuration $configuration): FileProce
             // important to detect if file has changed
             $this->printFile($file, $configuration, $filePath);
 
-            // no change in current iteration, stop
+            // no change in current iteration: stop, once the post rectors ran
             if (! $file->hasChanged()) {
-                break;
+                if ($rulesReachedFixedPoint) {
+                    break;
+                }
+
+                $rulesReachedFixedPoint = true;
+                continue;
             }
 
             $fileHasChanged = true;

tests/Issues/ImportedNameInNextPass/Fixture/nullable_enum_param.php.inc

@@ -0,0 +1,39 @@
+<?php
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Fixture;
+
+use Rector\Tests\Issues\ImportedNameInNextPass\Source\Directory;
+
+final class NullableEnumParam
+{
+    public function run(?Directory $directory): void
+    {
+        if ($directory === null) {
+            return;
+        }
+
+        echo $directory->value;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Fixture;
+
+use Rector\Tests\Issues\ImportedNameInNextPass\Source\Directory;
+
+final class NullableEnumParam
+{
+    public function run(?Directory $directory): void
+    {
+        if (!$directory instanceof Directory) {
+            return;
+        }
+
+        echo $directory->value;
+    }
+}
+
+?>

tests/Issues/ImportedNameInNextPass/Fixture/nullable_final_class_param.php.inc

@@ -0,0 +1,39 @@
+<?php
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Fixture;
+
+use Rector\Tests\Issues\ImportedNameInNextPass\Source\ArrayObject;
+
+final class NullableFinalClassParam
+{
+    public function run(?ArrayObject $arrayObject): void
+    {
+        if ($arrayObject === null) {
+            return;
+        }
+
+        echo 'set';
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Fixture;
+
+use Rector\Tests\Issues\ImportedNameInNextPass\Source\ArrayObject;
+
+final class NullableFinalClassParam
+{
+    public function run(?ArrayObject $arrayObject): void
+    {
+        if (!$arrayObject instanceof ArrayObject) {
+            return;
+        }
+
+        echo 'set';
+    }
+}
+
+?>

tests/Issues/ImportedNameInNextPass/Fixture/skip_written_short_instanceof.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Fixture;
+
+use Rector\Tests\Issues\ImportedNameInNextPass\Source\Directory;
+
+final class SkipWrittenShortInstanceof
+{
+    public function run(?Directory $directory): void
+    {
+        if (! $directory instanceof Directory) {
+            return;
+        }
+
+        echo $directory->value;
+    }
+}

tests/Issues/ImportedNameInNextPass/ImportedNameInNextPassTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class ImportedNameInNextPassTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

tests/Issues/ImportedNameInNextPass/Source/ArrayObject.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Source;
+
+final class ArrayObject
+{
+}

tests/Issues/ImportedNameInNextPass/Source/Directory.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\ImportedNameInNextPass\Source;
+
+enum Directory: string
+{
+    case One = 'one';
+}

tests/Issues/ImportedNameInNextPass/config/configured_rule.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\CodeQuality\Rector\If_\ExplicitNullableObjectInstanceRector;
+use Rector\Config\RectorConfig;
+use Rector\DeadCode\Rector\If_\RemoveAlwaysTrueIfConditionRector;
+
+return RectorConfig::configure()
+    ->withRules([ExplicitNullableObjectInstanceRector::class, RemoveAlwaysTrueIfConditionRector::class])
+    ->withImportNames();