[Transform]Move ReservedFnFunctionRector to Php74 namespace (#1471)

Co-authored-by: GitHub Action <action@github.com>

config/set/php74.php

@@ -11,6 +11,7 @@
 use Rector\Php74\Rector\FuncCall\FilterVarToAddSlashesRector;
 use Rector\Php74\Rector\FuncCall\GetCalledClassToStaticClassRector;
 use Rector\Php74\Rector\FuncCall\MbStrrposEncodingArgumentPositionRector;
+use Rector\Php74\Rector\Function_\ReservedFnFunctionRector;
 use Rector\Php74\Rector\LNumber\AddLiteralSeparatorToNumberRector;
 use Rector\Php74\Rector\MethodCall\ChangeReflectionTypeToStringToGetNameRector;
 use Rector\Php74\Rector\Property\RestoreDefaultNullToNullableTypePropertyRector;
@@ -59,4 +60,6 @@
     $services->set(RestoreDefaultNullToNullableTypePropertyRector::class);
 
     $services->set(CurlyToSquareBracketArrayStringRector::class);
+
+    $services->set(ReservedFnFunctionRector::class);
 };

rules-tests/Transform/Rector/Function_/ReservedFnFunctionRector/Fixture/fixture.php.inc → rules-tests/Php74/Rector/Function_/ReservedFnFunctionRector/Fixture/fixture.php.inc

@@ -1,25 +1,25 @@
 <?php
 
-namespace Rector\Tests\Transform\Rector\Function_\ReservedFnFunctionRector\Fixture;
+namespace Rector\Tests\Php74\Rector\Function_\ReservedFnFunctionRector\Fixture;
 
 class Fixture
 {
     public function run()
     {
-        function reservedFn($value)
+        function fn($value)
         {
             return $value;
         }
 
-        reservedFn(5);
+        fn(5);
     }
 }
 
 ?>
 -----
 <?php
 
-namespace Rector\Tests\Transform\Rector\Function_\ReservedFnFunctionRector\Fixture;
+namespace Rector\Tests\Php74\Rector\Function_\ReservedFnFunctionRector\Fixture;
 
 class Fixture
 {

rules-tests/Transform/Rector/Function_/ReservedFnFunctionRector/ReservedFnFunctionRectorTest.php → rules-tests/Php74/Rector/Function_/ReservedFnFunctionRector/ReservedFnFunctionRectorTest.php

@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace Rector\Tests\Transform\Rector\Function_\ReservedFnFunctionRector;
+namespace Rector\Tests\Php74\Rector\Function_\ReservedFnFunctionRector;
 
 use Iterator;
 use Rector\Testing\PHPUnit\AbstractRectorTestCase;
@@ -15,6 +15,7 @@ final class ReservedFnFunctionRectorTest extends AbstractRectorTestCase
      */
     public function test(SmartFileInfo $fileInfo): void
     {
+        $this->markTestSkipped('Requires tweaked PHP Parser to verify `fn` as valid function to simulate php <7.4');
         $this->doTestFileInfo($fileInfo);
     }
 

rules-tests/Transform/Rector/Function_/ReservedFnFunctionRector/config/configured_rule.php → rules-tests/Php74/Rector/Function_/ReservedFnFunctionRector/config/configured_rule.php

@@ -2,14 +2,10 @@
 
 declare(strict_types=1);
 
-use Rector\Transform\Rector\Function_\ReservedFnFunctionRector;
+use Rector\Php74\Rector\Function_\ReservedFnFunctionRector;
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
 
 return static function (ContainerConfigurator $containerConfigurator): void {
     $services = $containerConfigurator->services();
-    $services->set(ReservedFnFunctionRector::class)
-        ->configure([
-            // for testing purposes of "fn" even on PHP 7.3-
-            'reservedFn' => 'f',
-        ]);
+    $services->set(ReservedFnFunctionRector::class);
 };

rules/Php74/Rector/Function_/ReservedFnFunctionRector.php

@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Php74\Rector\Function_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Identifier;
+use PhpParser\Node\Name;
+use PhpParser\Node\Stmt\Function_;
+use PHPStan\Reflection\ReflectionProvider;
+use Rector\Core\Rector\AbstractRector;
+use Rector\Core\ValueObject\PhpVersionFeature;
+use Rector\VersionBonding\Contract\MinPhpVersionInterface;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @changelog https://github.com/php/php-src/pull/3941/files#diff-7e3a1a5df28a1cbd8c0fb6db68f243da
+ * @see \Rector\Tests\Php74\Rector\Function_\ReservedFnFunctionRector\ReservedFnFunctionRectorTest
+ */
+final class ReservedFnFunctionRector extends AbstractRector implements MinPhpVersionInterface
+{
+    /**
+     * @var string
+     */
+    private const NEW_ORIGINAL_NAME = 'f';
+
+    public function __construct(
+        private readonly ReflectionProvider $reflectionProvider
+    ) {
+    }
+
+    public function provideMinPhpVersion(): int
+    {
+        return PhpVersionFeature::RESERVED_FN_FUNCTION_NAME;
+    }
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition('Change fn() function name to f(), since it will be reserved keyword', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        function fn($value)
+        {
+            return $value;
+        }
+
+        fn(5);
+    }
+}
+CODE_SAMPLE
+                ,
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        function f($value)
+        {
+            return $value;
+        }
+
+        f(5);
+    }
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [Function_::class, FuncCall::class];
+    }
+
+    /**
+     * @param Function_|FuncCall $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $this->isName($node->name, 'fn')) {
+            return null;
+        }
+
+        $newName = self::NEW_ORIGINAL_NAME;
+        $count = 1;
+
+        while ($this->reflectionProvider->hasFunction(new Name($newName), null)) {
+            $newName = self::NEW_ORIGINAL_NAME . $count;
+            ++$count;
+        }
+
+        $node->name = $node instanceof FuncCall ? new Name($newName) : new Identifier($newName);
+        return $node;
+    }
+}