[Transform] Transform rules() to withRules() on RectorConfigBuilderRector (#5566)

Author: samsonasik

rules-tests/Transform/Rector/FileWithoutNamespace/RectorConfigBuilderRector/Fixture/rules_to_with_rules.php.inc

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Transform\Rector\FileWithoutNamespace\RectorConfigBuilderRector;
+use Rector\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector;
+use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(ReturnUnionTypeRector::class);
+    $rectorConfig->rules([
+        RectorConfigBuilderRector::class,
+        TypedPropertyFromAssignsRector::class
+    ]);
+};
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Transform\Rector\FileWithoutNamespace\RectorConfigBuilderRector;
+use Rector\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector;
+use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
+
+return \Rector\Config\RectorConfig::configure()->withRules([ReturnUnionTypeRector::class, RectorConfigBuilderRector::class, TypedPropertyFromAssignsRector::class]);
+
+?>

rules/Transform/Rector/FileWithoutNamespace/RectorConfigBuilderRector.php

@@ -19,6 +19,7 @@
 use Rector\Rector\AbstractRector;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+use Webmozart\Assert\Assert;
 
 /**
  * @see \Rector\Tests\Transform\Rector\FileWithoutNamespace\RectorConfigBuilderRector\RectorConfigBuilderRectorTest
@@ -108,6 +109,9 @@ public function refactor(Node $node): ?Node
 
                 if ($this->isName($rectorConfigStmt->expr->name, 'rule')) {
                     $rules->items[] = new ArrayItem($rectorConfigStmt->expr->getArgs()[0]->value);
+                } elseif ($this->isName($rectorConfigStmt->expr->name, 'rules')) {
+                    Assert::isAOf($rectorConfigStmt->expr->getArgs()[0]->value, Array_::class);
+                    $rules->items = array_merge($rules->items, $rectorConfigStmt->expr->getArgs()[0]->value->items);
                 } else {
                     // implementing method by method
                     return null;