avoid duplicate registration

Author: TomasVotruba

config/set/type-declaration-docblocks.php

@@ -2,11 +2,12 @@
 
 declare(strict_types=1);
 
+use Rector\Config\Level\TypeDeclarationDocblocksLevel;
 use Rector\Config\RectorConfig;
 
 /**
  * @experimental * 2025-09, experimental hidden set for type declaration in docblocks
  */
 return static function (RectorConfig $rectorConfig): void {
-    $rectorConfig->rules(\Rector\Config\Level\TypeDeclarationDocblocksLevel::RULES);
+    $rectorConfig->rules(TypeDeclarationDocblocksLevel::RULES);
 };

src/Configuration/RectorConfigBuilder.php

@@ -142,6 +142,8 @@ final class RectorConfigBuilder
      */
     private ?bool $isTypeCoverageLevelUsed = null;
 
+    private ?bool $isTypeCoverageDocblockLevelUsed = null;
+
     private ?bool $isDeadCodeLevelUsed = null;
 
     private ?bool $isCodeQualityLevelUsed = null;
@@ -225,6 +227,17 @@ public function __invoke(RectorConfig $rectorConfig): void
             ));
         }
 
+        if (in_array(
+            SetList::TYPE_DECLARATION_DOCBLOCKS,
+            $uniqueSets,
+            true
+        ) && $this->isTypeCoverageDocblockLevelUsed === true) {
+            throw new InvalidConfigurationException(sprintf(
+                'Your config already enables type declarations set.%sRemove "->withTypeCoverageDocblockLevel()" as it only duplicates it, or remove type declaration set.',
+                PHP_EOL
+            ));
+        }
+
         if (in_array(SetList::DEAD_CODE, $uniqueSets, true) && $this->isDeadCodeLevelUsed === true) {
             throw new InvalidConfigurationException(sprintf(
                 'Your config already enables dead code set.%sRemove "->withDeadCodeLevel()" as it only duplicates it, or remove dead code set.',
@@ -1030,6 +1043,8 @@ public function withTypeCoverageDocblockLevel(int $level): self
     {
         Assert::natural($level);
 
+        $this->isTypeCoverageDocblockLevelUsed = true;
+
         $levelRules = LevelRulesResolver::resolve($level, TypeDeclarationDocblocksLevel::RULES, __METHOD__);
 
         // too high