AddReturnDocblockForCommonObjectDenominatorRector

Find another rule

Add @return docblock array of objects, that have common denominator interface/parent class

 final class ExtensionProvider
 {
+    /**
+     * @return ExtensionInterface[]
+     */
     public function getExtensions(): array
     {
         return [
             new FirstExtension(),
             new SecondExtension(),
         ];
     }
 }

 class FirstExtension implements ExtensionInterface
 {
 }

 class SecondExtension implements ExtensionInterface
 {
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclarationDocblocks\Rector\ClassMethod\AddReturnDocblockForCommonObjectDenominatorRector;

return RectorConfig::configure()
    ->withRules([
        AddReturnDocblockForCommonObjectDenominatorRector::class,
    ]);