fix mixed[] override with empty array in DocblockReturnArrayFromDirectArrayInstanceRector (#7793)

Author: TomasVotruba

rules-tests/TypeDeclarationDocblocks/Rector/ClassMethod/DocblockReturnArrayFromDirectArrayInstanceRector/Fixture/skip_empty_array_mixed.php.inc

@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\TypeDeclarationDocblocks\Rector\ClassMethod\DocblockReturnArrayFromDirectArrayInstanceRector\Fixture;
+
+final class SkipEmptyArrayMixed
+{
+    /**
+     * @return mixed[]
+     */
+    private static function toArray(): array
+    {
+        return [];
+    }
+}

rules/TypeDeclarationDocblocks/Rector/ClassMethod/DocblockReturnArrayFromDirectArrayInstanceRector.php

@@ -9,7 +9,10 @@
 use PhpParser\Node\Stmt\ClassMethod;
 use PhpParser\Node\Stmt\Function_;
 use PhpParser\Node\Stmt\Return_;
+use PHPStan\PhpDocParser\Ast\PhpDoc\ReturnTagValueNode;
+use PHPStan\PhpDocParser\Ast\Type\ArrayTypeNode;
 use PHPStan\Type\Constant\ConstantArrayType;
+use Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfo;
 use Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfoFactory;
 use Rector\BetterPhpDocParser\PhpDocManipulator\PhpDocTypeChanger;
 use Rector\Rector\AbstractRector;
@@ -100,6 +103,10 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($this->shouldSkipReturnMixedAndEmptyArray($phpDocInfo, $soleReturn->expr)) {
+            return null;
+        }
+
         // resolve simple type
         $returnedType = $this->getType($soleReturn->expr);
         if (! $returnedType instanceof ConstantArrayType) {
@@ -116,4 +123,19 @@ public function refactor(Node $node): ?Node
 
         return $node;
     }
+
+    private function shouldSkipReturnMixedAndEmptyArray(PhpDocInfo $phpDocInfo, Array_ $array): bool
+    {
+        if ($array->items !== []) {
+            return false;
+        }
+
+        $returnTagValueNode = $phpDocInfo->getReturnTagValue();
+        if (! $returnTagValueNode instanceof ReturnTagValueNode) {
+            return false;
+        }
+
+        // better than array{}
+        return $returnTagValueNode->type instanceof ArrayTypeNode;
+    }
 }