[CodeQuality] Skip already has return type on TypeWillReturnCallableArrowFunctionRector

Author: samsonasik

rules-tests/CodeQuality/Rector/Class_/TypeWillReturnCallableArrowFunctionRector/Fixture/skip_already_return_typed.php.inc

@@ -0,0 +1,18 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\TypeWillReturnCallableArrowFunctionRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+use Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\TypeWillReturnCallableArrowFunctionRector\Source\SomeMockedClass;
+
+final class SkipAlreadyReturnTyped extends TestCase
+{
+    public function test($value): void
+    {
+        $this->createMock(SomeMockedClass::class)
+            ->method('nativeObject')
+            ->willReturnCallback(fn (object $object): \stdClass => $value);
+    }
+}
+
+?>

rules/CodeQuality/Rector/Class_/TypeWillReturnCallableArrowFunctionRector.php

@@ -239,14 +239,16 @@ public function refactor(Node $node): ?Class_
                 $hasChanged = true;
             }
 
-            $returnTypeNode = $this->staticTypeMapper->mapPHPStanTypeToPhpParserNode(
-                $parameterTypesAndReturnType->getReturnType(),
-                TypeKind::RETURN
-            );
+            if (! $innerArg->returnType instanceof Node) {
+                $returnTypeNode = $this->staticTypeMapper->mapPHPStanTypeToPhpParserNode(
+                    $parameterTypesAndReturnType->getReturnType(),
+                    TypeKind::RETURN
+                );
 
-            if ($returnTypeNode instanceof Node) {
-                $innerArg->returnType = $returnTypeNode;
-                $hasChanged = true;
+                if ($returnTypeNode instanceof Node) {
+                    $innerArg->returnType = $returnTypeNode;
+                    $hasChanged = true;
+                }
             }
         });