add known return mixed on get

Author: TomasVotruba

rules-tests/TypeDeclaration/Rector/ClassMethod/KnownMagicClassMethodTypeRector/Fixture/get_and_set.php.inc

@@ -21,7 +21,7 @@ namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\KnownMagicClassMethodT
 
 final class GetAndSet
 {
-    public function __get(string $method)
+    public function __get(string $method): mixed
     {
     }
 

rules/TypeDeclaration/Rector/ClassMethod/KnownMagicClassMethodTypeRector.php

@@ -110,6 +110,15 @@ public function refactor(Node $node): ?Node
                 }
             }
 
+            if ($this->isName($classMethod, MethodName::__GET) && $this->phpVersionProvider->isAtLeastPhpVersion(
+                PhpVersionFeature::MIXED_TYPE
+            )) {
+                if (! $classMethod->returnType instanceof \PhpParser\Node) {
+                    $classMethod->returnType = new Identifier('mixed');
+                    $hasChanged = true;
+                }
+            }
+
             if ($this->isName($classMethod, MethodName::__SET) && $this->phpVersionProvider->isAtLeastPhpVersion(
                 PhpVersionFeature::MIXED_TYPE
             )) {