AC-2855:Magento 2.4.4 admin panel - Error: Call to undefined method ReflectionUnionType::getName()

Author: faizan-shk

app/code/Magento/Backend/Model/Menu.php

@@ -318,4 +318,138 @@ public function populateFromArray(array $data)
         }
         $this->exchangeArray($items);
     }
+
+    // Need to override and suppress return type deprecation warnings for php8 compatibility
+
+    #[\ReturnTypeWillChange]
+    public function offsetExists($key)
+    {
+        return parent::offsetExists($key);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function offsetGet($key)
+    {
+        return parent::offsetGet($key);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function offsetSet($key, $value)
+    {
+        parent::offsetSet($key, $value);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function offsetUnset($key)
+    {
+        parent::offsetUnset($key);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function count()
+    {
+        return parent::count();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function append($value)
+    {
+        parent::append($value);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function getArrayCopy()
+    {
+        return parent::getArrayCopy();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function getFlags()
+    {
+        return parent::getFlags();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function setFlags($flags)
+    {
+        parent::setFlags($flags);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function asort($flags = SORT_REGULAR)
+    {
+        parent::asort($flags);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function ksort($flags = SORT_REGULAR)
+    {
+        parent::ksort($flags);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function uasort($callback)
+    {
+        parent::uasort($callback);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function uksort($callback)
+    {
+        parent::uksort($callback);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function exchangeArray($array)
+    {
+        return parent::exchangeArray($array);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function setIteratorClass($iteratorClass)
+    {
+        parent::setIteratorClass($iteratorClass);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function natsort()
+    {
+        parent::natsort();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function natcasesort()
+    {
+        parent::natcasesort();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function __serialize()
+    {
+        return parent::__serialize();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function __unserialize(array $data)
+    {
+        parent::__unserialize($data);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function getIterator()
+    {
+        return parent::getIterator();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function getIteratorClass()
+    {
+        return parent::getIteratorClass();
+    }
+
+    #[\ReturnTypeWillChange]
+    public function __debugInfo()
+    {
+        return parent::__debugInfo();
+    }
 }

lib/internal/Magento/Framework/Code/Generator/EntityAbstract.php

@@ -332,14 +332,22 @@ private function extractParameterType(
         /** @var string|null $typeName */
         $typeName = null;
         $parameterType = $parameter->getType();
-        if ($parameterType->getName() === 'array') {
+
+        if ($parameterType instanceof \ReflectionUnionType) {
+            $parameterType = $parameterType->getTypes();
+            $parameterType = implode('|', $parameterType);
+        } else {
+            $parameterType = $parameterType->getName();
+        }
+
+        if ($parameterType === 'array') {
             $typeName = 'array';
         } elseif ($parameterClass = $this->getParameterClass($parameter)) {
             $typeName = $this->_getFullyQualifiedClassName($parameterClass->getName());
-        } elseif ($parameterType->getName() === 'callable') {
+        } elseif ($parameterType === 'callable') {
             $typeName = 'callable';
         } else {
-            $typeName = $parameterType->getName();
+            $typeName = $parameterType;
         }
 
         if ($parameter->allowsNull()) {

lib/internal/Magento/Framework/Interception/Test/Unit/Code/Generator/InterceptorTest.php

@@ -90,7 +90,12 @@ public function interceptorDataProvider()
                 \Magento\Framework\Interception\Code\Generator\TSample::class,
                 \Magento\Framework\Interception\Code\Generator\TSample\Interceptor::class,
                 'TInterceptor'
-            ]
+            ],
+            [
+                \Magento\Framework\Interception\Code\Generator\SampleBackendMenu::class,
+                \Magento\Framework\Interception\Code\Generator\SampleBackendMenu\Interceptor::class,
+                'SampleBackendMenuInterceptor',
+            ],
         ];
     }
 }

lib/internal/Magento/Framework/Interception/Test/Unit/Code/Generator/_files/SampleBackendMenu.php

@@ -0,0 +1,13 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Framework\Interception\Code\Generator;
+
+use Magento\Backend\Model\Menu;
+
+class SampleBackendMenu extends Menu
+{
+
+}