[6.x] Fix reflector to handle parent and add tests (#33502)

* Fix reflector to handle parent and add tests

* Apply fixes from StyleCI (#33501)

Author: GrahamCampbell

src/Illuminate/Container/Util.php

@@ -55,8 +55,14 @@ public static function getParameterClassName($parameter)
 
         $name = $type->getName();
 
-        if ($name === 'self') {
-            return $parameter->getDeclaringClass()->getName();
+        if (! is_null($class = $parameter->getDeclaringClass())) {
+            if ($name === 'self') {
+                return $class->getName();
+            }
+
+            if ($name === 'parent' && $parent = $class->getParentClass()) {
+                return $parent->getName();
+            }
         }
 
         return $name;

src/Illuminate/Support/Reflector.php

@@ -23,8 +23,14 @@ public static function getParameterClassName($parameter)
 
         $name = $type->getName();
 
-        if ($name === 'self') {
-            return $parameter->getDeclaringClass()->getName();
+        if (! is_null($class = $parameter->getDeclaringClass())) {
+            if ($name === 'self') {
+                return $class->getName();
+            }
+
+            if ($name === 'parent' && $parent = $class->getParentClass()) {
+                return $parent->getName();
+            }
         }
 
         return $name;

tests/Support/SupportReflectorTest.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Illuminate\Tests\Support;
+
+use Illuminate\Contracts\Mail\Mailable;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Reflector;
+use Illuminate\Support\Testing\Fakes\BusFake;
+use Illuminate\Support\Testing\Fakes\MailFake;
+use Illuminate\Support\Testing\Fakes\PendingMailFake;
+use PHPUnit\Framework\TestCase;
+use ReflectionClass;
+
+class SupportReflectorTest extends TestCase
+{
+    public function testGetClassName()
+    {
+        $method = (new ReflectionClass(PendingMailFake::class))->getMethod('send');
+
+        $this->assertSame(Mailable::class, Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+
+    public function testEmptyClassName()
+    {
+        $method = (new ReflectionClass(MailFake::class))->getMethod('assertSent');
+
+        $this->assertNull(Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+
+    public function testStringTypeName()
+    {
+        $method = (new ReflectionClass(BusFake::class))->getMethod('dispatchedAfterResponse');
+
+        $this->assertNull(Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+
+    public function testSelfClassName()
+    {
+        $method = (new ReflectionClass(Model::class))->getMethod('newPivot');
+
+        $this->assertSame(Model::class, Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+
+    public function testParentClassName()
+    {
+        $method = (new ReflectionClass(B::class))->getMethod('f');
+
+        $this->assertSame(A::class, Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+
+    /**
+     * @requires PHP 8
+     */
+    public function testUnionTypeName()
+    {
+        $method = (new ReflectionClass(C::class))->getMethod('f');
+
+        $this->assertNull(Reflector::getParameterClassName($method->getParameters()[0]));
+    }
+}
+
+class A
+{
+}
+
+class B extends A
+{
+    public function f(parent $x)
+    {
+    }
+}
+
+if (PHP_MAJOR_VERSION >= 8) {
+    eval('
+namespace Illuminate\Tests\Support;
+
+class C
+{
+    public function f(A|Model $x)
+    {
+    }
+}'
+    );
+}