Add missing null check to ControllerReflector::getReflectionMethod (#1918)

* add null check

https://github.com/nelmio/NelmioApiDocBundle/issues/1909

* less code is better

* add tests for ControllerReflection::getReflectionMethod()

* lint fix

* style_ci fixes

Co-authored-by: Alexey <alshenestky@icloud.com>

Tests/Util/ControllerReflectorTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Nelmio\ApiDocBundle\Tests\Util;
+
+use Nelmio\ApiDocBundle\Tests\Functional\Controller\BazingaController;
+use Nelmio\ApiDocBundle\Util\ControllerReflector;
+use PHPUnit\Framework\TestCase;
+use ReflectionMethod;
+use Symfony\Component\DependencyInjection\Container;
+
+class ControllerReflectorTest extends TestCase
+{
+    public function testGetReflectionMethod(): void
+    {
+        $controllerReflector = new ControllerReflector(new Container());
+        $this->assertEquals(
+            ReflectionMethod::class,
+            get_class($controllerReflector->getReflectionMethod([BazingaController::class, 'userAction']))
+        );
+        $this->assertEquals(
+            ReflectionMethod::class,
+            get_class($controllerReflector->getReflectionMethod(BazingaController::class.'::userAction'))
+        );
+        $this->assertNull(
+            $controllerReflector->getReflectionMethod('UnknownController::userAction')
+        );
+        $this->assertNull($controllerReflector->getReflectionMethod(null));
+    }
+}

Util/ControllerReflector.php

@@ -38,15 +38,16 @@ class ControllerReflector
     /**
      * Returns the ReflectionMethod for the given controller string.
      *
-     * @return \ReflectionMethod|null
+     * @return \ReflectionMethod|null
      */
     public function getReflectionMethod($controller)
     {
         if (is_string($controller)) {
             $controller = $this->getClassAndMethod($controller);
-            if (null === $controller) {
+        }
-                return null;
+
-            }
+        if (null === $controller) {
+            return null;
         }
 
         return $this->geReflectionMethodByClassNameAndMethodName(...$controller);
@@ -122,7 +123,7 @@ class ControllerReflector
         if (!isset($class) || !isset($method)) {
             $this->controllers[$controller] = null;
 
-            return;
+            return null;
         }
 
         return $this->controllers[$controller] = [$class, $method];