flightphp
diff --git a/composer.json b/composer.json
@@ -27,21 +27,16 @@
         "ext-json": "*"
     },
     "autoload": {
-        "files": [
-            "flight/autoload.php"
-        ]
-    },
-    "autoload-dev": {
         "classmap": [
-            "tests/classes/"
+            "flight/Flight.php"
         ],
         "psr-4": {
-            "Tests\\PHP8\\": [
-                "tests/named-arguments"
-            ],
-            "Tests\\Server\\": "tests/server",
-            "Tests\\ServerV2\\": "tests/server-v2",
-            "tests\\groupcompactsyntax\\": "tests/groupcompactsyntax"
+            "flight\\": "flight"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "tests\\": "tests"
         }
     },
     "require-dev": {
@@ -80,7 +75,7 @@
         ],
         "test-server-v2": [
             "echo \"Running Test Server\"",
-            "@php -S localhost:8000 -t tests/server-v2"
+            "@php -S localhost:8000 -t tests/server_v2"
         ],
         "test-performance": [
             "echo \"Running Performance Tests...\"",

diff --git a/flight/Flight.php b/flight/Flight.php
@@ -11,8 +11,6 @@
 use flight\core\EventDispatcher;
 use Psr\Container\ContainerInterface;
 
-require_once __DIR__ . '/autoload.php';
-
 /**
  * The Flight class is a static representation of the framework.
  *

diff --git a/flight/autoload.php b/flight/autoload.php
@@ -7,4 +7,8 @@
 require_once __DIR__ . '/Flight.php';
 require_once __DIR__ . '/core/Loader.php';
 
-Loader::autoload(true, [dirname(__DIR__)]);
+if (file_exists(__DIR__ . '/../vendor/autoload.php')) {
+    return require_once __DIR__ . '/../vendor/autoload.php';
+}
+
+Loader::autoload(true, dirname(__DIR__));
diff --git a/flight/core/Loader.php b/flight/core/Loader.php
@@ -48,10 +48,9 @@ class Loader
      * Registers a class.
      *
      * @param string $name Registry name
-     * @param class-string<T>|Closure(): T $class Class name or function to instantiate class
+     * @param class-string<T>|(Closure(): T) $class Class name or function to instantiate class
      * @param array<int, mixed> $params Class initialization parameters
-     * @param ?Closure(T $instance): void $callback $callback Function to call after object instantiation
-     *
+     * @param null|(Closure(T $instance): void) $callback $callback Function to call after object instantiation
      * @template T of object
      */
     public function register(string $name, $class, array $params = [], ?callable $callback = null): void
@@ -215,12 +214,14 @@ public static function loadClass(string $class): void
      */
     public static function addDirectory($dir): void
     {
-        if (\is_array($dir) || \is_object($dir)) {
+        if (is_iterable($dir)) {
             foreach ($dir as $value) {
                 self::addDirectory($value);
             }
-        } elseif (\is_string($dir)) {
-            if (!\in_array($dir, self::$dirs, true)) {
+        } elseif (is_string($dir)) {
+            $dir = str_replace(['/', '\\'], DIRECTORY_SEPARATOR, $dir);
+
+            if (!in_array($dir, self::$dirs, true)) {
                 self::$dirs[] = $dir;
             }
         }

diff --git a/index.php b/index.php
@@ -2,8 +2,7 @@
 
 declare(strict_types=1);
 
-require_once 'flight/Flight.php';
-// require 'flight/autoload.php';
+require_once __DIR__ . '/flight/autoload.php';
 
 Flight::route('/', function () {
     echo 'hello world!';

diff --git a/phpunit.xml.dist b/phpunit.xml.dist
@@ -2,7 +2,6 @@
 <phpunit
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
-    bootstrap="tests/phpunit_autoload.php"
     executionOrder="random"
     beStrictAboutOutputDuringTests="true"
     beStrictAboutTodoAnnotatedTests="true"
@@ -15,14 +14,11 @@
         <include>
             <directory suffix=".php">flight/</directory>
         </include>
-		<exclude>
-			<file>flight/autoload.php</file>
-		</exclude>
     </coverage>
     <testsuites>
         <testsuite name="default">
             <directory>tests/</directory>
-            <exclude>tests/named-arguments/</exclude>
+            <exclude>tests/named_arguments/</exclude>
         </testsuite>
     </testsuites>
     <logging />

diff --git a/tests/EventSystemTest.php b/tests/EventSystemTest.php
@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace flight\tests;
+namespace tests;
 
 use Flight;
 use PHPUnit\Framework\TestCase;

diff --git a/tests/LoaderTest.php b/tests/LoaderTest.php
@@ -4,10 +4,12 @@
 
 namespace tests;
 
+use Closure;
 use flight\core\Loader;
 use tests\classes\Factory;
 use tests\classes\User;
 use PHPUnit\Framework\TestCase;
+use ReflectionClass;
 use tests\classes\TesterClass;
 
 class LoaderTest extends TestCase
@@ -17,7 +19,11 @@ class LoaderTest extends TestCase
     protected function setUp(): void
     {
         $this->loader = new Loader();
-        $this->loader->autoload(true, __DIR__ . '/classes');
+    }
+
+    protected function tearDown(): void
+    {
+        Loader::setV2ClassLoading(true);
     }
 
     // Autoload a class
@@ -85,7 +91,7 @@ public function testSharedInstance(): void
     // Gets an object from a factory method
     public function testRegisterUsingCallable(): void
     {
-        $this->loader->register('e', ['\tests\classes\Factory', 'create']);
+        $this->loader->register('e', Closure::fromCallable([Factory::class, 'create']));
 
         $obj = $this->loader->load('e');
 
@@ -140,29 +146,32 @@ public function testNewInstance6Params(): void
 
     public function testAddDirectoryAsArray(): void
     {
-        $loader = new class extends Loader {
-            public function getDirectories()
-            {
-                return self::$dirs;
-            }
-        };
-        $loader->addDirectory([__DIR__ . '/classes']);
-        self::assertEquals([
-            dirname(__DIR__),
-            __DIR__ . '/classes'
-        ], $loader->getDirectories());
+        $loader = new Loader();
+        $loader::addDirectory([__DIR__ . '/classes']);
+
+        $dirsProperty = (new ReflectionClass(Loader::class))->getProperty('dirs');
+
+        if (PHP_VERSION_ID < 80100) {
+            $dirsProperty->setAccessible(true);
+        }
+
+        $dirs = $dirsProperty->getValue($loader);
+
+        self::assertEquals([__DIR__ . DIRECTORY_SEPARATOR . 'classes'], $dirs);
     }
 
     public function testV2ClassLoading(): void
     {
-        $loader = new class extends Loader {
-            public static function getV2ClassLoading()
-            {
-                return self::$v2ClassLoading;
-            }
-        };
-        $this->assertTrue($loader::getV2ClassLoading());
+        $loader = new Loader();
+
+        $v2ClassLoadingProperty = (new ReflectionClass(Loader::class))->getProperty('v2ClassLoading');
+
+        if (PHP_VERSION_ID < 80100) {
+            $v2ClassLoadingProperty->setAccessible(true);
+        }
+
+        $this->assertTrue($v2ClassLoadingProperty->getValue($loader));
         $loader::setV2ClassLoading(false);
-        $this->assertFalse($loader::getV2ClassLoading());
+        $this->assertFalse($v2ClassLoadingProperty->getValue($loader));
     }
 }
diff --git a/tests/named-arguments/ExampleClass.php → tests/named_arguments/ExampleClass.php b/tests/named-arguments/ExampleClass.php → tests/named_arguments/ExampleClass.php
@@ -2,6 +2,8 @@
 
 declare(strict_types=1);
 
+namespace tests\named_arguments;
+
 // phpcs:ignore PSR1.Classes.ClassDeclaration.MissingNamespace
 class ExampleClass
 {

diff --git a/tests/named-arguments/FlightTest.php → tests/named_arguments/FlightTest.php b/tests/named-arguments/FlightTest.php → tests/named_arguments/FlightTest.php
@@ -2,10 +2,9 @@
 
 declare(strict_types=1);
 
-namespace Tests\PHP8;
+namespace tests\named_arguments;
 
 use DateTimeImmutable;
-use ExampleClass;
 use Flight;
 use flight\Container;
 use flight\Engine;

diff --git a/tests/phpunit_autoload.php b/tests/phpunit_autoload.php