Do not instantiate the controller just for fetching the middleware

src/Illuminate/Routing/Contracts/ControllerDispatcher.php

@@ -19,9 +19,9 @@ public function dispatch(Route $route, $controller, $method);
     /**
      * Get the middleware for the controller instance.
      *
-     * @param  \Illuminate\Routing\Controller  $controller
+     * @param  string  $controllerClass
      * @param  string  $method
      * @return array
      */
-    public function getMiddleware($controller, $method);
+    public function getMiddleware(string $controllerClass, string $method): array;
 }

src/Illuminate/Routing/Controller.php

@@ -11,7 +11,7 @@ abstract class Controller
      *
      * @var array
      */
-    protected $middleware = [];
+    protected static $middleware = [];
 
     /**
      * Register middleware on the controller.
@@ -20,10 +20,10 @@ abstract class Controller
      * @param  array  $options
      * @return \Illuminate\Routing\ControllerMiddlewareOptions
      */
-    public function middleware($middleware, array $options = [])
+    public static function middleware($middleware, array $options = [])
     {
         foreach ((array) $middleware as $m) {
-            $this->middleware[] = [
+            static::$middleware[] = [
                 'middleware' => $m,
                 'options' => &$options,
             ];
@@ -37,9 +37,9 @@ public function middleware($middleware, array $options = [])
      *
      * @return array
      */
-    public function getMiddleware()
+    public static function getMiddleware()
     {
-        return $this->middleware;
+        return static::$middleware;
     }
 
     /**

src/Illuminate/Routing/ControllerDispatcher.php

@@ -51,17 +51,17 @@ public function dispatch(Route $route, $controller, $method)
     /**
      * Get the middleware for the controller instance.
      *
-     * @param  \Illuminate\Routing\Controller  $controller
+     * @param  string  $controllerClass
      * @param  string  $method
      * @return array
      */
-    public function getMiddleware($controller, $method)
+    public function getMiddleware(string $controllerClass, string $method): array
     {
-        if (! method_exists($controller, 'getMiddleware')) {
+        if (! method_exists($controllerClass, 'getMiddleware')) {
             return [];
         }
 
-        return collect($controller->getMiddleware())->reject(function ($data) use ($method) {
+        return collect($controllerClass::getMiddleware())->reject(function ($data) use ($method) {
             return static::methodExcludedByOptions($method, $data['options']);
         })->pluck('middleware')->all();
     }

src/Illuminate/Routing/Route.php

@@ -270,14 +270,24 @@ protected function runController()
     public function getController()
     {
         if (! $this->controller) {
-            $class = $this->parseControllerCallback()[0];
-
-            $this->controller = $this->container->make(ltrim($class, '\\'));
+            $this->controller = $this->container->make($this->getControllerClass());
         }
 
         return $this->controller;
     }
 
+    /**
+     * Get the controller class for the route.
+     *
+     * @return string
+     */
+    public function getControllerClass(): string
+    {
+        $class = $this->parseControllerCallback()[0];
+
+        return ltrim($class, '\\');
+    }
+
     /**
      * Get the controller method used for the route.
      *
@@ -1068,7 +1078,7 @@ public function controllerMiddleware()
         }
 
         return $this->controllerDispatcher()->getMiddleware(
-            $this->getController(), $this->getControllerMethod()
+            $this->getControllerClass(), $this->getControllerMethod()
         );
     }
 

tests/Integration/Routing/Fixtures/ControllerWithStaticallyDefinedMiddleware.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Routing\Fixtures;
+
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Illuminate\Routing\Controller;
+
+class ControllerWithStaticallyDefinedMiddleware extends Controller
+{
+    public function __construct()
+    {
+        $_SERVER['controller_with_statically_defined_middleware_was_constructed'] = true;
+    }
+
+    public static function getMiddleware(): array
+    {
+        static::middleware('auth');
+
+        static::middleware(function (Request $request): RedirectResponse {
+            return new RedirectResponse('https://www.foo.com');
+        });
+
+        return parent::getMiddleware();
+    }
+
+    public function __invoke(): Response
+    {
+        return new Response('foobar');
+    }
+}

tests/Integration/Routing/RoutingMiddlewareTest.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Routing;
+
+use Illuminate\Auth\GenericUser;
+use Illuminate\Contracts\Routing\Registrar;
+use Illuminate\Tests\Integration\Routing\Fixtures\ControllerWithStaticallyDefinedMiddleware;
+use Orchestra\Testbench\TestCase;
+
+final class RoutingMiddlewareTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        unset($_SERVER['controller_with_statically_defined_middleware_was_constructed']);
+
+        parent::tearDown();
+    }
+
+    public function testControllerIsNotInstantiatedWhenStaticallyDefiningMiddlewareOnIt()
+    {
+        $this->withoutExceptionHandling();
+        $this->actingAs(new GenericUser([]));
+
+        $_SERVER['controller_with_statically_defined_middleware_was_constructed'] = false;
+
+        /** @var Registrar $router */
+        $router = $this->app->make(Registrar::class);
+
+        $router->get('test-route', ControllerWithStaticallyDefinedMiddleware::class);
+
+        $response = $this->get('test-route');
+
+        $response->assertRedirect('https://www.foo.com');
+
+        $this->assertFalse($_SERVER['controller_with_statically_defined_middleware_was_constructed']);
+    }
+}