test: fix some test case errors.

Author: ping-yee

tests/system/Router/RouterTest.php

@@ -250,13 +250,16 @@ public function testAutoRouteFindsControllerWithSubfolder(): void
 
         rmdir(APPPATH . 'Controllers/Subfolder');
 
+        $this->expectException(PageNotFoundException::class);
+
         $this->assertSame('MyController', $router->controllerName());
         $this->assertSame('someMethod', $router->methodName());
     }
 
     public function testAutoRouteFindsDashedSubfolder(): void
     {
         $this->collection->setAutoRoute(true);
+
         $router = new Router($this->collection, $this->request);
         $router->setTranslateURIDashes(true);
 
@@ -266,6 +269,8 @@ public function testAutoRouteFindsDashedSubfolder(): void
 
         rmdir(APPPATH . 'Controllers/Dash_folder');
 
+        $this->expectException(PageNotFoundException::class);
+
         $this->assertSame('Dash_folder/', $router->directory());
         $this->assertSame('Mycontroller', $router->controllerName());
         $this->assertSame('somemethod', $router->methodName());
@@ -329,6 +334,7 @@ public function testAutoRouteFindsDefaultDashFolder(): void
     public function testAutoRouteFindsMByteDir(): void
     {
         $this->collection->setAutoRoute(true);
+
         $router = new Router($this->collection, $this->request);
         $router->setTranslateURIDashes(true);
 
@@ -338,6 +344,8 @@ public function testAutoRouteFindsMByteDir(): void
 
         rmdir(APPPATH . 'Controllers/Φ');
 
+        $this->expectException(PageNotFoundException::class);
+
         $this->assertSame('Φ/', $router->directory());
         $this->assertSame('Home', $router->controllerName());
         $this->assertSame('index', $router->methodName());