'/test-path']); $handler = new class implements \Psr\Http\Server\RequestHandlerInterface { public function handle(\Psr\Http\Message\ServerRequestInterface $request): \Psr\Http\Message\ResponseInterface { return new Response(); } }; // Act $response = $middleware->process($request, $handler); // Assert $this->assertInstanceOf(\Psr\Http\Message\ResponseInterface::class, $response); $this->assertSame(200, $response->getStatusCode()); } }