public function testHtmlHeaders() { $received_header = null; $this->response->addEventHandler(Response::HEADER_ADDED_EVENT, function (Response $response, $header) use(&$received_header) { $received_header = $header; }); $this->response->setResponseType(Response::HTML); $this->response->render(); $this->assertTrue($this->response->isHtml()); $this->assertSame('Content-Type: text/html', $received_header); }