session_regenerate_id() - 单元测试 Yii 控制器中已经发送的标头

我正在尝试对我的控制器(Yii 框架)进行单元测试.

I'm trying to unit-test my controller (Yii framework).

/** 
   * @dataProvider provider
   */
  public function testActionEdit_view_login($controller){
    $user = new CWebUser;
    $user->id = 978;
    $identity = new UserIdentity('me@test.com', '123456');
    $user->login($identity);
    $controller->actionEdit();

    $output = ob_get_contents();
    assertContains('Add/Change Profile Picture:', $output);
    assertContains('bio', $output);
    assertContains('specialties', $output);
    assertContains('change login', $output);
    assertContains('New Password', $output);
  }

当我这样做

$user->login($identity);

为了登录，我收到以下错误:

in order to login, I get the following error:

session_regenerate_id(): Cannot regenerate session id - headers already sent

我已经尝试通过将其放在课程开头来缓冲输出:

I've already tried buffering the output by putting this at the beginning of the class:

public static function setUpBeforeClass(){
  ob_start();
}

我还将 ob_clean() 放在 setUp() 中，将 ob_end_clean() 放在 tearDownAfterClass() 中.

I also put ob_clean() in setUp() and ob_end_clean() in tearDownAfterClass().

我仍然收到标题已经发送的消息.文件中没有空格或换行符，当我注释掉特定的测试方法时，它完美地工作.login() 似乎导致了问题.

Still I get the message that headers have already been sent. There are no spaces or newlines in the file, when I comment out the specific test method, it works perfectly. The login() seems to cause the problem.

有人知道如何防止这种情况发生/可能对控制器进行不同的单元测试吗?

Anyone got ideas how to prevent this / maybe unit-test the controller differently?

谢谢，先生