testAction() function returns null on debug() in CakePhp testing

Question

I was trying to learn how to use unit testing in CakePhp, I'm trying to write a controller test. I read about testAction() and debug() function, but It doesn't work for me, I mean, the test method passes, but the debug() returns null (because testAction does)

This is my code:

<?php
App::uses('Controller', 'Controller');
App::uses('View', 'View');
App::uses('PostsController', 'Controller');

class PostsControllerTest extends ControllerTestCase {
    public function setUp() {
       parent::setUp();
       $Controller = new Controller();
       $View = new View($Controller);
       $this->Posts = new PostsController($View);
    }

    public function testIndex() {
          $result = $this->testAction('Posts/Index');
        debug($result);        

    }
}

Posts/index controller returns a list of all posts stored in the DB.

Answer 1

I'm assuming you're using CakePHP 2.

$this->testAction() can return a few different results, depending on the options you give it.

For example, if you set the return option to vars, the testAction() method will return an array of the vars that have been set in the tested action:

public function testIndex() {
    $result = $this->testAction('/posts/index', array('return' => 'vars'));
    debug($result);
}

In this example, the debug data should be an array of the vars that you set in the /posts/index action.

The CakePHP documentation describes the possible results that you can have returned here: http://book.cakephp.org/2.0/en/development/testing.html#choosing-the-return-type

Note that the default option, result, gives you the value that your controller action returns. For most controller actions this will be null, so the fact that you're getting null in your example is to be expected.

Answer 2

mtnorthrop's answer did work for me, but only once I also dealt with my site's authorization as well. If your site uses authorization, then testAction('/action', array('return' => 'contents') will return null. I've seen a few solutions for this:

One is to follow the solution given here: CakePHP Unit Test Not Returning Content or View where you check in AppController::beforeFilter() whether you are in debug mode, and if so, always authenticate the user:

// For Mock Objects and Debug >= 2 allow all (this is for PHPUnit Tests)
if(preg_match('/Mock_/',get_class($this)) && Configure::read('debug') >= 2){
    $this->Auth->allow();
}

Another is to follow the suggestions given in this discussion: https://groups.google.com/forum/#!topic/cake-php/eWCO2bf5t98 and to mock the Auth object using the ControllerTestCase's generate function:

class MyControllerTest extends ControllerTestCase {
    public function setUp() {
        parent::setUp();
        $this->controller = $this->generate('My',
            array('components' => array(
                'Auth' => array('isAuthorized')
            ))
        );
        $this->controller->Auth->expects($this->any())
            ->method('isAuthorized')
            ->will($this->returnValue(true));

    }
}

Note (I'm using CakePhp 2.3.8)