unit testing legacy code - zend-framework

Question

I'm new to unit testing and trying to unit test the model validation of an old zend application which is using forms.
Inside one of the forms it creates an instance of a second class and I'm struggling to understand how I can mock the dependent object. The form reads as follows :
class Default_Form_Timesheet extends G10_Form {
public function init() {
parent::init();
$this->addElement( 'hidden', 'idTimesheet', array( 'filters' => array ('StringTrim' ), 'required' => false, 'label' => false ) );
$this->addElement('checkbox', 'storyFilter', array('label' => 'Show my stories'));
$user = new Default_Model_User();
$this->addElement('select', 'idUser', array('filters' => array('StringTrim'), 'class' => 'idUser', 'required' => true, 'label' => 'User'));
$this->idUser->addMultiOption("","");
$this->idUser->addMultiOptions($user->fetchDeveloper());
...
......
My problem occurs when the call is made to $user->fetchDeveloper(). I suspect it has something todo with mocking objects and dependency injection but any guidence would be appreciated. My Failing unit test reads as follows...
require_once TEST_PATH . '/ControllerTestCase.php';
class TimesheetValidationTest extends ControllerTestCase {
public $Timesheet;
public $UserStub;
protected function setUp()
{
$this->Timesheet = new Default_Model_Timesheet();
parent::setUp();
}
/**
* #dataProvider timesheetProvider
*/
public function testTimesheetValid( $timesheet ) {
$UserStub = $this->getMock('Default_Model_User', array('fetchDeveloper'));
$UserStub->expects( $this->any() )
->method('fetchDeveloper')
->will( $this->returnValue(array(1 => 'Mickey Mouse')));
$Timesheet = new Default_Model_Timesheet();
$this->assertEquals(true, $Timesheet->isValid( $timesheet ) );
}
My data provider is in a separate file.
It is terminating at the command line with no output and I'm a bit stumped. Any help would be greatly appreciated.

Answer 1

You can't mock the Default_Model_User class in your test for the form. Because your code is instantiating the class internally you are not able to replace it with a mock.
You have a couple of options for testing this code.
You look into what fetchDeveloper is doing and control what it is returning. Either via a mock object that you can inject somewhere (looks unlikely) or by setting some data so that you know what the data will be. This will make your test a little brittle in that it could break when the data you are using changes.
The other option is to refactor the code so that you can pass the mock into your form. You can set a constructor that would allow you to set the Default_Model_User class and then you would be able to mock it with your test as written.
The constructor would like like this:
class Default_Form_Timesheet extends G10_Form {
protected $user;
public function __construct($options = null, Default_Model_User $user = null){
if(is_null($user)) {
$user = new Default_Model_User();
}
$this->user = $user;
parent::__construct($options);
}
Zend Framework allows options to be passed to forms constructor which I am not sure if you use in your code anywhere so this should not break any of your current functionality. When can then pass an optional Default_Model_User again so as to not break your current functionality. You need to set the values for $this->user before calling parent::__construct otherwise Zend will throw an error.
Now your init function will have to change from:
$user = new Default_Model_User();
to
$user = $this->user;
In your test you can now pass in your mock object and it will be used.
public function testTimesheetValid( $timesheet ) {
$UserStub = $this->getMock('Default_Model_User', array('fetchDeveloper'));
$UserStub->expects( $this->any() )
->method('fetchDeveloper')
->will( $this->returnValue(array(1 => 'Mickey Mouse')));
$Timesheet = new Default_Model_Timesheet(null, $UserStub);
$this->assertEquals(true, $Timesheet->isValid( $timesheet ) );
}
Creating a mock doesn't replace the object so that when new is called that your mock object is created. It creates a new object that extends your class that you can now pass around. new is a death to testability.