Zend 2: Unit tests for form class

Question

I'm just starting using PHPUnit with Zend and need little help to figure out how these tests should work.

I want to test if form return any error message if I do not pass any POST parameters.

The problem is that one field from my form is using Doctrine's DoctrineModule\Form\Element\ObjectSelect

    ...
    $this->add(array(
        'type' => 'DoctrineModule\Form\Element\ObjectSelect',
        'name' => 'user',
        'attributes' => array(
            'id' => 'user-label',
        ),
        'options' => array(
            'object_manager' => $em,
            'target_class' => 'Application\Entity\User',
            'property' => 'username',
            'label' => 'User:',
            'display_empty_item' => true,
            'empty_item_label'   => '---',
            'label_generator' => function($entity) {
                return $entity->getUsername();
            },
        ),
    ));
    ...

I get following error:
Fatal error: Call to a member function getIdentifierFieldNames() on null

I tried override this field with mocked object, however Zend doesn't allow objects in type, just class name (string), so this code doesn't work:

public function testIfFormIsValid()
{
    $objectSelect = $this->getMockBuilder('DoctrineModule\Form\Element\ObjectSelect')
        ->disableOriginalConstructor()
        ->getMock();
    $objectSelect->expects($this->any())
        ->method('getValueOptions')
        ->will($this->returnValue(array()));

    $form = new \AppModuleComment\Form\Comment('form', array(
        'em' => $this->em  // Mocked object
    ));
    $form->add(array(
        'type' => $objectSelect,
        'name' => 'user',
        'attributes' => array(
            'id' => 'user-label',
        ),
        'options' => array(
            'object_manager' => $this->em,
            'target_class' => 'Application\Entity\User',
            'property' => 'username',
            'label' => 'User:',
            'display_empty_item' => true,
            'empty_item_label'   => '---',
            'label_generator' => function($entity) {
                return $entity->getUsername();
            },
        ),
    ));

    $data = array(
        'id' => null,
        'user' => null
    );

    $form->setData($data);
    $this->assertTrue($form->isValid(), 'Form is not valid');
}    

What am I doing wrong? How should I test such code?

Answer 1

It seems you are testing functionality of Zend or Doctrine (or both) and not your own code. When you use libraries you should trust these libraries.

What happens is: Form\Form::add() uses Form\Factory::create() to create from the array an element. Form\Factory::create() uses Form\FormElementManager::get() to get an element from the given type.

Your type is an object and because Form\FormElementManager::get() can not handle objects your script will fail.

It seems you want to test that if post is empty Form::valid() calls ObjectSelect::valid() but this does not verify if the value is null. That's code from Doctrine / Zend not yours. Don't test it.

More interesting it gets when you want to mock the result of an select from within Doctrines ObjectSelect. But that's another question.