PHPUnit with Zend Framework

i have studied some examples for PHPUnit with Zend Framework, but there is one part iam not understanding.

In the most examples, the Application Bootstrap runs from some kind of baseClass 开发者_开发知识库inside the setUp() Method.

Why not in __construct()? Is there any good reason?

Example iam talking about

Just for the record, I guess this is the concrete piece of code you're referring to:

class ControllerTestCase extends Zend_Test_PHPUnit_ControllerTestCase
{
    public $application;

    public function setUp()
    {
        $this->application = new Zend_Application(
            APPLICATION_ENV,
            APPLICATION_PATH . '/config/settings.ini'
        );

        $this->bootstrap = array($this, 'bootstrap');
        parent::setUp();
    }

    public function tearDown()
    {
        Zend_Controller_Front::getInstance()->resetInstance();
        $this->resetRequest();
        $this->resetResponse();

        $this->request->setPost(array());
        $this->request->setQuery(array());
    }

    public function bootstrap()
    {
        $this->application->bootstrap();
    }
}

In unit testing, the setUp and tearDown methods are used to

set the world up in a known state and then return it to its original state when the test is complete. This known state is called the fixture of the test.

The way fixtures are handled may differ between xUnit libraries, yet the concept remains the same. See also the fixtures chapter in the PHPUnit manual:

PHPUnit supports sharing the setup code. Before a test method is run, a template method called setUp() is invoked. setUp() is where you create the objects against which you will test. Once the test method has finished running, whether it succeeded or failed, another template method called tearDown() is invoked. tearDown() is where you clean up the objects against which you tested.

Hence, PHPUnit takes care of executing the setUp method before every single test method included in the test case class, while tearDown is processed after each execution.

Having that said, the Zend Framework provides with an extra layer on top of PHPUnit for running functional tests, this is, black-boxed tests on features rather than on individual units of source code. This is achieved by extending Zend_Test_PHPUnit_ControllerTestCase so that the access to the application resources is guaranteed.

In this particular example, the application is bootstrapped before every test in the test case is executed. This makes sense if we take into account that we don't need the application resources everywhere, like for instance in raw unit tests (part of other test cases).