Testing constructor args in phpunit

Question

We use Varien_Http_Client to make http requests from a Magento extension, like this:

public function callApi(…)
{
    <SNIP>

    // Set default factory adapter to socket in case curl isn't installed.
    $client = new Varien_Http_Client($apiUri, array(
        'adapter' => 'Zend_Http_Client_Adapter_Socket',
        'timeout' => $timeout, 
    ));
    $client->setRawData($xmlDoc->saveXML())->setEncType('text/xml');
    $response = $client->request($method);
    $results = '';
    if ($response->isSuccessful()) {
        $results = $response->getBody();
    }
    return $results;
}

I understand I should avoid testing the internals of Varien_Http_Client; rather, I should test that we are sending it the right inputs, and handling its outputs correctly. I can mock Varien_Http_Client easily enough, but even if I refactor this code to let me replace the Varien_Http_Client with its mock, I don't understand how to generally* test that the constructor was called with the expected arguments, since the constructor is called by PHPUnit::getMock.

I don't need a mock object; I need a mock class. How can I test that a constructor was called with expected arguments?

* (In this case I know ways to work around this problem specific to Varien_Http_Client, but what can I do with more opaque third-party code?)

Cyprian · Accepted Answer · 2013-07-01 10:46:10Z

4

This is what we call "untestable" code. When you build dependencies inside your methods, there is no way to mock them. Every use of "new" keyword in your model is a signal that you should consider injecting the object instead of create it inside. In my opinion, the only exception from that rule is when you create a "data container" object or factory class. But in these cases probably you can test the object because methods will return it.

So as you said, the method you showed need a little refactor, for example:

class ApiClass
{
    protected $client;

    public function __construct(Varien_Http_Client $client)
    {
        $this->client = $client;
    }

    public function callApi()
    {
        $this->client->setRawData($xmlDoc->saveXML())->setEncType('text/xml');

        (...)

Best!

answered Jul 1, 2013 at 10:46

Cyprian

11.4k1 gold badge52 silver badges47 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

kojiro Over a year ago

Thanks! But I'm not out of the woods yet. I have to instantiate the Varien_Http_Client somewhere, and wherever that happens, I'll probably want to test, right? How do I avoid it again down the line?

Cyprian Over a year ago

Good point. Of course there always is some place where you need create a service inside a class. That's why I've write that you should just consider injecting. In practice you can minimize these places and limit them by for example make one class responsible for creating dependencies, like service container pattern. In practice also I admit directly creating dependencies in upper layers of the app, for example controller in MVC and presenter in MVP

Collectives™ on Stack Overflow

Testing constructor args in phpunit

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related