Dependency on mock method with PHPUnit - php

Question

I'm attempting to write PHPUnit tests for an Email abstraction class i'm using. The class interacts with the Mailgun API but I don't want to touch this in my test, I just want to return the response I would expect from Mailgun.
Within my test I have a setup method:
class EmailTest extends PHPUnit_Framework_TestCase
{
private $emailService;
public function setUp()
{
$mailgun = $this->getMockBuilder('SlmMail\Service\MailgunService')
->disableOriginalConstructor()
->getMock();
$mailgun->method('send')
->willReturn('<2342423#sandbox54533434.mailgun.org>');
$this->emailService = new Email($mailgun);
parent::setUp();
}
public function testEmailServiceCanSend()
{
$output = $this->emailService->send("me#test.com");
var_dump($output);
}
}
This is the basic outline of the email class
use Zend\Http\Exception\RuntimeException as ZendRuntimeException;
use Zend\Mail\Message;
use SlmMail\Service\MailgunService;
class Email
{
public function __construct($service = MailgunService::class){
$config = ['domain' => $this->domain, 'key' => $this->key];
$this->service = new $service($config['domain'], $config['key']);
}
public function send($to){
$message = new Message;
$message->setTo($to);
$message->setSubject("test subject");
$message->setFrom($this->fromAddress);
$message->setBody("test content");
try {
$result = $this->service->send($message);
return $result;
} catch(ZendRuntimeException $e) {
/**
* HTTP exception - (probably) triggered by network connectivity issue with Mailgun
*/
$error = $e->getMessage();
}
}
}
var_dump($output); is currently outputting NULL rather than the string i'm expecting. The method send i'm stubbing in the mock object has a dependency through an argument, and when I call $mailgun->send() directly it errors based on this so I wonder if this is what is failing behind the scenes. Is there a way to pass this argument in, or should I approach this a different way?

Answer 1

It is strange it does not throw an exception in Email::__construct.
The expected parameter is a string, and the MailgunService object is instantiated within the email constructor. In your test you are passing the object, so I would expect and error at line
$this->service = new $service($config['domain'], $config['key']);
What you need is:
class Email
{
public function __construct($service = null){
$config = ['domain' => $this->domain, 'key' => $this->key];
$this->service = $service?: new MailgunService($config['domain'], $config['key']);
}
Also, it may not be a good idea to catch an exception and return nothing in Email::send.