phpspec demo

Email.php

<?php
namespace App;

class Email
{
    protected $body;

    public function setBody($body)
    {
        $this->body = $body;
    }
    public function getBody()
    {
        return $this->body;
    }
}

EmailFactory.php

<?php
namespace App;

class EmailFactory
{
    public function createEmail($body)
    {
        $email = new Email();
        $email->setBody($body);

        return $email;
    }
}

EmailFactorySpec.php

<?php

namespace spec\App;

use App\Email;
use App\EmailFactory;
use PhpSpec\ObjectBehavior;
use Prophecy\Argument;

class EmailFactorySpec extends ObjectBehavior
{
    function it_is_initializable()
    {
        $this->shouldHaveType(EmailFactory::class);
    }

    function it_creates_email_with_body_content()
    {
        $body = 'abc';
        $email = $this->createEmail($body);

        $email->shouldBeAnInstanceOf(Email::class);
        $email->getBody()->shouldBeEqualTo($body);
    }
}

EmailService.php

<?php
namespace App;

interface EmailService
{
    public function send(Email $email);
}

Service.php

<?php
namespace App;

class Service
{
    protected $emailService;
    protected $emailFactory;

    public function __construct(EmailService $emailService, EmailFactory $emailFactory)
    {
        $this->emailService = $emailService;
        $this->emailFactory = $emailFactory;
    }

    public function testFunc()
    {
        $email = $this->emailFactory->createEmail('abc');

        $this->emailService->send($email);
    }
}

ServiceSpec.php

<?php

namespace spec\App;

use App\Email;
use App\EmailFactory;
use App\EmailService;
use App\Service;
use PhpSpec\ObjectBehavior;
use Prophecy\Argument;

class ServiceSpec extends ObjectBehavior
{
    function it_is_initializable(EmailService $emailService, EmailFactory $emailFactory)
    {
        $this->beConstructedWith($emailService, $emailFactory);

        $this->shouldHaveType(Service::class);
    }

    function it_creates_email_with_body_abc(EmailService $emailService, EmailFactory $emailFactory, Email $email)
    {
        $this->beConstructedWith($emailService, $emailFactory);

        $emailFactory->createEmail('abc')->willReturn($email);
        $emailService->send($email)->shouldBeCalled();

        $this->testFunc();
    }
}