Symfony2 unit testing cannot instantiate class in test class - php

Question

I am working with Symfony2 and trying to write some PHPUnit test for one of my classes.
This is what I have done so far following Symfony2 testing Docs i created a folder under Tests directory with a file myClassTest.php ini it:
<?php
namespace Test\TestBundle\Tests\Template;
use Test\TestBundle\Dto\Template\myTemplate;
class myTemplateTest extends \PHPUnit_Framework_TestCase
{
public function testMyMethod()
{
$test = new myTemplate();
}
}
This is myTemplate:
<?php
namespace Test\TestBundle\Dto\Template;
use Test\TestBundle\Doctrine\DatabaseRepository;
use Test\TestBundle\Validation\ValidationClass;
class myTemplate
{
/**
* #var ValidationClass
*/
private $validate;
/**
* #var DatabaseRepository
*/
private $db;
/**
* #param ValidationClass $validation
* #param DatabaseRepository $databaseRepository
*/
public function __construct(
ValidationClass $validation,
DatabaseRepository $databaseRepository
) {
$this->validate = $validation;
$this->db = $databaseRepository;
}
}
Errors:
Argument 1 passed to Test\TestBundle\Dto\Template\myTemplate::__construct()
must be an instance of Test\TestBundle\Validation\ValidationClass, string given,
called in Dev/project/src/Test/TestBundle/Tests/Template/myTemplateTest.php
More Errors:
This error points to the injected service in the construct $validation
Dev/project/src/Test/TestBundle/Dto/Template/myTemplate.php:42
This error corresponds to the instantiate class of myTemplate class
Dev/project/src/Test/TestBundle/Tests/Dto/Template/myTemplateTest.php:15
I understand the errors well i think I do but i have no idea how to fix it and these errors are shown when i run phpunit test.

Answer 1

For testing with PHPUnit, you should use Mocks and Stubs for imitation logic in your depends classes.
Before initialize myTemplate in test case, you should create a mock of this objects, or create original objects.
$validationMock = $this->getMock('ValidationClass');
$dbRepositoryMock = $this->getMock('DatabaseRepository');
$myTemplate = new myTemplate($validationMock, $dbRepositoryMock);
And after you can use invocation system for control called methods.
For more information, please visit PHPUnit site:
https://phpunit.de/manual/current/en/test-doubles.html