Magento 2 Unit Test error: Call to a member function getBaseUrl() on null

Question

I am looking to write basic unit tests for some helper functions that I am working on for a Magento 2 module. I am able to execute my custom module unit tests but I am getting the following error for the first test.

When I execute the tests for my module I get the following error:

Call to a member function getBaseUrl() on null

My Helper code is below: I will be adding quite a few functions to it later and the function its self returns the correct result if I call it else where in my code, I am not able to get the test working.

namespace MyModuleSpace\MyModule\Helper;
use Magento\Framework\App\Helper\Context;
use Magento\Store\Model\StoreManagerInterface;
class Data extends \Magento\Framework\App\Helper\AbstractHelper {
 /**
 * Attribute to hold storeManager Object
 *
 * @var object
 */
 protected $storeManager;
 /**
 * _construct
 *
 * @param Context $context
 * @param StoreManagerInterface $storeManager
 */
 public function __construct(Context $context, StoreManagerInterface $storeManager) {
 $this->storeManager = $storeManager;
 parent::__construct($context);
 }
 /**
 * No params needed. Returns base site URL.
 *
 * @return string
 */
 public function getBaseURL() {
 return $this->storeManager->getStore()->getBaseUrl();
 }
}

My Unit Test code is

namespace MyModuleSpace\MyModule\Test\Unit\Helper;
//class HelperTest extends \PHPUnit_Framework_TestCase { // not usable as it is not supported
class HelperTest extends \PHPUnit\Framework\TestCase {
 protected $helper;
 /**
 * Sets up the Mock (reflection) objects and properties for tests...
 *
 */
 protected function setUp() {
 $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
 $this->helper = $objectManager->getObject('MyModuleSpace\MyModule\Helper\Data');
 }
 /**
 * Run unit tests for getBaseURL()
 */
 public function testGetBaseURL() {
 $baseUrl = $this->helper->getBaseUrl();
 // Test we are returning a string...
 $this->assertTrue(is_string($baseUrl));
 }
}

I am not sure what I am doing wrong but any help would be appreciated.

• Sanjay Gohil: have you found a solution?, If yes, can you please tell me how.

Answer 1

It's bad practise to use ObjecManager, so thats should be improved first. Use your construct to instantiate the classes that you need, including the helper.

• Baber: I agree, I have found a better approach, just got to figure out how to close this question. Followed a bad example from some research I had...
• BBQ.: To close a question, you can simply accept an answer.
• Shapeshifter: Use of this object manager in unit tests is totally acceptable
• open-ecommerce.org: as @Shapeshifter said there is not need to inject classes with a constructor in unit tests and your are not answering his question