Create Unit Test for Observer Class

Question

I wants to create the unit test for this observer class. I tried diff-2 ways but didn't get any help. Can anyone create the unit test for this it would be helpful

<?php
    
    declare(strict_types=1);
    
    namespace VendorName\ModuleName\Observer;
    
    use VendorName\ModuleName\Helper\Connection as SFMCHelper;
    use VendorName\ModuleName\Helper\Queue as QueueHelper;
    use Magento\Framework\Event\Manager;
    use Magento\Framework\Event\ObserverInterface;
    
    class CustomerSaveAfterObserver implements ObserverInterface
    {
        /**
         * @var QueueHelper
         */
        protected QueueHelper $queueHelper;
    
        /**
         * @var SFMCHelper
         */
        protected SFMCHelper $sfmcHelper;
    
        /**
         * @param SFMCHelper  $sfmcHelper
         * @param QueueHelper $queueHelper
         */
        public function __construct(
            SFMCHelper  $sfmcHelper,
            QueueHelper $queueHelper
        ) {
            $this->sfmcHelper = $sfmcHelper;
            $this->queueHelper = $queueHelper;
        }
    
        /**
         * Customer save after event handler
         *
         * @param \Magento\Framework\Event\Observer $observer
         * @return void
         */
        public function execute(\Magento\Framework\Event\Observer $observer)
        {
            $customerId = $observer->getCustomerDataObject()->getId();
            if ($customerId && $this->sfmcHelper->isAutoSyncEnabled()) {
                $this->queueHelper->publishSFMCMessage($customerId, QueueHelper::SFMC_EVENT_CUSTOMER_UPDATE);
            }
        }
    }

Thanks in Advance

Answer 1

<?php

declare(strict_types=1);

namespace VendorName\ModuleName\Test\Unit\Observer;

use Magento\Framework\Event\Observer;
use VendorName\ModuleName\Observer\CustomerSaveAfterObserver;
use VendorName\ModuleName\Helper\Connection as SFMCHelper;
use VendorName\ModuleName\Helper\Queue as QueueHelper;
/* Change this to your class, don't forget to change the property class */
use Magento\Customer\Api\Data\CustomerInterface as CustomerDataObject;

class CustomerSaveAfterObserverTest extends \PHPUnit\Framework\TestCase
{
    /**
     * @var CustomerSaveAfterObserver
     */
    protected $customerSaveAfterObserver;

    /**
     * @var SFMCHelper
     */
    protected $sfmcHelper;

    /**
     * @var QueueHelper
     */
    protected $queueHelper;

    /**
     * Change this to your class, don't forget to change the import
     * @var CustomerDataObject
     */
    protected $customertDataObject;

    /**
     * @var Observer
     */
    protected $observer;

    /**
     * @return void
     */
    public function setUp(): void
    {
        $this->sfmcHelper = $this->createMock(SFMCHelper::class);
        $this->queueHelper = $this->createMock(QueueHelper::class);

        $this->observer = $this->getMockBuilder(Observer::class)
            ->disableOriginalConstructor()
            ->addMethods(['getCustomerDataObject'])
            ->getMock();

        // Maybe useless depend on your class
        $this->customertDataObject = $this->getMockBuilder(CustomerDataObject::class)
            ->disableOriginalConstructor()
            ->getMockForAbstractClass();

        $this->customerSaveAfterObserver = new CustomerSaveAfterObserver(
            $this->sfmcHelper,
            $this->queueHelper
        );
    }

    /**
     * @return void
     */
    public function testExecute()
    {
        $customerId = '1';
        $this->observer->expects(self::once())
            ->method('getCustomerDataObject')
            ->willReturn($this->customertDataObject);

        $this->customertDataObject->expects(self::once())
            ->method('getId')
            ->willReturn($customerId);

        // I assume this value should be true
        // Implement to fit you method return value
        $this->sfmcHelper->expects(self::once())
            ->method('isAutoSyncEnabled')
            ->willReturn(true);

        // Can be useless depend on your method utility
        $this->queueHelper->expects(self::once())
            ->method('publishSFMCMessage')
            ->with($customerId, QueueHelper::SFMC_EVENT_CUSTOMER_UPDATE);
            //->willReturn(true);

        $this->customerSaveAfterObserver->execute($this->observer);
    }
}