ENGCOM-6513: [LayeredNavigation] Covering the ProductAttributeGridBuildObserver for LayeredNavigation … #26154

 - Merge Pull Request #26154 from eduard13/magento2:layered-navigation-unit-test
 - Merged commits:
   1. c7bb3b4

Author: magento-engcom-team

app/code/Magento/LayeredNavigation/Test/Unit/Observer/Grid/ProductAttributeGridBuildObserverTest.php

@@ -0,0 +1,102 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\LayeredNavigation\Test\Unit\Observer\Grid;
+
+use Magento\Catalog\Block\Adminhtml\Product\Attribute\Grid;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Module\Manager;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\LayeredNavigation\Observer\Grid\ProductAttributeGridBuildObserver;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Class ProductAttributeGridBuildObserverTest
+ *
+ * Testing adding new grid column for Layered Navigation
+ */
+class ProductAttributeGridBuildObserverTest extends TestCase
+{
+    /**
+     * @var ProductAttributeGridBuildObserver
+     */
+    private $observer;
+
+    /**
+     * @var Manager|MockObject
+     */
+    private $moduleManagerMock;
+
+    /**
+     * @var Observer|MockObject
+     */
+    private $observerMock;
+
+    /**
+     * @var Grid|MockObject
+     */
+    private $gridMock;
+
+    /**
+     * Set Up
+     */
+    protected function setUp()
+    {
+        $objectManager = new ObjectManager($this);
+        $this->moduleManagerMock = $this->createMock(Manager::class);
+        $this->gridMock = $this->createMock(Grid::class);
+        $this->observerMock = $this->getMockBuilder(Observer::class)
+            ->disableOriginalConstructor()
+            ->setMethods(['getGrid'])
+            ->getMock();
+
+        $this->observer = $objectManager->getObject(
+            ProductAttributeGridBuildObserver::class,
+            [
+                'moduleManager' => $this->moduleManagerMock,
+            ]
+        );
+    }
+
+    /**
+     * Testing the column adding if the output is not enabled
+     */
+    public function testColumnAddingOnDisabledOutput()
+    {
+        $enabledOutput = false;
+
+        $this->moduleManagerMock->expects($this->once())
+            ->method('isOutputEnabled')
+            ->with('Magento_LayeredNavigation')
+            ->willReturn($enabledOutput);
+
+        $this->observerMock->expects($this->never())
+            ->method('getGrid');
+
+        $this->observer->execute($this->observerMock);
+    }
+
+    /**
+     * Testing the column adding if the output is enabled
+     */
+    public function testColumnAddingOnEnabledOutput()
+    {
+        $enabledOutput = true;
+
+        $this->moduleManagerMock->expects($this->once())
+            ->method('isOutputEnabled')
+            ->with('Magento_LayeredNavigation')
+            ->willReturn($enabledOutput);
+
+        $this->observerMock->expects($this->once())
+            ->method('getGrid')
+            ->willReturn($this->gridMock);
+
+        $this->observer->execute($this->observerMock);
+    }
+}