ACP2E-3165: [Cloud] Getting error while checking the data in import data using CSV

 - Added the test coverage.

Author: devarul

app/code/Magento/CustomerImportExport/Test/Unit/Model/Import/Customer/StorageTest.php

@@ -0,0 +1,137 @@
+<?php
+/*************************************************************************
+ * ADOBE CONFIDENTIAL
+ * ___________________
+ *
+ * Copyright 2024 Adobe
+ * All Rights Reserved.
+ *
+ * NOTICE: All information contained herein is, and remains
+ * the property of Adobe and its suppliers, if any. The intellectual
+ * and technical concepts contained herein are proprietary to Adobe
+ * and its suppliers and are protected by all applicable intellectual
+ * property laws, including trade secret and copyright laws.
+ * Dissemination of this information or reproduction of this material
+ * is strictly forbidden unless prior written permission is obtained
+ * from Adobe.
+ *************************************************************************
+ */
+declare(strict_types=1);
+
+namespace Magento\CustomerImportExport\Test\Unit\Model\Import\Customer;
+
+use Magento\CustomerImportExport\Model\ResourceModel\Import\Customer\Storage;
+use Magento\Customer\Model\ResourceModel\Customer\CollectionFactory;
+use Magento\Customer\Model\ResourceModel\Customer\Collection;
+use Magento\Customer\Model\Config\Share;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\DB\Select;
+use PHPUnit\Framework\MockObject\Exception;
+use PHPUnit\Framework\TestCase;
+use ReflectionClass;
+use ReflectionException;
+
+class StorageTest extends TestCase
+{
+    /**
+     * @var Storage
+     */
+    private Storage $storage;
+
+    /**
+     * @var Collection|MockObject
+     */
+    private mixed $customerCollectionMock;
+
+    /**
+     * @var Share|MockObject
+     */
+    private mixed $configShareMock;
+
+    /**
+     * @var AdapterInterface|MockObject
+     */
+    private mixed $connectionMock;
+
+    /**
+     * @inheritdoc
+     * @throws Exception
+     */
+    protected function setUp(): void
+    {
+        $collectionFactoryMock = $this->createMock(CollectionFactory::class);
+        $this->customerCollectionMock = $this->createMock(Collection::class);
+        $this->configShareMock = $this->createMock(Share::class);
+        $this->connectionMock = $this->createMock(AdapterInterface::class);
+
+        $collectionFactoryMock->method('create')
+            ->willReturn($this->customerCollectionMock);
+
+        $this->storage = new Storage(
+            $collectionFactoryMock,
+            $this->configShareMock,
+            ['page_size' => 4]
+        );
+    }
+
+    /**
+     * Test loadCustomersData method when the scope is set to global.
+     *
+     * @throws Exception|ReflectionException
+     */
+    public function testLoadCustomersData()
+    {
+        $customerIdentifiers = [
+            'test@example.com_2' => ['email' => 'test@example.com', 'website_id' => 2],
+            'test@example.com_3' => ['email' => 'test@example.com', 'website_id' => 3],
+            'test@example.com_4' => ['email' => 'test@example.com', 'website_id' => 4],
+            'test@example.com_5' => ['email' => 'test@example.com', 'website_id' => 5]
+        ];
+
+        $selectMock = $this->createMock(Select::class);
+        $selectMock->expects($this->once())
+            ->method('getPart')
+            ->willReturn(['main_table' => 'customer_entity']);
+
+        $this->customerCollectionMock->expects($this->once())
+            ->method('getSelect')
+            ->willReturn($selectMock);
+        $connectionMock = $this->getConnectionMock();
+        $this->customerCollectionMock
+            ->expects($this->once())
+            ->method('getConnection')
+            ->willReturn($connectionMock);
+
+        $this->configShareMock->expects($this->once())
+            ->method('isGlobalScope')
+            ->willReturn(true);
+
+        $reflection = new ReflectionClass($this->storage);
+        $customerIdsProperty = $reflection->getProperty('_customerIds');
+        $loadCustomersDataMethod = $reflection->getMethod('loadCustomersData');
+        $loadCustomersDataMethod->setAccessible(true);
+        $loadCustomersDataMethod->invokeArgs($this->storage, [$customerIdentifiers]);
+        $customerIds = $customerIdsProperty->getValue($this->storage);
+        $this->assertArrayHasKey('test@example.com', $customerIds);
+    }
+
+    /**
+     * Mock DB connection and return customer data's
+     *
+     * @return AdapterInterface|MockObject
+     * @throws Exception
+     */
+    private function getConnectionMock(): AdapterInterface|MockObject
+    {
+        $customerData = [
+            'email' => 'test@example.com',
+            'website_id' => 1,
+            'entity_id' => 1,
+            'store_id' => 1
+        ];
+        $this->connectionMock->expects($this->once())
+            ->method('fetchAll')->willReturn([$customerData]);
+
+        return $this->connectionMock;
+    }
+}