CreateTest.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
declare(strict_types=1);

namespace Magento\Sales\Model\Order;

use Magento\Checkout\Model\Session as CheckoutSession;
use Magento\Framework\Data\Form\FormKey;
use Magento\Framework\ObjectManagerInterface;
use Magento\Quote\Api\GuestCartManagementInterface;
use Magento\Quote\Model\Quote;
use Magento\Quote\Model\QuoteIdMask;
use Magento\Quote\Model\QuoteIdMaskFactory;
use Magento\Sales\Model\OrderRepository;
use Magento\TestFramework\Helper\Bootstrap;
use Magento\TestFramework\Mail\Template\TransportBuilderMock;
use PHPUnit\Framework\Constraint\StringContains;

/**
 * Class verifies order creation.
 *
 * @magentoDbIsolation enabled
 * @magentoAppArea frontend
 */
class CreateTest extends \PHPUnit\Framework\TestCase
{
    /**
     * @var ObjectManagerInterface
     */
    private $objectManager;

    /**
     * @var TransportBuilderMock
     */
    private $transportBuilder;

    /**
     * @var QuoteIdMaskFactory
     */
    private $quoteIdMaskFactory;

    /**
     * @var FormKey
     */
    private $formKey;

    /**
     * @inheritdoc
     */
    protected function setUp()
    {
        parent::setUp();
        $this->objectManager = Bootstrap::getObjectManager();
        $this->transportBuilder = $this->objectManager->get(TransportBuilderMock::class);
        $this->quoteIdMaskFactory = $this->objectManager->get(QuoteIdMaskFactory::class);
        $this->formKey = $this->objectManager->get(FormKey::class);
    }

    /**
     * @magentoDataFixture Magento/Sales/_files/guest_quote_with_addresses.php
     * @return void
     */
    public function testSendEmailOnOrderPlace(): void
    {
        /** @var Quote $quote */
        $quote = $this->objectManager->create(Quote::class);
        $quote->load('guest_quote', 'reserved_order_id');

        $checkoutSession = $this->objectManager->get(CheckoutSession::class);
        $checkoutSession->setQuoteId($quote->getId());

        /** @var QuoteIdMask $quoteIdMask */
        $quoteIdMask = $this->quoteIdMaskFactory->create();
        $quoteIdMask->load($quote->getId(), 'quote_id');
        $cartId = $quoteIdMask->getMaskedId();

        /** @var GuestCartManagementInterface $cartManagement */
        $cartManagement = $this->objectManager->get(GuestCartManagementInterface::class);
        $orderId = $cartManagement->placeOrder($cartId);
        $order = $this->objectManager->get(OrderRepository::class)->get($orderId);

        $message = $this->transportBuilder->getSentMessage();
        $subject = __('Your %1 order confirmation', $order->getStore()->getFrontendName())->render();
        $assert = $this->logicalAnd(
            new StringContains($order->getBillingAddress()->getName()),
            new StringContains(
                'Thank you for your order from ' . $order->getStore()->getFrontendName()
            ),
            new StringContains(
                "Your Order <span class=\"no-link\">#{$order->getIncrementId()}</span>"
            )
        );

        $this->assertEquals($message->getSubject(), $subject);
        $this->assertThat($message->getRawMessage(), $assert);
    }
}