<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

use Magento\Store\Api\WebsiteRepositoryInterface;
use Magento\TestFramework\Workaround\Override\Fixture\Resolver;

Resolver::getInstance()->requireDataFixture('Magento/Store/_files/second_website_with_two_stores.php');

$objectManager =  \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
/** @var WebsiteRepositoryInterface $websiteRepository */
$websiteRepository = $objectManager->get(WebsiteRepositoryInterface::class);
$websiteId = $websiteRepository->get('test')->getId();
/** @var \Magento\Config\Model\ResourceModel\Config $configResource */
$configResource = $objectManager->get(\Magento\Config\Model\ResourceModel\Config::class);
$configResource->saveConfig(
    \Magento\Directory\Model\Currency::XML_PATH_CURRENCY_DEFAULT,
    'EUR',
    \Magento\Store\Model\ScopeInterface::SCOPE_WEBSITE,
    $websiteId
);
$configResource->saveConfig(
    \Magento\Directory\Model\Currency::XML_PATH_CURRENCY_ALLOW,
    'EUR',
    \Magento\Store\Model\ScopeInterface::SCOPE_WEBSITE,
    $websiteId
);
$configResource->saveConfig(
    \Magento\Catalog\Helper\Data::XML_PATH_PRICE_SCOPE,
    \Magento\Store\Model\Store::PRICE_SCOPE_WEBSITE,
    'default',
    0
);

/**
 * Configuration cache clean is required to reload currency setting
 */
/** @var Magento\Config\App\Config\Type\System $config */
$config = $objectManager->get(\Magento\Config\App\Config\Type\System::class);
$config->clean();

$observer = $objectManager->get(\Magento\Framework\Event\Observer::class);
$objectManager->get(\Magento\Catalog\Observer\SwitchPriceAttributeScopeOnConfigChange::class)
    ->execute($observer);

/** @var \Magento\Directory\Model\ResourceModel\Currency $rate */
$rate = $objectManager->create(\Magento\Directory\Model\ResourceModel\Currency::class);
$rate->saveRates([
    'USD' => ['EUR' => 2],
    'EUR' => ['USD' => 0.5]
]);