<?php
/**
 * Copyright © 2016 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */

/** @var \Magento\Catalog\Setup\CategorySetup $installer */
$installer = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create('Magento\Catalog\Setup\CategorySetup');

/** @var $attribute \Magento\Catalog\Model\ResourceModel\Eav\Attribute */
$attribute = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create(
    'Magento\Catalog\Model\ResourceModel\Eav\Attribute'
);
$attribute->setData(
    [
        'attribute_code' => 'test_attribute',
        'entity_type_id' => $installer->getEntityTypeId('catalog_product'),
        'is_global' => 1,
        'is_user_defined' => 1,
        'frontend_input' => 'text',
        'is_used_for_promo_rules' => 1,
        'backend_type' => 'text',
    ]
);
$attribute->save();

/* Assign attribute to attribute set */
$installer->addAttributeToGroup('catalog_product', 'Default', 'General', $attribute->getId());

/** @var \Magento\Eav\Model\Config $eavConfig */
$eavConfig = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->get('Magento\Eav\Model\Config');
$eavConfig->clear();