_model = \Magento\TestFramework\Helper\Bootstrap::getObjectManager() ->create(\Magento\Store\Model\App\Emulation::class); \Magento\TestFramework\Helper\Bootstrap::getInstance() ->loadArea(\Magento\Backend\App\Area\FrontNameResolver::AREA_CODE); $design = \Magento\TestFramework\Helper\Bootstrap::getObjectManager() ->get(\Magento\Framework\View\DesignInterface::class); $this->_model->startEnvironmentEmulation(1); $this->_model->stopEnvironmentEmulation(); $this->assertEquals(\Magento\Backend\App\Area\FrontNameResolver::AREA_CODE, $design->getArea()); } }