getRequest()->setMethod(HttpRequest::METHOD_POST); $this->getRequest()->setPostValue( [ 'description' => 'Some URL rewrite description', 'options' => 'R', 'request_path' => 'admin', 'target_path' => "target_path", 'store_id' => 1, ] ); $this->dispatch('backend/admin/url_rewrite/save'); $this->assertSessionMessages( $this->containsEqual(__(sprintf( 'URL key "%s" matches a reserved endpoint name (%s). Use another URL key.', $requestPath, $reservedWords ))), \Magento\Framework\Message\MessageInterface::TYPE_ERROR ); } }