class ViewsKernelTestBase

abstract class ViewsKernelTestBase extends KernelTestBase {
    use ViewResultAssertionTrait;
    
    /**
     * Views to be enabled.
     *
     * Test classes should override this property and provide the list of testing
     * views.
     *
     * @var array
     */
    public static $testViews = [];
    
    /**
     * {@inheritdoc}
     */
    public static $modules = [
        'path_alias',
        'system',
        'views',
        'views_test_config',
        'views_test_data',
        'user',
    ];
    
    /**
     * {@inheritdoc}
     *
     * @param bool $import_test_views
     *   Should the views specified on the test class be imported. If you need
     *   to setup some additional stuff, like fields, you need to call false and
     *   then call createTestViews for your own.
     */
    protected function setUp($import_test_views = TRUE) {
        parent::setUp();
        $this->installSchema('system', [
            'sequences',
            'key_value_expire',
        ]);
        $this->setUpFixtures();
        if ($import_test_views) {
            ViewTestData::createTestViews(get_class($this), [
                'views_test_config',
            ]);
        }
    }
    
    /**
     * Sets up the configuration and schema of views and views_test_data modules.
     *
     * Because the schema of views_test_data.module is dependent on the test
     * using it, it cannot be enabled normally.
     */
    protected function setUpFixtures() {
        // First install the system module. Many Views have Page displays have menu
        // links, and for those to work, the system menus must already be present.
        $this->installConfig([
            'system',
        ]);
        
        /** @var \Drupal\Core\State\StateInterface $state */
        $state = $this->container
            ->get('state');
        // Define the schema and views data variable before enabling the test module.
        $state->set('views_test_data_schema', $this->schemaDefinition());
        $state->set('views_test_data_views_data', $this->viewsData());
        $this->container
            ->get('views.views_data')
            ->clear();
        $this->installConfig([
            'views',
            'views_test_config',
            'views_test_data',
        ]);
        foreach ($this->schemaDefinition() as $table => $schema) {
            $this->installSchema('views_test_data', $table);
        }
        $this->container
            ->get('router.builder')
            ->rebuild();
        // Load the test dataset.
        $data_set = $this->dataSet();
        $query = Database::getConnection()->insert('views_test_data')
            ->fields(array_keys($data_set[0]));
        foreach ($data_set as $record) {
            $query->values($record);
        }
        $query->execute();
    }
    
    /**
     * Orders a nested array containing a result set based on a given column.
     *
     * @param array $result_set
     *   An array of rows from a result set, with each row as an associative
     *   array keyed by column name.
     * @param string $column
     *   The column name by which to sort the result set.
     * @param bool $reverse
     *   (optional) Boolean indicating whether to sort the result set in reverse
     *   order. Defaults to FALSE.
     *
     * @return array
     *   The sorted result set.
     */
    protected function orderResultSet($result_set, $column, $reverse = FALSE) {
        $order = $reverse ? -1 : 1;
        usort($result_set, function ($a, $b) use ($column, $order) {
            if ($a[$column] == $b[$column]) {
                return 0;
            }
            return $order * ($a[$column] < $b[$column] ? -1 : 1);
        });
        return $result_set;
    }
    
    /**
     * Executes a view with debugging.
     *
     * @param \Drupal\views\ViewExecutable $view
     *   The view object.
     * @param array $args
     *   (optional) An array of the view arguments to use for the view.
     */
    protected function executeView($view, array $args = []) {
        $view->setDisplay();
        $view->preExecute($args);
        $view->execute();
        $verbose_message = '<pre>Executed view: ' . (string) $view->build_info['query'] . '</pre>';
        if ($view->build_info['query'] instanceof SelectInterface) {
            $verbose_message .= '<pre>Arguments: ' . print_r($view->build_info['query']
                ->getArguments(), TRUE) . '</pre>';
        }
        $this->verbose($verbose_message);
    }
    
    /**
     * Returns the schema definition.
     *
     * @internal
     */
    protected function schemaDefinition() {
        return ViewTestData::schemaDefinition();
    }
    
    /**
     * Returns the views data definition.
     */
    protected function viewsData() {
        return ViewTestData::viewsData();
    }
    
    /**
     * Returns a very simple test dataset.
     */
    protected function dataSet() {
        return ViewTestData::dataSet();
    }

}