trait DatabaseTestsTrait in Search API 8

trait DatabaseTestsTrait {

  /**
   * Asserts that the given table exists and has a primary key.
   *
   * @param string $table
   *   The name of the table.
   * @param string|null $message
   *   (optional) The message to print for the assertion, or NULL to use an
   *   automatically generated one.
   */
  protected function assertHasPrimaryKey($table, $message = NULL) {
    $schema = \Drupal::database()
      ->schema();
    $this
      ->assertTrue($schema
      ->tableExists($table), "Table {$table} exists.");
    if (!$message) {
      $message = "Table {$table} has a primary key.";
    }

    // The database layer doesn't support generic introspection into primary
    // keys. The simplest way to test whether a primary key exists is therefore
    // to try to create one and see whether that leads to an exception.
    try {
      $schema
        ->addPrimaryKey($table, []);
      $this
        ->assertTrue(FALSE, $message);
    } catch (SchemaObjectExistsException $e) {
      $this
        ->assertTrue(TRUE, $message);
    } catch (\Exception $e) {

      // Trying to create a primary key with an empty fields list will probably
      // still throw an exception, so we catch that as well.
      $this
        ->assertTrue(FALSE, $message);
    }
  }

  /**
   * Asserts that the given table exists and does not have a primary key.
   *
   * @param string $table
   *   The name of the table.
   * @param string|null $message
   *   (optional) The message to print for the assertion, or NULL to use an
   *   automatically generated one.
   */
  protected function assertNotHasPrimaryKey($table, $message = NULL) {
    $schema = \Drupal::database()
      ->schema();
    $this
      ->assertTrue($schema
      ->tableExists($table), "Table {$table} exists.");
    if (!$message) {
      $message = "Table {$table} does not have a primary key.";
    }

    // The database layer doesn't support generic introspection into primary
    // keys. The simplest way to make sure a table does not have a primary key
    // is trying to drop it and checking the return value.
    $this
      ->assertFalse($schema
      ->dropPrimaryKey($table), $message);
  }

}