class MockRouteProvider

class MockRouteProvider implements RouteProviderInterface {

  /**
   * A collection of routes for this route provider.
   *
   * @var \Symfony\Component\Routing\RouteCollection
   */
  protected $routes;

  /**
   * Constructs a new MockRouteProvider.
   *
   * @param \Symfony\Component\Routing\RouteCollection $routes
   *   The route collection to use for this provider.
   */
  public function __construct(RouteCollection $routes) {
    $this->routes = $routes;
  }

  /**
   * Implements \Drupal\Core\Routing\RouteProviderInterface::getRouteCollectionForRequest().
   *
   * Simply return all routes to prevent
   * \Symfony\Component\Routing\Exception\ResourceNotFoundException.
   */
  public function getRouteCollectionForRequest(Request $request) {
    return $this->routes;
  }

  /**
   * {@inheritdoc}
   */
  public function getRouteByName($name) {
    $routes = $this
      ->getRoutesByNames([
      $name,
    ]);
    if (empty($routes)) {
      throw new RouteNotFoundException(sprintf('Route "%s" does not exist.', $name));
    }
    return reset($routes);
  }

  /**
   * {@inheritdoc}
   */
  public function preLoadRoutes($names) {

    // Nothing to do.
  }

  /**
   * {@inheritdoc}
   */
  public function getRoutesByNames($names) {
    $routes = [];
    foreach ($names as $name) {
      $routes[] = $this->routes
        ->get($name);
    }
    return $routes;
  }

  /**
   * {@inheritdoc}
   */
  public function getRoutesByPattern($pattern) {
    return new RouteCollection();
  }

  /**
   * {@inheritdoc}
   */
  public function getAllRoutes() {
    return $this->routes
      ->all();
  }

  /**
   * {@inheritdoc}
   */
  public function reset() {
    $this->routes = [];
  }

}