ViewAjaxController example

    $this->renderer->expects($this->any())
      ->method('executeInRenderContext')
      ->willReturnCallback(function DRenderContext $context, callable $callable) {
        return $callable();
      });
    $this->currentPath = $this->getMockBuilder('Drupal\Core\Path\CurrentPathStack')
      ->disableOriginalConstructor()
      ->getMock();
    $this->redirectDestination = $this->createMock('\Drupal\Core\Routing\RedirectDestinationInterface');

    $this->viewAjaxController = new ViewAjaxController($this->viewStorage, $this->executableFactory, $this->renderer, $this->currentPath, $this->redirectDestination);

    $element_info_manager = $this->createMock('\Drupal\Core\Render\ElementInfoManagerInterface');
    $element_info_manager->expects($this->any())
      ->method('getInfo')
      ->with('status_messages')
      ->willReturn([]);
    $request_stack = new RequestStack();
    $request_stack->push(new Request());
    $this->renderer = new Renderer(
      $this->createMock('\Drupal\Core\Controller\ControllerResolverInterface'),
      $this->createMock('\Drupal\Core\Theme\ThemeManagerInterface'),