AJAX link render array example nojs does not work

With this patch, nojs fallback is working for me.
It may be related with the route default, not entirely sure, but the change points to it.

The last patch doesn't apply anymore

$ git apply --index 0001-Issue-2933639-Make-ajax_example.library-depend-on-dr.patch
error: patch failed: ajax_example/ajax_example.routing.yml:81
error: ajax_example/ajax_example.routing.yml: patch does not apply

Rerolled the attached patch and fix the errors in the tests.

I agree.

I think also in the 8.7.x world, the form handler/controller method wouldn't even use the "$nojs" parameter and instead detect the wrapper from the request, something like this. I took this from search_api module

use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
use Symfony\Component\HttpFoundation\RequestStack;

...

    // If this is an AJAX request, just remove the row in question.
    if ($success && $this->getRequest()->request->get(AjaxResponseSubscriber::AJAX_REQUEST_PARAMETER)) {
      $response = new AjaxResponse();
      $response->addCommand(new RemoveCommand("tr[data-field-row-id='$field_id']"));
      return $response;
    }
    // Redirect to the index's "Fields" page.
    $url = $search_api_index->toUrl('fields');
    return $this->redirect($url->getRouteName(), $url->getRouteParameters());

@jlbellido, thanks for the new patch and fix.
@earthday47, that sounds interesting, I investigated a bit, and added a new issue with a lot more details, see #3046262: Consider ajax detection approach.

I have added the latest patch to 8.x-1.x.