How to check if view result is not empty

That is not possible with this approach. If you need to create some wrapper around the view I would suggest move it to view template.

Well, there is a trick. If a view returns nothing ("empty result behavior" is not configured).

{% set view = drupal_view('view_name')|render  %}
{%  if view|striptags|trim %}
  <div class="wrapper">
    {{ view }}
  </div>
{% endif %}

striptags and trim filters are needed in case the view returns empty markup with no content.

I had the same issue and sometimes the suggested solution did not work for me.
So I made myself some thoughts and created a patch for this.

With this patch applied, empty views are never getting printed out. The twig syntax has not changed, so we still can print out views with this:

{{ drupal_view('myView', 'myDisplay') }}

Additional it is now possible to do stuff like this:

{% set view_myView = drupal_view('myView', 'myDisplay') %}
  {% if view_myView %}
    <div class="misc">
      {{ view_myView }}
    </div>
  {% endif %}

Cheers :)

Some people would like to display "Empty result text" or "View attachment" when a view has no results. The patch #4 is not acceptable for them. Furthermore it breaks backward compatibility.
Closing this as the reporter was given an answer.

Interesting way to deal with someone who just wanted to help...
As mentioned your way did not work always so I think the feature request is still open.
In case of just rejecting my patch, it would be better to extend it and improve the module.

@sgurlt I appreciate any help but this patch is not acceptable for reasons explained in #6.

For anyone landing here from a search engine, the pattern has changed.

{% set view = drupal_view_result('related', 'block_1')|length %}
{% if view > 0 %}
  {{ drupal_view('related', 'block_1') }}
{% endif %}

https://git.drupalcode.org/project/twig_tweak/-/blob/3.x/docs/views.md#c...