Is it possible to check the appearance of the element outside scope?
Test components with the vue-test-utils and jest. There is a component in which the button is implicitly causes the modal window, while in the local state changes nothing (so it would be possible to check the status of any isModalOpen). The only solution here I see to check for element in DOM. But there is a problem.
As we all know, vue-test-utils in the tests I propose to create a wrapper that has a number of methods to access the DOM component. With wrapper you can test render the component in its various States. However, the wrapper does not allow to reach the outer scope, document, and others like them. Of course, you can give the component root in the App, and then make a wrapper.vm.$parent, but again, it is impossible outside wrapper API to check the DOM component - only if the refs, but this approach does not work there.
In General, check the opening modal window using vue-test-utils? Who faced?