Call to undefined method MetadataBag::getMasquerade() at MasqueradeCacheContext.php line 31

Added MR with simple solution for this problem

Curious why the bag is different but better replace check for bag classname

Curious why the bag is different

This is hidden somewhere deep in Drupal core I think. We do bootstrap Drupal core with custom code (similar to index.php) for bunch of our specific integrational tests. So I did not dig to deep about masquerade and core interaction :)

better replace check for bag classname

Done: check replaced to instanceof.

Any chance to have this merged at least to -dev branch?
Thanks.

Experiencing the same issue with Drupal Test Traits, the MR fixes it.

Would be good to get this committed, nice n simple fix.

This simple fix points out to bugs in tests because this check means that service is not decorated, moreover all other parts of code supposing that metadatabag is decorated and then it should be fixed in all places

So instead of "wont't fix" I wanna get more opinions why unit tests should be able to partially mock functionality?
See masquerade.services.yml

  masquerade.session_manager.metadata_bag:
    class: Drupal\masquerade\Session\MetadataBag
    decorates: session_manager.metadata_bag
    parent: session_manager.metadata_bag
    public: false

I did some digging, and while I don't have any answers I do have some further information.

The test that was triggering the error looks like this:

$this->setCurrentUser($this->createUser()->addRole('regional_manager'));
$url = Url::fromRoute('my_module.my_route');
$request = Request::create($url->toString(), 'HEAD');
$response = \Drupal::service('http_kernel')->handle($request);

But if I change this to use ::drupalLogin and ::drupalGet then the bag is decorated correctly.

Similarly, If I remove the access toolbar permission from the role and revert to the original test, then MasqueradeCacheContext::getContext does not get invoked and the test passes.

Finally, if I remove the masquerade_switch_back item from masquerade_toolbar then again the test passes.

Hopefully that helps to explain this.