Unhandled promise rejection, TypeError in sidebarMockInterceptor
Currently on master
we get a lot of these when running karma:
ERROR: TypeError{stack: 'sidebarMockInterceptor@http://localhost:9876/base/spec/javascripts/test_bundle.js?577337d4dcccae5d0627cad6749610f8955c8586:198501:61
See for example: https://gitlab.com/gitlab-org/gitlab-ce/builds/15885713