In [`spec/javascripts/blob/notebook/index_spec.js`] axios requests are mocked but the tests don't wait for the mock response. This leads to a racing condition and the tests not being reliable. You can see at least one test not using the mock response on CI: ``` iPython notebook renderer ✔ shows loading icon 22 01 2018 17:18:30.300:WARN [web-server]: 404: /test ``` (https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/49009523) Also you can try yourself with ```diff - mock = new MockAdapter(axios); + mock = new MockAdapter(axios, { delayResponse: 10000 }); ``` (which leads to failing tests) [`spec/javascripts/blob/notebook/index_spec.js`]: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/spec/javascripts/blob/notebook/index_spec.js