This code is meant to illustrate the issue described in cypress-io/cypress#781. The issue does look to be related to XHR requests that were initiated in one request but do not complete until just prior to the next test. To reproduce you'll need to use ruby, bundler, and yarn:
bundle installyarn install./app.rbto start the Sinatra appyarn run cypress open
When you run the cookies_spec.js you should see the first can login spec succeed and the second render logged out state fail. The work around that I am currently using is to do what others have suggested and introducing a visit into a afterEach hook that takes the browser to a non-existent page so as to ensure the browser window cancels out any pending XHR requests that may affect cookies (or localstrage for that matter, as was the case with our app). You can uncomment the afterEach line to see this workaround resolve the issue.