I'd disagree it needs end-to-end. Testing that proper sleep calls are made followed by an error can be done in unit tests. Unit tests already mock network call

I'd disagree it needs end-to-end. Testing that proper sleep calls are made followed by an error can be done in unit tests. Unit tests already mock network calls so create mocks to return errors instead. https://news.ycombinator.com/item?id=49384968 https://news.ycombinator.com/item?id=49384968