Some developers argue on the real value of testing Rake tasks since they’re only used once or on rare particular occasions. Others think it’s enough to extract all the logic out of them to properly tested objects (we’ll look into that later). Before fully diving into the question of how to test them (and if it’s really worth it), we’ll take a quick look at Rake tasks themselves.

https://blog.10pines.com/2019/01/14/testing-rake-tasks/