Personally, I do end-to-end tests for some basic cases just to make sure everything works together.
But most of the tests are more fine-grained. So in your example, I'd test the core logic against fake Facebook API responses and a fake outgoing email call. That lets me easily test some of the weirder cases. E.g. if Facebook breaks, will the job skip that user and keep going rather than blowing up?
But most of the tests are more fine-grained. So in your example, I'd test the core logic against fake Facebook API responses and a fake outgoing email call. That lets me easily test some of the weirder cases. E.g. if Facebook breaks, will the job skip that user and keep going rather than blowing up?