> architectural patterns that exist only/mainly to make unit testing easier? > try to encapsulate as much logic as I can into pure functions These are one and

> architectural patterns that exist only/mainly to make unit testing easier? > try to encapsulate as much logic as I can into pure functions These are one and the same. The suggestion may as well have been "the IO monad is hard to test, so move as much code as you can out into pure functions"