In functional, statically typed programmings languages, there is a pattern where business logic, including "actions", is encoded in types. This article [1] gives an example of filesystem manipulations that are encoded in a "FreeF" type.

When business rules are encoded in datatypes, it's easy to check that the encoding and the transformations are complete, and the logic can easily be mock-tested.

[1] http://degoes.net/articles/modern-fp