> Test-first units leads to an overly complex web of intermediary objects and indirection in order to avoid doing anything that's "slow". Like hitting the database. Or file IO. Or going through the browser to test the whole system. It's given birth to some truly horrendous monstrosities of architecture. A dense jungle of service objects, command patterns, and worse.
Maybe your name is David, and you don't do test-first programming, and neither do I for that matter. But don't think for a second that separation of concerns is an artifact of TDD. And yes, having a service layer is a good thing. Even if you're doing a TODO app.
Fast forward to today, Rails Controllers become the API which other interfaces can consume via JSON, XML, or even HTML or simply stream of texts if configured.
If you can dictates that "here's an endpoint that you can poke, I will not provide WS-*" (in other words: you can dictate the requirements), then there's no need for a service layer.
Uh. In any complex application, you write services which are responsible for various business needs, and whose responsibilities only loosely overlap the way your webapp is accessed from the outside. You may even have services only used by other services.
And obviously, stuffing your business logic along with your web glue (whatever concrete representation you're sending to the outside, you're still stuffing parameters in a template, essentially) still violates SRP. Not to mention that it makes it utterly impossible to reuse outside of your web application, something which is sometimes desirable.
I don't disagree with you. In fact, I am writing those services whether it is for the API component or in the web glue on projects I worked on.
I'm just pointing out that there are a fraction of Rails crowd that don't think these services are needed is partly because of how things work in Rails.
Maybe your name is David, and you don't do test-first programming, and neither do I for that matter. But don't think for a second that separation of concerns is an artifact of TDD. And yes, having a service layer is a good thing. Even if you're doing a TODO app.