Ruby - How to highlight public interface definition about guides HOT 5 CLOSED

HI @petrachi - thank you for this discussion on public / private method organization!

To answer the question "how does thoughtbot do this" - we separate public and private methods like in your first example:

class MyClass
  def a_public_method
  end

  private

  def a_private_method
  end
end

I think the other ways of separating public and private methods that you show are interesting, but I think the reasoning behind them is flawed. You say "The problem is as the class becomes bigger, the split between public and private becomes less and less visible. (And sometimes you have big, enormous classes, and no time to refactor)"

While this is certainly the case, I think it is a mistake to develop a coding style that makes it easier to write big fat Ruby classes. I know what you mean about private methods getting buried when classes are long. But, if you do your best to break out smaller classes (Sandi Metz suggests classes be no more than 100 lines) then the problem will be solved.

So I guess my perspective on this is that the public / private divide is not a problem. And if a developer does not have time to refactor large classes, that is going to lead to even bigger problems down the road.

Thanks again for this thoughtful explanation. I will leave this issue open for others to weigh in on.

from guides.

That's a great summary, Jessie. I agree with all of your points.

from guides.

Hi, thanks for your response.

I understand now that class should be small, and that code guidelines should prevent against creating big classes.

For me, the problem is that the application I'm working on is seven years old, and it is just recently that we learn about programmation design (like the Sandi Metz recommandations about class length). So we have a lot of legacy code, not time or ressources to refactor them all today, and they are a pain to work with.

So the thing I'm looking for is probably not to include into a guideline, but a temporary solution to know how to deal with public interface visibility in classes that are 1500 lines long. How would you do it, and do you have better ideas than what I exposed earlier ?

from guides.

@petrachi prepending an underscore to the private method names doesn't hurt readability that much IMO (especially if you have a Python background). If I was in your situation, I would combine the best practice of private below public with the naming convention.

class MyClass
  def public_method
  end

  private

  def _private_method
  end

  def _another_private_method
  end
end

Under normal circumstances I would follow @jessieay's advice.

from guides.

I'm going to close this, as it doesn't seem like we're going to make a change to the guides based on this discussion.

from guides.