Cop that checks class structure

[bbatsov]

This is probably one of the most important rules in the style guide that lacks a cop.

P.S. We should probably create a list of rules that we're not currently enforcing.

[d4rk5eed]

+1
What about duplicate methods?

class A
  def method
     #legacy implementation
  end
  def method
     #new implementation
  end
end

[bbatsov]

@d4rk5eed Yeah, such a cop would be useful (and very easy to implement).

[alexdowad]

I don't like the "enforced class structure". I prefer to group methods/constants/etc. according to what they are used for, not put them in a rigid order which doesn't reflect their meaning.

The "duplicate method" cop is a good idea; I'll add one right now.

[alexdowad]

OK, it turns out we already had a "duplicate method" cop... but I just gave it a major upgrade. Have a look at the open PR.

[bbatsov]

I don't like the "enforced class structure". I prefer to group methods/constants/etc. according to what they are used for, not put them in a rigid order which doesn't reflect their meaning.

I don't think the order conveys that much meaning. I've been applying exactly the same structure in my classes for as long as I can remember and this makes it really easy for me to get my bearings. For me this is one of the most important cops that's still missing.

[alexdowad]

I've implemented a Style/ClassStructure cop.

One thing I have found is that the rule about nested classes is a prime source of false positives. Many classes may have a "helper" class which is tucked down at the bottom of the class body. The style guide's order forces these nested classes to be pulled up to the top, above the methods which actually use them.

[bbatsov]

Well, this can always be made configurable.

[bbatsov]

@alexdowad Btw, what happened to this cop? I thought it was going to get a PR of its own.

[alexdowad]

@bbatsov I'm not interested in working on it further. There are better things to work on. So I haven't opened another PR.

[bbatsov]

Got it.

[yob]

Even though it'd need more work, is the cop available on branch somewhere? I'd be interested in running it over our code base to see what happens.

[bbatsov]

It's here - alexdowad@acf7a72