Lint/NonLocalExitFromIterator false positive

[zachlatta]

I think I'm get a false positive from Lint/NonLocalExitFromIterator in the below code:

VCR.configure do |c|
  # ...

  def server_cookies(response)
    raw_cookies = response.headers['Set-Cookie']
    return if raw_cookies.nil? || raw_cookies.empty?

    raw_cookies.map { |ck| parse_server_cookie(ck) }
  end
end

---

Expected behavior

No flags should be raised.

Actual behavior

It's flagged with:

W: Non-local exit from iterator, without return value. next, break, Array#find, Array#any?, etc. is preferred.

Curiously, this only seems to happen when there's a block argument specified in the VCR.configure block – try omitting |c| to see what I mean.

Steps to reproduce the problem

1. Create a file with the above code snippet as its contents
2. Run Rubocop on it

RuboCop version

Include the output of rubocop -V. Here's an example:

bundle exec rubocop -V
0.46.0 (using Parser 2.3.3.1, running on ruby 2.3.1 x86_64-linux)

[Drenmi]

Nice find @zachlatta! I think the reason we've missed this is that it's a pretty uncommon (at least to me) edge case. But there's no reason why we couldn't account for this, that I can see. 😀

[bbatsov]

Yeah, that should be easy to fix.