Add new Layout/EmptyLinesAroundArguments Cop

[garettarrowood]

While applying a fix for issue #5052 in PR #5066 , it was discovered that the autocorrection for Style/BracesArondHashParameters is a little aggressive. When I applied changes to stop it from removing legitimate \ns, it created snippets similar to the example below.

Adding this EmptyLine Cop would resolve this scenario and still allow Style/BracesArondHashParameters autocorrection to be improved to cleaner results. The cleaner results I refer to our found in this example, this example and this example.

---

Desired behavior

For this code snippet register a Stlye/EmptyLinesAroundArguments offense.

foo(

  bar: 1

)

Then, autocorrect that snippet to:

foo(
  bar: 1
)

Actual behavior

Above snippet registers no offense.

Steps to reproduce the problem

See above.

RuboCop version

0.51.0 (using Parser 2.4.0.0, running on ruby 2.3.3 x86_64-darwin15)

[Drenmi]

This cop should go in the Layout department, not Style. 🙂

[deepj]

Hm, it seems this doesn't work properly. I have something like

# frozen_string_literal: true

require 'csv'
require_relative '../../importer/base'

module Labels
  module Csv
    class Import < Importer::Base

And that issue occurs on

app/services/labels/csv/import.rb:4:1: C: Layout/EmptyLinesAroundArguments: Empty line detected around arguments.
require_relative '../../importer/base'
^
app/services/labels/csv/import.rb:7:1: C: Layout/EmptyLinesAroundArguments: Empty line detected around arguments.
  module Csv

I guess this is not expected behaviour...

[fotinakis]

We also got this cop triggered on a require line. (and the require line had an underscore in it, similar to the above)

[zhisme]

I also had this cop offense in this example.

# bad
config.enabled = Rails.env.in?(%w[production staging])

C: Layout/EmptyLinesAroundArguments: Empty line detected around arguments.

# good
config.enabled = Rails.env.in?(
    %w[production staging]
    )

no offense