Remove useless Layout/SpaceAfterColon Cop

[AdrienSdy]

Is your feature request related to a problem? Please describe.

The Layout/SpaceAfterColon, checks space needed between colon and value in ruby 1.9 hash syntax. It's already check with Layout/AlignHash.
Each style describe in this latter cop guarantee at least one space between separators and values.

Also since #6649 release in 0.70.0 (2019-05-21), user can choose multiple alignement style, reinforcing the feeling than the Layout/SpaceAfterColon cop is become useless.

Describe the solution you'd like

Remove this cop which has become useless.

---

What do you think ?

[koic]

I think that roles of Layout/SpaceAfterColon cop and Layout/AlignHash cop are different.

Layout/AlignHash cop is a cop for Hash style. For example, Layout/SpaceAfterColon cop has detected a kwargs. This is not detected by Layout/AlignHash cop.

% cat example.rb
# frozen_string_literal: true

def m(foo:1, bar:2)
end

% rubocop
Inspecting 1 file
C

Offenses:

example.rb:3:1: C: Style/EmptyMethod: Put empty method definitions on a single line.
def m(foo:1, bar:2) ...
^^^^^^^^^^^^^^^^^^^
example.rb:3:10: C: Layout/SpaceAfterColon: Space missing after colon.
def m(foo:1, bar:2)
         ^
example.rb:3:17: C: Layout/SpaceAfterColon: Space missing after colon.
def m(foo:1, bar:2)
                ^

1 file inspected, 3 offenses detected

It can not be detected when Layout/SpaceAfterColon is disabled.

% cat .rubocop.yml
Layout/SpaceAfterColon:
  Enabled: false

% rubocop
Inspecting 1 file
C

Offenses:

example.rb:3:1: C: Style/EmptyMethod: Put empty method definitions on a single line.
def m(foo:1, bar:2) ...
^^^^^^^^^^^^^^^^^^^

1 file inspected, 1 offense detected

So Layout/SpaceAfterColon cop cannot be removed as it works.

[AdrienSdy]

@koic

You agree, I forgot to check the inline hash.