From dd00af35b3c0391c0b2027bbef4cb9afa6a47e53 Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Sat, 5 Sep 2020 17:37:28 +0900
Subject: [PATCH] Fix a false positive for `Style/ClassAndModuleChildren`

This PR fixes the following incorrect auto-correct for
`Style/ClassAndModuleChildren` when using cbase class name.

```console
% cat example.rb
class ::Foo
end

% bundle exec rubocop -A --only Style/ClassAndModuleChildren
(snip)

Inspecting 1 file
C

Offenses:

example.rb:1:7: C: [Corrected] Style/ClassAndModuleChildren: Use nested
module/class definitions instead of compact style.
class ::Foo
      ^^^^^

1 file inspected, 1 offense detected, 1 offense corrected

% cat example.rb
module
  class Foo
  end
end

% ruby -c example.rb
example.rb:3: syntax error, unexpected '\n', expecting '.' or &. or ::
or '['
```
---
 CHANGELOG.md                                             | 1 +
 lib/rubocop/cop/style/class_and_module_children.rb       | 1 +
 spec/rubocop/cop/style/class_and_module_children_spec.rb | 7 +++++++
 3 files changed, 9 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46254b1fb36..4a0743aeea4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 * [#8627](https://github.com/rubocop-hq/rubocop/issues/8627): Fix a false positive for `Lint/DuplicateRequire` when same feature argument but different require method. ([@koic][])
 * [#8572](https://github.com/rubocop-hq/rubocop/issues/8572): Fix a false positive for `Style/RedundantParentheses` when parentheses are used like method argument parentheses. ([@koic][])
 * [#8653](https://github.com/rubocop-hq/rubocop/pull/8653): Fix a false positive for `Layout/DefEndAlignment` when using refinements and `private def`. ([@koic][])
+* [#8655](https://github.com/rubocop-hq/rubocop/pull/8655): Fix a false positive for `Style/ClassAndModuleChildren` when using cbase class name. ([@koic][])
 
 ### Changes
 
diff --git a/lib/rubocop/cop/style/class_and_module_children.rb b/lib/rubocop/cop/style/class_and_module_children.rb
index 9bc5d1ca638..294eb011ad1 100644
--- a/lib/rubocop/cop/style/class_and_module_children.rb
+++ b/lib/rubocop/cop/style/class_and_module_children.rb
@@ -32,6 +32,7 @@ class ClassAndModuleChildren < Base
                       'nested style.'
 
         def on_class(node)
+          return if node.identifier.children[0]&.cbase_type?
           return if node.parent_class && style != :nested
 
           check_style(node, node.body)
diff --git a/spec/rubocop/cop/style/class_and_module_children_spec.rb b/spec/rubocop/cop/style/class_and_module_children_spec.rb
index a78a9a438bf..a8a5527996d 100644
--- a/spec/rubocop/cop/style/class_and_module_children_spec.rb
+++ b/spec/rubocop/cop/style/class_and_module_children_spec.rb
@@ -60,6 +60,13 @@ module BarModule
       RUBY
     end
 
+    it 'accepts cbase class name' do
+      expect_no_offenses(<<~RUBY)
+        class ::Foo
+        end
+      RUBY
+    end
+
     it 'accepts :: in parent class on inheritance' do
       expect_no_offenses(<<~RUBY)
         class FooClass