1 files changed, 43 insertions, 0 deletions
diff --git a/lib/rubocop/cop/style/array_literal_delimiter.rb b/lib/rubocop/cop/style/array_literal_delimiter.rb
new file mode 100644
index 00000000000..1b0638ce26c
--- /dev/null
+++ b/lib/rubocop/cop/style/array_literal_delimiter.rb
@@ -0,0 +1,43 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Style
+      # This cop enforces square brackets for Array literal `%`-style
+      # delimiters.
+      #
+      # @example
+      #
+      #   # bad
+      #   %w(foo bar) + %w{baz qux}
+      #
+      #   # good
+      #   %w[foo bar] + %w[baz qux]
+      class ArrayLiteralDelimiter < RuboCop::Cop::Cop
+        def on_array(*args)
+          array = args.first
+
+          first, last = array.loc.begin, array.loc.end
+
+          return unless first && last
+          return unless first.source.start_with?('%')
+
+          return if first.source.start_with?('%w[', '%W[', '%i[', '%I[') &&
+            last.source == ']'
+
+          add_offense(array, :expression, "TODO")
+        end
+
+        def autocorrect(node)
+          -> (corrector) do
+            style = node.loc.begin.source[0..-2]
+
+            corrector.replace(node.loc.begin, "#{style}[")
+            corrector.replace(node.loc.end, ']')
+          end
+        end
+      end
+    end
+  end
+end