Replaces `tag: true` into `:tag` in the specs

Replaces all the explicit include metadata syntax in the specs (tag:
true) into the implicit one (:tag).
Added a cop to prevent future errors and handle autocorrection.

2 files changed, 75 insertions, 0 deletions

diff --git a/rubocop/cop/rspec/verbose_include_metadata.rb b/rubocop/cop/rspec/verbose_include_metadata.rb
new file mode 100644
index 00000000000..58390622d60
--- /dev/null
+++ b/rubocop/cop/rspec/verbose_include_metadata.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+require 'rubocop-rspec'
+
+module RuboCop
+  module Cop
+    module RSpec
+      # Checks for verbose include metadata used in the specs.
+      #
+      # @example
+      #   # bad
+      #   describe MyClass, js: true do
+      #   end
+      #
+      #   # good
+      #   describe MyClass, :js do
+      #   end
+      class VerboseIncludeMetadata < Cop
+        MSG = 'Use `%s` instead of `%s`.'
+
+        SELECTORS = %i[describe context feature example_group it specify example scenario its].freeze
+
+        def_node_matcher :include_metadata, <<-PATTERN
+          (send {(const nil :RSpec) nil} {#{SELECTORS.map(&:inspect).join(' ')}}
+            !const
+            ...
+            (hash $...))
+        PATTERN
+
+        def_node_matcher :invalid_metadata?, <<-PATTERN
+          (pair
+            (sym $...)
+            (true))
+        PATTERN
+
+        def on_send(node)
+          invalid_metadata_matches(node) do |match|
+            add_offense(node, :expression, format(MSG, good(match), bad(match)))
+          end
+        end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            invalid_metadata_matches(node) do |match|
+              corrector.replace(match.loc.expression, good(match))
+            end
+          end
+        end
+
+        private
+
+        def invalid_metadata_matches(node)
+          include_metadata(node) do |matches|
+            matches.select(&method(:invalid_metadata?)).each do |match|
+              yield match
+            end
+          end
+        end
+
+        def bad(match)
+          "#{metadata_key(match)}: true"
+        end
+
+        def good(match)
+          ":#{metadata_key(match)}"
+        end
+
+        def metadata_key(match)
+          match.children[0].source
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb
index 1b6e8991a17..1df23899efb 100644
--- a/rubocop/rubocop.rb
+++ b/rubocop/rubocop.rb
@@ -21,3 +21,4 @@ require_relative 'cop/migration/reversible_add_column_with_default'
 require_relative 'cop/migration/timestamps'
 require_relative 'cop/migration/update_column_in_batches'
 require_relative 'cop/rspec/single_line_hook'
+require_relative 'cop/rspec/verbose_include_metadata'