1 files changed, 51 insertions, 0 deletions
diff --git a/rubocop/cop/api/ensure_string_detail.rb b/rubocop/cop/api/ensure_string_detail.rb
new file mode 100644
index 00000000000..bc999525055
--- /dev/null
+++ b/rubocop/cop/api/ensure_string_detail.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require_relative '../../code_reuse_helpers'
+
+module RuboCop
+  module Cop
+    module API
+      class EnsureStringDetail < RuboCop::Cop::Base
+        include CodeReuseHelpers
+
+        # This cop checks that API detail entries use Strings
+        #
+        # https://gitlab.com/gitlab-org/gitlab/-/issues/379037
+        #
+        # @example
+        #
+        # # bad
+        # detail ['Foo bar baz bat', 'http://example.com']
+        #
+        # # good
+        # detail 'Foo bar baz bat. http://example.com'
+        #
+        # end
+        #
+        MSG = 'Only String objects are permitted in API detail field.'
+
+        def_node_matcher :detail_in_desc, <<~PATTERN
+          (block
+            (send nil? :desc ...)
+            _args
+            `(send nil? :detail $_ ...)
+          )
+        PATTERN
+
+        RESTRICT_ON_SEND = %i[detail].freeze
+
+        def on_send(node)
+          return unless in_api?(node)
+
+          parent = node.each_ancestor(:block).first
+          detail_arg = detail_in_desc(parent)
+
+          return unless detail_arg
+          return if [:str, :dstr].include?(detail_arg.type)
+
+          add_offense(node)
+        end
+      end
+    end
+  end
+end