1 files changed, 29 insertions, 0 deletions
diff --git a/rubocop/cop/ruby_interpolation_in_translation.rb b/rubocop/cop/ruby_interpolation_in_translation.rb
new file mode 100644
index 00000000000..b9411fcfd6c
--- /dev/null
+++ b/rubocop/cop/ruby_interpolation_in_translation.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    class RubyInterpolationInTranslation < RuboCop::Cop::Cop
+      MSG = "Don't use ruby interpolation \#{} inside translated strings, instead use \%{}"
+
+      TRANSLATION_METHODS = ':_ :s_ :N_ :n_'
+      RUBY_INTERPOLATION_REGEX = /.*\#\{.*\}/
+
+      def_node_matcher :translation_method?, <<~PATTERN
+        (send nil? {#{TRANSLATION_METHODS}} $dstr ...)
+      PATTERN
+
+      def_node_matcher :plural_translation_method?, <<~PATTERN
+        (send nil? :n_ str $dstr ...)
+      PATTERN
+
+      def on_send(node)
+        interpolation = translation_method?(node) || plural_translation_method?(node)
+        return unless interpolation
+
+        interpolation.descendants.each do |possible_violation|
+          add_offense(possible_violation, message: MSG) if possible_violation.type != :str
+        end
+      end
+    end
+  end
+end