1 files changed, 23 insertions, 0 deletions
diff --git a/rubocop/cop/polymorphic_associations.rb b/rubocop/cop/polymorphic_associations.rb
new file mode 100644
index 00000000000..7d554704550
--- /dev/null
+++ b/rubocop/cop/polymorphic_associations.rb
@@ -0,0 +1,23 @@
+require_relative '../model_helpers'
+
+module RuboCop
+  module Cop
+    # Cop that prevents the use of polymorphic associations
+    class PolymorphicAssociations < RuboCop::Cop::Cop
+      include ModelHelpers
+
+      MSG = 'Do not use polymorphic associations, use separate tables instead'.freeze
+
+      def on_send(node)
+        return unless in_model?(node)
+        return unless node.children[1] == :belongs_to
+
+        node.children.last.each_node(:pair) do |pair|
+          key_name = pair.children[0].children[0]
+
+          add_offense(pair, :expression) if key_name == :polymorphic
+        end
+      end
+    end
+  end
+end