1 files changed, 27 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb
new file mode 100644
index 0000000000..ed313fc9d4
--- /dev/null
+++ b/activerecord/lib/active_record/relation/predicate_builder/class_handler.rb
@@ -0,0 +1,27 @@
+module ActiveRecord
+  class PredicateBuilder
+    class ClassHandler # :nodoc:
+      def initialize(predicate_builder)
+        @predicate_builder = predicate_builder
+      end
+
+      def call(attribute, value)
+        print_deprecation_warning
+        predicate_builder.build(attribute, value.name)
+      end
+
+      protected
+
+      attr_reader :predicate_builder
+
+      private
+
+      def print_deprecation_warning
+        ActiveSupport::Deprecation.warn(<<-MSG.squish)
+          Passing a class as a value in an Active Record query is deprecated and
+          will be removed. Pass a string instead.
+        MSG
+      end
+    end
+  end
+end