1 files changed, 46 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb b/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb
new file mode 100644
index 0000000000..28c7483c95
--- /dev/null
+++ b/activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  class PredicateBuilder
+    class AssociationQueryValue # :nodoc:
+      def initialize(associated_table, value)
+        @associated_table = associated_table
+        @value = value
+      end
+
+      def queries
+        [associated_table.association_join_foreign_key.to_s => ids]
+      end
+
+      # TODO Change this to private once we've dropped Ruby 2.2 support.
+      # Workaround for Ruby 2.2 "private attribute?" warning.
+      protected
+        attr_reader :associated_table, :value
+
+      private
+        def ids
+          case value
+          when Relation
+            value.select_values.empty? ? value.select(primary_key) : value
+          when Array
+            value.map { |v| convert_to_id(v) }
+          else
+            convert_to_id(value)
+          end
+        end
+
+        def primary_key
+          associated_table.association_join_primary_key
+        end
+
+        def convert_to_id(value)
+          case value
+          when Base
+            value._read_attribute(primary_key)
+          else
+            value
+          end
+        end
+    end
+  end
+end