From e617fb57f5a388d5f0a47fd5e576588dd10066b0 Mon Sep 17 00:00:00 2001 From: Ryuta Kamizono Date: Mon, 30 Oct 2017 23:55:48 +0900 Subject: Fix preloading polymorphic association when through association has already loaded If through association has already loaded, `source_type` is ignored to loaded through records. The loaded records should be filtered by `source_type` in that case. Fixes #30904. --- .../associations/preloader/through_association.rb | 20 ++++++++++++++++---- .../associations/nested_through_associations_test.rb | 11 +++++++++++ 2 files changed, 27 insertions(+), 4 deletions(-) (limited to 'activerecord') diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb index fa32cc5553..5bd49b041a 100644 --- a/activerecord/lib/active_record/associations/preloader/through_association.rb +++ b/activerecord/lib/active_record/associations/preloader/through_association.rb @@ -13,18 +13,30 @@ module ActiveRecord end def associated_records_by_owner(preloader) + already_loaded = owners.first.association(through_reflection.name).loaded? through_scope = through_scope() - preloader.preload(owners, - through_reflection.name, - through_scope) + unless already_loaded + preloader.preload(owners, through_reflection.name, through_scope) + end through_records = owners.map do |owner| center = owner.association(through_reflection.name).target [owner, Array(center)] end - reset_association(owners, through_reflection.name, through_scope) + if already_loaded + if source_type = reflection.options[:source_type] + through_records.map! do |owner, center| + center = center.select do |record| + record[reflection.foreign_type] == source_type + end + [owner, center] + end + end + else + reset_association(owners, through_reflection.name, through_scope) + end middle_records = through_records.flat_map(&:last) diff --git a/activerecord/test/cases/associations/nested_through_associations_test.rb b/activerecord/test/cases/associations/nested_through_associations_test.rb index 4cf5a9ffc4..11ee45917f 100644 --- a/activerecord/test/cases/associations/nested_through_associations_test.rb +++ b/activerecord/test/cases/associations/nested_through_associations_test.rb @@ -579,6 +579,17 @@ class NestedThroughAssociationsTest < ActiveRecord::TestCase assert !c.post_taggings.empty? end + def test_polymorphic_has_many_through_when_through_association_has_already_loaded + cake_designer = CakeDesigner.create!(chef: Chef.new) + drink_designer = DrinkDesigner.create!(chef: Chef.new) + department = Department.create!(chefs: [cake_designer.chef, drink_designer.chef]) + Hotel.create!(departments: [department]) + hotel = Hotel.includes(:chefs, :cake_designers, :drink_designers).take + + assert_equal [cake_designer], hotel.cake_designers + assert_equal [drink_designer], hotel.drink_designers + end + def test_polymorphic_has_many_through_joined_different_table_twice cake_designer = CakeDesigner.create!(chef: Chef.new) drink_designer = DrinkDesigner.create!(chef: Chef.new) -- cgit v1.2.3