Kasper Timm Hansen cea392eb96 Polymorphic has_one touch: Reset association cache result after create transaction ... In case of a polymorphic association there's no automatic inverse_of to assign the inverse record. So to get the record there needs to be a query executed, however, if the query fires within the transaction that's trying to create the associated record, no record can be found. And worse, the nil result is cached on the association so after the transaction commits the record can't be found. That's what happens if touch is enabled on a polymorphic has_one association. Consider a Comment with a commentable association that needs to be touched. For `Comment.create(commentable: Post.new)`, the existing code essentially does `commentable.send(:comment)` within the create transaction for the comment and thus not finding the comment. Now we're purposefully clearing the cache in case we've tried accessing the association within the transaction and found no object. Before: ``` kaspth-imac 2.6.3 ~/code/rails/activerecord master *= ARCONN=postgresql bin/test test/cases/associations/has_one_associations_test.rb -n /commit/ Using postgresql Run options: -n /commit/ --seed 46022 D, [2019-07-19T03:30:37.864537 #96022] DEBUG -- : Chef Load (0.2ms) SELECT "chefs".* FROM "chefs" WHERE "chefs"."employable_id" = $1 AND "chefs"."employable_type" = $2 LIMIT $3 [["employable_id", 1], ["employable_type", "DrinkDesignerWithPolymorphicTouchChef"], ["LIMIT", 1]] D, [2019-07-19T03:30:37.865013 #96022] DEBUG -- : Chef Create (0.2ms) INSERT INTO "chefs" ("employable_id", "employable_type") VALUES ($1, $2) RETURNING "id" [["employable_id", 1], ["employable_type", "DrinkDesignerWithPolymorphicTouchChef"]] D, [2019-07-19T03:30:37.865201 #96022] DEBUG -- : TRANSACTION (0.1ms) RELEASE SAVEPOINT active_record_1 D, [2019-07-19T03:30:37.874136 #96022] DEBUG -- : TRANSACTION (0.1ms) ROLLBACK D, [2019-07-19T03:30:37.874323 #96022] DEBUG -- : TRANSACTION (0.1ms) ROLLBACK F Failure: HasOneAssociationsTest#test_polymorphic_has_one_with_touch_option_on_create_wont_cache_assocation_so_fetching_after_transaction_commit_works [/Users/kaspth/code/rails/activerecord/test/cases/associations/has_one_associations_test.rb:716]: --- expected +++ actual @@ -1 +1 @@ -#<Chef id: 1, employable_id: 1, employable_type: "DrinkDesignerWithPolymorphicTouchChef", department_id: nil, employable_list_type: nil, employable_list_id: nil> +nil ``` After: ``` kaspth-imac 2.6.3 ~/code/rails/activerecord master *= ARCONN=postgresql bin/test test/cases/associations/has_one_associations_test.rb -n /commit/ Using postgresql Run options: -n /commit/ --seed 46022 D, [2019-07-19T03:30:22.479387 #95973] DEBUG -- : Chef Create (0.3ms) INSERT INTO "chefs" ("employable_id", "employable_type") VALUES ($1, $2) RETURNING "id" [["employable_id", 1], ["employable_type", "DrinkDesignerWithPolymorphicTouchChef"]] D, [2019-07-19T03:30:22.479574 #95973] DEBUG -- : TRANSACTION (0.1ms) RELEASE SAVEPOINT active_record_1 D, [2019-07-19T03:30:22.482051 #95973] DEBUG -- : Chef Load (0.1ms) SELECT "chefs".* FROM "chefs" WHERE "chefs"."employable_id" = $1 AND "chefs"."employable_type" = $2 LIMIT $3 [["employable_id", 1], ["employable_type", "DrinkDesignerWithPolymorphicTouchChef"], ["LIMIT", 1]] D, [2019-07-19T03:30:22.482317 #95973] DEBUG -- : TRANSACTION (0.1ms) ROLLBACK D, [2019-07-19T03:30:22.482437 #95973] DEBUG -- : TRANSACTION (0.1ms) ROLLBACK . Finished in 0.088498s, 11.2997 runs/s, 22.5994 assertions/s. 1 runs, 2 assertions, 0 failures, 0 errors, 0 skips ``` Notice the select now fires after the commit.		2019-07-31 05:59:23 +02:00
..
mysql2_specific_schema.rb	MySQL: Fix schema dumping enum and set columns correctly	2019-07-05 18:42:41 +09:00
oracle_specific_schema.rb	Use squiggly heredoc to strip odd indentation in the executed SQL	2018-11-22 19:43:53 +09:00
postgresql_specific_schema.rb	Enable Layout/EmptyLinesAroundBlockBody to reduce review cost in the future	2018-07-12 21:29:48 +09:00
schema.rb	Polymorphic has_one touch: Reset association cache result after create transaction	2019-07-31 05:59:23 +02:00
sqlite_specific_schema.rb	add mysql and sqlite3 default test	2018-09-01 22:09:01 -04:00