From bc6ac8609cf79f28047c0928b9433e00e6ea1f09 Mon Sep 17 00:00:00 2001 From: Sean Griffin Date: Tue, 30 Jun 2015 09:53:56 -0700 Subject: Correct through associations using scopes The changes introduced to through associations in c80487eb were quite interesting. Changing `relation.merge!(scope)` to `relation = relation.merge(scope)` should in theory never cause any changes in behavior. The subtle breakage led to a surprising conclusion. The old code wasn't doing anything! Since `merge!` calls `instance_exec` when given a proc, and most scopes will look something like `has_many :foos, -> { where(foo: :bar) }`, if we're not capturing the return value, it's a no-op. However, removing the `merge` causes `unscope` to break. While we're merging in the rest of the chain elsewhere, we were never merging in `unscope` values, causing a breakage on associations where a default scope was being unscoped in an association scope (yuk!). This is subtly related to #20722, since it appears we were previously relying on this mutability. Fixes #20721. Fixes #20727. --- .../test/cases/associations/has_many_through_associations_test.rb | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'activerecord/test/cases/associations/has_many_through_associations_test.rb') diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb index 1d545af5a5..c34387f06d 100644 --- a/activerecord/test/cases/associations/has_many_through_associations_test.rb +++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb @@ -1158,4 +1158,11 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase post_through = organization.posts.build assert_equal post_direct.author_id, post_through.author_id end + + def test_has_many_through_with_scope_that_should_not_be_fully_merged + Club.has_many :distinct_memberships, -> { distinct }, class_name: "Membership" + Club.has_many :special_favourites, through: :distinct_memberships, source: :member + + assert_nil Club.new.special_favourites.distinct_value + end end -- cgit v1.2.3