From 8987cda2bb64fe289f7a28b2833a2786cfbc8259 Mon Sep 17 00:00:00 2001 From: Jon Leighton Date: Fri, 4 Mar 2011 22:29:40 +0000 Subject: When preloading has_and_belongs_to_many associations, we should only instantiate one AR object per actual record in the database. (Even when IM is off.) --- activerecord/test/cases/associations/eager_test.rb | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'activerecord/test/cases') diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb index 26808ae931..48406a9b98 100644 --- a/activerecord/test/cases/associations/eager_test.rb +++ b/activerecord/test/cases/associations/eager_test.rb @@ -525,6 +525,22 @@ class EagerAssociationTest < ActiveRecord::TestCase assert posts[1].categories.include?(categories(:general)) end + # This is only really relevant when the identity map is off. Since the preloader for habtm + # gets raw row hashes from the database and then instantiates them, this test ensures that + # it only instantiates one actual object per record from the database. + def test_has_and_belongs_to_many_should_not_instantiate_same_records_multiple_times + welcome = posts(:welcome) + categories = Category.includes(:posts) + + general = categories.find { |c| c == categories(:general) } + technology = categories.find { |c| c == categories(:technology) } + + post1 = general.posts.to_a.find { |p| p == posts(:welcome) } + post2 = technology.posts.to_a.find { |p| p == posts(:welcome) } + + assert_equal post1.object_id, post2.object_id + end + def test_eager_with_has_many_and_limit_and_conditions_on_the_eagers posts = authors(:david).posts.find(:all, :include => :comments, -- cgit v1.2.3