If a has_many goes :through a belongs_to, and the foreign key of the belongs_to changes, then the has_many should be considered stale.

3 files changed, 68 insertions, 23 deletions

diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 1820f95261..cdde9a80d3 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -17,7 +17,7 @@ require 'models/essay'
 class BelongsToAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :developers, :projects, :topics,
            :developers_projects, :computers, :authors, :author_addresses,
-           :posts, :tags, :taggings, :comments
+           :posts, :tags, :taggings, :comments, :sponsors, :members
 
   def test_belongs_to
     Client.find(3).firm.name
@@ -488,39 +488,53 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_reassigning_the_parent_id_updates_the_object
-    original_parent = Firm.create! :name => "original"
-    updated_parent = Firm.create! :name => "updated"
+    client = companies(:second_client)
 
-    client = Client.new("client_of" => original_parent.id)
-    assert_equal original_parent, client.firm
-    assert_equal original_parent, client.firm_with_condition
-    assert_equal original_parent, client.firm_with_other_name
+    client.firm
+    client.firm_with_condition
+    firm_proxy                = client.send(:association_instance_get, :firm)
+    firm_with_condition_proxy = client.send(:association_instance_get, :firm_with_condition)
 
-    client.client_of = updated_parent.id
-    assert_equal updated_parent, client.firm
-    assert_equal updated_parent, client.firm_with_condition
-    assert_equal updated_parent, client.firm_with_other_name
+    assert !firm_proxy.stale_target?
+    assert !firm_with_condition_proxy.stale_target?
+    assert_equal companies(:first_firm), client.firm
+    assert_equal companies(:first_firm), client.firm_with_condition
+
+    client.client_of = companies(:another_firm).id
+
+    assert firm_proxy.stale_target?
+    assert firm_with_condition_proxy.stale_target?
+    assert_equal companies(:another_firm), client.firm
+    assert_equal companies(:another_firm), client.firm_with_condition
   end
 
   def test_polymorphic_reassignment_of_associated_id_updates_the_object
-    member1 = Member.create!
-    member2 = Member.create!
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+
+    sponsor.sponsorable
+    proxy = sponsor.send(:association_instance_get, :sponsorable)
+
+    assert !proxy.stale_target?
+    assert_equal members(:groucho), sponsor.sponsorable
 
-    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
-    assert_equal member1, sponsor.sponsorable
+    sponsor.sponsorable_id = members(:some_other_guy).id
 
-    sponsor.sponsorable_id = member2.id
-    assert_equal member2, sponsor.sponsorable
+    assert proxy.stale_target?
+    assert_equal members(:some_other_guy), sponsor.sponsorable
   end
 
   def test_polymorphic_reassignment_of_associated_type_updates_the_object
-    member1 = Member.create!
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
 
-    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
-    assert_equal member1, sponsor.sponsorable
+    sponsor.sponsorable
+    proxy = sponsor.send(:association_instance_get, :sponsorable)
 
-    sponsor.sponsorable_type = "Firm"
-    assert_not_equal member1, sponsor.sponsorable
-  end
+    assert !proxy.stale_target?
+    assert_equal members(:groucho), sponsor.sponsorable
+
+    sponsor.sponsorable_type = 'Firm'
 
+    assert proxy.stale_target?
+    assert_equal companies(:first_firm), sponsor.sponsorable
+  end
 end
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 a417345780..e98d178ff5 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -19,6 +19,7 @@ require 'models/book'
 require 'models/subscription'
 require 'models/categorization'
 require 'models/category'
+require 'models/essay'
 
 class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   fixtures :posts, :readers, :people, :comments, :authors, :categories,
@@ -534,4 +535,19 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, authors(:mary).categories.count
     assert_equal 1, authors(:mary).categories.general.count
   end
+
+  def test_has_many_through_belongs_to_should_update_when_the_through_foreign_key_changes
+    post = posts(:eager_other)
+
+    post.author_categorizations
+    proxy = post.send(:association_instance_get, :author_categorizations)
+
+    assert !proxy.stale_target?
+    assert_equal authors(:mary).categorizations.sort_by(&:id), post.author_categorizations.sort_by(&:id)
+
+    post.author_id = authors(:david).id
+
+    assert proxy.stale_target?
+    assert_equal authors(:david).categorizations.sort_by(&:id), post.author_categorizations.sort_by(&:id)
+  end
 end
diff --git a/activerecord/test/cases/associations/has_one_through_associations_test.rb b/activerecord/test/cases/associations/has_one_through_associations_test.rb
index f6365e0216..7d55d909a7 100644
--- a/activerecord/test/cases/associations/has_one_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_through_associations_test.rb
@@ -251,4 +251,19 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
       members(:groucho).club_through_many
     end
   end
+
+  def test_has_one_through_belongs_to_should_update_when_the_through_foreign_key_changes
+    minivan = minivans(:cool_first)
+
+    minivan.dashboard
+    proxy = minivan.send(:association_instance_get, :dashboard)
+
+    assert !proxy.stale_target?
+    assert_equal dashboards(:cool_first), minivan.dashboard
+
+    minivan.speedometer_id = speedometers(:second).id
+
+    assert proxy.stale_target?
+    assert_equal dashboards(:second), minivan.dashboard
+  end
 end