Setting the id of a belongs_to object updates all referenced objects [#2989 state:resolved]

1 files changed, 37 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 1b0c00bd5a..1820f95261 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -486,4 +486,41 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     new_firm = accounts(:signals37).build_firm(:name => 'Apple')
     assert_equal new_firm.name, "Apple"
   end
+
+  def test_reassigning_the_parent_id_updates_the_object
+    original_parent = Firm.create! :name => "original"
+    updated_parent = Firm.create! :name => "updated"
+
+    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.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
+  end
+
+  def test_polymorphic_reassignment_of_associated_id_updates_the_object
+    member1 = Member.create!
+    member2 = Member.create!
+
+    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
+    assert_equal member1, sponsor.sponsorable
+
+    sponsor.sponsorable_id = member2.id
+    assert_equal member2, sponsor.sponsorable
+  end
+
+  def test_polymorphic_reassignment_of_associated_type_updates_the_object
+    member1 = Member.create!
+
+    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
+    assert_equal member1, sponsor.sponsorable
+
+    sponsor.sponsorable_type = "Firm"
+    assert_not_equal member1, sponsor.sponsorable
+  end
+
 end