Pass the attribute and option hashes to build_association

The build_association method was added as an API for plugins
to hook into in 1398db0. This commit restores this API and the
ability to override class.new to return a subclass based on
a virtual attribute in the attributes hash.

2 files changed, 29 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 0e33fa9c8e..522ac56d82 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1455,4 +1455,17 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
 
     assert_equal "RED!", car.bulbs.to_a.first.color
   end
+
+  def test_new_is_called_with_attributes_and_options
+    car = Car.create(:name => 'honda')
+
+    bulb = car.bulbs.build
+    assert_equal Bulb, bulb.class
+
+    bulb = car.bulbs.build(:bulb_type => :custom)
+    assert_equal Bulb, bulb.class
+
+    bulb = car.bulbs.build({ :bulb_type => :custom }, :as => :admin)
+    assert_equal CustomBulb, bulb.class
+  end
 end
diff --git a/activerecord/test/cases/associations/has_one_associations_test.rb b/activerecord/test/cases/associations/has_one_associations_test.rb
index 356a4a7a09..38e622f90f 100644
--- a/activerecord/test/cases/associations/has_one_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_associations_test.rb
@@ -410,4 +410,20 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     bulb = car.create_frickinawesome_bulb(:frickinawesome => false)
     assert_equal true, bulb.frickinawesome?
   end
+
+  def test_new_is_called_with_attributes_and_options
+    car = Car.create(:name => 'honda')
+
+    bulb = car.build_bulb
+    assert_equal Bulb, bulb.class
+
+    bulb = car.build_bulb
+    assert_equal Bulb, bulb.class
+
+    bulb = car.build_bulb(:bulb_type => :custom)
+    assert_equal Bulb, bulb.class
+
+    bulb = car.build_bulb({ :bulb_type => :custom }, :as => :admin)
+    assert_equal CustomBulb, bulb.class
+  end
 end