Created a method to automatically find inverse associations and cache

the results. Added tests to check to make sure that inverse associations are
automatically found when has_many, has_one, or belongs_to associations
are defined.

1 files changed, 82 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index ec128acf28..b1f0be3204 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -5,6 +5,88 @@ require 'models/interest'
 require 'models/zine'
 require 'models/club'
 require 'models/sponsor'
+require 'models/rating'
+require 'models/comment'
+require 'models/car'
+require 'models/bulb'
+
+class AutomaticInverseFindingTests < ActiveRecord::TestCase
+  fixtures :ratings, :comments, :cars
+
+  def test_has_one_and_belongs_to_should_find_inverse_automatically
+    car_reflection = Car.reflect_on_association(:bulb)
+    bulb_reflection = Bulb.reflect_on_association(:car)
+
+    assert_respond_to car_reflection, :has_inverse?
+    assert car_reflection.has_inverse?, "The Car reflection should have an inverse"
+    assert_equal bulb_reflection, car_reflection.inverse_of, "The Car reflection's inverse should be the Bulb reflection"
+
+    assert_respond_to bulb_reflection, :has_inverse?
+    assert bulb_reflection.has_inverse?, "The Bulb reflection should have an inverse"
+    assert_equal car_reflection, bulb_reflection.inverse_of, "The Bulb reflection's inverse should be the Car reflection"
+  end
+
+  def test_has_many_and_belongs_to_should_find_inverse_automatically
+    comment_reflection = Comment.reflect_on_association(:ratings)
+    rating_reflection = Rating.reflect_on_association(:comment)
+
+    assert_respond_to comment_reflection, :has_inverse?
+    assert comment_reflection.has_inverse?, "The Comment reflection should have an inverse"
+    assert_equal rating_reflection, comment_reflection.inverse_of, "The Comment reflection's inverse should be the Rating reflection"
+  end
+
+  def test_has_one_and_belongs_to_automatic_inverse_shares_objects
+    car = Car.first
+    bulb = Bulb.create!(car: car)
+
+    assert_equal car.bulb, bulb, "The Car's bulb should be the original bulb"
+
+    car.bulb.color = "Blue"
+    assert_equal car.bulb.color, bulb.color, "Changing the bulb's color on the car association should change the bulb's color"
+
+    bulb.color = "Red"
+    assert_equal bulb.color, car.bulb.color, "Changing the bulb's color should change the bulb's color on the car association"
+  end
+
+  def test_has_many_and_belongs_to_automatic_inverse_shares_objects_on_rating
+    comment = Comment.first
+    rating = Rating.create!(comment: comment)
+
+    assert_equal rating.comment, comment, "The Rating's comment should be the original Comment"
+
+    rating.comment.body = "Brogramming is the act of programming, like a bro."
+    assert_equal rating.comment.body, comment.body, "Changing the Comment's body on the association should change the original Comment's body"
+
+    comment.body = "Broseiden is the king of the sea of bros."
+    assert_equal comment.body, rating.comment.body, "Changing the original Comment's body should change the Comment's body on the association"
+  end
+
+  def test_has_many_and_belongs_to_automatic_inverse_shares_objects_on_comment
+    rating = Rating.create!
+    comment = Comment.first
+    rating.comment = comment
+
+    assert_equal rating.comment, comment, "The Rating's comment should be the original Comment"
+
+    rating.comment.body = "Brogramming is the act of programming, like a bro."
+    assert_equal rating.comment.body, comment.body, "Changing the Comment's body on the association should change the original Comment's body"
+
+    comment.body = "Broseiden is the king of the sea of bros."
+    assert_equal comment.body, rating.comment.body, "Changing the original Comment's body should change the Comment's body on the association"
+  end
+
+  def test_polymorphic_and_has_many_through_relationships_should_not_have_inverses
+    sponsor_reflection = Sponsor.reflect_on_association(:sponsorable)
+
+    assert_respond_to sponsor_reflection, :has_inverse?
+    assert !sponsor_reflection.has_inverse?, "A polymorphic association should not find an inverse automatically"
+
+    club_reflection = Club.reflect_on_association(:members)
+
+    assert_respond_to club_reflection, :has_inverse?
+    assert !club_reflection.has_inverse?, "A has_many_through association should not find an inverse automatically"
+  end
+end
 
 class InverseAssociationTests < ActiveRecord::TestCase
   def test_should_allow_for_inverse_of_options_in_associations