add self referential has_many :through example [Rick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4006 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/test/associations_join_model_test.rb

@@ -9,7 +9,7 @@ require 'fixtures/categorization'
 
 class AssociationsJoinModelTest < Test::Unit::TestCase
   self.use_transactional_fixtures = false
-  fixtures :posts, :authors, :categories, :categorizations, :comments, :tags, :taggings
+  fixtures :posts, :authors, :categories, :categorizations, :comments, :tags, :taggings, :author_favorites
 
   def test_has_many
     assert_equal categories(:general), authors(:david).categories.first
@@ -294,6 +294,17 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
     end
   end
 
+  def test_self_referential_has_many_through
+    assert_equal [authors(:mary)], authors(:david).favorite_authors
+    assert_equal [],               authors(:mary).favorite_authors
+  end
+
+  def test_add_to_self_referential_has_many_through
+    new_author = Author.create(:name => "Bob")
+    authors(:david).author_favorites.create :favorite_author => new_author
+    assert_equal [new_author, authors(:mary)], authors(:david).reload.favorite_authors
+  end
+
   private
     # create dynamic Post models to allow different dependency options
     def find_post_with_dependency(post_id, association, association_name, dependency)

activerecord/test/fixtures/author.rb

@@ -25,9 +25,12 @@ class Author < ActiveRecord::Base
 
   has_many :categorizations
   has_many :categories, :through => :categorizations
-  
+
   has_many :nothings, :through => :kateggorisatons, :class_name => 'Category'
 
+  has_many :author_favorites
+  has_many :favorite_authors, :through => :author_favorites, :order => 'name'
+
   belongs_to :author_address
 
   attr_accessor :post_log
@@ -60,4 +63,9 @@ end
 
 class AuthorAddress < ActiveRecord::Base
   has_one :author
+end
+
+class AuthorFavorite < ActiveRecord::Base
+  belongs_to :author
+  belongs_to :favorite_author, :class_name => "Author", :foreign_key => 'favorite_author_id'
 end

activerecord/test/fixtures/author_favorites.yml

@@ -0,0 +1,4 @@
+david_mary:
+  id: 1
+  author_id: 1
+  favorite_author_id: 2

activerecord/test/fixtures/db_definitions/schema.rb

@@ -25,4 +25,8 @@ ActiveRecord::Schema.define do
     t.column :author_address_id, :integer
   end
 
+  create_table :author_favorites, :force => true do |t|
+    t.column :author_id, :integer
+    t.column :favorite_author_id, :integer
+  end
 end