Initial nested_has_many_through support [#1152]

6 files changed, 58 insertions, 12 deletions

diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index f131dc01f6..0b1a3db1e4 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -394,14 +394,6 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
     end
   end
 
-  def test_has_many_through_has_many_through
-    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).tags }
-  end
-
-  def test_has_many_through_habtm
-    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).post_categories }
-  end
-
   def test_eager_load_has_many_through_has_many
     author = Author.find :first, :conditions => ['name = ?', 'David'], :include => :comments, :order => 'comments.id'
     SpecialComment.new; VerySpecialComment.new
diff --git a/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
new file mode 100644
index 0000000000..36de709ffc
--- /dev/null
+++ b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
@@ -0,0 +1,43 @@
+require "cases/helper"
+require 'models/author'
+require 'models/post'
+require 'models/person'
+require 'models/reference'
+require 'models/job'
+require 'models/reader'
+require 'models/comment'
+require 'models/tag'
+require 'models/tagging'
+require 'models/owner'
+require 'models/pet'
+require 'models/toy'
+require 'models/contract'
+require 'models/company'
+require 'models/developer'
+require 'models/subscriber'
+require 'models/book'
+require 'models/subscription'
+
+class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase
+  fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings
+
+  def test_has_many_through_a_has_many_through_association_on_source_reflection
+    author = authors(:david)
+    assert_equal [tags(:general), tags(:general)], author.tags
+  end
+
+  def test_has_many_through_a_has_many_through_association_on_through_reflection
+    author = authors(:david)
+    assert_equal [subscribers(:first), subscribers(:second), subscribers(:second)], author.subscribers
+  end
+
+  def test_distinct_has_many_through_a_has_many_through_association_on_source_reflection
+    author = authors(:david)
+    assert_equal [tags(:general)], author.distinct_tags
+  end
+
+  def test_distinct_has_many_through_a_has_many_through_association_on_through_reflection
+    author = authors(:david)
+    assert_equal [subscribers(:first), subscribers(:second)], author.distinct_subscribers
+  end
+end
\ No newline at end of file
diff --git a/activerecord/test/fixtures/books.yml b/activerecord/test/fixtures/books.yml
index 473663ff5b..fb48645456 100644
--- a/activerecord/test/fixtures/books.yml
+++ b/activerecord/test/fixtures/books.yml
@@ -1,7 +1,9 @@
 awdr:
+  author_id: 1
   id: 1
   name: "Agile Web Development with Rails"
 
 rfr:
+  author_id: 1
   id: 2
   name: "Ruby for Rails"
diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index 34bfd2d881..94810e2f34 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -83,14 +83,20 @@ class Author < ActiveRecord::Base
   has_many :author_favorites
   has_many :favorite_authors, :through => :author_favorites, :order => 'name'
 
-  has_many :tagging,  :through => :posts # through polymorphic has_one
-  has_many :taggings, :through => :posts, :source => :taggings # through polymorphic has_many
-  has_many :tags,     :through => :posts # through has_many :through
+  has_many :tagging,         :through => :posts # through polymorphic has_one
+  has_many :taggings,        :through => :posts, :source => :taggings # through polymorphic has_many
+  has_many :tags,            :through => :posts # through has_many :through (on source reflection + polymorphic)
+  has_many :distinct_tags,   :through => :posts, :source => :tags, :select => "DISTINCT tags.*", :order => "tags.name"
   has_many :post_categories, :through => :posts, :source => :categories
 
+  has_many :books
+  has_many :subscriptions,        :through => :books
+  has_many :subscribers,          :through => :subscriptions # through has_many :through (on through reflection)
+  has_many :distinct_subscribers, :through => :subscriptions, :source => :subscriber, :select => "DISTINCT subscribers.*", :order => "subscribers.nick"
+
   has_one :essay, :primary_key => :name, :as => :writer
 
-  belongs_to :author_address, :dependent => :destroy
+  belongs_to :author_address,       :dependent => :destroy
   belongs_to :author_address_extra, :dependent => :delete, :class_name => "AuthorAddress"
 
   scope :relation_include_posts, includes(:posts)
diff --git a/activerecord/test/models/book.rb b/activerecord/test/models/book.rb
index 1e030b4f59..d27d0af77c 100644
--- a/activerecord/test/models/book.rb
+++ b/activerecord/test/models/book.rb
@@ -1,4 +1,6 @@
 class Book < ActiveRecord::Base
+  has_many :authors
+
   has_many :citations, :foreign_key => 'book1_id'
   has_many :references, :through => :citations, :source => :reference_of, :uniq => true
 
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index ea62833d81..dbd5da45eb 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -71,6 +71,7 @@ ActiveRecord::Schema.define do
   end
 
   create_table :books, :force => true do |t|
+    t.integer :author_id
     t.column :name, :string
   end