Add support for nested through associations in JoinAssociation. Hence Foo.joins(:bar) will work for through associations. There is some duplicated code now, which will be refactored.

9 files changed, 86 insertions, 5 deletions

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
index a5d3f27702..ba75b70941 100644
--- a/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
@@ -17,18 +17,37 @@ require 'models/developer'
 require 'models/subscriber'
 require 'models/book'
 require 'models/subscription'
+require 'models/rating'
+
+# NOTE: Some of these tests might not really test "nested" HMT associations, as opposed to ones which
+# are just one level deep. But it's all the same thing really, as the "nested" code is being 
+# written in a generic way which applies to "non-nested" HMT associations too. So let's just shove
+# all useful tests in here for now and then work out where they ought to live properly later.
 
 class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase
-  fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings
+  fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings,
+           :people, :readers, :references, :jobs, :ratings, :comments
 
   def test_has_many_through_a_has_many_through_association_on_source_reflection
     author = authors(:david)
     assert_equal [tags(:general), tags(:general)], author.tags
+    
+    # Only David has a Post tagged with General
+    authors = Author.joins(:tags).where('tags.id' => tags(:general).id)
+    assert_equal [authors(:david)], authors.uniq
+    
+    # This ensures that the polymorphism of taggings is being observed correctly
+    authors = Author.joins(:tags).where('taggings.taggable_type' => 'FakeModel')
+    assert authors.empty?
   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
+    
+    # All authors with subscribers where one of the subscribers' nick is 'alterself'
+    authors = Author.joins(:subscribers).where('subscribers.nick' => 'alterself')
+    assert_equal [authors(:david)], authors
   end
 
   def test_distinct_has_many_through_a_has_many_through_association_on_source_reflection
@@ -44,11 +63,41 @@ class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase
   def test_nested_has_many_through_with_a_table_referenced_multiple_times
     author = authors(:bob)
     assert_equal [posts(:misc_by_bob), posts(:misc_by_mary)], author.similar_posts.sort_by(&:id)
+    
+    # Mary and Bob both have posts in misc, but they are the only ones.
+    authors = Author.joins(:similar_posts).where('posts.id' => posts(:misc_by_bob).id)
+    assert_equal [authors(:mary), authors(:bob)], authors.uniq.sort_by(&:id)
+    
+    # Check the polymorphism of taggings is being observed correctly (in both joins)
+    authors = Author.joins(:similar_posts).where('taggings.taggable_type' => 'FakeModel')
+    assert authors.empty?
+    authors = Author.joins(:similar_posts).where('taggings_authors_join.taggable_type' => 'FakeModel')
+    assert authors.empty?
   end
   
-  def test_nested_has_many_through_as_a_join
-    # All authors with subscribers where one of the subscribers' nick is 'alterself'
-    authors = Author.joins(:subscribers).where('subscribers.nick' => 'alterself')
-    assert_equal [authors(:david)], authors
+  def test_has_many_through_with_foreign_key_option_on_through_reflection
+    assert_equal [posts(:welcome), posts(:authorless)], people(:david).agents_posts
+    assert_equal [authors(:david)], references(:david_unicyclist).agents_posts_authors
+    
+    references = Reference.joins(:agents_posts_authors).where('authors.id' => authors(:david).id)
+    assert_equal [references(:david_unicyclist)], references
+  end
+  
+  def test_has_many_through_with_foreign_key_option_on_source_reflection
+    assert_equal [people(:michael), people(:susan)], jobs(:unicyclist).agents
+    
+    jobs = Job.joins(:agents)
+    assert_equal [jobs(:unicyclist), jobs(:unicyclist)], jobs
+  end
+
+  def test_has_many_through_with_sti_on_through_reflection
+    ratings = posts(:sti_comments).special_comments_ratings.sort_by(&:id)
+    assert_equal [ratings(:special_comment_rating), ratings(:sub_special_comment_rating)], ratings
+    
+    # Ensure STI is respected in the join
+    scope = Post.joins(:special_comments_ratings).where(:id => posts(:sti_comments).id)
+    assert scope.where("comments.type" => "Comment").empty?
+    assert !scope.where("comments.type" => "SpecialComment").empty?
+    assert !scope.where("comments.type" => "SubSpecialComment").empty?
   end
 end
diff --git a/activerecord/test/fixtures/ratings.yml b/activerecord/test/fixtures/ratings.yml
new file mode 100644
index 0000000000..34e208efa3
--- /dev/null
+++ b/activerecord/test/fixtures/ratings.yml
@@ -0,0 +1,14 @@
+normal_comment_rating:
+  id: 1
+  comment_id: 8
+  value: 1
+
+special_comment_rating:
+  id: 2
+  comment_id: 6
+  value: 1
+
+sub_special_comment_rating:
+  id: 3
+  comment_id: 12
+  value: 1
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 88061b2145..1a3fb42b66 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -7,6 +7,7 @@ class Comment < ActiveRecord::Base
               :conditions => { "posts.author_id" => 1 }
 
   belongs_to :post, :counter_cache => true
+  has_many :ratings
 
   def self.what_are_you
     'a comment...'
diff --git a/activerecord/test/models/job.rb b/activerecord/test/models/job.rb
index 3333a02e27..46b1d87aa1 100644
--- a/activerecord/test/models/job.rb
+++ b/activerecord/test/models/job.rb
@@ -2,4 +2,6 @@ class Job < ActiveRecord::Base
   has_many :references
   has_many :people, :through => :references
   belongs_to :ideal_reference, :class_name => 'Reference'
+  
+  has_many :agents, :through => :people
 end
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index 951ec93c53..d35c51b660 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -13,6 +13,9 @@ class Person < ActiveRecord::Base
   belongs_to :primary_contact, :class_name => 'Person'
   has_many :agents, :class_name => 'Person', :foreign_key => 'primary_contact_id'
   belongs_to :number1_fan, :class_name => 'Person'
+  
+  has_many :agents_posts, :through => :agents, :source => :posts
+  has_many :agents_posts_authors, :through => :agents_posts, :source => :author
 
   scope :males, :conditions => { :gender => 'M' }
   scope :females, :conditions => { :gender => 'F' }
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index a3cb9c724a..f3b78c3647 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -46,6 +46,8 @@ class Post < ActiveRecord::Base
   has_one  :very_special_comment_with_post, :class_name => "VerySpecialComment", :include => :post
   has_many :special_comments
   has_many :nonexistant_comments, :class_name => 'Comment', :conditions => 'comments.id < 0'
+  
+  has_many :special_comments_ratings, :through => :special_comments, :source => :ratings
 
   has_and_belongs_to_many :categories
   has_and_belongs_to_many :special_categories, :join_table => "categories_posts", :association_foreign_key => 'category_id'
diff --git a/activerecord/test/models/rating.rb b/activerecord/test/models/rating.rb
new file mode 100644
index 0000000000..12c4b5affa
--- /dev/null
+++ b/activerecord/test/models/rating.rb
@@ -0,0 +1,3 @@
+class Rating < ActiveRecord::Base
+  belongs_to :comment
+end
diff --git a/activerecord/test/models/reference.rb b/activerecord/test/models/reference.rb
index 4a17c936f5..2feb15d706 100644
--- a/activerecord/test/models/reference.rb
+++ b/activerecord/test/models/reference.rb
@@ -1,6 +1,8 @@
 class Reference < ActiveRecord::Base
   belongs_to :person
   belongs_to :job
+  
+  has_many :agents_posts_authors, :through => :person
 end
 
 class BadReference < ActiveRecord::Base
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index dbd5da45eb..2fa9a4521e 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -449,6 +449,11 @@ ActiveRecord::Schema.define do
     t.string :type
   end
 
+  create_table :ratings, :force => true do |t|
+    t.integer :comment_id
+    t.integer :value
+  end
+
   create_table :readers, :force => true do |t|
     t.integer :post_id, :null => false
     t.integer :person_id, :null => false