Add has_one :through support, finally. Closes #4756 [thechrisoshow]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9067 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

11 files changed, 145 insertions, 2 deletions

diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index 1034cb67e9..3d59b97f70 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -631,7 +631,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
       assert_equal comments.first.post, comments[1].post
     end
   end
-
+  
   private
     # create dynamic Post models to allow different dependency options
     def find_post_with_dependency(post_id, association, association_name, dependency)
diff --git a/activerecord/test/cases/associations_test.rb b/activerecord/test/cases/associations_test.rb
index 50643066b9..768d2b2600 100755
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -20,6 +20,10 @@ require 'models/parrot'
 require 'models/pirate'
 require 'models/treasure'
 require 'models/price_estimate'
+require 'models/club'
+require 'models/member'
+require 'models/membership'
+require 'models/sponsor'
 
 class AssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :developers, :projects, :developers_projects,
@@ -186,7 +190,7 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_equal companies(:first_firm).account, Account.find(1)
     assert_equal Account.find(1).credit_limit, companies(:first_firm).account.credit_limit
   end
-
+  
   def test_has_one_cache_nils
     firm = companies(:another_firm)
     assert_queries(1) { assert_nil firm.account }
@@ -476,6 +480,63 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
 
 end
 
+class HasOneThroughAssociationsTest < ActiveRecord::TestCase
+  fixtures :members, :clubs, :memberships, :sponsors
+  
+  def setup
+    @member = members(:groucho)
+  end
+
+  def test_has_one_through_with_has_one
+    assert_equal clubs(:boring_club), @member.club
+  end
+
+  def test_has_one_through_with_has_many
+    assert_equal clubs(:moustache_club), @member.favourite_club
+  end
+  
+  def test_creating_association_creates_through_record
+    new_member = Member.create(:name => "Chris")
+    new_member.club = Club.create(:name => "LRUG")
+    assert_not_nil new_member.current_membership
+    assert_not_nil new_member.club
+  end
+  
+  def test_replace_target_record
+    new_club = Club.create(:name => "Marx Bros")
+    @member.club = new_club
+    @member.reload
+    assert_equal new_club, @member.club
+  end
+  
+  def test_replacing_target_record_deletes_old_association
+    assert_no_difference "Membership.count" do
+      new_club = Club.create(:name => "Bananarama")
+      @member.club = new_club
+      @member.reload      
+    end
+  end
+  
+  def test_has_one_through_polymorphic
+    assert_equal clubs(:moustache_club), @member.sponsor_club
+  end
+  
+  def has_one_through_to_has_many
+    assert_equal 2, @member.fellow_members.size
+  end
+  
+  def test_has_one_through_eager_loading
+    members = Member.find(:all, :include => :club)
+    assert_equal 2, members.size
+    assert_not_nil assert_no_queries {members[0].club}
+  end
+  
+  def test_has_one_through_eager_loading_through_polymorphic
+    members = Member.find(:all, :include => :sponsor_club)
+    assert_equal 2, members.size
+    assert_not_nil assert_no_queries {members[0].sponsor_club}    
+  end
+end
 
 class HasManyAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :developers, :projects,
diff --git a/activerecord/test/fixtures/clubs.yml b/activerecord/test/fixtures/clubs.yml
new file mode 100644
index 0000000000..1986d28229
--- /dev/null
+++ b/activerecord/test/fixtures/clubs.yml
@@ -0,0 +1,6 @@
+boring_club:
+  name: Banana appreciation society
+moustache_club:
+  name: Moustache and Eyebrow Fancier Club
+crazy_club:
+  name: Skull and bones
\ No newline at end of file
diff --git a/activerecord/test/fixtures/members.yml b/activerecord/test/fixtures/members.yml
new file mode 100644
index 0000000000..67a6cc459a
--- /dev/null
+++ b/activerecord/test/fixtures/members.yml
@@ -0,0 +1,4 @@
+groucho:
+  name: Groucho Marx
+some_other_guy:
+  name: Englebert Humperdink
\ No newline at end of file
diff --git a/activerecord/test/fixtures/memberships.yml b/activerecord/test/fixtures/memberships.yml
new file mode 100644
index 0000000000..99fbe46d9b
--- /dev/null
+++ b/activerecord/test/fixtures/memberships.yml
@@ -0,0 +1,20 @@
+membership_of_boring_club:
+  joined_on: <%= 3.weeks.ago.to_s(:db) %>
+  club: boring_club
+  member: groucho
+  favourite: false
+  type: CurrentMembership
+  
+membership_of_favourite_club:
+  joined_on: <%= 3.weeks.ago.to_s(:db) %>
+  club: moustache_club
+  member: groucho
+  favourite: true
+  type: Membership
+
+other_guys_membership:
+  joined_on: <%= 4.weeks.ago.to_s(:db) %>
+  club: boring_club
+  member: some_other_guy
+  favourite: false
+  type: CurrentMembership
diff --git a/activerecord/test/fixtures/sponsors.yml b/activerecord/test/fixtures/sponsors.yml
new file mode 100644
index 0000000000..c116df0534
--- /dev/null
+++ b/activerecord/test/fixtures/sponsors.yml
@@ -0,0 +1,3 @@
+moustache_club_sponsor_for_groucho:
+  sponsor_club: moustache_club
+  sponsorable: groucho (Member)
\ No newline at end of file
diff --git a/activerecord/test/models/club.rb b/activerecord/test/models/club.rb
new file mode 100644
index 0000000000..171445df3e
--- /dev/null
+++ b/activerecord/test/models/club.rb
@@ -0,0 +1,6 @@
+class Club < ActiveRecord::Base
+  has_many :memberships
+  has_many :members, :through => :memberships
+  has_many :current_memberships
+  has_many :sponsors
+end
\ No newline at end of file
diff --git a/activerecord/test/models/member.rb b/activerecord/test/models/member.rb
new file mode 100644
index 0000000000..688725f200
--- /dev/null
+++ b/activerecord/test/models/member.rb
@@ -0,0 +1,9 @@
+class Member < ActiveRecord::Base
+  has_one :current_membership
+  has_many :memberships
+  has_many :fellow_members, :through => :club, :source => :members
+  has_one :club, :through => :current_membership
+  has_one :favourite_club, :through => :memberships, :conditions => ["memberships.favourite = ?", true], :source => :club
+  has_one :sponsor, :as => :sponsorable
+  has_one :sponsor_club, :through => :sponsor
+end
\ No newline at end of file
diff --git a/activerecord/test/models/membership.rb b/activerecord/test/models/membership.rb
new file mode 100644
index 0000000000..905f948c37
--- /dev/null
+++ b/activerecord/test/models/membership.rb
@@ -0,0 +1,9 @@
+class Membership < ActiveRecord::Base
+  belongs_to :member
+  belongs_to :club
+end
+
+class CurrentMembership < Membership
+  belongs_to :member
+  belongs_to :club
+end
diff --git a/activerecord/test/models/sponsor.rb b/activerecord/test/models/sponsor.rb
new file mode 100644
index 0000000000..50c2c2d76c
--- /dev/null
+++ b/activerecord/test/models/sponsor.rb
@@ -0,0 +1,4 @@
+class Sponsor < ActiveRecord::Base
+  belongs_to :sponsor_club, :class_name => "Club", :foreign_key => "club_id"
+  belongs_to :sponsorable, :polymorphic => true
+end
\ No newline at end of file
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 33aa6e2ea4..724226c359 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -49,6 +49,10 @@ ActiveRecord::Schema.define do
       t.integer :category_id, :null => false
       t.integer :post_id, :null => false
     end
+    
+    create_table :clubs, :force => true do |t|
+      t.string :name
+    end
 
     create_table :colnametests, :force => true do |t|
       t.integer :references, :null => false
@@ -117,6 +121,17 @@ ActiveRecord::Schema.define do
       t.integer :version, :null => false, :default => 0
     end
 
+    create_table :members, :force => true do |t|
+      t.string :name
+    end
+
+    create_table :memberships, :force => true do |t|
+      t.datetime :joined_on
+      t.integer :club_id, :member_id
+      t.boolean :favourite, :default => false
+      t.string :type
+    end
+
     create_table :minimalistics, :force => true do |t|
     end
 
@@ -177,6 +192,12 @@ ActiveRecord::Schema.define do
       t.integer :post_id, :null => false
       t.integer :person_id, :null => false
     end
+    
+    create_table :sponsors, :force => true do |t|
+      t.integer :club_id
+      t.integer :sponsorable_id
+      t.integer :sponsorable_type
+    end
 
     create_table :subscribers, :force => true, :id => false do |t|
       t.string :nick, :null => false