Introduce preload query strategy for eager :includes. Closes #9640.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8672 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 101 insertions, 11 deletions

diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index 0e351816d3..9ceb507e91 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -1,5 +1,6 @@
 require 'abstract_unit'
 require 'models/post'
+require 'models/tagging'
 require 'models/comment'
 require 'models/author'
 require 'models/category'
@@ -9,7 +10,7 @@ require 'models/reader'
 
 class EagerAssociationTest < ActiveSupport::TestCase
   fixtures :posts, :comments, :authors, :categories, :categories_posts,
-            :companies, :accounts, :tags, :people, :readers
+            :companies, :accounts, :tags, :taggings, :people, :readers
 
   def test_loading_with_one_association
     posts = Post.find(:all, :include => :comments)
@@ -56,6 +57,13 @@ class EagerAssociationTest < ActiveSupport::TestCase
     assert posts.first.comments.include?(comments(:greetings))
   end
 
+  def test_duplicate_middle_objects
+    comments = Comment.find :all, :conditions => 'post_id = 1', :include => [:post => :author]
+    assert_no_queries do
+      comments.each {|comment| comment.post.author.name}
+    end
+  end
+
   def test_loading_from_an_association
     posts = authors(:david).posts.find(:all, :include => :comments, :order => "posts.id")
     assert_equal 2, posts.first.comments.size
@@ -353,6 +361,17 @@ class EagerAssociationTest < ActiveSupport::TestCase
     assert_equal posts(:sti_post_and_comments, :sti_comments), Post.find(:all, :include => [:author, :comments], :conditions => "authors.name = 'David'", :order => 'UPPER(posts.title) DESC, posts.id', :limit => 2, :offset => 1)
   end
 
+  def test_preload_with_interpolation
+    assert_equal [comments(:greetings)], Post.find(posts(:welcome).id, :include => :comments_with_interpolated_conditions).comments_with_interpolated_conditions
+  end
+
+  def test_polymorphic_type_condition
+    post = Post.find(posts(:thinking).id, :include => :taggings)
+    assert post.taggings.include?(taggings(:thinking_general))
+    post = SpecialPost.find(posts(:thinking).id, :include => :taggings)
+    assert post.taggings.include?(taggings(:thinking_general))
+  end
+
   def test_eager_with_multiple_associations_with_same_table_has_many_and_habtm
     # Eager includes of has many and habtm associations aren't necessarily sorted in the same way
     def assert_equal_after_sort(item1, item2, item3 = nil)
@@ -405,34 +424,40 @@ class EagerAssociationTest < ActiveSupport::TestCase
 
   def test_preconfigured_includes_with_belongs_to
     author = posts(:welcome).author_with_posts
-    assert_equal 5, author.posts.size
+    assert_no_queries {assert_equal 5, author.posts.size}
   end
 
   def test_preconfigured_includes_with_has_one
     comment = posts(:sti_comments).very_special_comment_with_post
-    assert_equal posts(:sti_comments), comment.post
+    assert_no_queries {assert_equal posts(:sti_comments), comment.post}
   end
 
   def test_preconfigured_includes_with_has_many
     posts = authors(:david).posts_with_comments
     one = posts.detect { |p| p.id == 1 }
-    assert_equal 5, posts.size
-    assert_equal 2, one.comments.size
+    assert_no_queries do
+      assert_equal 5, posts.size
+      assert_equal 2, one.comments.size
+    end
   end
 
   def test_preconfigured_includes_with_habtm
     posts = authors(:david).posts_with_categories
     one = posts.detect { |p| p.id == 1 }
-    assert_equal 5, posts.size
-    assert_equal 2, one.categories.size
+    assert_no_queries do
+      assert_equal 5, posts.size
+      assert_equal 2, one.categories.size
+    end
   end
 
   def test_preconfigured_includes_with_has_many_and_habtm
     posts = authors(:david).posts_with_comments_and_categories
     one = posts.detect { |p| p.id == 1 }
-    assert_equal 5, posts.size
-    assert_equal 2, one.comments.size
-    assert_equal 2, one.categories.size
+    assert_no_queries do
+      assert_equal 5, posts.size
+      assert_equal 2, one.comments.size
+      assert_equal 2, one.categories.size
+    end
   end
 
   def test_count_with_include
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index 23ed9d1c5e..c8ae42d78c 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -317,7 +317,7 @@ class AssociationsJoinModelTest < ActiveSupport::TestCase
       assert_equal posts(:welcome, :thinking), tags(:general).taggables
     end
     assert_raise ActiveRecord::EagerLoadPolymorphicError do
-      assert_equal posts(:welcome, :thinking), tags(:general).taggings.find(:all, :include => :taggable)
+      assert_equal posts(:welcome, :thinking), tags(:general).taggings.find(:all, :include => :taggable, :conditions => 'bogus_table.column = 1')
     end
   end
 
@@ -331,6 +331,7 @@ class AssociationsJoinModelTest < ActiveSupport::TestCase
     assert_no_queries do
       assert_equal desired, tag_with_include.tagged_posts
     end
+    assert_equal 4, tag_with_include.taggings.length
   end
 
   def test_has_many_through_has_many_find_all
@@ -546,6 +547,62 @@ class AssociationsJoinModelTest < ActiveSupport::TestCase
     assert_equal comment_ids.sort.reverse, authors(:david).ordered_uniq_comments_desc.map(&:id)
   end
 
+  def test_polymorphic_has_many
+    expected = taggings(:welcome_general)
+    p = Post.find(posts(:welcome).id, :include => :taggings)
+    assert_no_queries {assert p.taggings.include?(expected)}
+    assert posts(:welcome).taggings.include?(taggings(:welcome_general))
+  end
+
+  def test_polymorphic_has_one
+    expected = posts(:welcome)
+
+    tagging  = Tagging.find(taggings(:welcome_general).id, :include => :taggable)
+    assert_no_queries { assert_equal expected, tagging.taggable}
+  end
+
+  def test_polymorphic_belongs_to
+    p = Post.find(posts(:welcome).id, :include => {:taggings => :taggable})
+    assert_no_queries {assert_equal posts(:welcome), p.taggings.first.taggable}
+  end
+
+  def test_preload_polymorphic_has_many_through
+    posts           = Post.find(:all, :order => 'posts.id')
+    posts_with_tags = Post.find(:all, :include => :tags, :order => 'posts.id')
+    assert_equal posts.length, posts_with_tags.length
+    posts.length.times do |i|
+      assert_equal posts[i].tags.length, assert_no_queries { posts_with_tags[i].tags.length }
+    end
+  end
+
+  def test_preload_polymorph_many_types
+    taggings = Tagging.find :all, :include => :taggable, :conditions => ['taggable_type != ?', 'FakeModel']
+    assert_no_queries do
+      taggings.first.taggable.id
+      taggings[1].taggable.id
+    end
+
+    taggables = taggings.map(&:taggable)
+    assert taggables.include?(items(:dvd))
+    assert taggables.include?(posts(:welcome))
+  end
+
+  def test_preload_polymorphic_has_many
+    posts               = Post.find(:all, :order => 'posts.id')
+    posts_with_taggings = Post.find(:all, :include => :taggings, :order => 'posts.id')
+    assert_equal posts.length, posts_with_taggings.length
+    posts.length.times do |i|
+      assert_equal posts[i].taggings.length, assert_no_queries { posts_with_taggings[i].taggings.length }
+    end
+  end
+
+  def test_belongs_to_shared_parent
+    comments = Comment.find(:all, :include => :post, :conditions => 'post_id = 1')
+    assert_no_queries do
+      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 451a17b3bf..b21f0cc9e2 100755
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -21,6 +21,11 @@ class AssociationsTest < ActiveSupport::TestCase
   fixtures :accounts, :companies, :developers, :projects, :developers_projects,
            :computers
 
+  def test_include_with_order_works
+    assert_nothing_raised {Account.find(:first, :order => 'id', :include => :firm)}
+    assert_nothing_raised {Account.find(:first, :order => :id, :include => :firm)}
+  end
+
   def test_bad_collection_keys
     assert_raise(ArgumentError, 'ActiveRecord should have barked on bad collection keys') do
       Class.new(ActiveRecord::Base).has_many(:wheels, :name => 'wheels')
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 53dcbb74f3..176a0ddc1e 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -13,6 +13,9 @@ class Post < ActiveRecord::Base
     end
   end
 
+  has_many :comments_with_interpolated_conditions, :class_name => 'Comment',
+      :conditions => ['#{"#{aliased_table_name}." rescue ""}body = ?', 'Thank you for the welcome']
+
   has_one  :very_special_comment
   has_one  :very_special_comment_with_post, :class_name => "VerySpecialComment", :include => :post
   has_many :special_comments