Add efficient #include? to AssociationCollection (for has_many/has_many :through/habtm). [stopdropandrew]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9200 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

5 files changed, 98 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 682869e585..069d6a3841 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Add efficient #include? to AssociationCollection (for has_many/has_many :through/habtm).  [stopdropandrew]
+
 * PostgreSQL: create_ and drop_database support.  #9042 [ez, pedz, nicksieger]
 
 * Ensure that validates_uniqueness_of works with with_scope. Closes #9235. [nik.wakelin, cavalle]
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index d8b988d889..3b8954e435 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -159,6 +159,11 @@ module ActiveRecord
         end
       end
 
+      def include?(record)
+        return false unless record.is_a?(@reflection.klass)
+        return @target.include?(record) if loaded?
+        exists?(record)
+      end
 
       protected
         def method_missing(method, *args)
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 83c9865205..7d418ba701 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,6 +1,6 @@
 module ActiveRecord
   module Associations
-    class HasManyThroughAssociation < AssociationProxy #:nodoc:
+    class HasManyThroughAssociation < AssociationCollection #:nodoc:
       def initialize(owner, reflection)
         super
         reflection.check_validity!
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index d4db4ef770..2b929d4480 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -639,7 +639,37 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
       assert_equal comments.first.post, comments[1].post
     end
   end
+
+  def test_has_many_through_include_uses_array_include_after_loaded
+    david = authors(:david)
+    category = david.categories.first
+
+    assert_no_queries do
+      assert david.categories.loaded?
+      assert david.categories.include?(category)
+    end
+  end
+
+  def test_has_many_through_include_checks_if_record_exists_if_target_not_loaded
+    david = authors(:david)
+    category = david.categories.first
+
+    david.reload
+    assert ! david.categories.loaded?
+    assert_queries(1) do
+      assert david.categories.include?(category)
+    end
+    assert ! david.categories.loaded?
+  end
   
+  def test_has_many_through_include_returns_false_for_non_matching_record_to_verify_scoping
+    david = authors(:david)
+    category = Category.create!(:name => 'Not Associated')
+
+    assert ! david.categories.loaded?
+    assert ! david.categories.include?(category)
+  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 5a9e32f774..3e2b104a13 100755
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -1330,6 +1330,36 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal authors(:david).hello_post_comments, authors(:david).hello_post_comments_with_hash_conditions
   end
 
+  def test_include_uses_array_include_after_loaded
+    firm = companies(:first_firm)
+    client = firm.clients.first
+
+    assert_no_queries do
+      assert firm.clients.loaded?
+      assert firm.clients.include?(client)
+    end
+  end
+
+  def test_include_checks_if_record_exists_if_target_not_loaded
+    firm = companies(:first_firm)
+    client = firm.clients.first
+
+    firm.reload
+    assert ! firm.clients.loaded?
+    assert_queries(1) do
+      assert firm.clients.include?(client)
+    end
+    assert ! firm.clients.loaded?
+  end
+
+  def test_include_returns_false_for_non_matching_record_to_verify_scoping
+    firm = companies(:first_firm)
+    client = Client.create!(:name => 'Not Associated')
+
+    assert ! firm.clients.loaded?
+    assert ! firm.clients.include?(client)
+  end
+
 end
 
 class BelongsToAssociationsTest < ActiveRecord::TestCase
@@ -2046,6 +2076,36 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     assert_equal developers(:david), active_record.developers.find(developers(:david).id), "Ruby find"
   end
 
+  def test_include_uses_array_include_after_loaded
+    project = projects(:active_record)
+    developer = project.developers.first
+    
+    assert_no_queries do
+      assert project.developers.loaded?
+      assert project.developers.include?(developer)
+    end
+  end
+  
+  def test_include_checks_if_record_exists_if_target_not_loaded
+    project = projects(:active_record)
+    developer = project.developers.first
+
+    project.reload
+    assert ! project.developers.loaded?
+    assert_queries(1) do
+      assert project.developers.include?(developer)
+    end
+    assert ! project.developers.loaded?
+  end
+
+  def test_include_returns_false_for_non_matching_record_to_verify_scoping
+    project = projects(:active_record)
+    developer = Developer.create :name => "Bryan", :salary => 50_000
+
+    assert ! project.developers.loaded?
+    assert ! project.developers.include?(developer)
+  end
+
   def test_find_in_association_with_custom_finder_sql
     assert_equal developers(:david), projects(:active_record).developers_with_finder_sql.find(developers(:david).id), "SQL find"