Make sure habtm and has_one are safely used

CHANGELOG

@@ -1,3 +1,7 @@
+* Make sure habtm and has_one are safely used
+
+
+
 *0.0.2 (October 10th, 2008)*
 
 * Updated README with new installation instructions

lib/activerecord/lib/active_record/associations.rb

@@ -306,6 +306,27 @@ def collection_reader_method(reflection, association_proxy_class, options)
         end
       end
 
+      def has_and_belongs_to_many(association_id, options = {}, &extension)
+        reflection = create_has_and_belongs_to_many_reflection(association_id, options, &extension)
+
+        add_multiple_associated_validation_callbacks(reflection.name) unless options[:validate] == false
+        add_multiple_associated_save_callbacks(reflection.name)
+        collection_accessor_methods(reflection, HasAndBelongsToManyAssociation, options)
+
+        # Don't use a before_destroy callback since users' before_destroy
+        # callbacks will be executed after the association is wiped out.
+        old_method = "destroy_without_habtm_shim_for_#{reflection.name}"
+        class_eval <<-end_eval unless method_defined?(old_method)
+          alias_method :#{old_method}, :destroy_without_callbacks
+          def destroy_without_callbacks
+            #{reflection.name}.clear
+            #{old_method}
+          end
+        end_eval
+
+        add_association_callbacks(reflection.name, options)
+      end
+
       def collection_accessor_methods(reflection, association_proxy_class, options, writer = true)
         collection_reader_method(reflection, association_proxy_class, options)
 

tasks/cached_models_tasks.rake

@@ -3,7 +3,7 @@ require 'active_record'
 require 'active_record/fixtures'
 
 path_to_fixtures = File.dirname(__FILE__) + '/../test/fixtures'
-fixtures = %w( authors blogs posts comments tags )
+fixtures = %w( addresses authors blogs posts categories categories_posts comments tags )
 
 desc 'Run default task (test)'
 task :cached_models => 'cached_models:test'
@@ -21,6 +21,17 @@ namespace :cached_models do
   desc 'Create CachedModels test database tables'
   task :create_tables => :environment do
     ActiveRecord::Schema.define do
+      create_table :addresses, :force => true do |t|
+        t.integer :author_id
+        t.string :street
+        t.string :zip
+        t.string :city
+        t.string :state
+        t.string :country
+
+        t.timestamps
+      end
+
       create_table :authors, :force => true do |t|
         t.integer :blog_id
         t.string  :first_name
@@ -32,7 +43,7 @@ namespace :cached_models do
 
       create_table :blogs, :force => true do |t|
         t.string :title
-        
+
         t.timestamps
       end
 
@@ -46,30 +57,44 @@ namespace :cached_models do
         t.timestamps
       end
 
+      create_table :categories, :force => true do |t|
+        t.string :name
+
+        t.timestamps
+      end
+
+      create_table :categories_posts, :force => true do |t|
+        t.integer :category_id
+        t.integer :post_id
+      end
+
       create_table :comments, :force => true do |t|
         t.integer :post_id
         t.string :email
         t.text :text
-        
+
         t.timestamps
       end
-      
+
       create_table :tags, :force => true do |t|
         t.integer :taggable_id
         t.string :taggable_type
         t.string :name
-        
+
         t.timestamps
       end
     end
   end
 
   desc 'Drops CachedModels test database tables'
   task :drop_tables => :environment do
+    ActiveRecord::Base.connection.drop_table :addresses
     ActiveRecord::Base.connection.drop_table :authors
     ActiveRecord::Base.connection.drop_table :posts
     ActiveRecord::Base.connection.drop_table :comments
     ActiveRecord::Base.connection.drop_table :tags
+    ActiveRecord::Base.connection.drop_table :categories
+    ActiveRecord::Base.connection.drop_table :categories_posts
   end
 
   desc 'Load fixtures'

test/active_record/associations/has_and_belongs_to_many_association_test.rb

@@ -0,0 +1,12 @@
+require File.dirname(__FILE__) + '/../../test_helper'
+
+class HasAndBelongsToManyAssociationTest < Test::Unit::TestCase
+  include ActiveRecord::Associations
+
+  def test_should_not_raise_exception
+    assert_nothing_raised ArgumentError do
+      posts(:welcome).categories
+      categories(:announcements).posts
+    end
+  end
+end

test/active_record/associations/has_one_association_test.rb

@@ -0,0 +1,12 @@
+require File.dirname(__FILE__) + '/../../test_helper'
+
+class HasOneAssociationTest < Test::Unit::TestCase
+  include ActiveRecord::Associations
+
+  def test_should_not_raise_exception_when_use_has_one
+    assert_nothing_raised ArgumentError do
+      authors(:luca).address
+      addresses(:luca).author
+    end
+  end
+end

test/fixtures/addresses.yml

@@ -0,0 +1,7 @@
+luca:
+  author_id: 1
+  street: 1 infinite loop
+  zip: 95014
+  city: Cupertino
+  state: California
+  country: United States

test/fixtures/categories.yml

@@ -0,0 +1,3 @@
+announcements:
+  id: 1
+  name: Announcements

test/fixtures/categories_posts.yml

@@ -0,0 +1,3 @@
+welcome_announcements:
+  category_id: 1
+  post_id: 1

test/models/address.rb

@@ -0,0 +1,3 @@
+class Address < ActiveRecord::Base
+  belongs_to :author
+end

test/models/author.rb

@@ -7,4 +7,5 @@ class Author < ActiveRecord::Base
   has_many :cached_posts_with_comments, :class_name => 'Post', :include => :comments, :cached => true
   has_many :comments, :through => :posts
   has_many :cached_comments, :through => :posts, :source => :comments, :cached => true
+  has_one :address
 end

test/models/category.rb

@@ -0,0 +1,3 @@
+class Category < ActiveRecord::Base
+  has_and_belongs_to_many :posts
+end

test/models/post.rb

@@ -4,4 +4,5 @@ class Post < ActiveRecord::Base
   has_many :comments
   has_many :tags, :as => :taggable
   has_many :cached_tags, :as => :taggable, :class_name => 'Tag', :cached => true
+  has_and_belongs_to_many :categories
 end