Added descriptive error messages for invalid has_many :through associations: going through :has_one or :has_and_belongs_to_many [Rick]

Added support for going through a polymorphic has_many association: (closes #4401) [Rick]


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4169 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 21 insertions, 0 deletions

diff --git a/activerecord/test/associations_join_model_test.rb b/activerecord/test/associations_join_model_test.rb
index f0ee2eb9e7..b7f0af173b 100644
--- a/activerecord/test/associations_join_model_test.rb
+++ b/activerecord/test/associations_join_model_test.rb
@@ -295,6 +295,22 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
     assert_equal comments(:more_greetings), authors(:david).comments.find(2)
   end
 
+  def test_has_many_through_polymorphic_has_one
+    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).tagging }
+  end
+
+  def test_has_many_through_polymorphic_has_many
+    assert_equal [taggings(:welcome_general), taggings(:thinking_general)], authors(:david).taggings.uniq.sort_by { |t| t.id }
+  end
+
+  def test_has_many_through_has_many_through
+    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).tags }
+  end
+
+  def test_has_many_through_habtm
+    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).post_categories }
+  end
+
   def test_eager_load_has_many_through_has_many
     author = Author.find :first, :conditions => ['name = ?', 'David'], :include => :comments, :order => 'comments.id'
     SpecialComment.new; VerySpecialComment.new
diff --git a/activerecord/test/fixtures/author.rb b/activerecord/test/fixtures/author.rb
index 1a9b6d788a..99142f6621 100644
--- a/activerecord/test/fixtures/author.rb
+++ b/activerecord/test/fixtures/author.rb
@@ -31,6 +31,11 @@ class Author < ActiveRecord::Base
   has_many :author_favorites
   has_many :favorite_authors, :through => :author_favorites, :order => 'name'
 
+  has_many :tagging,  :through => :posts # through polymorphic has_one
+  has_many :taggings, :through => :posts, :source => :taggings # through polymorphic has_many
+  has_many :tags,     :through => :posts # through has_many :through
+  has_many :post_categories, :through => :posts, :source => :categories
+
   belongs_to :author_address
 
   attr_accessor :post_log