Ticket #9734: has_many_through_size_use_counter_cache_r7675.diff

test/associations/join_model_test.rb

@@ -457 +457 @@
-    assert !author.comments.loaded?
-  end
-
+  uses_mocha('has_many_through_collection_size_uses_counter_cache_if_it_exists') do
+    def test_has_many_through_collection_size_uses_counter_cache_if_it_exists
+      author = authors(:david)
+      author.stubs(:read_attribute).with('comments_count').returns(100)
+      assert_equal 100, author.comments.size
+      assert !author.comments.loaded?
+    end
+  end
+
-  def test_adding_junk_to_has_many_through_should_raise_type_mismatch
-    assert_raise(ActiveRecord::AssociationTypeMismatch) { posts(:thinking).tags << "Uhh what now?" }
-  end

lib/active_record/associations/has_many_through_association.rb

@@ -100 +100 @@
-      # calling collection.size if it has. If it's more likely than not that the collection does have a size larger than zero
-      # and you need to fetch that collection afterwards, it'll take one less SELECT query if you use length.
-      def size
-
+
+
+
-      end
-
-      # Calculate sum using SQL, not Enumerable
@@ -258 +260 @@
-        end
-
-        alias_method :sql_conditions, :conditions
+
+        def has_cached_counter?
+          @owner.attribute_present?(cached_counter_attribute_name)
+        end
+
+        def cached_counter_attribute_name
+          "#{@reflection.name}_count"
+        end
-    end
-  end
-end