Ensure HasManyThroughAssociation#destroy delete orphan records [#2251 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

2 files changed, 15 insertions, 2 deletions

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 2dca84b911..e8dbae9011 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -17,6 +17,13 @@ module ActiveRecord
         end
       end
 
+      def destroy(*records)
+        transaction do
+          delete_records(flatten_deeper(records))
+          super
+        end
+      end
+
       # Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been loaded and
       # 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 fewer SELECT query if you use #length.
diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index 97efca7891..51c70b9819 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -93,7 +93,7 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_destroy_association
-    assert_difference "Person.count", -1 do
+    assert_difference ["Person.count", "Reader.count"], -1 do
       posts(:welcome).people.destroy(people(:michael))
     end
 
@@ -102,7 +102,7 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_destroy_all
-    assert_difference "Person.count", -1 do
+    assert_difference ["Person.count", "Reader.count"], -1 do
       posts(:welcome).people.destroy_all
     end
 
@@ -110,6 +110,12 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert posts(:welcome).people(true).empty?
   end
 
+  def test_should_raise_exception_for_destroying_mismatching_records
+    assert_no_difference ["Person.count", "Reader.count"] do
+      assert_raise(ActiveRecord::AssociationTypeMismatch) { posts(:welcome).people.destroy(posts(:thinking)) }
+    end
+  end
+
   def test_replace_association
     assert_queries(4){posts(:welcome);people(:david);people(:michael); posts(:welcome).people(true)}