add unit test to verify that the store updated signal actually fired. Also fix…

add unit test to verify that the store updated signal actually fired. Also fix bug where cloning item doesn't update the inherited metadata caches

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -13,6 +13,7 @@ import copy
 from json import loads
 
 from django.contrib.auth.models import User
+from django.dispatch import Signal
 from contentstore.utils import get_modulestore
 
 from .utils import ModuleStoreTestCase, parse_json
@@ -591,6 +592,32 @@ class ContentStoreTest(ModuleStoreTestCase):
 
         self.assertNotEquals(new_discussion_item.discussion_id, '$$GUID$$')
 
+    def test_update_modulestore_signal_did_fire(self):
+
+        import_from_xml(modulestore(), 'common/test/data/', ['full'])
+        module_store = modulestore('direct')
+
+        try:
+            module_store.modulestore_update_signal = Signal(providing_args=['modulestore', 'course_id', 'location'])
+
+            self.got_signal = False
+
+            def _signal_hander(modulestore=None, course_id=None, location=None, **kwargs):
+                self.got_signal = True
+
+            module_store.modulestore_update_signal.connect(_signal_hander)
+
+            new_component_location = Location('i4x', 'edX', 'full', 'html', 'new_component')
+            source_template_location = Location('i4x', 'edx', 'templates', 'html', 'Blank_HTML_Page')
+
+            # crate a new module
+            module_store.clone_item(source_template_location, new_component_location)
+
+        finally:
+            module_store.modulestore_update_signal = None
+
+        self.assertTrue(self.got_signal)
+
     def test_metadata_inheritance(self):
         import_from_xml(modulestore(), 'common/test/data/', ['full'])
 

common/lib/xmodule/xmodule/modulestore/mongo.py

@@ -537,6 +537,7 @@ class MongoModuleStore(ModuleStoreBase):
         Clone a new item that is a copy of the item at the location `source`
         and writes it to `location`
         """
+        item = None
         try:
             source_item = self.collection.find_one(location_to_query(source))
 
@@ -568,7 +569,6 @@ class MongoModuleStore(ModuleStoreBase):
                 course.tabs = existing_tabs
                 self.update_metadata(course.location, course._model_data._kvs._metadata)
 
-            return item
         except pymongo.errors.DuplicateKeyError:
             raise DuplicateItemError(location)
 
@@ -576,6 +576,8 @@ class MongoModuleStore(ModuleStoreBase):
         self.refresh_cached_metadata_inheritance_tree(Location(location))
         self.fire_updated_modulestore_signal(get_course_id_no_run(Location(location)), Location(location))
 
+        return item
+
     def fire_updated_modulestore_signal(self, course_id, location):
         if self.modulestore_update_signal is not None:
             self.modulestore_update_signal.send(self, modulestore=self, course_id=course_id,