add unit test

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -421,6 +421,17 @@ class ContentStoreTest(ModuleStoreTestCase):
         self.assertIn('markdown', problem.metadata, "markdown is missing from metadata")
         self.assertNotIn('markdown', problem.editable_metadata_fields, "Markdown slipped into the editable metadata fields")
 
+    def test_import_metadata_with_attempts_empty_string(self):
+        import_from_xml(modulestore(), 'common/test/data/', ['simple'])
+        ms = modulestore('direct')
+        asserted = False
+        try:       
+            effort = ms.get_item(Location(['i4x', 'edX', 'simple', 'problem', 'ps01-simple', None]))
+        except ItemNotFoundError:
+            asserted = True
+
+        # make sure we found the item (e.g. it didn't error while loading)
+        self.assertFalse(asserted)   
 
 class TemplateTestCase(ModuleStoreTestCase):