Catch BSON errors as well as PyMongo errors when emitting

MongoDB events.

TNL-2035

common/djangoapps/track/backends/mongodb.py

@@ -7,6 +7,7 @@ import logging
 import pymongo
 from pymongo import MongoClient
 from pymongo.errors import PyMongoError
+from bson.errors import BSONError
 
 from track.backends import BaseBackend
 
@@ -89,8 +90,9 @@ class MongoBackend(BaseBackend):
         """Insert the event in to the Mongo collection"""
         try:
             self.collection.insert(event, manipulate=False)
-        except PyMongoError:
-            # The event will be lost in case of a connection error.
+        except (PyMongoError, BSONError):
+            # The event will be lost in case of a connection error or any error
+            # that occurs when trying to insert the event into Mongo.
             # pymongo will re-connect/re-authenticate automatically
             # during the next event.
             msg = 'Error inserting to MongoDB event tracker backend'

common/test/acceptance/tests/studio/test_studio_split_test.py

@@ -1044,7 +1044,6 @@ class GroupConfigurationsTest(ContainerBase, SplitTestMixin):
         rendered_group_names = self.get_select_options(page=courseware_page, selector=".split-test-select")
         self.assertListEqual(group_names, rendered_group_names)
 
-    @skip  # TODO fix this, see TNL-2035
     def test_split_test_LMS_staff_view(self):
         """
         Scenario: Ensure that split test is correctly rendered in LMS staff mode as it is