Merge pull request #11522 from edx/gabe/remove-ga-fields

copy event on write

common/djangoapps/track/shim.py

@@ -177,7 +177,10 @@ class GoogleAnalyticsProcessor(object):
         context = event.get('context', {})
         course_id = context.get('course_id')
 
+        copied_event = event.copy()
         if course_id is not None:
-            event['label'] = course_id
+            copied_event['label'] = course_id
 
-        event['nonInteraction'] = 1
+        copied_event['nonInteraction'] = 1
+
+        return copied_event

common/djangoapps/track/tests/test_shim.py

@@ -149,3 +149,70 @@ class GoogleAnalyticsProcessorTestCase(EventTrackingTestCase):
             'timestamp': FROZEN_TIME,
         }
         assert_events_equal(expected_event, emitted_event)
+
+
+@override_settings(
+    EVENT_TRACKING_BACKENDS={
+        '0': {
+            'ENGINE': 'eventtracking.backends.routing.RoutingBackend',
+            'OPTIONS': {
+                'backends': {
+                    'first': {'ENGINE': 'track.tests.InMemoryBackend'}
+                },
+                'processors': [
+                    {
+                        'ENGINE': 'track.shim.GoogleAnalyticsProcessor'
+                    }
+                ]
+            }
+        },
+        '1': {
+            'ENGINE': 'eventtracking.backends.routing.RoutingBackend',
+            'OPTIONS': {
+                'backends': {
+                    'second': {
+                        'ENGINE': 'track.tests.InMemoryBackend'
+                    }
+                }
+            }
+        }
+    }
+)
+class MultipleShimGoogleAnalyticsProcessorTestCase(EventTrackingTestCase):
+    """Ensure changes don't impact other backends"""
+
+    def test_multiple_backends(self):
+        data = {
+            sentinel.key: sentinel.value,
+        }
+
+        context = {
+            'path': sentinel.path,
+            'user_id': sentinel.user_id,
+            'course_id': sentinel.course_id,
+            'org_id': sentinel.org_id,
+            'client_id': sentinel.client_id,
+        }
+        with self.tracker.context('test', context):
+            self.tracker.emit(sentinel.name, data)
+
+        segment_emitted_event = self.tracker.backends['0'].backends['first'].events[0]
+        log_emitted_event = self.tracker.backends['1'].backends['second'].events[0]
+
+        expected_event = {
+            'context': context,
+            'data': data,
+            'label': sentinel.course_id,
+            'name': sentinel.name,
+            'nonInteraction': 1,
+            'timestamp': FROZEN_TIME,
+        }
+        assert_events_equal(expected_event, segment_emitted_event)
+
+        expected_event = {
+            'context': context,
+            'data': data,
+            'name': sentinel.name,
+            'timestamp': FROZEN_TIME,
+        }
+        assert_events_equal(expected_event, log_emitted_event)