Fix incorrect attribute for key prefix in RedisTrackerStore

Fix RasaHQ#7306

rasa/core/tracker_store.py

@@ -346,18 +346,20 @@ def save(self, tracker, timeout=None):
             timeout = self.record_exp
 
         serialised_tracker = self.serialise_tracker(tracker)
-        self.red.set(self.prefix + tracker.sender_id, serialised_tracker, ex=timeout)
+        self.red.set(
+            self.key_prefix + tracker.sender_id, serialised_tracker, ex=timeout
+        )
 
     def retrieve(self, sender_id: Text) -> Optional[DialogueStateTracker]:
-        stored = self.red.get(self.prefix + sender_id)
+        stored = self.red.get(self.key_prefix + sender_id)
         if stored is not None:
             return self.deserialise_tracker(sender_id, stored)
         else:
             return None
 
     def keys(self) -> Iterable[Text]:
         """Returns keys of the Redis Tracker Store"""
-        return self.red.keys(self.prefix + "*")
+        return self.red.keys(self.key_prefix + "*")
 
 
 class DynamoTrackerStore(TrackerStore):

tests/shared/core/test_trackers.py

@@ -77,20 +77,15 @@
 
 
 class MockRedisTrackerStore(RedisTrackerStore):
-    # skipcq:PYL-W0231
-    # can't call call super init since it would init a redis connection
     def __init__(self, _domain: Domain) -> None:
+        super().__init__(_domain)
+
+        # Patch the Redis connection in RedisTrackerStore using fakeredis
         self.red = fakeredis.FakeStrictRedis()
-        self.record_exp = None
 
         # added in redis==3.3.0, but not yet in fakeredis
         self.red.connection_pool.connection_class.health_check_interval = 0
 
-        # Defined in RedisTrackerStore but needs to be added for the MockRedisTrackerStore
-        self.prefix = "tracker:"
-
-        TrackerStore.__init__(self, _domain)
-
 
 def stores_to_be_tested():
     temp = tempfile.mkdtemp()