update docs/tests for $facet removal

Author: timgraham

docs/ref/models/encrypted-fields.rst

@@ -124,16 +124,16 @@ may vary.
 - :meth:`~django.db.models.query.QuerySet.alias`,
   :meth:`~django.db.models.query.QuerySet.annotate`,
   :meth:`~django.db.models.query.QuerySet.distinct`: Cannot group on field
-  '_id.value' which is encrypted with the random algorithm or whose encryption
-  properties are not known until runtime.
+  '<encrypted_field>' which is encrypted with the random algorithm or whose
+  encryption properties are not known until runtime.
 - :meth:`~django.db.models.query.QuerySet.dates`,
   :meth:`~django.db.models.query.QuerySet.datetimes`: If the value type is a
   date, the type of the index must also be date (and vice versa).
 - :meth:`~django.db.models.query.QuerySet.in_bulk`: Encrypted fields can't have
   unique constraints.
-
-# TODO: add details about joined queries after
-https://github.com/mongodb/django-mongodb-backend/pull/443 is finalized.
+- Queries that join multiple collections and require the ``let`` operator. Such
+  queries usually involve expressions or subqueries: Non-empty 'let' field is
+  not allowed in the $lookup aggregation stage over an encrypted collection.
 
 There are also several ``QuerySet`` methods that aren't permitted on any models
 (regardless of whether or not they have encrypted fields) that use a database
@@ -142,10 +142,8 @@ sample error message from the database.
 
 - :meth:`~django.db.models.query.QuerySet.update`: Multi-document updates are
   not allowed with Queryable Encryption.
-- :meth:`~django.db.models.query.QuerySet.aggregate`,
-  :meth:`~django.db.models.query.QuerySet.count`: Aggregation stage
-  $internalFacetTeeConsumer is not allowed or supported with automatic
-  encryption.
+- :meth:`~django.db.models.query.QuerySet.aggregate`: Invalid reference to an
+  encrypted field within aggregate expression.
 - :meth:`~django.db.models.query.QuerySet.union`: Aggregation stage $unionWith
   is not allowed or supported with automatic encryption.
 

tests/encryption_/test_fields.py

@@ -5,7 +5,7 @@
 
 from bson import ObjectId
 from django.db import DatabaseError
-from django.db.models import Avg, F, Q
+from django.db.models import Avg, Count, F, Q
 
 from django_mongodb_backend.fields import (
     EncryptedArrayField,
@@ -243,14 +243,18 @@ def test_time(self):
 
 
 class QueryTests(EncryptionTestCase):
-    def test_aggregate(self):
+    def test_aggregate_avg(self):
         msg = (
-            "Aggregation stage $internalFacetTeeConsumer is not allowed or "
-            "supported with automatic encryption."
+            "csfle \"analyze_query\" failed: Accumulator '$avg' cannot aggregate encrypted fields."
         )
         with self.assertRaisesMessage(DatabaseError, msg):
             list(IntegerModel.objects.aggregate(Avg("value")))
 
+    def test_aggregate_count(self):
+        msg = "Invalid reference to an encrypted field within aggregate expression: value"
+        with self.assertRaisesMessage(DatabaseError, msg):
+            list(IntegerModel.objects.aggregate(Count("value")))
+
     def test_alias(self):
         msg = (
             "Cannot group on field '_id.value' which is encrypted with the "
@@ -291,12 +295,9 @@ def test_contains(self):
         self.assertIs(CharModel.objects.contains(obj), True)
 
     def test_count(self):
-        msg = (
-            "Aggregation stage $internalFacetTeeConsumer is not allowed or "
-            "supported with automatic encryption."
-        )
-        with self.assertRaisesMessage(DatabaseError, msg):
-            list(CharModel.objects.count())
+        CharModel.objects.create(value="a")
+        CharModel.objects.create(value="b")
+        self.assertEqual(CharModel.objects.count(), 2)
 
     def test_dates(self):
         msg = (