Add support for JSONArray function

Author: WaVEV

django_mongodb_backend/features.py

@@ -87,8 +87,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         # of $setIsSubset must be arrays. Second argument is of type: null"
         # https://jira.mongodb.org/browse/SERVER-99186
         "model_fields_.test_arrayfield.QueryingTests.test_contained_by_subquery",
-        # JSONArray not implemented.
-        "db_functions.json.test_json_array.JSONArrayTests",
         # Some usage of prefetch_related() raises "ColPairs is not supported."
         "known_related_objects.tests.ExistingRelatedInstancesTests.test_one_to_one_multi_prefetch_related",
         "known_related_objects.tests.ExistingRelatedInstancesTests.test_one_to_one_prefetch_related",

django_mongodb_backend/functions.py

@@ -1,5 +1,6 @@
 from django.db import NotSupportedError
 from django.db.models.expressions import Func
+from django.db.models.functions import JSONArray
 from django.db.models.functions.comparison import Cast, Coalesce, Greatest, Least, NullIf
 from django.db.models.functions.datetime import (
     Extract,
@@ -238,6 +239,7 @@ def register_functions():
     Cot.as_mql = cot
     Extract.as_mql = extract
     Func.as_mql = func
+    JSONArray.as_mql = process_lhs
     Left.as_mql = left
     Length.as_mql = length
     Log.as_mql = log