Fix bug on vendors that does not support expression indexes

Author: WaVEV

django_mongodb_backend/schema.py

@@ -352,15 +352,15 @@ def _remove_field_index(self, model, field, column_prefix=""):
             )
         collection.drop_index(index_names[0])
 
-    def _check_supported_expressions(self, expressions):
+    def _check_supports_expression_indexes(self, expressions):
         if self.connection.vendor == "mongodb":
-            for expression in expressions:
-                expression = (
-                    expression.expression if isinstance(expression, OrderBy) else expression
+            return all(
+                isinstance(
+                    expression.expression if isinstance(expression, OrderBy) else expression, F
                 )
-                if not isinstance(expression, F):
-                    return False
-        return True
+                for expression in expressions
+            )
+        return self.connection.features.supports_expression_indexes
 
     def _unique_supported(
         self,
@@ -374,11 +374,7 @@ def _unique_supported(
             (not condition or self.connection.features.supports_partial_indexes)
             and (not deferrable or self.connection.features.supports_deferrable_unique_constraints)
             and (not include or self.connection.features.supports_covering_indexes)
-            and (
-                not expressions
-                or self._check_supported_expressions(expressions)
-                or self.connection.features.supports_expression_indexes
-            )
+            and (not expressions or self._check_supports_expression_indexes(expressions))
             and (
                 nulls_distinct is None
                 or self.connection.features.supports_nulls_distinct_unique_constraints