db: Split reset_queries into a new module zerver.lib.db_connections.

Fixes an import cycle that breaks mypy inference with django-stubs:

zproject.settings → zproject.computed_settings → zerver.lib.db →
django.db → django.db.backends.base.base →
django.db.backends.base.features → django.db.models.base →
django.db.models.options → django.contrib.contenttypes.fields →
django.contrib.contenttypes.models → confirmation.models → django.conf
→ zproject.settings

Signed-off-by: Anders Kaseorg <anders@zulip.com>

zerver/lib/db.py

@@ -51,11 +51,3 @@ class TimeTrackingConnection(connection):
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         self.queries: List[Dict[str, str]] = []
         super().__init__(*args, **kwargs)
-
-
-def reset_queries() -> None:
-    from django.db import connections
-
-    for conn in connections.all():
-        if conn.connection is not None:
-            conn.connection.queries = []

zerver/lib/db_connections.py

@@ -0,0 +1,7 @@
+from django.db import connections
+
+
+def reset_queries() -> None:
+    for conn in connections.all():
+        if conn.connection is not None:
+            conn.connection.queries = []

zerver/middleware.py

@@ -25,7 +25,7 @@ from sentry_sdk import set_tag
 from typing_extensions import Annotated, Concatenate, ParamSpec, override
 
 from zerver.lib.cache import get_remote_cache_requests, get_remote_cache_time
-from zerver.lib.db import reset_queries
+from zerver.lib.db_connections import reset_queries
 from zerver.lib.debug import maybe_tracemalloc_listen
 from zerver.lib.exceptions import ErrorCode, JsonableError, MissingAuthenticationError, WebhookError
 from zerver.lib.markdown import get_markdown_requests, get_markdown_time

zerver/worker/base.py

@@ -16,7 +16,7 @@ from returns.curry import partial
 from typing_extensions import override
 
 from zerver.lib.context_managers import lockfile
-from zerver.lib.db import reset_queries
+from zerver.lib.db_connections import reset_queries
 from zerver.lib.per_request_cache import flush_per_request_caches
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.queue import SimpleQueueClient

zerver/worker/missedmessage_emails.py

@@ -11,7 +11,7 @@ from django.db.utils import IntegrityError
 from django.utils.timezone import now as timezone_now
 from typing_extensions import override
 
-from zerver.lib.db import reset_queries
+from zerver.lib.db_connections import reset_queries
 from zerver.lib.email_notifications import MissedMessageData, handle_missedmessage_emails
 from zerver.lib.per_request_cache import flush_per_request_caches
 from zerver.models import ScheduledMessageNotificationEmail