Some extra hints

Author: adamchainz

src/django_mysql/utils.py

@@ -132,7 +132,9 @@ def collapse_spaces(string: str) -> str:
     return " ".join(filter(None, bits))
 
 
-def index_name(model: Model, *field_names: str, using: str = DEFAULT_DB_ALIAS) -> str:
+def index_name(
+    model: type[Model], *field_names: str, using: str = DEFAULT_DB_ALIAS
+) -> str:
     """
     Returns the name of the index existing on field_names, or raises KeyError
     if no such index exists.

tests/testapp/test_locks.py

@@ -3,11 +3,13 @@
 import queue
 from threading import Thread
 from typing import TYPE_CHECKING
+from typing import cast
 
 import pytest
 from django.db import OperationalError
 from django.db import connection
 from django.db import connections
+from django.db.backends.mysql.base import DatabaseWrapper
 from django.db.transaction import TransactionManagementError
 from django.db.transaction import atomic
 from django.test import TestCase
@@ -34,7 +36,7 @@ class LockTests(TestCase):
     def setUpClass(cls):
         super().setUpClass()
 
-        cls.supports_lock_info = connection.mysql_is_mariadb
+        cls.supports_lock_info = cast(DatabaseWrapper, connection).mysql_is_mariadb
         if cls.supports_lock_info:
             with connection.cursor() as cursor:
                 cursor.execute(
@@ -229,7 +231,7 @@ def tearDown(self):
         Customer.objects.using("other").all().delete()
         super().tearDown()
 
-    def is_locked(self, connection_name, table_name):
+    def is_locked(self, connection_name: str, table_name: str) -> bool:
         conn = connections[connection_name]
         with conn.cursor() as cursor:
             cursor.execute(
@@ -239,7 +241,9 @@ def is_locked(self, connection_name, table_name):
             rows = cursor.fetchall()
             if rows:
                 assert len(rows) == 1
-                return rows[0][2] > 0
+                value = rows[0][2]
+                assert isinstance(value, int)
+                return value > 0
             else:  # pragma: no cover
                 # MySQL 8+ closes the table really quickly. If it's closed,
                 # it's not locked.

tests/testapp/test_size_fields.py

@@ -22,7 +22,7 @@
 forceDataError = override_mysql_variables(SQL_MODE="STRICT_TRANS_TABLES")
 
 
-def migrate(name):
+def migrate(name: str) -> None:
     call_command(
         "migrate", "testapp", name, verbosity=0, skip_checks=True, interactive=False
     )