Use mypy 1.0

synapse/__init__.py

@@ -64,7 +64,9 @@
 try:
     from canonicaljson import set_json_library
 
-    set_json_library(json)
+    # type-ignore: I think there has been a regression in mypy 1.0.0 in how it checks
+    # modules against Protocols.
+    set_json_library(json)  # type: ignore[arg-type]
 except ImportError:
     pass
 

synapse/storage/engines/postgres.py

@@ -22,7 +22,7 @@
     IncorrectDatabaseSetup,
     IsolationLevel,
 )
-from synapse.storage.types import Cursor
+from synapse.storage.types import Cursor, DBAPI2Module
 
 if TYPE_CHECKING:
     from synapse.storage.database import LoggingDatabaseConnection
@@ -35,7 +35,9 @@ class PostgresEngine(
     BaseDatabaseEngine[psycopg2.extensions.connection, psycopg2.extensions.cursor]
 ):
     def __init__(self, database_config: Mapping[str, Any]):
-        super().__init__(psycopg2, database_config)
+        # Cast: mypy 1.0.0 doesn't seem to think that the module implements the protocol.
+        # AFAICS this is a false positive.
+        super().__init__(cast(DBAPI2Module, psycopg2), database_config)
         psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
 
         # Disables passing `bytes` to txn.execute, c.f. #6186. If you do

synapse/storage/engines/sqlite.py

@@ -15,18 +15,20 @@
 import sqlite3
 import struct
 import threading
-from typing import TYPE_CHECKING, Any, List, Mapping, Optional
+from typing import TYPE_CHECKING, Any, List, Mapping, Optional, cast
 
 from synapse.storage.engines import BaseDatabaseEngine
-from synapse.storage.types import Cursor
+from synapse.storage.types import Cursor, DBAPI2Module
 
 if TYPE_CHECKING:
     from synapse.storage.database import LoggingDatabaseConnection
 
 
 class Sqlite3Engine(BaseDatabaseEngine[sqlite3.Connection, sqlite3.Cursor]):
     def __init__(self, database_config: Mapping[str, Any]):
-        super().__init__(sqlite3, database_config)
+        # Cast: mypy 1.0.0 doesn't seem to think that the module implements the protocol.
+        # AFAICS this is a false positive.
+        super().__init__(cast(DBAPI2Module, sqlite3), database_config)
 
         database = database_config.get("args", {}).get("database")
         self._is_in_memory = database in (