Fix transaction typing (#2232)

* refactor: update TransactionContext to use concrete type for __aenter__ method

* chore: updated CHANGELOG

* Updated CHANGELOG

Updated the CHANGELOG with the correct PR number.

Author: vlakius

CHANGELOG.rst

@@ -25,6 +25,8 @@ Fixed
 - ``MigrationRecorder`` no longer emits tortoise's own ``pk`` field ``DeprecationWarning`` when applying migrations; it now builds its bookkeeping model with ``primary_key=True``. (#2203)
 - ``QuerySet.count()`` now matches the limited query result for the LIMIT/OFFSET edge cases: it returns ``0`` (instead of a negative number) when ``offset()`` exceeds the total row count, and ``0`` (instead of the total) for ``limit(0)``. (#2208)
 - Field declarations on models now resolve to their concrete type (e.g. ``CharField[str]``) in Pyright/Pylance instead of ``Field[Unknown]``; the ``Field.__new__`` type-check stub now returns ``Self``. (#2216)
+- ``TransactionContext`` now returns a ``TransactionalDBClient`` instead of a raw database connection. This change gives the correct inferred type for the transaction context. (#2232)
+
 
 1.1.7
 -----

tortoise/backends/base/client.py

@@ -306,14 +306,14 @@ async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
         self._lock.release()
 
 
-class TransactionContext(Generic[T_conn]):
+class TransactionContext:
     """A context manager interface for transactions. It is returned from in_transaction
     and _in_transaction."""
 
     client: TransactionalDBClient
 
     @abc.abstractmethod
-    async def __aenter__(self) -> T_conn: ...
+    async def __aenter__(self) -> TransactionalDBClient: ...
 
     @abc.abstractmethod
     async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None: ...

tortoise/backends/sqlite/client.py

@@ -16,7 +16,6 @@
     Capabilities,
     ConnectionWrapper,
     NestedTransactionContext,
-    T_conn,
     TransactionalDBClient,
     TransactionContext,
 )
@@ -191,7 +190,7 @@ async def ensure_connection(self) -> None:
             await self.connection._parent.create_connection(with_db=True)
             self.connection._connection = self.connection._parent._connection
 
-    async def __aenter__(self) -> T_conn:
+    async def __aenter__(self) -> TransactionalDBClient:
         await self._trxlock.acquire()
         await self.ensure_connection()
         self.token = get_connections().set(self.connection_name, self.connection)