draft: add shortcuts for transaction

peewee_async/databases.py

@@ -101,6 +101,20 @@ async def aio_close(self) -> None:
 
         await self.pool_backend.close()
 
+    async def _aio_begin(self, use_savepoint: bool = False) -> Transaction:
+        _connection_context = connection_context.get()
+        if _connection_context is None:
+            raise Exception("This method can only be called within the aio_connection context manager")
+        tr = Transaction(_connection_context.connection, is_savepoint=use_savepoint)
+        await tr.begin()
+        return tr
+
+    async def aio_begin(self) -> Transaction:
+        return await self._aio_begin()
+
+    async def aio_savepoint(self) -> Transaction:
+        return await self._aio_begin(use_savepoint=True)
+
     def aio_atomic(self) -> AbstractAsyncContextManager[None]:
         """Create an async context-manager which runs any queries in the wrapped block
         in a transaction (or save-point if blocks are nested).

tests/test_transaction.py

@@ -110,9 +110,8 @@ async def t3() -> None:
 
 @dbs_all
 async def test_transaction_manual_work(db: AioDatabase) -> None:
-    async with db.aio_connection() as connection:
-        tr = Transaction(connection)
-        await tr.begin()
+    async with db.aio_connection():
+        tr = await db.aio_begin()
         await TestModel.aio_create(text="FOO")
         assert await TestModel.aio_get_or_none(text="FOO") is not None
         try:
@@ -180,14 +179,12 @@ async def test_savepoint_rollback(db: AioDatabase) -> None:
 
 @dbs_all
 async def test_savepoint_manual_work(db: AioDatabase) -> None:
-    async with db.aio_connection() as connection:
-        tr = Transaction(connection)
-        await tr.begin()
+    async with db.aio_connection():
+        tr = await db.aio_begin()
         await TestModel.aio_create(text="FOO")
         assert await TestModel.aio_get_or_none(text="FOO") is not None
 
-        savepoint = Transaction(connection, is_savepoint=True)
-        await savepoint.begin()
+        savepoint = await db.aio_savepoint()
         try:
             await TestModel.aio_create(text="FOO")
         except:  # noqa: E722