Fix dbapi error to comply with pep

clickhouse_sqlalchemy/drivers/asynch/base.py

@@ -1,5 +1,3 @@
-import asynch
-
 from sqlalchemy.sql.elements import TextClause
 from sqlalchemy.pool import AsyncAdaptedQueuePool
 
@@ -25,7 +23,7 @@ class ClickHouseDialect_asynch(ClickHouseDialect_native):
 
     @classmethod
     def import_dbapi(cls):
-        return AsyncAdapt_asynch_dbapi(asynch)
+        return AsyncAdapt_asynch_dbapi()
 
     @classmethod
     def get_pool_class(cls, url):

clickhouse_sqlalchemy/drivers/asynch/connector.py

@@ -1,5 +1,7 @@
 import asyncio
 
+import asynch
+import asynch.errors
 from sqlalchemy.engine.interfaces import AdaptedConnection
 from sqlalchemy.util.concurrency import await_only
 
@@ -109,15 +111,12 @@ def fetchall(self):
 
 
 class AsyncAdapt_asynch_dbapi:
-    def __init__(self, asynch):
-        self.asynch = asynch
+    def __init__(self):
         self.paramstyle = 'pyformat'
         self._init_dbapi_attributes()
 
-    class Error(Exception):
-        pass
-
     def _init_dbapi_attributes(self):
+        self.Error = asynch.errors.ClickHouseException
         for name in (
                 'ServerException',
                 'UnexpectedPacketFromServerError',
@@ -141,12 +140,12 @@ def _init_dbapi_attributes(self):
                 'ProgrammingError',
                 'NotSupportedError',
         ):
-            setattr(self, name, getattr(self.asynch.errors, name))
+            setattr(self, name, getattr(asynch.errors, name))
 
     def connect(self, *args, **kwargs) -> 'AsyncAdapt_asynch_connection':
         return AsyncAdapt_asynch_connection(
             self,
-            await_only(self.asynch.connect(*args, **kwargs))
+            await_only(asynch.connect(*args, **kwargs))
         )
 
 

tests/drivers/asynch/test_base.py

@@ -1,7 +1,10 @@
+import asynch.errors
+import sqlalchemy
+import sqlalchemy.event
 from sqlalchemy.engine.url import URL
 
 from clickhouse_sqlalchemy.drivers.asynch.base import ClickHouseDialect_asynch
-from tests.testcase import BaseTestCase
+from tests.testcase import AsynchSessionTestCase, BaseTestCase
 
 
 class TestConnectArgs(BaseTestCase):
@@ -46,3 +49,22 @@ def test_no_auth(self):
         self.assertEqual(
             str(connect_args[0][0]), 'clickhouse://localhost:9001/default'
         )
+
+
+class DBApiTestCase(AsynchSessionTestCase):
+    async def test_error_handler(self):
+        class MockedException(Exception):
+            pass
+
+        def handle_error(e: sqlalchemy.engine.ExceptionContext):
+            if isinstance(
+                e.original_exception,
+                asynch.errors.ServerException,
+            ):
+                raise MockedException()
+
+        engine = self.session.get_bind()
+        sqlalchemy.event.listen(engine, 'handle_error', handle_error)
+
+        with self.assertRaises(MockedException):
+            await self.session.execute(sqlalchemy.text('SELECT'))

tests/drivers/asynch/test_insert.py

@@ -1,8 +1,8 @@
-from sqlalchemy import Column, func, text
-
-from clickhouse_sqlalchemy import engines, types, Table
+import sqlalchemy.exc
 from asynch.errors import TypeMismatchError
+from sqlalchemy import Column, func, text
 
+from clickhouse_sqlalchemy import Table, engines, types
 from tests.testcase import AsynchSessionTestCase
 
 
@@ -45,16 +45,18 @@ async def test_types_check(self):
         await self.run_sync(metadata.drop_all)
         await self.run_sync(metadata.create_all)
 
-        with self.assertRaises(TypeMismatchError) as ex:
+        with self.assertRaises(sqlalchemy.exc.DBAPIError) as ex:
             await self.session.execute(
                 table.insert(),
                 [{'x': -1}],
                 execution_options=dict(types_check=True),
             )
+        self.assertTrue(isinstance(ex.exception.orig, TypeMismatchError))
         self.assertIn('-1 for column "x"', str(ex.exception))
 
-        with self.assertRaises(TypeMismatchError) as ex:
+        with self.assertRaises(sqlalchemy.exc.DBAPIError) as ex:
             await self.session.execute(table.insert(), {'x': -1})
+        self.assertTrue(isinstance(ex.exception.orig, TypeMismatchError))
         self.assertIn(
             'Repeat query with types_check=True for detailed info',
             str(ex.exception)