run handle error for commit/rollback fail and cancel transaction

Fixed bug in asyncpg dialect where a failure during a "commit" or less
likely a "rollback" should cancel the entire transaction; it's no longer
possible to emit rollback. Previously the connection would continue to
await a rollback that could not succeed as asyncpg would reject it.

Fixes: #5824
Change-Id: I5a4916740c269b410f4d1a78ed25191de344b9d0

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/fixtures.py b/lib/sqlalchemy/testing/fixtures.py
index dcdeee5c9..08cab051e 100644
--- a/lib/sqlalchemy/testing/fixtures.py
+++ b/lib/sqlalchemy/testing/fixtures.py
@@ -107,6 +107,14 @@ class TestBase(object):
         engines.testing_reaper._drop_testing_engines("fixture")
 
     @config.fixture()
+    def async_testing_engine(self, testing_engine):
+        def go(**kw):
+            kw["asyncio"] = True
+            return testing_engine(**kw)
+
+        return go
+
+    @config.fixture()
     def metadata(self, request):
         """Provide bound MetaData for a single test, dropping afterwards."""