fix: Only set AUTOCOMMIT isolation level during internal fixture setu…

…p which requires it.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pytest-mock-resources"
-version = "2.6.9"
+version = "2.6.10"
 description = "A pytest plugin for easily instantiating reproducible mock resources."
 authors = [
     "Omar Khan <oakhan3@gmail.com>",

src/pytest_mock_resources/container/postgres.py

@@ -89,9 +89,7 @@ def check_fn(self):
             s.close()
 
 
-def get_sqlalchemy_engine(
-    config, database_name, isolation_level="AUTOCOMMIT", async_=False, **engine_kwargs
-):
+def get_sqlalchemy_engine(config, database_name, async_=False, autocommit=False, **engine_kwargs):
     # For backwards compatibility, our hardcoded default is psycopg2, and async fixtures
     # will not work with psycopg2, so we instead swap the default to the preferred async driver.
     drivername = config.drivername
@@ -107,11 +105,14 @@ def get_sqlalchemy_engine(
         database=database_name,
     )
 
+    if autocommit:
+        engine_kwargs["isolation_level"] = "AUTOCOMMIT"
+
     if getattr(url.get_dialect(), "is_async", None):
         from sqlalchemy.ext.asyncio import create_async_engine
 
-        engine = create_async_engine(url, **engine_kwargs, isolation_level=isolation_level)
+        engine = create_async_engine(url, **engine_kwargs)
     else:
-        engine = sqlalchemy.create_engine(url, **engine_kwargs, isolation_level=isolation_level)
+        engine = sqlalchemy.create_engine(url, **engine_kwargs)
 
     return engine

src/pytest_mock_resources/fixture/postgresql.py

@@ -113,7 +113,9 @@ def _sync_fixture(pmr_config, engine_manager_kwargs, engine_kwargs):
     conn.close()
     root_engine.dispose()
 
-    root_engine = cast(Engine, get_sqlalchemy_engine(pmr_config, pmr_config.root_database))
+    root_engine = cast(
+        Engine, get_sqlalchemy_engine(pmr_config, pmr_config.root_database, autocommit=True)
+    )
     with root_engine.connect() as root_conn:
         with root_conn.begin() as trans:
             template_database, template_manager, engine_manager = create_engine_manager(
@@ -136,7 +138,9 @@ def _sync_fixture(pmr_config, engine_manager_kwargs, engine_kwargs):
 
     # Everything below is normal per-test context. We create a brand new database/engine/manager
     # distinct from what might have been used for the template database.
-    root_engine = cast(Engine, get_sqlalchemy_engine(pmr_config, pmr_config.root_database))
+    root_engine = cast(
+        Engine, get_sqlalchemy_engine(pmr_config, pmr_config.root_database, autocommit=True)
+    )
     with root_engine.connect() as root_conn:
         with root_conn.begin() as trans:
             database_name = _produce_clean_database(root_conn, createdb_template=template_database)
@@ -148,7 +152,9 @@ def _sync_fixture(pmr_config, engine_manager_kwargs, engine_kwargs):
 
 
 async def _async_fixture(pmr_config, engine_manager_kwargs, engine_kwargs):
-    root_engine = get_sqlalchemy_engine(pmr_config, pmr_config.root_database, async_=True)
+    root_engine = get_sqlalchemy_engine(
+        pmr_config, pmr_config.root_database, async_=True, autocommit=True
+    )
 
     root_conn = await async_retry(root_engine.connect, retries=DEFAULT_RETRIES)
     await root_conn.close()

src/pytest_mock_resources/hooks.py

@@ -108,7 +108,9 @@ def pytest_sessionfinish(session, exitstatus):
                 try:
                     container = docker.container.inspect(container_id)
                 except Exception:
-                    warnings.warn(f"Unrecognized container {container_id}")
+                    warnings.warn(
+                        f"Unrecognized container {container_id}. You may need to manually delete/edit {fn}"
+                    )
                 else:
                     try:
                         container.kill()

tests/fixture/test_postgres.py

@@ -45,3 +45,13 @@ def test_createdb_template(createdb_template_pg):
     """Assert successful usage of a fixture which sets the `createdb_template` argument."""
     with createdb_template_pg.begin() as conn:
         conn.execute(Thing.__table__.insert().values({"id": 1}))
+
+
+nested_transaction = create_postgres_fixture(Base)
+
+
+def test_nested_transaction(nested_transaction):
+    """Assert success with a fixture relying on being in a transaction (like SAVEPOINT)."""
+    with nested_transaction.begin() as conn:
+        with conn.begin_nested():
+            conn.execute(Thing.__table__.insert().values({"id": 1}))