Use Config.stash in pytest_session{start,finish}

Author: khaeru

ixmp/testing/__init__.py

@@ -74,6 +74,7 @@
 if TYPE_CHECKING:
     from _pytest.mark import ParameterSet
     from ixmp4.core import Run
+    from sqlalchemy import Engine  # noqa: F401
 
     try:
         # Pint 0.25.1 or later
@@ -108,6 +109,10 @@
 #: :any:`True` if testing is occurring on GitHub Actions runners/machines.
 GHA = "GITHUB_ACTIONS" in os.environ
 
+# Pytest stash keys
+KEY_ENGINE = pytest.StashKey["Engine"]()
+KEY_IXMP4_PG_NAME = pytest.StashKey[str]()
+
 _uname = platform.uname()
 
 #: Pytest marks for use throughout the test suite.
@@ -179,7 +184,7 @@ def pytest_sessionstart(session: pytest.Session) -> None:
     - :data:`.jdbc._GC_AGGRESSIVE` is set to :any:`False` to disable aggressive garbage
       collection, which can be slow.
     """
-    from ixmp.backend import available, jdbc
+    from ixmp.backend import jdbc
 
     if not session.config.option.ixmp_user_config:
         ixmp_config.clear()
@@ -194,34 +199,29 @@ def pytest_sessionstart(session: pytest.Session) -> None:
         from xdist import get_xdist_worker_id
 
         db_name = f"ixmp_test_{get_xdist_worker_id(session)}"
-
-        engine = create_engine(
-            "postgresql+psycopg://postgres:postgres@localhost:5432/postgres",
-            isolation_level="AUTOCOMMIT",
-        )
+        url = "postgresql+psycopg://postgres:postgres@localhost:5432/postgres"
+        engine = create_engine(url, isolation_level="AUTOCOMMIT")
         with engine.connect() as connection:
             connection.execute(text(f"CREATE DATABASE {db_name}"))
 
-        engine.dispose()
+        # Store for pytest_sessionfinish()
+        session.config.stash[KEY_ENGINE] = engine
+        session.config.stash[KEY_IXMP4_PG_NAME] = db_name
 
 
 def pytest_sessionfinish(
     session: pytest.Session, exitstatus: int | pytest.ExitCode
 ) -> None:
-    if "ixmp4" in available():
-        from sqlalchemy import create_engine, text
-        from xdist import get_xdist_worker_id
+    try:
+        from sqlalchemy import text
 
-        db_name = f"ixmp_test_{get_xdist_worker_id(session)}"
+        engine = session.config.stash[KEY_ENGINE]
+        db_name = session.config.stash[KEY_IXMP4_PG_NAME]
 
-        engine = create_engine(
-            "postgresql+psycopg://postgres:postgres@localhost:5432/postgres",
-            isolation_level="AUTOCOMMIT",
-        )
         with engine.connect() as connection:
             connection.execute(text(f"DROP DATABASE {db_name}"))
-
-        engine.dispose()
+    except (ImportError, KeyError):
+        pass
 
 
 def pytest_report_header(config: pytest.Config, start_path: Path) -> str: