test db setup

src/db.py

@@ -9,6 +9,18 @@ from sqlalchemy.orm import Session, sessionmaker
 
 DATABASE_URL_DEFAULT = "sqlite:///finanz.db"
 
+# Optional: allow an external engine (e.g. for testing with in-memory SQLite)
+_engine: Engine | None = None
+
+
+def set_engine(engine: Engine) -> None:
+    global _engine
+    _engine = engine
+
+
+def get_set_engine() -> Engine | None:
+    return _engine
+
 
 def get_engine() -> Engine:
     url = os.environ.get("DATABASE_URL", DATABASE_URL_DEFAULT)