Make lock optional for force_rollback sessions

based/database.py

@@ -58,7 +58,7 @@ def __init__(
             raise ValueError("Invalid database URL")
         schema = url_parts[0]
 
-        if force_rollback or (schema == "sqlite" and use_lock):
+        if use_lock and (force_rollback or schema == "sqlite"):
             self._lock = Lock()
 
         if schema == "sqlite":

tests/test_backend.py

@@ -25,6 +25,27 @@ async def test_database_force_rollback(
             assert movie is None
 
 
+async def test_database_force_rollback_with_lock(
+    table: sqlalchemy.Table,
+    database_url: str,
+    gen_movie: typing.Callable[[], typing.Tuple[str, int]],
+):
+    title, year = gen_movie()
+
+    async with based.Database(
+        database_url, force_rollback=True, use_lock=True,
+    ) as database:
+        async with database.session() as session:
+            query = table.insert().values(title=title, year=year)
+            await session.execute(query)
+
+    async with based.Database(database_url, force_rollback=True) as database:
+        async with database.session() as session:
+            query = table.select().where(table.c.title == title)
+            movie = await session.fetch_one(query)
+            assert movie is None
+
+
 async def test_database_no_force_rollback(
     table: sqlalchemy.Table,
     database_url: str,