for AsyncEngine created in function scope, close and clean-up pooled connections adding await engine.dispose()

tests/conftest.py

@@ -1,14 +1,8 @@
 import pytest
 from httpx import AsyncClient
-from sqlalchemy.exc import SQLAlchemyError
-from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
-from sqlalchemy.orm import sessionmaker
-from sqlalchemy.pool import NullPool
-
-from the_app import config
-from the_app.database import get_db
 from the_app.main import app
 from the_app.models.base import Base
+from the_app.database import engine
 
 
 @pytest.fixture(
@@ -20,32 +14,13 @@ def anyio_backend(request):
     return request.param
 
 
-global_settings = config.get_settings()
-url = global_settings.asyncpg_test_url
-engine = create_async_engine(url, poolclass=NullPool, future=True)
-
-async_session = sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
-
-
-async def get_test_db():
-    session = async_session()
-    try:
-        yield session
-        await session.commit()
-    except SQLAlchemyError as ex:
-        await session.rollback()
-        raise ex
-    finally:
-        await session.close()
-
-
-app.dependency_overrides[get_db] = get_test_db
-
-
 async def start_db():
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.drop_all)
         await conn.run_sync(Base.metadata.create_all)
+    # for AsyncEngine created in function scope, close and
+    # clean-up pooled connections
+    await engine.dispose()
 
 
 @pytest.fixture