I am trying to setup testdb for production environment FastAPI application

below is my project structure

my_project
    main.py
    api
        v1
            users
                app.py
    database
        connection.py
    tests
        conftest.py
        users_test.py

conftest.py looks like this

DATABASE_URL = settings.mysql_test_url
print("Database URL used for tests:", DATABASE_URL)

engine = create_engine(DATABASE_URL)
TestSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def override_get_db():
    print("Using test database session")
    db = TestSessionLocal()
    try:
        yield db
    finally:
        db.close()


@pytest.fixture(scope="module")
def test_db():
    app.dependency_overrides[get_db] = override_get_db
    Base.metadata.create_all(bind=engine)
    client = TestClient(app)
    yield client
    Base.metadata.drop_all(bind=engine)

one of my test cases look this

from tests.conftest import test_db,TestSessionLocal


def test_signup(test_db,setup_db):
    response = test_db.post("/public/user/sign-up", json={"email": "[email protected]", "password": "password"})
    assert response.status_code == 200

Problem

schema is creating in testdb (i verified by uncommenting drop all line)
but data is writing in main db(prod db)
I have used override of dependency but still its not working.

Anything i need to change here

Thanks for time and response.