TIL: How to use fixtures conditionally with pytest
TIL: How to use fixtures conditionally with pytest
Pytest has changed the way I write unit tests: As I work on them, I am constantly looking out for opportunities to use pytest.mark.parametrize to extend the scope of my tests, or pytest.fixture to manage resources used by tests. Recently, I learned it is possible to parametrize fixtures with pytest.mark.parametrize using the indirect argument:
import socket
import pytest
import app
@pytest.fixture
def db_client(request):
match request.param:
case "postgres":
client = app.setup_postgres_client()
case "TCP":
client = app.setup_sqlite_client()
case _:
raise ValueError("Only UDP or TCP socket types are supported")
yield client
app.teardown_db_client(client)
@pytest.mark.parameterize("db_client", ["postgres", "sqlite"], indirect=True)
def test_app(my_socket):
app.flush(db_client)
...As showcased, this allows me to generate multiple test cases that each interact with a different database client1, pretty useful if your application can work with multiple databases.
Footnotes
1
Each client should be adapted to have the same common interface so that they can be used interchangeably by our app.