Using pytest fixture with parameter from mark

Question

I try to create a test case in pytest. I want to use parameterized fixtures to get parameters from the @pytest.mark.parametrize decorator and create more types of tests. My code looks right now:

@pytest.mark.parametrize( 
    "a",
    ["1", "2"],
    ids=["a:1", "a:2"]
)
@pytest.mark.parametrize(  # type: ignore
    "fixture_a",
    [{"b": 1}],
    ids=["b:1"],
    indirect=["fixture_a"],
)
def test_postgres_basic(fixture_a, a):
    ...

What do I want?

I want to send parameter a to fixture_a so fixture request.param wouldn't be {"b": 1} but something like {"b":1, a: "1"} and {"b":1, a: "2"}. Is it possible in some easy way?

Thank you

Answer 1

An alternative is just define the value of a manually in the dict to be passed to the fixture.

import pytest


@pytest.fixture
def fixture_a(request):
    print(f"{request.param=}")
    return request.param


@pytest.mark.parametrize( 
    "fixture_a, a",
    [
        ({"a": 1, "b": 1}, "1"),
        ({"a": 2, "b": 1}, "2"),
    ],
    ids=["a:1", "a:2"],
    indirect=["fixture_a"],
)
def test_postgres_basic(fixture_a, a):
    print(fixture_a, a)

Output

$ pytest -q -rP
..
[100%]
================================================================================================= PASSES ==================================================================================================
________________________________________________________________________________________ test_postgres_basic[a:1] _________________________________________________________________________________________
------------------------------------------------------------------------------------------ Captured stdout setup ------------------------------------------------------------------------------------------
request.param={'a': 1, 'b': 1}
------------------------------------------------------------------------------------------ Captured stdout call -------------------------------------------------------------------------------------------
{'a': 1, 'b': 1} 1
________________________________________________________________________________________ test_postgres_basic[a:2] _________________________________________________________________________________________
------------------------------------------------------------------------------------------ Captured stdout setup ------------------------------------------------------------------------------------------
request.param={'a': 2, 'b': 1}
------------------------------------------------------------------------------------------ Captured stdout call -------------------------------------------------------------------------------------------
{'a': 2, 'b': 1} 2
2 passed in 0.06s