How to use multiple pytest fixtures with same parameterized input to test methods in a class

Question

I want to achieve something like this:

my conftest.py will contain:

fixture_1 - will do some manipulation with input such as a, b, c using request.param
fixture_2 - will do some manipulation with input such as a, b, c using request.param
fixture_3 - will do some manipulation with input such as a, b, c using request.param

@pytest.mark.parametrize('param_name', ['a', 'b', 'c'], indirect=True)
class TestDummy(object):

    def test_x(self, fixture_1):
        fixture_1_output = fixture_1
        assert False

    def test_y(self, fixture_2):
        fixture_2_output = fixture_2
        assert False

    def test_z(self, fixture_3):
        fixture_3_output = fixture_3
        assert False

Any suggestion would be highly appreciated.

score 1 · Accepted Answer · answered Feb 19 '22 at 19:38

You cannot directly patameterize the fixture name this way. Either you use parametrize for each test separately:

def params():
   return ['a', 'b', 'c']

class TestDummy:
    @pytest.parametrize(fixture_1, params, indirect=True)
    def test_x(self, fixture_1):
        fixture_1_output = fixture_1
        assert False

    @pytest.parametrize(fixture_2, params, indirect=True)
    def test_y(self, fixture_2):
        fixture_2_output = fixture_2
        assert False

    @pytest.parametrize(fixture_3, params, indirect=True)
    def test_z(self, fixture_3):
        fixture_3_output = fixture_3
        assert False

(I moved the parameters into an extra function for convenience)

Or you have to do the parametrization dynamically based on the fixture name using pytest_generate_tests:

def pytest_generate_tests(metafunc):
    fixtures = [f for f in metafunc.fixturenames if f.startswith("fixture_")]
    if len(fixtures) == 1:
        metafunc.parametrize(fixtures[0], ['a', 'b', 'c'], indirect=True)

class TestDummy:
    def test_x(self, fixture_1):
        fixture_1_output = fixture_1
        assert False

    def test_y(self, fixture_2):
        fixture_2_output = fixture_2
        assert False

    def test_z(self, fixture_3):
        fixture_3_output = fixture_3
        assert False

    def test_something_else(self):
        pass

You need to determine which tests to parametrize - in this example all tests are parametrized which have exactly one fixture with a name starting with "fixture_", you may have to adapt ths to your needs.

In this example, the first 3 tests will be parametrized, but not the last one (test_something_else).

Thanks MrBean Bremen, Appreciate your time. Also could you also suggest how can we share the result of any fixture such as fixture_1 in test y and test z ? — Shiva Kumar, Feb 20 '22 at 14:52
Sorry, don't understand what you mean by that. Can you elaborate a bit? — MrBean Bremen, Feb 20 '22 at 16:51

How to use multiple pytest fixtures with same parameterized input to test methods in a class

1 Answers1