pytest.mark.parametrize using django.test.SimpleTestCase

I’m using pytest 3.2.2 and Django 1.11.5 on Python 3.6.2 on Windows.

The following code

import django.test
 importpytest

 class ParametrizeTest:
     @pytest.mark.parametrize("param", ["a", "b"])
     def test_pytest(self, param):
         print(param)
         assert False
 

Works as expected:

scratch_test.py::ParametrizeTest::test_pytest[a] FAILED scratch_test.py::ParametrizeTest::test_pytest[b] failed

But once I changed it to use Django SimpleTestCase, like this:

class ParametrizeTest(django.test.SimpleTestCase):
    ...
 

It failed

TypeError: test_pytest() is missing 1 required positional parameter: ‘param’

Can anyone explain why? How to do it?
(I actually even need to use django.test.TestCase and access the database.)

I installed the following pytest plugins:

Plugin:random-0.2,mock-1.6.2,django-3.1.2,cov-2.5.1

But turning any (or all) of them off via -p no:random etc. will not help.

1> wim.. :

The Django test class is a unittest.TestCase subclass. Parameterization is not supported, this is documented in the pytest functions section of unittest.TestCase subclasses:

The following pytest functions do not work and may never work due to different design philosophies:

Clamps (except autouse clamps)

Parameterization

Customized hook

If you need parameterized tests and a pytest runner, your best option is to abandon the unit test style – this means moving setup/teardown into fixtures (the pytest-django plugin has Hardware components are implemented for you) and tested using module-level functionality.

2> Lutz Prechel..:

Use @pytest.mark.django_db

Thank you, thank you, for this helpful answer. RTFM, again.

For clarity, here is the preparation will (inheritance is equivalent to testing TestCase, not just SimpleTestCase). Make sure pytest-django is installed, then do the following:

import pytest

 @pytest.mark.django_db
 class ParametrizeTest:
     @pytest.mark.parametrize("param", ["a", "b"])
     def test_pytest(self, param):
         print(param)
         assert False
 

(As an aside, interestingly, one of the reasons I originally decided to use pytest was that the idea of ​​using pure test functionality rather than test methods appealed to me; I like the lightweight approach.
But now I still almost exclusively use test classes and methods because I prefer the clear grouping of tests they provide. )