run dependant tests with pytest

Question

With pytest, I'm setting dependencies using the library pytest-dependency. I also add markers to those tests. Here is an ECM :

# test_test.py
import pytest

@pytest.mark.dependency()
def test_a():
   assert True

@pytest.mark.category
@pytest.mark.dependency(depends=['test_a'])
def test_b():
   assert True

with the pytest.ini file to set the marker :

; pytest.ini
[pytest]
markers =
    category: category of tests.

When I try to run the test with the marker, as it is dependant on test_a which doesn't have the marker category, it is skipped :

user@pc → [~/Documents/test] $ pytest -vv -k category
============================================== test session starts ===============================================
platform darwin -- Python 3.9.8, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- /usr/local/opt/python@3.9/bin/python3.9
cachedir: .pytest_cache
rootdir: /Users/saigre/Documents/test, configfile: pytest.ini
plugins: dependency-0.5.1
collected 2 items / 1 deselected / 1 selected

test_test.py::test_b SKIPPED (test_b depends on test_a)                                                    [100%]

======================================== 1 skipped, 1 deselected in 0.05s ========================================

Is there a way to force the run of test_a because of the dependency. A solution would be to add the marker to the first test, but it would be complicated for the case I'm working on...

EDIT for @MrBean Bremen : I made an example of the scheme of dependency If I want to add a marker on a test, I would have to put this marker on all the branches, and the "root" would have many markers. It is not that it is complicated to do, but tedious.

If you filter by markers, this is not possible, AFAIK. Can you elaborate on why you can't add the marker to `test_a`? — MrBean Bremen, Nov 22 '21 at 14:47
I see. The only other possibility I see (aside from just adding the markers) is to add the markers programmatically, for example in `pytest_collection_modifyitems` using `item.addmarker()`, but for that, you would have to know or detect the dependencies in that place, which is probably not easier. Or write a plugin that automatically copies markers to dependent tests... — MrBean Bremen, Nov 22 '21 at 15:17
I am also searching for something that would add the dependent test cases automatically if not explicitly selected. — vk-code, Sep 02 '22 at 05:09
I am also facing same, when we filter with marker, `pytest` should know, this marker is depend on `test_a` then it should run `test_a` first. — Nilesh, Dec 01 '22 at 16:58

score 2 · Accepted Answer · answered Nov 29 '21 at 09:08

You can try this (something similar I have implemented):

Put all your test from the same category in a class, which inherits from a base class that has test_a. Put each class in a separate file, and pass that specific file to pytest. This way, you can get rid of markers as well.

Consider a pseudo example:

# tests/test_a.py #
import pytest

class TestA:

    @pytest.mark.dependency(name="TEST-A")
    def test_a(self):
        print("TEST-A was called")
        assert False


# tests/test_b.py #
import pytest
from tests.test_a import TestA

class TestB(TestA):

    def test_b1(self):
        print("TEST-B1 was called")
        assert True

    @pytest.mark.dependency(depends=["TEST-A"])
    def test_b2(self):
        print("TEST-B2 was called")
        assert True

Now, on CLI, just do this: $ pytest tests/test_b.py

tests/test_b.py::TestB::test_a <- tests/test_a.py FAILED                      [ 33%]
tests/test_b.py::TestB::test_b1 PASSED                                        [ 66%]
tests/test_b.py::TestB::test_b2 SKIPPED (test_b2 depends on TEST-A)           [100%]

===================================== FAILURES ======================================
___________________________________ TestB.test_a ____________________________________

self = <tests.test_b.TestB object at 0x7fc21886db20>

    @pytest.mark.dependency(name="TEST-A")
    def test_a(self):
        print("TEST-A was called")
>       assert False
E       assert False

tests/test_a.py:8: AssertionError
------------------------------- Captured stdout call --------------------------------
TEST-A was called
====================================== PASSES =======================================
___________________________________ TestB.test_b1 ___________________________________
------------------------------- Captured stdout call --------------------------------
TEST-B1 was called
============================== short test summary info ==============================
PASSED tests/test_b.py::TestB::test_b1
SKIPPED [1] ...: test_b2 depends on TEST-A
FAILED tests/test_b.py::TestB::test_a - assert False
====================== 1 failed, 1 passed, 1 skipped in 0.19s =======================

run dependant tests with pytest

1 Answers1