pytest-subtests

unittest subTest() support and subtests fixture.

This pytest plugin was generated with Cookiecutter along with @hackebrot's cookiecutter-pytest-plugin template.

Features

Adds support for TestCase.subTest.
New subtests fixture, providing similar functionality for pure pytest tests.

Requirements

Python >= 3.5.
pytest >= 5.3.

pytest 6.2+

pytest 6.2 now issues a warning when internal classes are used by third-party code, which is the case for pytest-subtests which needs to use some internal classes to integrate with other pytest features (such as capturing and debugging).

For now users can ignore those warnings by adding this to their configuration file:

[pytest]
filterwarnings =
    ignore:A private pytest class or function was used.:PytestDeprecationWarning

Installation

You can install pytest-subtests via pip from PyPI:

$ pip install pytest-subtests

Usage

unittest subTest() example

import unittest


class T(unittest.TestCase):
    def test_foo(self):
        for i in range(5):
            with self.subTest("custom message", i=i):
                self.assertEqual(i % 2, 0)


if __name__ == "__main__":
    unittest.main()

Output

λ pytest .tmp\test-unit-subtest.py
======================== test session starts ========================
...
collected 1 item

.tmp\test-unit-subtest.py FF.                                  [100%]

============================= FAILURES ==============================
_________________ T.test_foo [custom message] (i=1) _________________

self = <test-unit-subtest.T testMethod=test_foo>

    def test_foo(self):
        for i in range(5):
            with self.subTest('custom message', i=i):
>               self.assertEqual(i % 2, 0)
E               AssertionError: 1 != 0

.tmp\test-unit-subtest.py:9: AssertionError
_________________ T.test_foo [custom message] (i=3) _________________

self = <test-unit-subtest.T testMethod=test_foo>

    def test_foo(self):
        for i in range(5):
            with self.subTest('custom message', i=i):
>               self.assertEqual(i % 2, 0)
E               AssertionError: 1 != 0

.tmp\test-unit-subtest.py:9: AssertionError
================ 2 failed, 1 passed in 0.07 seconds =================

`subtests` fixture example

def test(subtests):
    for i in range(5):
        with subtests.test(msg="custom message", i=i):
            assert i % 2 == 0

Output

λ pytest .tmp\test-subtest.py
======================== test session starts ========================
...
collected 1 item

.tmp\test-subtest.py .F.F..                                    [100%]

============================= FAILURES ==============================
____________________ test [custom message] (i=1) ____________________

    def test(subtests):
        for i in range(5):
            with subtests.test(msg='custom message', i=i):
>               assert i % 2 == 0
E               assert (1 % 2) == 0

.tmp\test-subtest.py:4: AssertionError
____________________ test [custom message] (i=3) ____________________

    def test(subtests):
        for i in range(5):
            with subtests.test(msg='custom message', i=i):
>               assert i % 2 == 0
E               assert (3 % 2) == 0

.tmp\test-subtest.py:4: AssertionError
================ 2 failed, 1 passed in 0.07 seconds =================

Contributing

Contributions are very welcome. Tests can be run with tox:

tox -e py37,linting

License

Distributed under the terms of the MIT license, "pytest-subtests" is free and open source software

Issues

If you encounter any problems, please file an issue along with a detailed description.

nicoddemus/pytest-subtests