============== pytest-reverse

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Pytest plugin to reverse test order.

Testing a Django project? Check out my book Speed Up Your Django Tests <https://adamchainz.gumroad.com/l/suydt>__ which covers loads of recommendations to write faster, more accurate tests. I created pytest-reverse whilst working on the book!

Installation

Install with:

.. code-block:: bash

python -m pip install pytest-reverse

Python 3.8 to 3.12 supported.

Usage

Pytest will automatically find the plugin and use it when you run pytest. You can reverse test order by passing the --reverse flag:

.. code-block:: bash

pytest --reverse

You can make this always apply by adding it to the addopts setting in your pytest.ini (or other configuration file <https://docs.pytest.org/en/latest/customize.html#adding-default-options>__):

.. code-block:: ini

[pytest]
addopts = --reverse

History

I'm the creator and maintainer of pytest-randomly <https://github.com/pytest-dev/pytest-randomly>, a plugin for randomly ordering tests. @thbde opened an issue there pointing to the paper Empirically revisiting the test independence assumption <https://dl.acm.org/doi/10.1145/2610384.2610404>, which covers test reordering techniques. It turns out that reversal is nearly as effective as randomization.

Test reversal is available in Django's test runner <https://docs.djangoproject.com/en/dev/ref/django-admin/#cmdoption-test-reverse>__. I figured such an option or plugin would exist for pytest already, but it didn't, so I made it here.