https://github.com/mvollrath/pytest-nogarbage

Ensure a test produces no garbage.
https://github.com/mvollrath/pytest-nogarbage

garbage-collection pytest pytest-plugin python python3 testing

Last synced: over 1 year ago
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Ensure a test produces no garbage.

• Host: GitHub
• URL: https://github.com/mvollrath/pytest-nogarbage
• Owner: mvollrath
• License: mit
• Created: 2021-08-28T21:35:37.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2021-08-30T16:30:29.000Z (almost 5 years ago)
• Last Synced: 2024-10-18T23:18:28.058Z (over 1 year ago)
• Topics: garbage-collection, pytest, pytest-plugin, python, python3, testing
• Language: Python
• Homepage:
• Size: 7.81 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE

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README

          
================

pytest-nogarbage

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.. image:: https://img.shields.io/pypi/v/pytest-nogarbage.svg

    :target: https://pypi.org/project/pytest-nogarbage

    :alt: PyPI version

.. image:: https://img.shields.io/pypi/pyversions/pytest-nogarbage.svg

    :target: https://pypi.org/project/pytest-nogarbage

    :alt: Python 3.7+

.. image:: https://img.shields.io/pypi/implementation/pytest-nogarbage.svg

    :target: https://pypi.org/project/pytest-nogarbage

    :alt: CPython

.. image:: https://img.shields.io/pypi/l/pytest-nogarbage.svg

    :target: https://pypi.org/project/pytest-nogarbage

    :alt: MIT License

The purpose of this plugin is ensuring that portions of your Python code do not produce garbage or manually invoke garbage collection.

When the `nogarbage` pytest fixture is added to a test, it will cause an error under the following conditions:

* Garbage was collected after the test was run (circular references were remaining after the test was broken down).

* Garbage was explicitly collected  (`gc.collect()`) during the test.  Automatic garbage collection sweeps are disabled during the test.

You should use this plugin when:

* You intend to run a program with garbage collection disabled in production.

* You wish to verify elimination of garbage collection overhead produced by frequently called functions.

This tool is not for finding memory leaks; even if your code produces no garbage, native call-ins can still leak memory.  Garbage in CPython is specifically circular references between Python objects.

If you are interested in optimizing CPython garbage collection or unsure of the difference between garbage and memory leaks, the `gc docs`_ and `CPython Garbage Collection devguide`_ are excellent resources.

Requirements

------------

* Python 3.7+

* This plugin is only tested against CPython.

Installation

------------

You can install "pytest-nogarbage" via `pip`_ from `PyPI`_::

    $ pip install pytest-nogarbage

Usage

-----

Add the `nogarbage` fixture to your test to ensure it does not produce garbage::

    def test_circular(nogarbage):

        l1 = []

        l2 = [l1]

        l1.append(l2)

        # ERROR: Garbage collected after test.

    def test_collect(nogarbage):

        import gc

        gc.collect()

        # ERROR: Garbage collected during test.

Running the Tests

-----------------

This project uses `nox`_ to test against multiple Python versions::

    $ python3 -m venv .venv

    $ source .venv/bin/activate

    (.venv) $ pip install nox uv

    (.venv) $ nox

License

-------

Distributed under the terms of the `MIT`_ license, "pytest-nogarbage" is free and open source software.

.. _`MIT`: http://opensource.org/licenses/MIT

.. _`file an issue`: https://github.com/mvollrath/pytest-nogarbage/issues

.. _`nox`: https://nox.thea.codes/en/stable/

.. _`pip`: https://pypi.org/project/pip/

.. _`PyPI`: https://pypi.org/project

.. _`gc docs`: https://docs.python.org/3/library/gc.html

.. _`CPython Garbage Collection devguide`: https://devguide.python.org/garbage_collector/