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https://github.com/The-Compiler/pytest-mccabe

mccabe code complexity checker plugin for pytest. You might want to switch to pytest-flake8 or tox + flake8 instead.
https://github.com/The-Compiler/pytest-mccabe

Last synced: 3 months ago
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mccabe code complexity checker plugin for pytest. You might want to switch to pytest-flake8 or tox + flake8 instead.

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README 

        
pytest-mccabe

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



.. image:: https://travis-ci.org/The-Compiler/pytest-mccabe.svg?branch=master

    :target: https://travis-ci.org/The-Compiler/pytest-mccabe



pytest plugin for checking cyclomatic complexity of python source with

`mccabe`_.



**NOTE:** I (`@The-Compiler`_) stopped using this plugin in 2016. While I will still review pull requests and release new versions if needed by the community, I do not have the time to continue maintaining this plugin myself. You might want to consider switching to `pytest-flake8`_ or `tox`_ + `flake8`_ instead (see some `arguments`_ on why).



.. _mccabe: https://pypi.python.org/pypi/mccabe/

.. _@The-Compiler: https://github.com/The-Compiler

.. _pytest-flake8: https://github.com/tholo/pytest-flake8

.. _tox: https://tox.readthedocs.io/

.. _arguments: https://github.com/The-Compiler/pytest-mccabe/issues/7#issuecomment-654698075



Usage

-----



install via::



    pip install pytest-mccabe



if you then type::



    pytest --mccabe



every file ending in ``.py`` will be discovered and run through mccabe,

starting from the command line arguments.



Simple usage example

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



Consider you have this (deliberately bad and complex) code:



.. code-block:: python



    # module.py



    import random

    import os.path



    def some_function():

        num = random.random()

        if 0 <= num < 0.1:

            print("1")

        elif 0.1 <= num < 0.2:

            print("2")

        elif 0.2 <= num < 0.3:

            print("3")

        elif 0.3 <= num < 0.4:

            print("4")

        elif 0.4 <= num < 0.5:

            print("5")

        elif 0.5 <= num < 0.6:

            print("6")

        elif 0.6 <= num < 0.7:

            print("7")

        elif 0.7 <= num < 0.8:

            print("8")

        elif 0.8 <= num < 0.9:

            print("9")

        elif 0.9 <= num < 1:

            print("10")



Running pytest with pytest-mccabe installed shows you this function is

considered too complex::



   $ pytest -q --mccabe module.py

   F

   ============================== FAILURES ==============================

   ____________________________ mccabe-check ____________________________

   .../module.py:4: C901 'some_function' is too complex (11)



Configuring mccabe complexity per project and file

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



You may configure the maximum complexity for your project

by adding an ``mccabe-complexity`` entry to pytest config file (e.g.

``setup.cfg``) like this:



.. code-block:: ini



    [pytest]

    mccabe-complexity=15



Rerunning with the above example will now look better::



    $ pytest -q --mccabe foo.py

    .

    1 passed in 0.00 seconds



If you have some files where you want to set a higher complexity than the

project-wide one, you can start a mccabe-complexity line with a glob-pattern:



.. code-block:: ini



    [pytest]

    mccabe-complexity =

        *.py 7

        magic.py 10



Ignoring certain functions

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



You can exclude certain functions from the complexity check by adding comments

like this:



.. code-block:: python



    def some_function():  # noqa

        ...



    def another_function():  # pragma: no mccabe

        ...



(both will work - ``# noqa`` is mainly there for `flake8`_ compatibility)



.. _flake8: https://pypi.python.org/pypi/flake8



Running mccabe checks and no other tests

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



You can restrict your test run to only perform "mccabe" tests

and not any other tests by typing::



    pytest --mccabe -m mccabe



This will only run tests that are marked with the "mccabe" keyword

which is added for the mccabe test items added by this plugin.



If you are using pytest < 2.4, then use the following invocation

to the same effect::



    pytest --mccabe -k mccabe



Notes

-----



The repository of this plugin is at https://github.com/The-Compiler/pytest-mccabe



For more info on pytest see https://pytest.org



The code is based on Florian Schulze's excellent `pytest-flakes`_ - Thanks!



.. _pytest-flakes: https://pypi.python.org/pypi/pytest-flakes



Changes

=======



0.1

---



- Initial release.



1.0

---



- Drop support for Python 2.6, 3.2, 3.3 and 3.4

- Add support for Python 3.5, 3.6 and 3.7

- Make this plugin compatible with pytest 4.x and 5.x

- Drop support for "setup.py test"

- Remove outdated pytest-cache dependency

- Various code/CI cleanups



2.0

---



- Drop support for Python 2.7

- Drop support for pytest < 5.4

- Add support for Python 3.8 (no changes required)

- Fix deprecation warnings with pytest >= 5.4 (thanks to Martin Thoma for the PR!)

- Various code/CI cleanups