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Cosmic Ray: mutation testing for Python

"Four human beings -- changed by space-born cosmic rays into something more than merely human."

-- The Fantastic Four

Cosmic Ray is a mutation testing tool for Python 3.

It makes small changes to your source code, running your test suite for each one. Here's how the mutations look:

.. image:: docs/source/cr-in-action.gif

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Contributing

The easiest way to contribute is to use Cosmic Ray and submit reports for defects or any other issues you come across. Please see CONTRIBUTING.rst for more details.

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