twosigma/marbles

marbles

Read better test failures.

• Free software: MIT license
• Documentation: https://marbles.readthedocs.io

Overview

marbles is a Python unittest extension that allows test authors to write richer tests that expose more information on test failure to help you debug failing tests faster.

• Treat test failures as documentation
• Contextualize failures without digging through test code and dropping debugging statements everywhere
• Write clearer, more explicit tests

Features

• Drop-in unittest replacement
• Information-rich failure messages
  • The full statement that failed (instead of just the last line)
  • Local variables in scope at the time the test failed
  • Optional annotation provided by the test author with details about the test
  • Ability to toggle traceback
• Semantically-rich assertion methods
• Assertion logging

Demo

You can run the example tests provided to see what a marbles failure message looks like

You can also run your existing unittest tests with marbles

python -m marbles test_module.py

Marbles also creates a setuptools command so if you are used to running python setup.py test, you can now run:

python setup.py marbles

You can go one step further and alias the command test to run marbles by adding the following to setup.cfg:

[aliases]
test = marbles

Installing

pip install marbles