Testing Overview

ws4py is a Python library which means it can be tested in various fashion:

  • unit testing
  • functional testing
  • load testing

Though all of them are of useful, ws4py mostly relies on functional testing.

Unit Testing

Unit testing solves complex issues in a simple fashion:

  • Micro-validation of classes and functions
  • Ensure non-regression after modifications
  • Critique the design as early as possible for minimum impact

Too often, developers focus solely on the first two and fail to realise how much feedback they can get by writing a simple unit tests. Usually starting writing unit tests can take time because your code is too tightly coupled with itself or external dependencies. This should not the case, most of the time anyway. So make sure to reflect on your code design whenever you have difficulties setting up proper unit tests.


Unfortunately, for now ws4py has a rather shallow coverage as it relies more on the functional testing to ensure the package is sane. I hope to change this in the future.


ws4py uses the Python built-in unittest module. Make sure you read its extensive documentation.


Test execution can be done as follow:

cd test

python -m unittest discover  # execute all tests in the current directory

Tests can obviously be executed via nose, unittest2 or py.test if you prefer.

Functional Testing

ws4py relies heavily on the extensive testing suite provided by the Autobahn project.

The server test suite is used by many other WebSocket implementation out there and provides a great way to validate interopability so it must be executed before each release to the least. Please refer to the Requirements page to install the test suite.


  • Start the CherryPy server with PyPy 1.9

    pypy test/autobahn_test_servers.py --run-cherrypy-server-pypy
  • Start the CherryPy server with Python 3.2 and/or 3.3 if you can.

    python3 test/autobahn_test_servers.py --run-cherrypy-server-py3k
  • Start all servers with Python 2.7

    python2 test/autobahn_test_servers.py --run-all
  • Finally, execute the test suite as follow:

    wstest -m fuzzingclient -s test/fuzzingclient.json

The whole test suite will take a while to complete so be patient.