Software quality assurance

The following section includes information about the WNTR software repository, software tests, documentation, examples, bug reports, feature requests, and ways to contribute.

GitHub repository

WNTR is maintained in a version controlled repository. WNTR is hosted on US EPA GitHub organization at

Software tests

WNTR includes continuous integration software tests that are run using Travis CI. The tests are run each time changes are made to the repository. The tests cover a wide range of unit and integration tests designed to ensure that the code is performing as expected. New tests are developed each time new functionality is added to the code. Testing status (passing/failed) and code coverage statistics are posted on the README section at

Tests can also be run locally using the Python package nose. For more information on nose, see nose comes with a command line software tool called nosetests. Tests can be run in the WNTR directory using the following command:

nosetests -v --with-coverage --cover-package=wntr wntr


WNTR includes a user manual that is built using the Read the Docs service. The user manual is automatically rebuilt each time changes are made to the code. The documentation is publicly available at The user manual includes an overview, installation instructions, simple examples, and information on the code structure and functions. WNTR includes documentation on the API for all public functions, methods, and classes. New content is marked Draft.


WNTR includes examples to help new users get started. These examples are intended to demonstrate high level features and use cases for WNTR. The examples are tested to ensure they stay current with the software project.

Bug reports and feature requests

Bug reports and feature requests can be submitted to The core development team will prioritize and assign bug reports and feature requests to team members.


Software developers, within the core development team and external collaborators, are expected to follow standard practices to document and test new code. Software developers interested in contributing to the project are encouraged to create a Fork of the project and submit a Pull Request using GitHub. Pull requests will be reviewed by the core development team.

Pull requests must meet the following minimum requirements to be included in WNTR:

  • Code is expected to be documented using Read the Docs.
  • Code is expected to be sufficiently tested using Travis CI. Sufficient is judged by the strength of the test and code coverage. 80% code coverage is recommended.
  • Large files (> 1Mb) will not be committed to the repository without prior approval.
  • Network model files will not be duplicated in the repository. Network files are stored in examples/network and wntr/tests/networks_for_testing only.

Development team

WNTR was developed as part of a collaboration between the United States Environmental Protection Agency National Homeland Security Research Center, Sandia National Laboratories, and Purdue University. See for a list of contributors.