2. Running Unit Tests Locally

2.1. Background

Unit tests are included in METdataio and all of its sub-modules. The tests are found under the test/ directory in each module, e.g. METdbLoad/test/. These tests are run automatically when a pull request is raised on GitHub and must pass before any merge will be considered. When developing new features it is advisable to ensure the test pass by running them locally against your changes. To do this you must first have either a mysql or mariadb service running and setup with an appropriate user. Although either database can be used, this guide will focus on mariadb.

2.2. Database Setup

The setup of mariadb will be different depending on the operating system you are running, and the available privileges. If you encounter issues it is recommended you consult your system administrator for support appropriate to your system and environment. For up to date instructions on installing mariadb consult the MariaDB docs or the MariaDB GitHub page.

Below is an example setup on CentOS.

  1. Install mariadb-server:

$ sudo yum install mariadb-server

  1. start mariadb and change the root password. Note that by default there is no password for the root user:

$ sudo mariadb -u root -p
[MariaDB]> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root_password';
[MariaDB]> exit;

  1. start the mariadb service:

$ sudo systemctl start mariadb

2.3. Running Tests

Tests can be run using pytest. If required, you can install using either conda install pytest or pip install pytest.

$ pytest METdbLoad/test/

To check test coverage conda install pytest-cov, and using the –cov commands. For example:

$ pytest METdbLoad/test/ --cov METdbLoad/ush/ --cov-report term-missing

2.4. Writing Tests

All Pull Requests that change source code in METdataio should include appropriate unit tests. These tests should demonstrate that when the new source code is invoked it produces the desired results. For help with writing tests, and for examples of how to use pytest, refer ot the pytest documentation.

When writing new tests for METdataio you should be familiar with the content of conftest.py, noting that each sub module may have it’s own conftest.py. For example, when writing a test for METdbLoad you may want to instatiate an empty test database. To do this use the emptyDB test fixture, found in METdbLoad/conftest.py.

For further examples, refer to the existing tests for each module.