The plugin contains all the files needed for running tests.
Developers who would like to run the existing tests or add their tests to the test suite and execute them will have to follow these steps:
1. cd into the plugin directory.
2. Run the install script(you will need to have wget installed) – bash tests/bin/install-wp-tests.sh .
3. Run the plugin tests – phpunit

The install script installs a copy of WordPress in the /tmp directory along with the WordPress unit testing tools.