At least four test suites are available, testing different parts of PrestaShop:
Legacy tests: heritage from PrestaShop 1.6: mix of unit, integration and functional tests;
Legacy controllers: added to help with the Symfony migration, ensures that old Back Office controllers are still runnable;
Admin tests: specific to PrestaShop 1.7, tests
Symfony specific tests: specific to PrestaShop 1.7, test classes from
Each suite needs a specific PHPUnit configuration. This is why each test suite has a specific composer command:
This is thoroughly explained in the Puppeteer tests Readme file.