We use official "Symfony Demo Application" to demonstrate basics of Codeception functional tests. Check out tests directory to see functional and unit tests included. We use Symfony and Doctrine2 modules for zero-configuration Symfony testing.

composer install -n php bin/console doctrine:fixtures:load -n --env test php bin/codecept run 

Below goes official README of Symfony Demo Application:

The "Symfony Demo Application" is a reference application created to show how to develop applications following the Symfony Best Practices.

• PHP 7.1.3 or higher;
• PDO-SQLite PHP extension enabled;
• and the usual Symfony application requirements.

Install the Symfony client binary and run this command:

$ symfony new --demo my_project

Alternatively, you can use Composer:

$ composer create-project symfony/symfony-demo my_project

There's no need to configure anything to run the application. If you have installed the Symfony client binary, run this command to run the built-in web server and access the application in your browser at http://localhost:8000:

$ cd my_project/ $ symfony serve

If you don't have the Symfony client installed, run php bin/console server:run. Alternatively, you can configure a web server like Nginx or Apache to run the application.

Execute this command to run tests:

$ cd my_project/ $ ./bin/phpunit