If you have docker and docker-compose installed than:

docker-compose up

Installing on bare metal (you need PHP 7+):

composer install

• PHP 7.1
• Composer
• PHPUnit

Unit tests are provided in the /tests folder. To run these steps simply run following command from the project root:

bin/phpunit

• Used newest version of PHP (7.1)
• Tests implemented using PHPUnit 6 + including phpunit.xml config for easy execution
• Autoloading classes by composer (PSR-4 standard)
• Follows PSR-1, PSR-2 & PSR-4 guidelines
• Utilized Carbon PHP library for easier and more reliable manipulation of DateTime
• Made Allowed IPs configurable for each banner instance (on top of default ones as per specification)
• Current DateTime for deciding whether banner is displayed is also configurable for each Banner::isDisplayable() call (more flexibility)

• Validate IP address format (with regex)
• More options for the configuration
• Accept directly Carbon classes in the Banner constructor or even better DisplayPeriod instance
• More test cases possibly also with the data provider to cover multiple inputs with the same scenarios