Faker is a PHP library that generates fake data for you
The PHP Unit Testing framework.
Highly opinionated mocking framework for PHP 5.3+
PHP Hamcrest implementation [Official]
Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal is to offer a test double framework with a succinct API capable of clearly defining all possible object operations and interactions using a human readable Domain Specific Language (DSL).
Parallel testing for PHPUnit
Library that provides collection, processing, and rendering functionality for PHP code coverage information.
[Package] Laravel Testing Helper for Packages Development
PHP client for Selenium/WebDriver protocol. Previously facebook/php-webdriver