Enhancements to PHP code coverage in 2020
In 2003, with the release of Xdebug 1.2, Derick Rethans introduced the ability to collect code coverage data to the PHP ecosystem for the first time. In 2004, with the release of PHPUnit 2, Sebastian Bergmann made the first real use of this new power by allowing developers to evaluate the effectiveness of their test suites by generating coverage reports.