sebastianbergmann/phpunit ? reverse-engineered prompt

Build me a PHP testing framework like PHPUnit that lets me write test classes, run them from the command line, and get clear pass or fail output. I want the basics working first, discovering tests automatically, running individual tests or a whole suite, and showing helpful error messages when assertions fail.

Please include common assertions like equals, true, false, null, empty, and exception checking, plus support for setup and teardown around each test. It should be easy to use in normal PHP projects, with a simple config file for choosing test paths and options. If needed, look up current PHP docs online so the implementation matches modern PHP best practices.

Make it feel polished, with sensible defaults, good documentation in the README, and enough tests to prove the core behavior works. If there are existing conventions for PHPUnit style output or test naming, follow those closely so it feels familiar to anyone who has used it before.