Simple PHPUnit testing

Feature requests
1

Make testing with PHPUnit uber-easy:

  1. Support for different and switching PHP versions
  2. Built-in support or an add-on
  3. Themes and plugins, not limited to WP core

This has been talked about off and on for years, and somehow continues to be neglected. Even the tutorials on hacking it are neglected. I like Local, but contributing to most serious plugins require tests for multiple PHP versions nowadays, which makes Local a difficult option.

If WordPress is going to continue to mature, the development tools for WordPress need to do so as well.