Matt Glaman: My PHPUnit configuration for my Drupal projects

The other week, I was asked about how I maintain my PHPUnit config file for my Drupal projects. When running Drupal’s PHPUnit test suites, you typically copy and modify the distribution phpunit.xml.dist file which lives in the web/core subdirectory. There is just one problem. This directory is technically a vendor directory and is replaced during any updates to the drupal/core dependency of your Drupal project. Every minor version will cause your file to reset, or anytime you install dependencies if Drupal core is patched.

One thing I noticed is that since I first followed your tuts a while back, my phpunit.xml is gone.  I’m guessing it gets overwritten when core is updated.  Do you just keep a copy of the file and paste it in when that happens? Is there a better solution?