This project is for use with a Composer-managed Drupal site. This project is only needed to run the Drupal test suite on the site. Most sites probably do not need to use this project.
This project does not require
drupal/core, nor does it have any conflict
statements for any version of
drupal/core. These constraints were omitted
to avoid causing problems for sites trying to upgrade their version of
drupal/core. The consequence of this decision is that the version of
drupal/dev-dependencies might differ from the version of
installed. Generally speaking, it should be okay to run a newer version of
drupal/core. Using a newer version of
drupal/core might not work, though, as it is possible that new test
dependencies may have been added.