Change record status: 
Project: 
Introduced in branch: 
10.1.x
Introduced in version: 
10.1.0
Description: 

The PHPStan capabilities have been extended by adding phpstan/phpstan-phpunit as a dependency. This will find common errors in PHPUnit tests. If this causes PHPStan runs to fail you can either add the new fails to the baseline or you can fix your code. The original PHPStan change record details how to regenerate the baseline for Drupal core.