Regression testing. Verify that all the PHPUnit executions in the issue (GHA, CI, ...) are passing ok. Completeness testing. Install moodle-cs following the instructions . Run the following command: path/to/phpcs --standard=moodle \ --sniffs=moodle.PHPUnit.TestReturnType \ -s -p /path/to/your/moodle Wait the execution to finish (you should see some progress with dots...). Can be some good minutes (~10 minutes here) to examine all the code. Verify that there isn't any problem reported (the output, after the dots, only reports the execution time and the memory used). The end of the output has to look similar to this: ... ... ............................................................ 18360 / 18427 (100%) ............................................................ 18420 / 18427 (100%) ....... 18427 / 18427 (100%)     Time: 10 mins, 3.36 secs; Memory: 318.01MB