Tests
Running in Parallel
CRM's composer.json includes in require-dev ParaTest, which can be used to run CRM's test suite in parallel, significantly reducing execution time.
Tests can be run via DDEV: ddev exec ./vendor/bin/paratest
ParaTest also provides support for PhpStorm. It can be as simple as creating a runtime configuration with the "Use ParaTest" box checked with /path/to/crm/vendor/bin/paratest_for_phpstorm specified.
See ParaTest's GitHub page and PhpStorm's documentation for more information.