Hi, One thing that's always annoyed me about writing tests for an extension is that for the first test, you need to bootstrap it by adding a UnitTestsList hook, and copying the code for it from some other extension. Now that we have a proper extension registry, I wrote <https://gerrit.wikimedia.org/r/#/c/302944/> (merged by Florian!), which will automatically register any tests in an extension's "tests/phpunit/" directory. If you already have a UnitTestsList hook, the tests won't be duplicated or anything, but it is now safe to remove the hook. <https://phabricator.wikimedia.org/T142120> tracks updating extensions to do so by moving their tests into the standardized path and removing the hook. Note: this requires that the extension has already been converted to use extension.json.