Run the REST demo client Call core_course_update_categories(). You must move a category from a parent to another parent. Check that the moved category has a correct path. For example if it was moved from category1->id = 4 to category2->id = 5, then the path should have been updated from /4/X to /5/X You can check the path field in the DB table: course_categories Alternative test: you can take my phpunit test for this function in https://github.com/mouneyrac/moodle/commit/bae128d5e1124a191d00648e1aca57f6b407ca1c ( MDL-33529 ) - it's done and it will be much faster test to call this unit test (if you do so, comment the other PHPunit test because lots of them are related to fix waiting to be integrated. If you don't comment other tests they will throw errors to you.)