This testing will largely consist of trying out as many examples of Moodle dialogues as you can think of and checking that they still behave as they did before the change. Please try the following, plus any others you're aware of: Help popup (e.g. on the login page) Activity chooser Click-based drag/drop (e.g. in course) Any confirmation dialogues you're aware of Additionally, to test some of the other subclasses of the dialogue class: Edit help_ajax.php At some point after config.php has been included, throw a new moodle_exception Open the login page in the browser Click on the help icon Confirm that the ajaxException dialogue was displayed Remove the moodle_exception echo out some random junk at the end of the file Click on the help icon again Confirm that an exception dialogue was displayed Login to moodle as an admin/manager/teacher Navigate to a course's enrol page Remove a role from a user Confirm that you get a confirmation dialogue Navigate to a course and turn editing on Open the activity chooser Confirm that it was shown as expected Cancel the activity chooser Reopen it Confirm that it was shown again Add a new assignment instance As a student, upload a PDF to it Confirm that the filepicker was not displayed until you requested it As a tutor, Launch the PDF editor Confirm that no new dialogues are visible initially Click on the comment search button Confirm that the dialogue is now visible