As usual, test on as many browsers as feasibly possible. Open a course Open the activity chooser Ensure that nothing is currently selected (i.e., don't select anything) Press the return key Confirm nothing happens Using the keyboard up/down arrows, select an activity Press the return key Confirm that you're redirecting to the activity's add page Double-click on an activity Confirm that you're redirecting to the activity's add page Return to the course page Open the activity chooser Using the keyboard, select an activity Tab to the cancel button (not all browsers will - e.g. Safari on Mac) Press the return key Confirm that the activity chooser closes without submitting the form Open the activity chooser Using the keyboard, select an activity Press the Escape key on the keyboard Confirm that the activity chooser closes without submitting the form