One-liner to print the trigger context event (e.g. "before insert" or "after delete")

PrintTriggerEvent.java

trigger AccountTrigger on Account ( before insert, before update, before delete, after insert, after update, after delete, after undelete ) {

    System.debug( 'trigger event: ' + ( Trigger.isBefore ? 'before' : 'after' ) + ' ' + ( Trigger.isInsert ? 'insert' : Trigger.isUpdate ? 'update' : Trigger.isDelete ? 'delete' : 'undelete' ) );
    
}