MDL-40054 mod_lesson: added PHPUnit test for the grade_updated event
MDL-40054 mod_lesson: replaced 'grade view' add_to_log call with an event
MDL-40054 mod_lesson: added PHPUnit test for the essay_list_viewed event
MDL-40054 mod_lesson: replaced 'update highscores' add_to_log call with an event
MDL-40054 mod_lesson: added PHPUnit test for the highscore_added event
MDL-40054 mod_lesson: replaced 'view highscores' add_to_log call with an event
MDL-40054 mod_lesson: added PHPUnit test for the highscores_viewed event
MDL-40054 mod_lesson: replaced 'view' add_to_log call with an event