refactor: fix hlint errors

src/Handler/Course.hs

@@ -25,5 +25,4 @@ getCNotesR, postCNotesR :: TermId -> SchoolId -> CourseShorthand -> Handler Html
 -- PROBLEM: Correctors usually don't know Participants by name (anonymous), maybe notes are not shared?
 -- If they are shared, adjust MsgCourseUserNoteTooltip
 getCNotesR = postCNotesR
-postCNotesR _ _ _ = do
-  defaultLayout $ [whamlet|You have corrector access to this course.|]
+postCNotesR _ _ _ = defaultLayout [whamlet|You have corrector access to this course.|]

src/Handler/Course/ParticipantInvite.hs

@@ -128,20 +128,20 @@ postCAddUserR tid ssh csh = do
         -- register known users
         execWriterT $ mapM (registerUser cid) uids
 
-      when (not $ null emails) $
+      unless (null emails) $
         tell . pure <=< messageI Success . MsgCourseParticipantsInvited $ length emails
 
-      when (not $ null aurAlreadyRegistered) $ do
+      unless (null aurAlreadyRegistered) $ do
         let modalTrigger = [whamlet|_{MsgCourseParticipantsAlreadyRegistered (length aurAlreadyRegistered)}|]
             modalContent = $(widgetFile "messages/courseInvitationAlreadyRegistered")
         tell . pure <=< messageWidget Info $ msgModal modalTrigger (Right modalContent)
 
-      when (not $ null aurNoUniquePrimaryField) $ do
+      unless (null aurNoUniquePrimaryField) $ do
         let modalTrigger = [whamlet|_{MsgCourseParticipantsRegisteredWithoutField (length aurNoUniquePrimaryField)}|]
             modalContent = $(widgetFile "messages/courseInvitationRegisteredWithoutField")
         tell . pure <=< messageWidget Warning $ msgModal modalTrigger (Right modalContent)
 
-      when (not $ null aurSuccess) $
+      unless (null aurSuccess) $
         tell . pure <=< messageI Success . MsgCourseParticipantsRegistered $ length aurSuccess
 
     registerUser :: CourseId -> UserId -> WriterT AddRecipientsResult (YesodJobDB UniWorX) ()