Use switch/when statement

app/assets/javascripts/notes.js.coffee

@@ -106,14 +106,17 @@ class @Notes
     $textarea = $(e.target)
 
     # Edit previous note when UP arrow is hit
-    if $textarea.val() is '' and e.which is 38
+    switch e.which
+      when 38
+        return unless $textarea.val() is ''
+
         myLastNote = $("li.note[data-author-id='#{gon.current_user_id}'][data-editable]:last")
         if myLastNote.length
           myLastNoteEditBtn = myLastNote.find('.js-note-edit')
           myLastNoteEditBtn.trigger('click', [true, myLastNote])
 
       # Cancel creating diff note or editing any note when ESCAPE is hit
-    if e.which is 27
+      when 27
         discussionNoteForm = $textarea.closest('.js-discussion-note-form')
         if discussionNoteForm.length
           if $textarea.val() isnt ''
@@ -122,7 +125,7 @@ class @Notes
           @removeDiscussionNoteForm(discussionNoteForm)
           return
 
-      editNote = $textarea.closest(".note")
+        editNote = $textarea.closest('.note')
         if editNote.length
           originalText = $textarea.closest('form').data('original-note')
           newText = $textarea.val()
@@ -427,7 +430,7 @@ class @Notes
   ###
   cancelEdit: (e) =>
     e.preventDefault()
-    note = $(e.target).closest(".note")
+    note = $(e.target).closest('.note')
     @removeNoteEditForm(note)
 
   removeNoteEditForm: (note) ->