Be explicit which project and user ID are memoized

app/helpers/notes_helper.rb

@@ -71,10 +71,12 @@ module NotesHelper
   end
   def note_max_access_for_user(note)
-    user_id = note.author.id
-    project = note.project
-    @max_access_by_user_id ||= Hash.new { |hash, key| hash[key] = project.team.human_max_access(key) }
-    @max_access_by_user_id[user_id]
+    @max_access_by_user_id ||= Hash.new do |hash, key|
+      project = key[:project]
+      hash[key] = project.team.human_max_access(key[:user_id])
+    end
+    full_key = { project: note.project, user_id: note.author_id }
+    @max_access_by_user_id[full_key]
   end
 end

spec/helpers/notes_helper_spec.rb

@@ -22,11 +22,25 @@ describe NotesHelper do
     end
     it 'return human access levels' do
+      original_method = project.team.method(:human_max_access)
+      expect_any_instance_of(ProjectTeam).to receive(:human_max_access).exactly(3).times do |*args|
+        original_method.call(args[1])
+      end
+
       expect(helper.note_max_access_for_user(owner_note)).to eq('Owner')
       expect(helper.note_max_access_for_user(master_note)).to eq('Master')
       expect(helper.note_max_access_for_user(reporter_note)).to eq('Reporter')
       # Call it again to ensure value is cached
       expect(helper.note_max_access_for_user(owner_note)).to eq('Owner')
     end
+
+    it 'handles access in different projects' do
+      second_project = create(:empty_project)
+      second_project.team << [master, :reporter]
+      other_note = create(:note, author: master, project: second_project)
+
+      expect(helper.note_max_access_for_user(master_note)).to eq('Master')
+      expect(helper.note_max_access_for_user(other_note)).to eq('Reporter')
+    end
   end
 end