Add a test case

test/models/filter_test.rb

@@ -107,6 +107,9 @@ class FilterTest < ActiveSupport::TestCase
 
     filters(:jz_assignments).update!(stages: workflow_stages(:qa_triage, :qa_in_progress))
     assert_equal "Most discussed, tagged #Mobile, assigned to JZ, and staged in Triage or In Progress in all projects", filters(:jz_assignments).summary
+
+    filters(:jz_assignments).update!(stages: [], assignees: [], tags: [], buckets: [ buckets(:writebook) ])
+    assert_equal "Most discussed in Writebook", filters(:jz_assignments).summary
   end
 
   test "params without a key-value pair" do