Use Filter class method to digest fixture params

test/fixtures/filters.yml

@@ -3,4 +3,4 @@ jz_assignments:
   tags: mobile
   assignees: jz
   fields: <%= { indexed_by: :most_discussed }.to_json %>
-  params_digest: <%= Digest::MD5.hexdigest({ indexed_by: :most_discussed, tag_ids: [ ActiveRecord::FixtureSet.identify(:mobile) ], assignee_ids: [ ActiveRecord::FixtureSet.identify(:jz) ] }.to_json) %>
+  params_digest: <%= Filter.digest_params({ indexed_by: :most_discussed, tag_ids: [ ActiveRecord::FixtureSet.identify(:mobile) ], assignee_ids: [ ActiveRecord::FixtureSet.identify(:jz) ] }) %>

test/models/filter_test.rb

@@ -3,10 +3,10 @@ require "test_helper"
 class FilterTest < ActiveSupport::TestCase
   test "persistence" do
     assert_difference "users(:david).filters.count", +1 do
-      filter = users(:david).filters.persist!(indexed_by: "most_boosted")
+      filter = users(:david).filters.persist!(indexed_by: "most_boosted", tag_ids: [ tags(:mobile).id ])
 
       assert_changes "filter.reload.updated_at" do
-        assert_equal filter, users(:david).filters.persist!(indexed_by: "most_boosted")
+        assert_equal filter, users(:david).filters.persist!(indexed_by: "most_boosted", tag_ids: [ tags(:mobile).id ])
       end
     end
   end