Does not exclude message_html from attributes

app/models/broadcast_message.rb

@@ -4,7 +4,7 @@ class BroadcastMessage < ActiveRecord::Base
   include CacheMarkdownField
   include Sortable
 
-  cache_markdown_field :message, pipeline: :broadcast_message
+  cache_markdown_field :message, pipeline: :broadcast_message, hidden: false
 
   validates :message,   presence: true
   validates :starts_at, presence: true

spec/models/broadcast_message_spec.rb

@@ -95,6 +95,12 @@ describe BroadcastMessage do
     end
   end
 
+  describe '#attributes' do
+    it 'includes message_html field' do
+      expect(subject.attributes.keys).to include("cached_markdown_version", "message_html")
+    end
+  end
+
   describe '#active?' do
     it 'is truthy when started and not ended' do
       message = build(:broadcast_message)