[test] Add unit test for conference_helper#conference_color

spec/factories/conferences.rb

@@ -49,6 +49,7 @@ FactoryBot.define do
     ticket_layout { 'portrait' }
     description { Faker::Hipster.paragraph }
     organization
+    color { '#FFFFFF' }
     after(:create) do |conference|
       Role.where(name: 'organizer', resource: conference).first_or_create(description: 'For the organizers of the conference (who shall have full access)')
       Role.where(name: 'cfp', resource: conference).first_or_create(description: 'For the members of the CfP team')

spec/helpers/conference_helper_spec.rb

@@ -88,4 +88,15 @@ describe ConferenceHelper, type: :helper do
       expect(conference_logo_url(conference2)).to include('2.png')
     end
   end
+
+  describe '#conference_color' do
+    let(:conference2) { create(:conference, color: '#000000') }
+
+    it 'gives the correct conference color' do
+      expect(conference_color(conference2)).to eq('#000000')
+
+      conference2.color = ''
+      expect(conference_color(conference2)).to eq('#0B3559')
+    end
+  end
 end