Merge pull request #5540 from avalonmediasystem/empty_playlist_manifests

Manifest should still generate when playlist is empty

app/controllers/playlists_controller.rb

@@ -248,7 +248,8 @@ def manifest
 
     # Fetch all master files related to the playlist items in a single SpeedyAF::Base.where
     master_file_ids = @playlist.items.collect { |item| item.clip.master_file_id }
-    master_files = SpeedyAF::Proxy::MasterFile.where("id:#{master_file_ids.join(' id:')}", load_reflections: true)
+    master_files = []
+    master_files = SpeedyAF::Proxy::MasterFile.where("id:#{master_file_ids.join(' id:')}", load_reflections: true) if master_file_ids.present?
     media_objects = master_files.collect(&:media_object).uniq(&:id)
 
     # This small optimization relies on the assumption that can? :read, master_file is the same as can? :read, master_file.media_object

spec/controllers/playlists_controller_spec.rb

@@ -575,6 +575,19 @@
         expect(parsed_response['items'][0]['metadata']).to be_present
       end
 
+      context "when playlist is empty" do
+        let(:playlist) { FactoryBot.create(:playlist, items: [], visibility: Playlist::PUBLIC) }
+
+        it "returns a IIIF manifest" do
+          get :manifest, format: 'json', params: { id: playlist.id }, session: valid_session
+          expect(response).to have_http_status(200)
+          parsed_response = JSON.parse(response.body)
+          expect(parsed_response['@context']).to include "http://iiif.io/api/presentation/3/context.json"
+          expect(parsed_response['type']).to eq 'Manifest'
+          expect(parsed_response['items']).to be_empty
+        end
+      end
+
       context "when playlist owner" do
         before do
           login_user playlist.user.user_key