Handle the case where resource label is blank

Ref https://github.com/sul-dlss/sul-embed/pull/1769\#issuecomment-1817311430

app/components/embed/download/file_list_item_component.html.erb

@@ -1,6 +1,6 @@
 <li>
   <a href='<%= url %>' title='<%= file.title %>' target='_blank' rel='noopener noreferrer'>
-    Download <%= file.label %>
+    Download <%= file.label_or_filename %>
   </a>
   <%= render 'embed/restrictions_text_for_file', file: file %>
   <%= file_size %>

app/components/embed/media_wrapper_component.rb

@@ -19,7 +19,7 @@ def call # rubocop:disable Metrics/MethodLength
                 action: 'thumbnail-clicked@window->media-wrapper#toggleVisibility',
                 stanford_only: @file.stanford_only?,
                 location_restricted: @file.location_restricted?,
-                file_label: @file.label,
+                file_label: @file.label_or_filename,
                 slider_object: @file_index,
                 thumbnail_url: @thumbnail.presence,
                 default_icon: @type == 'audio' ? 'sul-i-file-music-1' : 'sul-i-file-video-3',

app/models/embed/purl/resource_file.rb

@@ -38,6 +38,10 @@ def stacks_url
         "#{Settings.stacks_url}/file/druid:#{@druid}"
       end
 
+      def label_or_filename
+        label.presence || filename
+      end
+
       def hierarchical_title
         title.split('/').last
       end

app/views/embed/body/_resource_file.html.erb

@@ -23,7 +23,7 @@
     <% end %>
 
     <div class='sul-embed-description' data-description='true'>
-      <%= file.label %>
+      <%= file.label_or_filename %>
     </div>
     <div class='sul-embed-download'>
       <i class='sul-i-download-3'></i>

spec/components/embed/media_wrapper_component_spec.rb

@@ -20,7 +20,7 @@
   end
 
   describe 'data-default-icon attribute' do
-    let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label: 'ignored', duration: nil) }
+    let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label_or_filename: 'ignored', duration: nil) }
 
     context 'with audio' do
       it 'renders the page' do
@@ -39,15 +39,15 @@
 
   describe 'data-stanford-only attribute' do
     context 'with Stanford only files' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label: 'ignored', duration: nil) }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label_or_filename: 'ignored', duration: nil) }
 
       it 'renders the page' do
         expect(page).to have_css('[data-stanford-only="true"]')
       end
     end
 
     context 'with public files' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label: 'ignored', duration: nil) }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label_or_filename: 'ignored', duration: nil) }
 
       it 'renders the page' do
         expect(page).to have_css('[data-stanford-only="false"]')
@@ -57,15 +57,15 @@
 
   describe 'duration' do
     context 'when the resource file has duration' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label: 'ignored', duration: '1:02') }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: false, label_or_filename: 'ignored', duration: '1:02') }
 
       it 'renders the page' do
         expect(page).to have_css('[data-duration="1:02"]')
       end
     end
 
     context 'when the resource file is missing duration' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label: 'ignored', duration: nil) }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label_or_filename: 'ignored', duration: nil) }
 
       it 'renders the page' do
         expect(page).not_to have_css('[data-duration]')
@@ -75,15 +75,15 @@
 
   describe 'data-location-restricted attribute' do
     context 'when location restricted' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: true, label: 'ignored', duration: nil) }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: false, location_restricted?: true, label_or_filename: 'ignored', duration: nil) }
 
       it 'renders the page' do
         expect(page).to have_css('[data-location-restricted="true"]')
       end
     end
 
     context 'when not location restricted' do
-      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label: 'ignored', duration: nil) }
+      let(:file) { instance_double(Embed::Purl::ResourceFile, stanford_only?: true, location_restricted?: false, label_or_filename: 'ignored', duration: nil) }
 
       it 'renders the page' do
         expect(page).to have_css('[data-location-restricted="false"]')

spec/models/embed/purl/resource_file_spec.rb

@@ -75,6 +75,22 @@
     end
   end
 
+  describe '#label_or_filename' do
+    subject { resource_file.label_or_filename }
+
+    context 'with a label' do
+      let(:resource_file) { described_class.new(label: 'The Resource Description') }
+
+      it { is_expected.to eq 'The Resource Description' }
+    end
+
+    context 'without a blank label' do
+      let(:resource_file) { described_class.new(label: '', filename: 'llama.mp3') }
+
+      it { is_expected.to eq 'llama.mp3' }
+    end
+  end
+
   describe 'image?' do
     it 'returns true if the mimetype of the file is an image' do
       stub_purl_xml_response_with_fixture(image_purl_xml)