Add test and refactor

This commit will add a test for #display_image.  Also, a refactor was
introduced to account for both Hyrax 2 and 3.  The method signature
of the `Hyrax.config.iiif_image_url_builder` lambda changed to add an
additional argument in Hyrax 3.

ref: https://github.com/samvera/hyrax/blob/2.x-stable/lib/hyrax/configuration.rb#L397-L399
ref: https://github.com/samvera/hyrax/blob/3.x-stable/lib/hyrax/configuration.rb#L250-L252

app/presenters/iiif_print/iiif_manifest_presenter_behavior.rb

@@ -28,7 +28,6 @@ def sequence_rendering
 
     module DisplayImagePresenterBehavior
       def display_image
-        # return nil unless model.image?
         return nil unless latest_file_id
 
         IIIFManifest::DisplayImage
@@ -41,11 +40,8 @@ def display_image
 
       def display_image_url(base_url)
         if ENV['SERVERLESS_IIIF_URL'].present?
-          Hyrax.config.iiif_image_url_builder.call(
-            latest_file_id,
-            ENV['SERVERLESS_IIIF_URL'],
-            Hyrax.config.iiif_image_size_default
-          ).gsub(%r{images/}, '')
+          # At the moment we are only concerned about Hyrax's default image url builder
+          iiif_image_url_builder(url_builder: Hyrax.config.iiif_image_url_builder)
         else
           super
         end
@@ -72,7 +68,7 @@ def work?
         false
       end
 
-        private
+      private
 
       def latest_file_id
         if ENV['SERVERLESS_IIIF_URL'].present?
@@ -85,6 +81,18 @@ def latest_file_id
       def serverless_latest_file_id
         @latest_file_id ||= digest_sha1
       end
+
+      def iiif_image_url_builder(url_builder:)
+        args = [
+          latest_file_id,
+          ENV['SERVERLESS_IIIF_URL'],
+          Hyrax.config.iiif_image_size_default
+        ]
+        # In Hyrax 3, Hyrax.config.iiif_image_url_builder takes an additional argument
+        args << image_format(alpha_channels) if url_builder.arity == 4
+
+        url_builder.call(*args).gsub(%r{images/}, '')
+      end
     end
   end
 end

spec/presenters/iiif_print/iiif_manifest_presenter_behavior_spec.rb

@@ -16,4 +16,33 @@
       expect(presenter.search_service).to include("#{solr_document.id}/iiif_search")
     end
   end
+
+  # this method is inside of the DisplayImagePresenterBehavior module
+  describe '#display_image' do
+    let(:presenter) { Hyrax::IiifManifestPresenter::DisplayImagePresenter.new(solr_document) }
+    let(:id) { 'abc123' }
+
+    context 'when serverless_iiif is enabled' do
+      let(:url) { 'serverless_iiif_url' }
+
+      it 'renders a serverless url' do
+        allow(ENV).to receive(:[])
+        allow(ENV).to receive(:[]).with('SERVERLESS_IIIF_URL').and_return(url)
+        allow(presenter).to receive(:latest_file_id).and_return(id)
+        expect(presenter.display_image.iiif_endpoint.url).to eq "#{url}/#{id}"
+        expect(presenter.display_image.iiif_endpoint.profile).to eq "http://iiif.io/api/image/2/level2.json"
+      end
+    end
+
+    context 'when serverless_iiif is not enabled' do
+      let(:iiif_info_url_builder) { ->(file_id, base_url) { "#{base_url}/#{file_id}" } }
+
+      it 'does not render a serverless url' do
+        allow(presenter).to receive(:latest_file_id).and_return(id)
+        allow(Hyrax.config).to receive(:iiif_image_server?).and_return(true)
+        allow(Hyrax.config).to receive(:iiif_info_url_builder).and_return(iiif_info_url_builder)
+        expect(presenter.display_image.iiif_endpoint.url).to eq "localhost/#{id}"
+      end
+    end
+  end
 end