Show old file name for renamed files in diffs

src/api/app/helpers/webui/request_helper.rb

@@ -97,7 +97,7 @@ def target_project_link(row)
   end
 
   def calculate_filename(filename, file_element)
-    return filename unless file_element['state'] == 'changed'
+    return filename unless ['changed', 'renamed'].include?(file_element['state'])
     return filename if file_element['old']['name'] == filename
 
     "#{file_element['old']['name']} -> #{filename}"

src/api/spec/helpers/webui/request_helper_spec.rb

@@ -70,6 +70,15 @@
       it { expect(calculate_filename(filename, file_element)).to eq(filename) }
       it { expect(calculate_filename(new_filename, file_element)).to eq("#{filename} -> #{new_filename}") }
     end
+
+    context 'for renamed files' do
+      let(:file_element) do
+        { state: 'renamed', old: { name: filename } }.with_indifferent_access
+      end
+      let(:new_filename) { 'apache3' }
+
+      it { expect(calculate_filename(new_filename, file_element)).to eq("#{filename} -> #{new_filename}") }
+    end
   end
 
   context 'source diffs' do